Coolant Leakage

I have a 3800 series II with the supercharger on it and am having problems with coolant leakage around the intake gasket. This appears to be a big problem on the 3800's. Even several lawsuits against Dex-Cool for it compromising the gasket seals. Other than that great engine. Does make a strange "ticking" noise too. Might be the lifters.

It is going to be a major swap. You will need to swap the motor, trans, maybe subframe, wiring harness, pcm, fab fuel lines, coolant lines, and probably AC lines. Not to mention the wiring you are going to have to figure out what wires do what and make lots of splices.

btay801, the 3800 and all GM V block motors have issues with Lower Intake Gaskets leaking. GM is laying the blame on dex cool as the fault for the blown gaskets. However the real issue is in fact the horrible shoddy design of GM gaskets. Seems as though the are actually made to blow. See this thread...

http://www.automotiveforums.com/vbulletin/showthread.php?t=958284

WOW! That is disgusting if it is the truth! I have searched this site for many hours and never say that thread. After I cleaned off the Dex-Cool and blew it dry with shop air I could actually see the coolant pushing just above the seal and below the intake! What are the best gaskets to run and what other mods can I do while in there. I have a 2001 GTP and want to put a smaller pulley on it eventually. I saw a video on youtube and the guy was saying to plug the coolant ports on the S/C and open up the throat of the "V" on the S/C outlet. Ever heard of any of that?

These posts have been moved to its own thread retitled "Coolant Leakage". Please try to keep the issue and content related to the thread posted in or on topic. Or simply start a new post with your issue.

I went with the GM Metal Framed Gaskets although they do have their own issues like oil leaks where the LIM mates with the block.

Fel-Pro brand LIM gaskets are probably your best bet. And even though they are plastic, they don't have those damn little slits in the coolant passages.

As far as Mods go, I just went ahead and installed a ported Lower intake manifold. It saved me from having to clean all that old gasket material off the old LIM. I just washed it off and shipped it back as a core. The ported one was about 200 shipped but I got 75 back for shipping back the core. When you order you can specify if you want the coolant passages to your throttle body blocked off. Since you live in a warmer climate, you could give it a shot. I had to leave the coolant flow through mine to keep the throttle plate from freezing open during the winter.

And BTW, that ticking of the lifters, usually that is a tell-tale sign that there is coolant contamination in your oil. While you are in there replacing your LIM gaskets, it may not be a bad idea to replace the lifters.

Thanks for the info. What brand intake did you buy? And what would be a good intake manifold that would support a smaller S?C pulley?

The "ticking" noise is very pronounced at cold start up then goes away after it is warm. Does this still sound like lifters?

See signature.

Ticking definatly sounds like it could be the lifters.

I now have an intake on order from Milzy Motor Sports. Where is a good place to get the lifters and how difficult to change them out? And who can I coult on locally to carry Fel-Pro gaskets? Auto Zone? Napa?

"Since you live in a warmer climate, you could give it a shot. I had to leave the coolant flow through mine to keep the throttle plate from freezing open during the winter."

It gets kinda frigid here too is Salt Lake. Usually never below 5 degrees Fahrenheit. And she is garaged. Can I still plug the jacket that goes around the S/C?

Thanks for all the useful information. You don't know how much I appreciate it!

I don't want to say either way on plugging the coolant passages. Someone else with more knowledge could answer that for you.

Fel-pro gaskets are usually available at most auto parts places.

The lifters could be quite expensive to replace all 12. Plus if you do want to replace lifters, you will also need to replace the valve cover gaskets while you are in there.

Well I finally am getting around to replacing my LIM due to coolant seepage that collects on the intake manifold indentations. As you can probably tell, it has been leaking slowly for a few months.

My concern is that I thought when I pulled the manifold I would see the deformed seals around the "V slits".:confused: As you can see from the pics, no bulging or deformation. Why are they leaking then?

Second, I will replace the o-ring from the water pump to the intake manifold. But is there another replaceable seal on the water pump side of the plastic elbow? Or do I just have to replace the whole water pump assembly?

Thanks in advance!

Bottom right coolant passage for the leak.

What year is your car? On 99+ 3800's there are two replacable coolant elbows. 98 and 97 you will have one replacable plastic elbow, and one o-ring on the other elbow. Be carefull, they tend to break off, so bofore you put it back together, make sure you dig all the pieces out.

Agreed with Tim's observation. The bottom intake gasket in your pic has failed both at the coolant passage and intake runner passage on the right side. This was definitely where your coolant was going.

