Oil Pump Drive Seal Leaking

[jpv123]

My car leaks oil really bad when its cold. My local mechanic sad it is the oil pump drive seal. He doesn't even want to do the job. He said it's too labor intensive and he can't tie up his bay that long. How big of a job is this? Anyone know how expensive to have it done professionally? Also should I do anything else during this surgery. I tried searching but couldn't find it.

[rudefyet]

there is a guide in the problems section of w-body.com....i'm going to attempt it when spring comes around but yeah the guide makes it seem pretty easy...it's a good bit of work but i don't think it would be too hard

[jpv123]

Thanks, But I have the 3.4 engine

[rudefyet]

ouch...sorry...shoulda looked at your signature...um...i honestly have no clue where to start there...hopefully someone with a 3.4 can help ya

[5speedz34]

Umm it is a o-ring under the intake manifold between the heads that was there when our cars had Distributors...(damn 2.8's). It is a O-ring that leaks with old age and to replace it you have to pull the rear head. What most ppl do is pull it up the best they can and just cover it in silicone, I think the best way to do it is get a o-ring from a mini-mag lite and slide that on and u should be good, and maybe put some jb weld on there.

 

-Tony

[93GTP]

Yup, to do it the proper way, as in replacing the o-ring, it's a lot of work. You need to pull the rear head, which means pulling the intakes, timing belt, cam carrier and cylinder head.

 

Here are some pics to demonstrate the location:

 

 

And here is my car with everything off it, and the problem permanently fixed (new oring and siliconed)

 

[stlunatics2oo3]

rudefety

 

 

the job on the 3.1 is easy as hell just takes bout hour and when you do it your should do the throttle body bypass. and prolly clean your throttle body i did mine myself it took about 2 hours but i could do it now in about an hour just do it soon cause if you wait the oil leak will get way worse. mine got way worse

 

 

thanks

 

happy holidays

 

Jeremy

[quaddriver]

Let that be a lesson! I know Ill get flamed but the DOHC 3.4 was an engineering nightmare/disaster - the designer should be shot or worse. The thing is, with the age of the cars now, simple jobs like this, or an alternator, or cam belts etc are causing the cars to be scrapped - not worth the repair (just hauled off a 92? 93? GP in mint condition otherwise)

 

For the record, under no circumstances should the 660 block have been adapted to DOHC - chevy should have taken a page from the olds 3.5DOHC, or just borrowed the damn engine. What they did is frighteningly akin to making a diesel out of a gas 350....to borrow a line "everyone was so busy seeing if they COULD do it, no one bothered to ask if they SHOULD...."

 

quite frankly, the number of valves and the methods of actuation have little to do with specific engine output - a pushrod 3.4 (a bored 3.1 which is a stroked 2.8) with off the shelf heads and cam from GM will make more power than the DOHC, at a lower RPM, have far less noise and rotational inertia and be servicable.....

 

I realize there is appeal to having a 'one-off' model, but stuff like this is always gonna be in the way

 

rant over

[topless94style]

Professional job, anywhere from 9-10 hours running you over $1000 for a $3 oring.

[93GTP]

Let that be a lesson! I know Ill get flamed but the DOHC 3.4 was an engineering nightmare/disaster - the designer should be shot or worse. The thing is, with the age of the cars now, simple jobs like this, or an alternator, or cam belts etc are causing the cars to be scrapped - not worth the repair (just hauled off a 92? 93? GP in mint condition otherwise)

 

For the record, under no circumstances should the 660 block have been adapted to DOHC - chevy should have taken a page from the olds 3.5DOHC, or just borrowed the damn engine. What they did is frighteningly akin to making a diesel out of a gas 350....to borrow a line "everyone was so busy seeing if they COULD do it, no one bothered to ask if they SHOULD...."

 

quite frankly, the number of valves and the methods of actuation have little to do with specific engine output - a pushrod 3.4 (a bored 3.1 which is a stroked 2.8) with off the shelf heads and cam from GM will make more power than the DOHC, at a lower RPM, have far less noise and rotational inertia and be servicable.....

 

I realize there is appeal to having a 'one-off' model, but stuff like this is always gonna be in the way

 

rant over

 

Yes there is some truth in the fact that 3.4 DOHC cars are actually being "put down" for relatively simple fixes. But many things you have said don't make sense to me.

