Hey everyone. I had my intake gasket replaced about 7 years ago at around 72-73k. It was the Felpro set and I ordered it myself to verify. I now have 129k. Except for a brief period where some unprofessional oil change place completely disregarded my instructions and put orange in there (hence why I haven't been to one in ages), it has run green and flushed every year or two since.

It seems that for the past couple years I have noticed a trace amount of liquid (no drops/dripping/pooling, just on top of where the gasket hangs near the RTV that catches my flashlight) next to the AC compressor. I have been told over the years by a few mechanics it is just oil and not a real issue. If I can reach it with a paper towel and try to look/sniff it I can never get a conclusive result but it does have a light green look to it (although sample contaminated from the RTV and oil around it). I also have condensation on the oil cap but that has been like that since day 1.

But lately and especially with the cold weather I would see it just after initial startup. It is right around the same place where I saw the dripping last time on the block when I actually went to get the gasket replaced. In terms of coolant loss I do notice a small amount in the reservoir lost from time to time but I barely drive the car and I had all hoses/t-stat/t-stat housing replaced 2 months ago as they were getting old and I was smelling antifreeze (sometimes I still do but I can't tell anymore....), so once again inconclusive. I just changed the oil this past weekend and once again no antifreeze contamination I can see or excess metal filings on the magnetic drain plug.

At what point should I look into having the gaskets replaced again if that is the case? Is there anywhere else it could be leaking in that area? Thanks for all of the tips, I am just afraid and frankly not ready to admit it needs another gasket until I have some more info.

EDIT: Sorry, force of habit and forgot since normally I tell this upfront. This is on the Jimmy with the infamous 4.3L gasket, not the 4.2L on my Trailblazer which already had it done anyway when I blew a valve spring.

 

I might get bashed for this, but I'll suggest it anyway........if i were you i would just ad a can of stop leak..........we have a combination of cast iron, cast aluminum. and cast plastic under the hood now.....all of it has it own expansion and contraction rate.......I have had four or five different chevy pickups and blazers since the late 80's and all of them seemed to loose coolant.....with temps fluctuating more during the winter it makes metal move more....
just my opinion.......it's a lot less work than tearing the top off again....

 

Stop leak will only prolong the inevitable at the expense of corrosion. The longer a leak is allowed to progress, the more corrosion/pitting there will be at the site of the leak. All that stop leak does is attempt to contain the leak by putting material into it, wherever that material decides to grab hold. It is up to you, but the sooner you replace, the better off your LIM & heads will be from the standpoint of holding the seal. These aren't paper gaskets anymore that pretty much adhere to both surfaces.

The problem with these trucks (96+) is that the LIM gaskets were made originally with a nylon cage with an overmolded rubber sealing ring around each port. The nylon cage would expand and crack, causing a leak. The updated gaskets available have an aluminum cage that is a much more robust design when properly installed.

 

Sorry if I missed it, but Felpro makes both an oem replica set of gaskets and the upgraded metal gaskets. Do you recall which ones you ordered? Just curious... I would suppose even the upgraded ones could fail now and again though too.

 

Good point, Doc!


MS95817 is the OEM style. MS98002T is the upgrade, and well worth the extra $40.

 

Why thank you!

 

Well thanks everyone for all of the tips. I think this truck needs another set for sure..... The temperature is bitter cold just before the snowstorm and when I went to check there is now a nice green spot behind the A/C compressor.... I guess that removes any doubt now. All it took was some very cold temps for it to build up.

I will order the MS98002T and some spark plugs (they were replaced a few months after the gasket), but what is the best way to proceed with this and what else should I have looked at or replaced in the process? At 129k not sure how much more I can get, but I hope to get as long as I can without a total overhaul.... At least I changed things like fluids and filters often, so it might be better off than average.

 

Ok truck is in the shop now... they are also doing the valve cover gaskets. They are in the kit anyway and leaking. Spark plugs are getting done also.