INTAKE GASKET MAIN PAGE, PLEASE POST Q'S&A'S HERE!

[Huney1]

Head crack: Overheating is the number one cause of cracked head(s), so if it hasn't overheated it's doubtful you have cracked heads because they usually don't crack for no reason. Simple test for head crack. Go to the parts store and ask for a kit that you put some coolant in then add the chemical and if it turns a certain color it indicates exhaust gases mixed with the coolant.

White exhaust smoke is water/steam so the IMG is leaking inside the engine then being blown out the exhaust as steam. Some white smoke when you first crank it is OK because water condenses inside the muffler and exhaust pipe, but it should quickly burn out.

Be glad it's not leaking inside running down in the oil sump where your oil looks like a chocolate milkshake. You want to be careful because if a lot of collant collects inside the combustion chamber it can cause a hydro-lock and the engine will turn over real slow or not at all, then when it does crank it wil run rough until the water burns out of the combustion chamber. If the coolant runs down around the rings into the oil sump that's isnt good. Keep a close eye on your oil dip stick and if you see little water droplets the coolant is mixing with the oil.

IMG leaks are wierd and they can leak anyplace so just have to take it as it comes. When mine leaked it ran outside on the garage floor, so in a way I was lucky because I put Bars Leak in it and it stopped leaking.

[1Bradymichael]

Originally Posted by wilrayca

Hi, I started loosing coolant about a week ago, and was putting off doing the IMG till next week. Van has been running a little rough since. Went to start it today and now I have lots of white smoke out of the exhaust. Has anybody had large amounts of smoke and the cause be the intake gasket, or am I now looking a head gasket as well.
Thanks

Odds are you have a head gasket out. The white smoke is usually the result of the coolant entering the com. chamber and burning.
However, it might be getting in the intake as well through one of the intake runners on your manifold.

I would read most of this thread and you'll get some good ideas how to determine where the leak is. If nothing else, take it to a shop and they can tell you.

I did mine back in June, and found out that a local mechanic does them for around 400$. He is that fast as he has done so many of them.
It was good to be able to do it myself, but I would take it there next time.
Make sure if you have it done that the o-ring for the oil pump drive is replaced at the same time. It costs about a buck for the part, but if it goes bad a lot of stuff has to come back off again. It is cheap insurance and they are known to leak. It will create a mess if it does go bad.

I would however have a hard time paying a GM garage around a grand to fix it.

[wilrayca]

Are the new bolts listed in the service bulletin any different from the old bolts? The dealers around here want 12-15 bucks each and I don't want to replace them if I don't have to.
Thanks

[Huney1]

I was told the difference in the bolts is they load the new ones down with LocTite so they won't come loose. LocTite comes in different forms so get the one that's sort'a thick like putty. That's what they used on mine and they used the old bolts.

There's a GM technical service bulletin on what to use so look around the threads and you'll find it, or run a search for it. meeting to attend so muct run for now. If you don't find the TSB I'll help you tomorrow. MOST important thing is you use nothing but the FelPro gasket that won't rot and the bolts must be torqued in a specific order. It's all in the TSB.

[wilrayca]

That's what I figured with the bolts. I have a copy of the TSB so don't worry about that. The Felpro gasket? I thought the general opinion was that the new GM gasket was the best thing to use.

[Huney1]

The GM gasket you get is probably made by FelPro. Anyway, I've shared all the info I have so I hope you get it fixed and enjoy many, many miles of happy motoring.

[papi62596]

Originally Posted by olson96

I have step by step instructions, I can email you the attachment

Mine just started to leak and needs to be replaced. Please email me the directions that you have.

Thanks- Nelson

[Huney1]

Wilrayca said; "I have a copy of the TSB so don't worry about that." Get him to give you the TSB number 'cause you'll need that to. Somewhere in here the whole TSB was posted so you can cut and paste it then print it out. We suggested putting up a sitcky for it, but I guess it didn't happen . . . .

Some vehicles (even though they are the same body style) have different procedures and tricks to getting the job done...so post the year and engine size so you get the correct information.

I found it: http://www.automotiveforums.com/vbul...=321467&page=2

[phipps]

I had posted some questions earlier in this thread in reference to my van's problem. Well here is how it turned out:

The rear head gasket ended up being blown and that head warped. The repair included milling both heads, replacing the head gaskets, replacing all the spark plugs, replacing the rear plug boots, replacing the IMG using the redesigned one, replacing the water pump, replacing the serpentine belt, changing the oil and flushing the coolant system.

Total bill ended up being $850, which from what I can tell is a pretty good price.

The mechanic suspects that maybe the IMG was leaking which led to a low coolant level which may have led to the water pump failure and the engine overheated warping the head and blowing the head gasket.

Thank you to everyone that answered my earlier questions!!

[phipps]

Originally Posted by wilrayca

Hi, I started loosing coolant about a week ago, and was putting off doing the IMG till next week. Van has been running a little rough since. Went to start it today and now I have lots of white smoke out of the exhaust. Has anybody had large amounts of smoke and the cause be the intake gasket, or am I now looking a head gasket as well.
Thanks

Those were almost my exact same symptoms and it turned out to be a head gasket.

[wilrayca]

Well, finally had a day off so I was able to remove the manifold today. The gasket was leaking at the drivers aft corner. Unfortunately I also have a blown headgasket on the rear bank. Did a leak down test and the pass rear cylinder just blows right into the coolant jackets. Looks like more work tommorrow. All in all not a bad job so far. The cost of parts is a little frustrating though.

[rhandwor]

Make sure you use a straight edge and check surfaces before reinstalling. Use a flashlight and check for cracks between the cylinder and also around the valves.
I personally would take the head to the machine shop and have it pressure tested. A small crack in the head can ruin a good reinstall.

[phipps]

I lucked out, the machine shop pressure tested my heads when they did the milling.

[wilrayca]

When putting the pushrods back in does the cam have to be rotated to take the pressure off the pushrod before tightening the rockers? The manual makes no mention of this. It just says 89 inlbs plus 30 degrees.
Thanks

[rhandwor]

I think this engine uses hydraulic lifters put oil on the cam and lifters then tighten down. Your are really compressing the lifter it will pump up when running.