Thread: head gasket replacement

Hey guys so I'm thinking of doing the head gaskets and possibly getting new heads. 04 gtp comp g. 150k. Still think my engine runs too hot and can't get to the bottom it. Ordered a new lower intake manifold and figure might as well do the heads since I'll be there for the second time. Anyway my questions are: what is the most important things to know when doing a job this serious? Second, will any head gasket work or does it need to be specific thickness? Quick search just showed multiple thickness, how do I know which to choose? And as for the heads, is it better to just buy some new or remanufactured? Or first see if mine can be machined? And is there such thing as performance heads for this car? Zzp has some for like $900 but some other sites have remans for like 3/400. Anything you guys can tell me about doing this will be greatly appreciated...I have only done one head gasket before and It was over 14 years ago.

To answer your question: "what is the most important things to know when doing a job this serious?",
I also have to ask the question: "what was your diagnosis for the "runs too hot" that makes you think you need new head gaskets, heads, and LIM?"

Hey quicksilver...the diagnosis for running too hot is basically it runs a bit above mid way, sometimes a notch or two, and fans come on and doesn't really cool it down much. I've bleed and bleed the cooling system, no help. And as for the LIM, when I took it out to change the gasket about a few months ago, I discovered a part of the LIM that was eaten away, where it should be flat, and so I stupidly put a bunch of permatex gasket maker where it was eaten , to try and make it flat, but then people told me this isn't the best idea and that after time that big chunk of gasket maker will possibly fall off and clog a coolant passage or something, so I decided to just buy a new Lim. At the time I couldn't find one so I went with the permatex. And since I'm doing it I figure why not just do the head gaskets and new heads while I'm in there, to make the engine last longer and so I hopefully don't have to rip it all apart for the third time and do it in the future. Or should I not do head gaskets unless absolutely necessary? I mean I don't quite now if it is overheating, now that it's cold out and I mainly drive at night, It doesn't get that hot. It was more in the summer when it's 90°out. I've also had people on here tell me there gtp runs below mid way at all times even in the hottest days, makes me think something is wrong with mine but never been able to figure it out.

Head gaskets are not a maintenance item. Unless there is evidence of a failure in the head gaskets, there is no need or benefit to changing them.
A head gaskets failure can include:
a) combustion gases in the coolant
b) coolant in one or more of the cylinders
c) coolant in the oil

For your LIM, I would say if there are no leaks, dont mess with it.

For your "running hot" situation, you need to know what the temperature actually is to make this judgment, a.k.a. "data", the number in Fahrenheit.
Get yourself an IR temp. gun and point at the top of the thermostat housing when the engine is hot, take note of the temp. Then, point the IR temp gun
at the inlet of the water pump, (big hose from the bottom of rad.) take note of the temp., you should have about a forty degree temp difference, (depending on the condition of your rad.) this is with the engine running, in "PARK",
a/c ON. Make sure your coolant is full, and holding proper pressure, and your rad. fans are "ON". The best time to to this is during the hottest part of the day,
this way you can get a good measurement of the efficiency of your cooling system.

Another thing you can do is get a cheap scanner/code reader that will show "live data" when the engine is running, it will show you the temperature the engine
is running at, and you can base your judgment on how "HOT" the engine is running, and then you can look at the gauge on the dash and compare, and take note
of any discrepancy in the two readings. Sometimes the dash gauge is not accurate, and misleading. The "data" the engine receives from the sensors has to be
accurate for the computer (PCM) to make accurate air/fuel ratio calculations.

Knowing the actual temperature in degrees is the most important part, this way when you make a repair you can re-test your cooling system
and compare the "data" from before and after to quantify your repair work, or "go back to the drawing board"!

Ok I remember you going over all this with me before...I actually did buy the IR temp gun and do this, and I wasn't getting a difference of 40° between upper and lower, not even close...it was like 20° max. I will have to go try again just to make sure I did it right, with fans on and everything. It's been cold lately so might have to wait a bit. But if I infact don't have enough difference in temp herez where should I start as far as parts go? Entire cooling system is new besides heater core. Could it be my cheaper ac Delco gold water pump? It was $30 instead of the better $100 one, could it not be pumping efficiently? The radiator is new from AutoZone...could I need the heavy duty radiator from zzp? Anyway I've decided against the head gaskets for now, and returning the LIM...you think that using the rtv on the LIM in the eaten away spot I'm describing won't harm things down the road? It seems to be a part that sits flush against the head but I'm not sure. Thanks for all your time and help with my gtp though quicksilver you da man