Question : 95 DOHC GTP GP cooling system issues.

[ARG3DOHC]

HELP.....HELP......HELP................ME
Ok , you guys are going to love this.
YES my DOHC is living up to its reputation as a service junky .

First the basic question is ;
"How do I tell the difference between a blown head gasket and a blown lower intake gasket ."
without taking the entire top end apart.
I want to figure this out somehow In order to determinre what my next move is.

Yes I have that lovely white smoke coming out of my *&^ tail pipes.

Now , for the explanation of how this all started.
I had a coolant leak showing itself on the front lower pass side.
Its turned out to be that wonderfull factory formed heater core pipe that runs
from the pump along the inside fender well to the firewall.
What a complete pain as I had to remove the alternator to put this in.
Next my variable assist power steering pump decides its done .
Leaking at the sensor , I try just replacing gaskets for the sensor , only to find out
they don't exist anywhere (strange sizes).
So I decided to replace entire unit with rebuilt ( that has decent warrantee)
THat works great , but the little Bas(^*! likes to wine .
Next for some reason I now can't remember I take off the upper intake manifold .
I think I was getting another leak at the wonderful O-Ring .
I find a new gasket set and only install the O-ring and upper cause < I did the lower
about a year ago.
Put its back together and get it hot to check for leaks , yep sure enough something is leaking
get back home , open the hood and there it is , the lower intake coolant inlet hose is leaking right
at the that damb inlet connector , OK fine .
Next within a minute Ive got white smoke out the tail pipes.
SO , My decision now is do I scrap it or completely rebuild this .
I need to figure out if its minor (IE lower intake manifold gasket) or major (Head gasket)
As Im currently out of work , I have the time , but this is making me very cranky.
And If I do the head gaskets , Its kinda like "well Im already there might as well rebuild the
entire enchilda right , cause at that point the engine is 2/3's torn apart anyway.
Im really not looking forward to doing that , please let it only be the lower intake manifld gasket !
Regards....Arrrrggggggg !

[dohc nut]

bubbles in radiator and/or overflow bottle

look for bubbles in the radiator and/or overflow bottle with the engine running the presence of bubbles(as there are in mine)indicates a compression leak into the cooling system namely the head gasket and/or cracked head. If you dont see bubbles this does not mean that the head gasket is ok. you must do compression and cylinder leakeage tests to know for sure. I am a licenced mechanic and in my experience lower intake leaks while they may cause some white smoke tend to cause a hydraulic lock on hot restarts and/or after sitting. Our general rule is white smoke = head gasket in most cases. I would agree with you that you should rebuild the whole thing. That is what im doing with my 94 GTP . I hope I have been helpful and I hope you dont scrap that wonderful car. By the way these engines are known for blowing head gaskets it was one of the only major problems that i have ever seen.

[Dave96z34]

By the way these engines are known for blowing head gaskets it was one of the only major problems that i have ever seen.

Not realy if that was true us bosted guys would have a big problem. Me iv been dumping 7.5 psi in to my engine for 3 years now 27K on a motor that had 140k to start with.

The only part of the engine thats junk are the valve seals and intake manifold gaskets.

[dohc nut]

while i am sure that you have no problems with your head gaskets and you may not ever. I myself have seen this quite a few times before. With my 94 gtp it ran beautiful,never ran low of oil,it was never revved up until warm,never overheated, never even misfired until one day it ran slightly rough blew white smoke,and started to get hot. I stopped and checked the overflow guess what nice stream of bubbles. i let it sit and limped home once it was cold. I will rebuild the whole thing as i am over 2ooK. I think gm gasket trouble has something to do with leaving dex cool in too long (turns acidic or something and eats gaskets.)same thing every time i've seen it(customers in the shop).I think I might try green coolant this time it's cheaper anyway.but i still maintain if you're doing head gaskets on this you shouldn't ignore the bottom might as well punch it out a little too .30 over maybe? just a thought you know while you're there....

[dohc nut]

you should probably replace that alternator now too. oh that reminds me does anyone know how that cooling duct goes on? mine is hanging between engine and trans loosely.