 

The timing belt on the 3.4 is no harder than timing belts on any other DOHC V engines. It's not that hard at all.

 

Alternator, yeah it takes time, but once again it's not hard, I've done mine 3 times (faulty ground was frying them), and does it make me want to get rid of my car? No. Does it make me want a 3.1? Hell no.

 

Your are 100% correct in saying that GM should have developed a new block rather than adapting an existing one. But it was pretty understandable. They saved a ton of money, and when it comes to a company like GM, thats the bottom line most of the time.

 

I don't understand you're comment on the 3.5 DOHC at all, they should have borrowed that design? How, the 3.4 came out well before the 3.5 did, and is basically a reason for the 3.5's success. GM learned a lot from development of the DOHC.

 

"quite frankly, the number of valves and the methods of actuation have little to do with specific engine output - a pushrod 3.4 (a bored 3.1 which is a stroked 2.8) with off the shelf heads and cam from GM will make more power than the DOHC, at a lower RPM, have far less noise and rotational inertia and be servicable....."

 

Yes actually, it does have a great effect on performance. The DOHC design is superior, period, which is why it's being used more and more by every car maker. If you want to compare same displacement engines stock vs. stock pushrod vs. DOHC, compare the 3.4 DOHC and the 3400. They are both stock and they are both not tuned for maximum performance by any means. But the numbers are 175hp for the 3400, and 210/215 for the DOHC.

 

It's not fair when you consider putting aftermarket parts on the pushrod to make the same power as the DOHC. Put a well designed head on the 3.4 DOHC and you will see the same gains. Same goes for the cams, but GM don't exactly put radical cams in there engines from the factory for several reasons. Such things as emissions, and reliability will stop that. Hell the 3.4 cams are by no means amazing, and big gains could be made with better ones.

 

The DOHC has many advantages, especially in the heads. Where there are no pushrods to run up through the heads. It enables the ports to be designed with much less resriction. Pushrods cause the ports to be oddly shaped because they have to be made around them.

 

It just annoys me when people dog on the 3.4, hell, it had 70 more hp than the 3.1 in the equivalent year, and 35 more than the 3400.

[rudefyet]

but let me chime in too add a fact the major difference in power between a pushrod and a DOHC engine is the you could say "torque to horsepower ratio"...lol...why the 3400 has 175hp it also has 205 lb.ft of torque...while the DOHC 3.4 has 210hp and 215lb.ft. of torque i'm not disagreeing in any way what i'm saying is if you take a pushrod 3.1 with 140hp and 180tq. and convert it to dohc you have an engine with roughly 180hp 185tq.

 

a pushrod engine produces more torque then horsepower therefore making it good in the low end...while a dohc evens out the hp and torque making it perform all the way through the powerband...if you take any engine and convert it directly to dohc...depending on if it's american made or foreign...it will have more hp then the pushrod and roughly the same torque maybe more maybe less...i would take a 3.4 Twin cam over my 3.1 any day but man if only there was a 3.8 twin cam

[quaddriver]

The timing belt on the 3.4 is no harder than timing belts on any other DOHC V engines. It's not that hard at all.

 

Define hard? A lot of people define hard as time consuming. What does the mitchell guide book the belts on a 3.4DOHC vs say any other DOHC v6?

 

Alternator, yeah it takes time, but once again it's not hard, I've done mine 3 times (faulty ground was frying them), and does it make me want to get rid of my car? No. Does it make me want a 3.1? Hell no.

 

If spending 6 hrs for an alternator is fun....most alts, even on transverse motors are done in <1 hr

 

How, the 3.4 came out well before the 3.5 did,

 

Not quite, the 3.5 is based on the Aurora/Northstar programme (as does the Quad 4) and all 3 motors date to the mid/late 80's and all 3 have their roots back to 1971 when olds made a DOHC455. The v6 however was not marketed in the US due to the use of buick and chevy engines

 

and is basically a reason for the 3.5's success.

 

I have to agree with that - it showed powertrain what NOT to do. Next to a 1975 265 inch SBC, and a 1980 262inch SBC, the 3.4DOHC is the shortest lived motor in GM history - as you said - money is the bottom line.

 

The DOHC design is superior, period, which is why it's being used more and more by every car maker.

