Engine Cooling problem
1995 Pontiac Trans Am V8 Two Wheel Drive Manual 132000 miles
i just need a second opinion. I have a 95 pontiac trans am, and am doing all the work myself. I had a problem the other day it was that my car was blowing white smoke out the exaust, and low coolent light comes on. I know that some how the coolent is getting past the head gaskets and into a cylinder, but thats not my problem that I have a question about. Its a LT1 350 V8 Chevy short block under the hood, and im thinking that since I don't see any " chocolate milk" in the oil pan, that it might not be nessessarily the head gaskets or the heads being warped or cracked, but the intake manifold gaskets going bad, since I didn't notice any antifreeze in the oil pan. Does this sound like it could be true? And what suggestion would you have on this issue. I do have the top end of the engine almost pulled apart, I just need to know if you think its a wise idea to just worry about the intake, or should I also be doing the heads as well? What can cause this since this is my first chevy V8?
You've removed half the upper end -just replace headgasket and intake too and hope and pray its not a cracked head or block when you put it back together.
October, 19, 2010 AT 4:35 PM
As a fellow 1995 Trans Am owner, lemme tell you, you're boned. The T/A LT1 and LS1 both have so-called " dry intakes" meaning no coolant passes through the intake. Instead, there are runners or tubes that pass the coolant from one bank to the other, eq'ing pressure. If you look at your intake (not hard to do. Pop the hood) you'll notice the coolant lines (both from the radiator and going to the heater core - the one to the heater core is the one with the metal piece and the small screw - the air bleeder valve is the proper technical term) both go into the block/heads directly, and underneath the elbow (90*) is your thermostat. The intake, being dry, means the coolant can only be getting in one of 2 ways: 1. The head gasket / warped head. PRAY this is you.
2. The block (very rare, but possible; LT-1s are Reverse Coolant Flow, and the head gets the colder coolant, which then passes down to the block, so head temps are lower, which they should be, while block temps are higher, which is also ideal). I'd vote for head gasket/head, while it's rare, if it was overheated (with stock settings of 180* thermostat and fans not activating until 215+ F) it's quite possible. Most tended to run 225-235, and city traffic would cause high operating temps, and later, blown head gaskets.
If you do replace the head gasket, I'd recommend either reprogramming fan temps or installing a manual override switch (keep automated control, but add manual overrides) and a 160* thermostat, which will keep your engine temps lower where they belong. Just my.02, take it or leave it (also ask it on LS1Tech, I bet they recommend the same thing, and say the same thing I told you).
Borg-Warner Engineer (laid off)
Regular mechanic (rebuilt my first engine at 13, built a Pro Stock motor at 17)