Automotive help needed

[HayZee518]

This is home related but not home construction. I am about to embark on something I haven't done in years. This is replace the intake manifold gasket on my 3.4 liter GM engine. The last work I did on ANY engine was way back in the 70's on a Buick. My engine experienced maybe four occurences of overheating, twice to red lined and no more. It is now sitting in the driveway waiting for the car doctor. Can anybody give me some tips that I should know about? I know after reading a bunch of stuff that GM has new bolts for the intake manifold. I know the new gasket needs to be beefed up so as not to leak again. I know dexcool is not the coolant of choice but some recommend against using the green coolant. This engine has about 146,000 miles on it. I read about the O ring on the fuel rail. Now to go finding a torque wrench with in-lb rating and crow foot metric tools.

[mrcaptainbob]

Head gasket repair...

Advil. And most likely you already have the shop manual for it. Both my sons are Michigan certified mechanics. I'll pose this issue to them on Tuesday eve and report back with any suggestions.

[HayZee518]

Actually Bob I haven't amanual yet. I been looking at a lot of stuff off the internet from guys that have done the repair. Some say this some say that some even offer things you should have purchased from the parts dealer that you didn't etc. I have a few friends that are willing to loan me their spare car for errands but I don't want to overstay their welcome and where I live is really out in the sticks. My nearest town in any direction is 30 miles.

[HayZee518]

I wouldn't wish this job on ANYONE! It's a real pain in the butt! The alternator is waaayyy in back on the left side facing the engine. the front pivot is there BUT they don't tell you about the two bolts underneath and in back. They're about an inch and a half from the firewall. A 13mm ratchet just about fits. Now I see why the GM techs get the big bucks! The intake manifold bolts have a 10mm hex head and look almost like a 1/4-20 bolt. I used a 1/4 inch ratchet to crack free the bolts and they came off by the fingers the rest of the way. Torqueing specs say tighten to 62 in-lbs. That's not much! Now to clean it up and wait for MONEY!!!

[mrcaptainbob]

Intake gasket....

Hi, Hayzee. Spoke with my older son today and his cautions are:
*Lots of patience.
*Take lots of pictures. The wiring harness especially needs to be put back EXACTLY as it was. (His emphasis.)
*Loosen bolts in criss cross fashion.
*New intake bolts are not req'd unless corroded. Usually new bolts are for the heads.
*Take a very close look around the head gasket areas as best as you can and look for the tell tale corrosion of small antifreeze leaks. Over heating could cause a head gasket leak as well as an intake one.
*Check spark plugs for being either very clean (indicates steam from anti freeze) or chalky white (also indicator of burning anti freeze).
*Check oil for coolant in it
*Check coolant (bottle and rest of system) for oil in it. Will manifest itself as a brownish, muddy goo.
*At this point consider replacing the t'stat as well as the water pump.
*The job is a PITA. (Son's words).
Sent you a PM.

[HayZee518]

3.4 liter gm engine

here's some pix I took of what I found after tearing it down.

[WVslottech]

here's some pix I took of what I found after tearing it down.

Why are you pulling the gasket?? You should have checked the thermostat first...maybe make sure the radiator isn't plugged and flowing normal.....the problem is still going to be there if you go to all the trouble of changing the gasket, and find that a 90 cent thermostat is stuck!!

[HayZee518]

Don't ya think I thought of that first? I changed the water pump and thermostat and the temp still went red lined. I burped the system after adding the anti freeze. THAT's why I pulled the intake manifold. All car forums say that the intake gasket with the dexcool coolant fail after about 89-140,000 miles. The 3.4 liter engine has been around since 1996 and is on Pontiac, Olds, Chevy - anything GM makes.

[WVslottech]

I realize you probably already know this ...but i'll tell you anyway.I have worked on alot of 3.4 liters.I have also found that alot of the problems lie in the heads,because they warp from bad gaskets from the factory similar to the dodge neon.If you have redlined the temperature I would not recommend putting it back together unless you have the cylinder heads flowed and pressure tested,because if you over heated it or went into the red with it you have warped or cracked the heads.You are right though they did come in 90's gm's.I am not trying to be a goof but I did the same thing you are doing 3 times before I junked my 97 grand am.I found that the problem wasn't anything more than a plugged radiator.If you do find that the heads are warped take them and have them milled to get them back to true.Also make sure you get the right thickness gaskets to accomodate the couple thousanths you will remove from the heads.

