GnatGoSplat Posted March 16, 2003 Report Share Posted March 16, 2003 Is there NOTHING easy to do on the 3.4 DOHC? The t-stat in the 94 Cutty was stuck open, so I thought I'd replace it. My jaw dropped when I read the procedure in the service manual... remove heater line from throttle body, depressure fuel lines, disconnect fuel lines, etc. On the 2.8, 3.1, and even my sister's Mitsubishi Eclipse, it's a 10-minute job TOPS. On the 3.4, I think it took me nearly 2hrs and I still haven't put coolant back in it to make sure it doesn't leak. What a pain. I don't have a fuel line disconnecting tool (this one has quick connects) so I thought I could find an alternate method. I had to remove: 1. Airbox 2. Fuel rail cover. 3. Plastic vacuum line harness. 4. Metal trans vacuum modulator pipe. 5. Tiny 8mm bolt holding metal heater pipe to head. 6. Heater hose at front of heater pipe (by water pump). 7. Heater hose to TB. Only then was I able to access both bolts on the t-stat housing neck. Complications: 1. I got too rough and tore up the hose at the water pump to heater pipe junction. 2. I dropped the tiny 8mm bolt into the great abyss. 3. Those spring clamps are a BITCH. In retrospect, I probably could have saved myself a lot of trouble by not disconnect the metal heater pipe by the water pump. I had done that because I thought that would let me move the heater pipe out of the way without disconnecting at the TB. I didn't want to disconnect at the TB because the spring clamp for its hose was clocked to where I couldn't get at it easily. I probably didn't need to completely remove that 8mm bolt that I lost either. Maybe this would have gone a lot easier had I bought or ordered the tool to disconnect the fuel lines??? Here's a pic showing all I had to disconnect to get that damn t-stat out. I was figuring this would be the best time to switch over to Dex-cool. Anyone know an easy way to completely flush the 3.4? There's no clearance for the heater hose (the one that runs down to the frame rail) to come off. :guns: 3.4 DOHC Quote Link to comment Share on other sites More sharing options...
brian89gp Posted March 17, 2003 Report Share Posted March 17, 2003 Damn you did it the hard way. I took off the air filter and tube, cut off that metal tab that is attached to the coolant bypass line and bolted to one of the thermostat bolts. I then undid the 2 bolts and changed the thermostat. All in all it took 15 minutes, 10 of which were spent cutting that piece off with a dremel. Quote Link to comment Share on other sites More sharing options...
luminator94 Posted March 17, 2003 Report Share Posted March 17, 2003 I always loved where my t-stat was on my Euro w/ the 3.1MPFI, right there with nothing blocking it, kudos to that GM engineer. The 3100 is pretty easy, but a little hard to get to. Aaron Quote Link to comment Share on other sites More sharing options...
GnatGoSplat Posted March 17, 2003 Author Report Share Posted March 17, 2003 Damn you did it the hard way. I took off the air filter and tube, cut off that metal tab that is attached to the coolant bypass line and bolted to one of the thermostat bolts. I then undid the 2 bolts and changed the thermostat. All in all it took 15 minutes, 10 of which were spent cutting that piece off with a dremel. Ya know, I SERIOUSLY considered cutting off that metal tab! Every time I pulled something off, I thought, "I could cut that metal tab off so easily...". But then I started thinking that some GM engineer who probably has a Master's Degree in mechanical engineering and had been working at GM for decades decided that tab should be there. After all, they went to the trouble to build the machine to stamp it and the jig to weld it on, so I thought it must be there for a reason and I decided not to cut it. Any problems with it rubbing other things or vibrating since you cut it off? Quote Link to comment Share on other sites More sharing options...
brian89gp Posted March 17, 2003 Report Share Posted March 17, 2003 Nope, its held pretty tightly in place anyways, I did try wiggling it one time and it is very sturdy. Course now that you have asked something is going to happen to it BTW, I have a tendency to remove all of those things that are a PITA to take off and serve no immediate purpose (the clamp that holds the fuel lines to the bottom of the TB, those 2 clips for the vacuum modulator line on the fuel rail, etc) and my car is still running more then a year later. Quote Link to comment Share on other sites More sharing options...
GnatGoSplat Posted March 17, 2003 Author Report Share Posted March 17, 2003 Heh! Oh well, I went through the annoying bleed procedure and the car seems to be happy now and all the irritation is now just a memory, so I guess I don't mind not cutting off that tab. I just hate 2nd guessing engineers that I would think had reasons to put things where they put them, but then again, maybe I'm giving them too much credit. I do constantly wonder whether much of this engine was designed by monkeys. Quote Link to comment Share on other sites More sharing options...
ismellrealbad Posted March 17, 2003 Report Share Posted March 17, 2003 Who places an alternator on the bottom of the engine next to the firewall? just thinking about having to change that is just one of the many reasons why i decided 100% against looking to buy a GTP. i see absolutley no logic to that. then theres the thought of the rear spark plugs, and now what you just showed me just to change the thermostat. i looked at that picture and almost got a headache. what a load of trash. Its a nice engine...........if you dont want to maintain it. so what other things am i thinking of that are abnormally hard to do on it? there have to be more Quote Link to comment Share on other sites More sharing options...
