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Rebuild or reseal??


John M
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You have an older car only 85,500 miles 3.4. Still runs great, will scream when asked... It leaks oil through the main seals and smokes (engine compartment not tail pipe). 

 

Do you put in new piston rings and bearings or just put in fresh seals?

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can you elaborate on that *smokes in the engine compartment?*

 

as in an oil leak onto one of the exhaust manifolds?

 

even at 85,000 miles, what's the history of the car prior use?         nice little old lady & runs to church or a youngster driving it like they stole it

 

can you actually see the oil leak around the forward crank main seal?

 

the rear crank seal would be a pain in the ass to do, the trans has to come off.......

 

assuming this is the DOHC the cam carrier cover seals do leak with age, if one pulls the cover & reinstalls with the same compressed worn o-ring gasket it will leak & it leaks down onto the exhaust manifold.

 

Giving the engine bay a regular bath helps to keep the engine oil leaks from being seen, my rear main has a slight weep to it but seeing as I bathe the engine regularly it is a minor issue.

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Agreed. Just did the same to my wife's Aztek 3.4 at 172,000 and the rings are still good! If you really want, you could remove the heads and do a valve job (exhaust valves are very prone to pitting on these engines), but on a mileage that low, I wouldn't bother. Mine was leaking out the oil pan, valve covers, and oil pump drive shaft thing. Having tore down a few of these engines though, if you have to do the heads and oil pan, it's better just to remove the whole engine if you have the tools.

 

Also, doing lower intake is a good idea and there's plenty of components you can replace as a preventative measure like water pump etc. Good luck!

 

Edit: LOL forgot about the dohc 3.4 (noob mistake), so I'm referencing a different engine, but the other advice is still relevant.  :mrgreen:

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Agreed. Just did the same to my wife's Aztek 3.4 at 172,000 and the rings are still good! If you really want, you could remove the heads and do a valve job (exhaust valves are very prone to pitting on these engines), but on a mileage that low, I wouldn't bother. Mine was leaking out the oil pan, valve covers, and oil pump drive shaft thing. Having tore down a few of these engines though, if you have to do the heads and oil pan, it's better just to remove the whole engine if you have the tools.

 

Also, doing lower intake is a good idea and there's plenty of components you can replace as a preventative measure like water pump etc. Good luck!

 

Edit: LOL forgot about the dohc 3.4 (noob mistake), so I'm referencing a different engine, but the other advice is still relevant.  :mrgreen:

The LA1 is a pushrod engine, one doesn't want to pull the heads on an LQ1 unless absolutely necessary.

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I imagine the easiest way to do anything on an LQ1 is to pull the engine. Is there clearance to shift it away from the tranny towards the passenger side for the rear seal?

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       nice little old lady & runs to church or a youngster driving it like they stole it

 

In my case I think it was both LOL.

No offense meant Dan I couldn't resist.

 

As far as suspect smoke from piston rings, valve guides, etc Ive had good luck reducing to eliminating it by adding Z-max to oil changes and using the Castrol Magnatec high mileage oil. IIRC A main seal isnt the most difficult thing to change one one of these through the passenger side wheel well assuming the crankshaft comes off relatively easy. But if your smelling burning oil from the engine its probably the oil pump shaft seal under the throttle body.

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 using the Castrol Magnatec high mileage oil

 

Years ago I thought I was doing something nice for my L36 by running high mileage oil with seal conditioner. Then it started raining oil under my car, I wouldn't use anything with seal conditioners regularly ever again. Maybe it was a coincidence that there was oil suddenly leaking from the oil pan gasket and both seals after a year with that stuff but I prefer not to believe in coincidences.

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When the oil-pump drive O-ring was puking oil, I thought the rear main was leaking.

 

Clean the engine compartment, look again.  May not be the main seal.

 

Popping the upper and lower intake manifold off for cleaning and inspection is not a bad idea.  If the brakes are high-effort, install a brake booster at the same time.

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The LA1 is a pushrod engine, one doesn't want to pull the heads on an LQ1 unless absolutely necessary.

Lol yeah... I've heard the space is a big concern. They're big engines. Reminds me of Nissan's dohc.

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If it were mine I’d have it crushed.

faint of heart?

 

working on the DOHC is no more difficult than working on the Northstar or any of the new GM 3.6 high feature engines, one just has to have patience when servicing it

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Thank you for the discussion. This vehicle is the last convertible made 1995. It was driven sparingly until my daughter purchased it, she put 50,000 miles on it. It is now resting again because of the work it needs.

 

My mechanic says the seals front and back, and oil pan need to be done. The water pump has been changed the valve seals, and valve covers have been done, timing belt too. The engine compartment is so tight I don't know how he did that. He is not willing to pull motor to do seals. My problem is when I drive it there is very little smoke. Others drive it it looks like it's on fire. Smells like steam to me but I am not sure because there's not much smoke. There is a lot of oil on the body pan. I have tried using one of those little cameras attached to your phone and have been unable to see leaks.

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I'm going to a-s-s-uuuuu-me that this was a typo.......

 

that would be very difficult while still in the car  :dance:

I should've specified relative to what but lost the joke thinking about engines. IIRC the chassis is right in the way of getting tools on the crank pulley to begin with.

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Remove the airbox and intake tube and look for wetness on the engine under the throttle body, theres a circular disc like part on top of the engine right next to where the engine/tranny come together. If you can see it, thats the oil pump drive shaft that likes to leak oil and causes alot of the smoking issues related to these kinds of engines.

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Have the intake manifold gaskets been replaced?

 

in the area around the *oil distribution cover* (a cast plate that is located in the centre of the valley between the cylinder banks under the manifold) fluids can build up in there, they won't flow out immediately as there are raised casting bosses at the front & rear end of the block casting keeping the junk in there, but when the fluid levels get high enough they will flow over the edges down either the front or the rear of the block.

 

At the time when the gaskets are done one cleans out this area, coolant fluid is common to find due to the intake gaskets leaking, oil not so, unless at some time the power steering pump sprung a leak and flowed into the valley.

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