 

No, the DOHC design is DIFFERENT. by supposedly allowing more rpm, you can move the torque peak up on the rpm curve, thereby moving the hp peak. Its a cheap way to make small engines appear to act like large engines, but they still lack the underlying torque

 

Lets go over all the shortfalls of the 660 programme:

 

1) It uses the same length rod as the SBC - so while the engine is narrow, it is very tall. This becomes an issue when body design uses a low slope - a prime example is the 91-93 grandam - the 3.1T code is a hard fit, the larger/more powerful Ncode buick 3.3 is an easier fit

 

2) the transverse design delayed the use of EFI on the 660 by a couple years as the DIS had to be invented, but had to use a different triggering mechanism. When a distributor is used, only TBI may be used

 

3) the original 660 design in the late 70's called for a crank driven external oil pump. this was ditched for the traditional cam driven system. when the distributor was ditched the infamous oil pump driveshaft adaptor was invented. This seal leaks on T codes, however its an easy 1 hr fix. And here is the rub, the DOHC was such a bandaid that the heads covered access to an item that has been known to leak by 30K miles since 1987!!!

 

4) following on, adding insult to injury, the DOHC STILL RETAINS the cam shaft!

 

5) the DOHC has 5 times the number of cam bearings as does the OHV versions - vastly increased parasitic drag

 

6) the high number of bearings mandates high oil pressures and increased volume - the DOHC oil pump takes twice as much hp to turn

 

7) initial versions of the motor used 2 small oil galleries that starved the 3/4 rod pair. ITs VERY unlikely that any 80-85 660s run without significant rod bearing damage to this day

 

8] the intake manifold is large and unsupported, resulting in countless water leaks at the xfer ports and internal vacuum leaks at the 3/4 intake (also due to a poor gasket design) years 87-93, 94-on use an intake set with a completely different set of fleas

 

9) the DOHC still retains the timing chain setup since it still has the cam shaft, the belt drive system was grafted on and forced relocation of all traditional top mounted assemblies to under the motor - alternators, water pumps, ps pumps, ac pumps etc now become major jobs

 

10) due to the width of the DOHC setup, it is now wider than a chevy small block and nearly as long (which explains GMs flirtation with the Lumina Z50 (a 5.0L EFI motor turned sideways)

 

11) the motor has a larger rotational moment - stressing original dogbone mounts, redesigned versions put stress on the subframe and engine cradle. It is possible over 100K miles to literally shake the car in two.

 

12) with all the extra gears, bearings and shafts, the nusiance noise level is much higher, resulting in the increased use of sound deadening material

 

And for what? the fastest 3.4s (z34 stick) are slower than the TGP and slower than the 94-on buick park avenue. Its kind of a bummer to watch grandpa pull away in a car with whitewalls.

 

Am I raggin on the 3.4? you betcha, its a hideous design not very well thought out - a bandaid if you will. The price you pay for having a one-off model. It is however, a cash cow for shops. And what sucks, is even if GM didnt want to continue the turbo 3.1, they could have looked at supercharging it or used off the shelf parts to stay naturally aspirated. The 3.4DOHC is not a shining moment in GM history, thats my story and Im sticking to it.

[rudefyet]

convincing enough argument for me...kinda helps when i just saw the that a TGP can beat a DOHC 3.4...hmm...ever since i've got my grand prix i've wanted nothing but a 3800 and that is never gonna change...i like torque...and from my experience dohc engines lack thereof...but hey honestly i'm not gonna say whats better cause it's a matter of preference...some people like DOHC some like pushrod....as for i grew up with DOHC being the shiznit...but they i discovered pushrod and i'll never go back...torque ratings are just so much more appealing now...lol...oh well i think i'm done with this thread...i don't feel like making anyone mad so if you like DOHC go for it if you like pushrod the hey you're not the only one

[4spdz34]

the 3.1 block is a different casting from the 3.4 block, so they are not the same, one has lifter bosses the other doesn't. and the rods being too long?

 

5.7/3.31= 1.72 according to alot of engine builders 1.7- 1.75 is a perfect rod/stroke ratio.

 

there are no bearings in the 3.4 cam carriers, the carriers themselves are the bearing surface.

 

and a stick 3.4 would rag on a park avenue or a tgp assuming all are in good condition.

 

the only accessory that is in a different place on 3.4 compared to a 3.1 is the alt.