Looks like he is even missing a chunk of the little plastic intake runner. I wonder where that is stuck in his system right now?...

It is a 2001 GTP. And where is the "chunk" off the intake rail you think I am missing?

Just to clarify, can i remove the elbow that comes out of the water pump to replace the o-ring? Look at the pic I attached to earlier post. Thanks for your help guys!

It's just a small piece of the plastic gasket, not the intake rail. Most likely this piece was sucked into the engine somewhere and is of no concern. On the coolant elbows, these are a known problem part and get brittle with age. I would replace the entire elbow(s) rather than replacing the o-rings, because if yours are original, they are probably getting to the point where they are going to break.

You were right Richtazz. The upper coolant elbow broke right where the o-ring seats when I pulled it. I got the intake all together tonight after snapping off one of the fuel rail attach studs. It just never seamed to bottom and then it twisted off! I got it out with pliers though. Gonna change the oil and flush the Dex-Cool out tomorrow and change to the good old green coolant. Thanks for all your help guys. I will have the moment of truth tomorrow night when I start it after the sealant cure time.

Anyone that is thinking about changing their Lower Intake Manifold gaskets...especially if you have the GTP, take lots of digital pictures. You will need them to reference. I saw a thread that a guy did this job in 4 hours. The guy must be a Superman or have done it before. Take your time. I spent 10+ hours from start to finish, granted I changed the plugs and wires while in there.

Just to clarify, Dex-cool is not the issue on these intake gasket failures. The only knock against Dex-cool (or any of the extended life coolants for that matter) is that it should be changed more often than the 5-year/150k mile claims (I would suggest 1/2 that to keep sludge from building up. All coolants currently available (other than old stock someone has had around forever) are based on the same chemical formula as Dex-cool, just the dye makes it different. The sludge that forms is caused by combustion by-products and traces of oil that used to darken the old silicated coolants. These sludge causing contaminants were trappped by the silicates in the old coolants, and then removed when a flush was done. Since the silicates damaged aluminum cooling system components, they had to be removed from the coolant formula, thus Dex-cool (and all other non-silicate coolant brands) was born.

I saw a thread that a guy did this job in 4 hours. The guy must be a Superman or have done it before. Take your time. I spent 10+ hours from start to finish, granted I changed the plugs and wires while in there.

Was that one of my posts? :rofl:

And yes, I couldn't probably count on two hands how many GM LIM gaskets I have done. The majority of them are 3100/3400, but there are plenty of 3800's series 1, and 2's, and a hand full of 350/305's.

And I could change the plugs and wires on the 3800 in about a half hour to 1hour depending on how hard it is to get the boots off the plugs. :lol2:

Just comes with working on the lots......

Good to know Richtazz about the coolant. Maybe I will stay with Dex-cool. I have read claims that Dex-cool caused failures, but It seems the finger pointing is coming from GM to cover for their shoddy LIM gasket design.

Hats off to you Tblake! You certainly must be a Superman. This was my first LIM change and I took my time to do it right. The Supercharger is alot heavier than i had expected too. I hope this MMS ported and polished intake nets some extra HP and TQ.

Thanks for your prompt responses Richtazz and Tblake. It made all the difference. I am not a car mechanic by trade. The aircraft mx manuals are much more detailed that this crappy Chilton dvd-rom I bought. No pictures for this entire job, just description and torques.

I think the spark plugs were a little overdue for being changed.:lol2:
The gaps on some where almost .090"! And a few were worn to a point.

you're welcome btay801, that's what we're here for.

On both the GM 3800's and 3100/3400 engines, I can do these intake jobs in about 4 hours myself. It comes from practice, and knowing what tools you'll need. I'd say the first 3.4 I did (in a minivan) took about 6 hours, the 3800 Vin-K's are much easier. I have yet to tackle a supercharged 3800, so I'm sure they take longer. I just did a 3800 VIN-K, and had the uim and lim off in less than an hour. I think cleaning the old parts up and getting all the gunk out takes as long or longer than actually R&R'ing the parts themselves. Without the cleaning time, I could do one of these jobs in about 2 hours on a good day where nothing fights me...LOL!

I like pictures!

BTW, how is it running?

She is running beautifully! NO LEAKS! After bleeding the air out of the cooling system the temp dropped to normal. Thanks for the help guys! I would have not attempted this without all the knowledge and tips that you all gave me.

I hope the user that is now having problems starting his GTP after changing the LIM gaskets finds his problem. I have been there, trying to figure out just what you did...or didn't do that caused the problem. That sucks.:banghead: