Originally Posted by Small Arms Collector

I just had my 1998 in to the mechanic for a random misfire code. No codes showed on the live counter, until the engine was allowed to cool (I have also had an on going cold start issue), and spraying parts cleaner at the intake body caused a noticeable increase in noise. He said the intake manifold gasket was bad and would need to be replaced, he said the leak was still minor and seemed to go away once the engine gets to 150 degrees or so but would get worse. Be said right now there is no fluid leaking it’s just a vacuum leak. He quoted about $600 to fix it.

Do you think he was right?
If the intake manifold casket is bad is $600 a reasonable cost to replace it?
Is this something that can wait until next summer? I have other pressing repairs that need done too like rebuilding the suspension (or at least replacing my CV joints and wheel bearings to get my ABS back), I could use a new power steering pump (it has a slow leak) and winter is coming up.
Will the cold in the winter make it undrivable, or unstartable?
Since replacing the intake manifold gasket involves taking apart the whole top of the engine, would it be worthwhile to preemptively go further and replace the head gasket? The head gasket has given me no indications of trouble, but if it could be done without much more cost it might be worthwhile just to replace it for the peace of mind. About how much more do you think that would cost?

This truck is normally just driven around town until I complete repairs, but if this is not done yet, do you think the truck would be OK to drive like this over the holidays (about 2 hours by freeway each way)?

Originally Posted by jetmac

This is my 3rd LIM gasket replacement on 3 different GM 4.3L. I used this link the first 2 times and it was very helpful. Unfortunately, the link is broken and I can't
use it to reference for my 3rd LIM replacement. THANKYOU!!! for including a PDF of this process. I haven't been able to find the one I thought I had.
This is by far THE best write up for this job.

Originally Posted by Small Arms Collector

Had the cooling system flushed today. Apparently when they replaced the gaskets they mixed green antifreeze with dex cool, and sludge was already starting to form, thankfully I got it all blasted out now and replaced with “universal” antifreeze, cleaned out the tank too.