11) the motor has a larger rotational moment - stressing original dogbone mounts, redesigned versions put stress on the subframe and engine cradle. It is possible over 100K miles to literally shake the car in two.

cause the cradle holds the car in 2 pieces? larger rotational movement? and thats a balance shaft or an intermediate shaft on a 3.4

 

 

so they oil pump drive shaft cover is in a bad place but so is the opti-spark on a lti and the starter on a 4.6 northstar. for every good thing there has to be a compromise

 

No, the DOHC design is DIFFERENT. by supposedly allowing more rpm, you can move the torque peak up on the rpm curve, thereby moving the hp peak. Its a cheap way to make small engines appear to act like large engines, but they still lack the underlying torque

 

by allowing more rpm? lol .cause of the motors high VE it is able to achieve the higher rpms and have power there.

[4spdz34]

and the 3.4 doesn't lack torque the gear ratios in a automatic just suck for the motor, ask anyone with a 5speed if they have problems with torque. i have a stall converter in my auto, it helps alot. i used to get beat off the line by alot of cars then i would pull on them once i got going, i never get beat outta the hole anymore, i even raced my dad, he was driving a 99 gtp he didn't beat me outta the whole and i had him by a car the whole time. its not about the motor with these cars its about getting that power to the ground. well i gotta go it time to put in my new motor.

[quaddriver]

the 3.1 block is a different casting from the 3.4 block, so they are not the same, one has lifter bosses the other doesn't. and the rods being too long?

 

5.7/3.31= 1.72 according to alot of engine builders 1.7- 1.75 is a perfect rod/stroke ratio.

 

there are no bearings in the 3.4 cam carriers, the carriers themselves are the bearing surface.

 

and a stick 3.4 would rag on a park avenue or a tgp assuming all are in good condition.

 

the only accessory that is in a different place on 3.4 compared to a 3.1 is the alt.

11) the motor has a larger rotational moment - stressing original dogbone mounts, redesigned versions put stress on the subframe and engine cradle. It is possible over 100K miles to literally shake the car in two.

cause the cradle holds the car in 2 pieces? larger rotational movement? and thats a balance shaft or an intermediate shaft on a 3.4

 

 

so they oil pump drive shaft cover is in a bad place but so is the opti-spark on a lti and the starter on a 4.6 northstar. for every good thing there has to be a compromise

 

No, the DOHC design is DIFFERENT. by supposedly allowing more rpm, you can move the torque peak up on the rpm curve, thereby moving the hp peak. Its a cheap way to make small engines appear to act like large engines, but they still lack the underlying torque

 

by allowing more rpm? lol .cause of the motors high VE it is able to achieve the higher rpms and have power there.

 

I didnt say the rods were too long, I just said they were long, so when the width was narrowed up, the engine grew tall - look at a 660 on an engine stand, its almost comical.

 

Whether or not there are actual soft metal bearing surfaces in the carriers is immaterial, its STILL a bearing surface, it STILL must be oiled, and friction occurs there - if you dont beleive me - plug up the galleries.

 

The bone stock, 5spd z34 did .3 seconds slower to 60 and .2-.3 seconds slower in the 1/4 than the bone stock buick park avenue. These are independant tests. Anyone line up a 34DOHC against a 02-03 bone stock impala with the 3800? was that sufficient as an example? not to mention, the impala weighs 4-500miles more

[topless94style]

I think the DOHC is a great engine. While it may cost alot to maintain, the engine will have an advantage over a pushrod. A pushrod may provide more tq compared to hp than a DOHC, the DOHC flows WAY better than a pushrod. If there was an aftermarket for the DOHC, these motors would stomp on the tgp and the 3800 not to mention other motors. The only accessory that looks hard to change is the alt. Everything else doesnt look hard at all. Engines make more power the more they can flow, 24 valves are alot better than 12. If there were headers to create good exhaust flow, and P&P your intake with maybe a CAI, you will see awesome gains in power because of the way this engine will flow.

 

I too love tq and the feeling of gettin slammed back into my seat, and i too used to be all for pushrod. But after owning this engine, i would love for all my future cars to have DOHC.

 

If you take a turbo 3.1 with exhaust work done, vs a turbo LQ1 with exhaust work done, the 3.4 will blow it away.