[HayZee518]

OK, now I'm really confused. when the engine was running and the temp went sky high, I shut down the engine, waited a few ten minutes and the temp dropped. The engine continued to run very smooth as if nothing happened. If the heads were cracked or warped, wouldn't it have run rough or backfired or any miriad of noises? I managed to get it home and during this time period the temp got to the 3/4 mark and didn't red line. When I got home I cracked open the right bleeder and hot steam and "some" fluid came out. I shut it off and waited a few. By this time all the coolant was in the plastic recovery tank. I cracked the radiator cap and all of the coolant got sucked back into the radiator. I used a garden hose and back flushed the radiator and had water coming out the other end. So judging from this, is the radiator still blocked if I get back flow through it?

[HayZee518]

I don't want to do anything unecessary as I don't have a bundle of cash or patience. I'm 61 and don't need this aggravation to add to my already depressed state. Guess I'll pull the heads and regasket them also.

[mrcaptainbob]

Red lining temp....

A Dage Neo! How 'bout that!! I just got one for my wife. Had 129K on it. Seemed okay at first, but then started overheating. Turned out to be a bad rad cap gasket! Well, this thing red lined REALLY bad! THought for sure the engine was cooked. A couple weeks later it puked antifreeze from under the hood while on the X-way. The rad top can cracked. We nursed it home by stopping off every so often, letting it cool down, add water. New rad time. Pump and T'stat, too. All is well now. Even though it red lined the gage a few times, it hasn't hurt stuff. From what I've been told, we are DAMN lucky!
Back to Hayzee's issue. Now that you're so far into it...doing the head gasket thing is a good idea. Surfacing the heads? Hard to say. IF possible to do it, then yes. You may not have damaged them. BUt it's better than to put that intake back on and find it's a head gasket. It's better to have them checked now rather than find...yadda-yadda-yadda. Ideally would've been to have pressure checked the system before you invested wrench time. But, it's still not a loss, as you noted, these engines do have a bad reputation. You're just solving issues before they happen. Glad you have a new pump and t-stat to go along with it all. And, at 61, you're still a little young. Us old timers (64) are willing to give you all the help we can...
THis'll be a comfy car when you're finished. It'll be freshened for another 80 to 100K. Keep us posted on your progress, Hayzee.

[HayZee518]

Oh I will play by play. Bob I called your son. Very impressive. He knows what he's talking about. I sent him a few pictures of my in-progress work. I pulled out the gaskets yesterday and looked at them with a big magnifying glass. You can see where the gasket material is squished near the bottom, but not touched at the top where the leaks happened. The gasket material on that plastic/rubber carrier are tubular shaped. If you ever heard of a plasti-gauge, it looks almost the same when compressed. Thing is with a gm car they mixed american and metric bolts together on the engine. The torque values for the engine bolts are in inch-pounds not foot-pounds like we are all used to. Smaller may be worth it, but not on these hot running engines.

[mrcaptainbob]

Inch#'s/Foot#'s...

If nothing else, HayZee, being inch pounds makes it easier to remove! YEah, that gasket may be squished near the botom without much evidence near the top, but it must've been doing something, as it held up for quite a long time! Not too much pressure on the intake gasket anyway. It's negative pressure in the chamber, but positive in the coolant passages. Neither of which is a very high psi. Play by play is the best way to do it. Just keep chippin' away, Hayzee. I did speak with my son tonight for a few. He hasn't received the pics yet, maybe they'll show tomorrow. And yes, he does know his business. A master mechanc on school bus deisels, all the way down to alcohal go-karts. This...from a kid that left MY ratchets in the mud when a kid! Now HIS (giant) Snap-On box has everything organized....
Are you planning to do the head gaskets, too?

[HayZee518]

I'm up in the air whether to do those or not. It was a real finger buster getting all I needed to get out now. I can just imagine how difficult it will be cracking loose the exhaust manifolds off the heads. That and the have heat shields on top of those. As far as the pix go, I sent them to his yahoo mail address as instructed. Maybe he gave me the wrong address