brian89gp Posted March 17, 2003 Report Share Posted March 17, 2003 o-ring Quote Link to comment Share on other sites More sharing options...
luminator94 Posted March 17, 2003 Report Share Posted March 17, 2003 Before I purchased my 98 GTP, I almost bought a 95 GTP. I never gave any thought whatsoever to the DOHC vs. S/C engines. This was before I ever even knew about this site. I just thought, DOHC is fast, but I did notice how everything was packed in there. When I popped the hood on the 98 GTP, I thought the layout was much more appealing. Plus the words: "3800 Series II Supercharged" was MUCH more appealing then "3.4 Dual Twin Cam" I'm glad I made the decision I did before I knew the truth about the DOHC. I think it would be a fun engine to own, but I don't have time for a high maintenance engine like that. Aaron Quote Link to comment Share on other sites More sharing options...
RedZMonte Posted March 17, 2003 Report Share Posted March 17, 2003 Heh! Oh well, I went through the annoying bleed procedure and the car seems to be happy now and all the irritation is now just a memory, so I guess I don't mind not cutting off that tab. I just hate 2nd guessing engineers that I would think had reasons to put things where they put them, but then again, maybe I'm giving them too much credit. I do constantly wonder whether much of this engine was designed by monkeys. they put it there so it would be one more pain in the ass you would have to pay allot for in order to fix when you took it to a dealer. RedZ Quote Link to comment Share on other sites More sharing options...
RedZMonte Posted March 17, 2003 Report Share Posted March 17, 2003 ROTFLMFA! I changed a 3800 GTP alternator and a T-stat in about 15min combind.. I finished both before the guy finished installing his "Street scenes Grills". (stock grill has 2 screws and 3 tabs.. new one has 3 screws...) so I can tell you can how easy it was next to the DOHC I would stick with regular coolant.. maybe try some "RedLine Water Wetter". RedZ Quote Link to comment Share on other sites More sharing options...
patgizz Posted March 17, 2003 Report Share Posted March 17, 2003 dude, the fuel line removal tool is $2 at advance. its a little peice of plastic that pops over the line and slides into the fitting and push those tabs out. Quote Link to comment Share on other sites More sharing options...
RedZMonte Posted March 17, 2003 Report Share Posted March 17, 2003 dude, the fuel line removal tool is $2 at advance. its a little peice of plastic that pops over the line and slides into the fitting and push those tabs out. its retarded how they do it.. the tool makes it work kind of like a chineese finger cuff. push the fuel line fowared, slip the tool in and pull the line off. had to do that when i did my 3800 Motor swap RedZ Quote Link to comment Share on other sites More sharing options...
GnatGoSplat Posted March 17, 2003 Author Report Share Posted March 17, 2003 Wow, only $2.00? Oh well, I'm not even sure how useful disconnecting the fuel lines would have been. That annoying tab on the heater pipe blocked the stud-bolt on the bottom, but the plastic vacuum harness is what was blocking the upper bolt. That's why I had to remove the fuel rail cover and disconnect the vacuum lines in order to get that vacuum harness to move out of the way. I had to disconnect the modulator pipe because it was blocking the vacuum harness. The weekend before, I changed the t-stat on my sister's '98 Eclipse. That was cake, it was right on top. 2 bolts and tada! All done! That car doesn't even have the annoying and time-consuming bleed procedure. Just fill & go. Quote Link to comment Share on other sites More sharing options...
boostnawd Posted April 24, 2003 Report Share Posted April 24, 2003 Great! So this is what I have to look forward to this weekend. I think I may just opt for Brian's cutting method... as soon as I figure out how to run power for my dremel outside. Quote Link to comment Share on other sites More sharing options...
brian89gp Posted April 24, 2003 Report Share Posted April 24, 2003 I have heard that you can fairly easily bend the tab down, in case cutting doesn't work out. Quote Link to comment Share on other sites More sharing options...
NOHC_WBody Posted April 24, 2003 Report Share Posted April 24, 2003 Is there NOTHING easy to do on the 3.4 DOHC? I thought the spark plugs were less of a pain in the ass on my 3.4 GTP than my 3.1 Cutlass. Quote Link to comment Share on other sites More sharing options...
CPSMonteZ34 Posted April 25, 2003 Report Share Posted April 25, 2003 Hadn't seen this one earlier, but when the whole intake gasket removal process went down, I too just bent that bracket to-and-fro until she snapped. Everything else was basically pushed-pulled-bent to clear the room for ANY tool to get into where the two bolts were to remove the t-stat housing. All I remember was not having good access for one bolt and had to use a box-end wrench with 1" strokes to deal with it. Talk about a slow process. Top that off with dropping one of the damned bleed screws into the abyss of the engine bay (got lost somewhere near the transmission mounting and skid plates) and had to use an aluminum screw that took me a half hour to find to plug the hole. There are a lot of engines that can do what the LQ1 can do, and they all fit into my favorite automobile, the car, so I can safely say that I phuckin' HATE this engine. ...but whatever makes my car go, I'll take care of it. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.