[rudefyet]

ok so the argument has now gone way over my head...lol...i'm one of those backyard mechanics i can fix lots of stuff but yeah...lol...um all i can say is i don't care wtf it is...whatever has the most power and mods for my car is the engine i want...for a w-body it's the L67 which is a pushrod...but for my nissan or my honda DOHC all the way...lol...i'm actually planning on getting some sort of convertable...but i dunno...i'm stuck between a 300ZX...a Mustang....maybe a Cutty....or maybe even a LeBaron...depends on what i find when i have the money...the nissan is DOHC V6 that has a higher power rating then a freakin Mustang GT with the 4.6L...i dunno if it's faster...but yeah if i get a cutty with a dohc i'll swap it ot for a pushrod...but if i get a lebaron with a sohc i'll swap a dohc in it asap...different companys do better with different engine configs...honestly i think gm does them all well and like all companys there are few lemons here or there...not saying the 3.4 is a complete lemon but it could have been made with more thought from what i understand...wouldn't keep me from owning one though

[Bolt_Crank]

TGP = forced induction

L67 = forced induction

 

you can't compare the two of those to the 3.4L because it's naturally aspirated.

 

and the LQ1 has more torque than the 3.1, it's just in a different place

 

and it has more torque than the 3400 which is a bored 3.1.

[4spdz34]

ok you are talking about the 60 degrees between the opposed cylinders.

i have raced an 03 monte carlo, they are good in first gear but have nothin after that. what was the 0-60 on the park avenue? the z34 it is 6.9 secs

[93GTP]

The timing belt on the 3.4 is no harder than timing belts on any other DOHC V engines. It's not that hard at all.

 

Define hard? A lot of people define hard as time consuming. What does the mitchell guide book the belts on a 3.4DOHC vs say any other DOHC v6?

 

Time consuming means hard? Uhh, ok... I've done timing belts on several cars, and it isn't really any shorter of a process. The only thing that makes it somewhat difficult with the 3.4 is the positioning of the engine relative to the strut tower. You can't blame this on anyone, the 3.4 isn't a small engine, and it's a FWD car. It's not hard to see why it's a little crammed.

 

Alternator, yeah it takes time, but once again it's not hard, I've done mine 3 times (faulty ground was frying them), and does it make me want to get rid of my car? No. Does it make me want a 3.1? Hell no.

 

If spending 6 hrs for an alternator is fun....most alts, even on transverse motors are done in <1 hr

 

6 hours? Even on my first attempt it didn't take near that long. And now that I've done it before I can definetely have it done in an hour, no problem. Still, why do people act like you have to change alternators every second day?

 

How, the 3.4 came out well before the 3.5 did,

 

Not quite, the 3.5 is based on the Aurora/Northstar programme (as does the Quad 4) and all 3 motors date to the mid/late 80's and all 3 have their roots back to 1971 when olds made a DOHC455. The v6 however was not marketed in the US due to the use of buick and chevy engines

 

Oh, so you're making a reference to the Quad 4 now. Well if you want to talk about crappy designed engines, there's the prime candidate. You say that spending a bit of time to change an alternator is bad. What about if your water pump dies on the Quad 4? Yeah, thats right, it's run off the timing chain. That's much worse than any problem the 3.4 had. So I guess those roots didn't help that design much. Not to mention the great cylinder heads they used on those engines.

 

Tell me another DOHC V6 mass produced by GM before the 3.4? Oh yeah that's right, there are none. It's hard to compare concept versus production, because the concepts are always much better than what actually hits the street.

 

and is basically a reason for the 3.5's success.

 

I have to agree with that - it showed powertrain what NOT to do. Next to a 1975 265 inch SBC, and a 1980 262inch SBC, the 3.4DOHC is the shortest lived motor in GM history - as you said - money is the bottom line.

 

So, basically what you're saying, because of how the the block still has a distributor drive, and to properly secure the lower intake manifold it had to be covered up, this is one of the worst designed engines GM has made? Well that's pretty dumb, this problem is so simple that it could have been corrected with a better o-ring, or even the use of an actual gasket between the plug and the block. Stupid yes, but it's hardly a HUGE design flaw. More like the use of an inferior quality gasket.

 

The reason it was one of the shortest lived engines ever made by GM was marketing, not the actual product. The point is, it never sold great, right from day one. GM did the shits of a job marketing it, and that's why it's gone.

 

The DOHC design is superior, period, which is why it's being used more and more by every car maker.

 

No, the DOHC design is DIFFERENT. by supposedly allowing more rpm, you can move the torque peak up on the rpm curve, thereby moving the hp peak. Its a cheap way to make small engines appear to act like large engines, but they still lack the underlying torque

 

You know what else is different. Flathead engines. Simply saying that they're different is a pretty weak argument. DOHC engines can easily have more valves. And a smaller, but larger amount of valves greatly improves the use of space in the combustion chamber. And due to their reduced size, they are lighter, which is another reason for the superior red lines of the DOHC engines.

 

Lets go over all the shortfalls of the 660 programme:

 

Well, for one, I was mostly comparing the the DOHC design to the OHV design, not the 60* V6 lineup.

 

1) It uses the same length rod as the SBC - so while the engine is narrow, it is very tall. This becomes an issue when body design uses a low slope - a prime example is the 91-93 grandam - the 3.1T code is a hard fit, the larger/more powerful Ncode buick 3.3 is an easier fit

 

This is a pretty weak argument, yes 60* motors are higher than 90* engines obviously, but this also means thet they're narrower, which can easily be labeled just as big an advantage.

 

2) the transverse design delayed the use of EFI on the 660 by a couple years as the DIS had to be invented, but had to use a different triggering mechanism. When a distributor is used, only TBI may be used

 

I don't understand how you're saying this is a weak point. The fact that EFI couldn't be used on it started the motion on the development of the DIS system, which is a far superior design, so this could be considered a good thing.

 

3) the original 660 design in the late 70's called for a crank driven external oil pump. this was ditched for the traditional cam driven system. when the distributor was ditched the infamous oil pump driveshaft adaptor was invented. This seal leaks on T codes, however its an easy 1 hr fix. And here is the rub, the DOHC was such a bandaid that the heads covered access to an item that has been known to leak by 30K miles since 1987!!!

 

Yes this is a frustrating design I know, but blame the use of a crappy o-ring and/or the lack of a gasket between the mating surfaces.

 

4) following on, adding insult to injury, the DOHC STILL RETAINS the cam shaft!

 

Yes once again this is an annoying design, but it enabled GM to save a LOT of money, and reuse many of the same or very similarily designed external belt driven parts. So that does save you money in replacements. It's not that big a problem anyway, it's not like the bearings on these things went bad. The only argument you could say against it is the power loss from the weight of a "unnecessary component", but the 3.4 still has tons more power than the equivalent pushrod engines.

 

5) the DOHC has 5 times the number of cam bearings as does the OHV versions - vastly increased parasitic drag

 

These bearings don't go bad, so it's not a problem. Once again the only argument you can say is the the power loss from this, but the parasitic drag between these parts when oil is between them is almost non existent.

 

6) the high number of bearings mandates high oil pressures and increased volume - the DOHC oil pump takes twice as much hp to turn

 

Same thing I've stated before. You'd think that all these "losses" (which are far smaller than what you think they are) would make the pushrod more powerful. But I guess numbers don't lie. I guess all this really proves how superior the DOHC design is.

 

7) initial versions of the motor used 2 small oil galleries that starved the 3/4 rod pair. ITs VERY unlikely that any 80-85 660s run without significant rod bearing damage to this day

 

How does this even relate to the DOHC?

 

8] the intake manifold is large and unsupported, resulting in countless water leaks at the xfer ports and internal vacuum leaks at the 3/4 intake (also due to a poor gasket design) years 87-93, 94-on use an intake set with a completely different set of fleas

 

This is not at all a problem on the 3.4. You're only bashing the 3.1 there.

 

9) the DOHC still retains the timing chain setup since it still has the cam shaft, the belt drive system was grafted on and forced relocation of all traditional top mounted assemblies to under the motor - alternators, water pumps, ps pumps, ac pumps etc now become major jobs

 

What? The power steering pump is right on top still, the water pump is on the front of the motor just like on the pushrods, same goes for the ac compressor, and as for the alternators, well yes I don't know of any DOHC V6 FWD cars that have the alternator located in the same position as the pushrod. It's getting pretty old that the biggest reason you hate DOHC engines is because of the alternator location. When it comes to better performance, I'm willing to have a crappier located alternator, because I thought we were supposed to be enthusiasts on this board? Enthusiasts shouldn't be turned off from such trivial reasons.

 

10) due to the width of the DOHC setup, it is now wider than a chevy small block and nearly as long (which explains GMs flirtation with the Lumina Z50 (a 5.0L EFI motor turned sideways)

 

Yes DOHC engines are larger, it's just part of the design. But the size can be drastically reduced with the integration of the cam carrier on the 3.4 DOHC into the head. And the 3.4 was fitted into the engine bay that was designed for the 3.1, so I don't see the problem.

 

If you want to talk about how pushrod's can fit into smaller places, why not compare the wankel rotary to the pushrod? The wankel rotary like used in the RX7 and RX8 is so low that it can be located much further back in the engine bay, resulting in a much better weight distributed car, which is why the RX8 has a perfect 50/50 weight distribution. So why aren't you driving a rotary powered car?

 

11) the motor has a larger rotational moment - stressing original dogbone mounts, redesigned versions put stress on the subframe and engine cradle. It is possible over 100K miles to literally shake the car in two.

 

Well this is just bullshit. I don't know where in the hell you came up with this. I've never ever, ever heard of this.

 

12) with all the extra gears, bearings and shafts, the nusiance noise level is much higher, resulting in the increased use of sound deadening material

 

GM didn't use any more sound deadening material in the 3.4 cars over the 3.1 cars. But yes the 3.4 is a louder engine, but it also sounds a hell of a lot better, which is why I like that. Perfect for the enthusiast.

 

And for what? the fastest 3.4s (z34 stick) are slower than the TGP and slower than the 94-on buick park avenue. Its kind of a bummer to watch grandpa pull away in a car with whitewalls.

 

Well that's a stupid comparison, boosted vs. N/A is a lame comparison. Boost a DOHC engine and yield the same results. This like comparing a turbo civic that can hand a Camaro SS it's ass. It's also a bummer to see a car that cost half the price of another just walk away from it in a race.

 

Am I raggin on the 3.4? you betcha, its a hideous design not very well thought out - a bandaid if you will. The price you pay for having a one-off model. It is however, a cash cow for shops. And what sucks, is even if GM didnt want to continue the turbo 3.1, they could have looked at supercharging it or used off the shelf parts to stay naturally aspirated. The 3.4DOHC is not a shining moment in GM history, thats my story and Im sticking to it.

 

I don't care if you rag on the 3.4 for a good reason, but saying it's a hideous design is pretty uneducated. Sure there are some problems associated with using the block they did, but there are also some problems with how underachieving the 3.1 pushrod is. All I have to say is if you can't fix a problem as simple as the alternator on the 3.4 cars, don't buy a 3.4 car. I don't care if you can't do a simple job, all that means is that there's another victim out there on the road for me.

[MaroonRegal]

Engine bashing is stupid, cut it out. We all own/drive W-bodies, so quit slamming on eachother's cars.

 

How many of the people here who are bashing the 3.4 have actually owned one? I'm sure there are people who don't like them, and have owned them, but are they car people? How many people who really know what's up in the car world have owned a 3.4 and hate them? I'm sure it's not a number greater than what can be explained by the concept of a lemon, or even just abuse.

 

GMs only truly bad engine's have 4 cylinders, not 6 (the big three's I4's have been very lacking until the last few years.) The 3.4 is a good engine, on the whole. Yes, there are a few design flaws, but they're minor. All of our engine's have design flaws. All engines have design flaws, period.

 

Most people who don't like the 3.4 don't own one, or don't care about cars. If they do care about cars, it's only to the point where they want to have the very fastest car, but they don't want to work for it or really even know anything about cars, just drive (abuse) them. Enough said.

[jpv123]

UMMM... What about my leak? Anyone, anyone...

[ZXXXIV]

I did mine myself in aboiut 4 hours using the silicone method.I ground off some of the plug top so it could be lifted up more.That gave me more room to put the silicone on.I also replaced the plugs and thermostat while doing this.Good luck.

[topless94style]

I tried fixing mine but didnt work out to well. I had a vac leak in the intake manifold, so i replaced those gaskets, along with plugs, and stat. I got some jbweld and slopped that all around the oring, but it didnt stick and slid off and we missed the other side, so the car still leaks. But, no big deal it should be fixed right in the spring.