Serie I Intake leaks
 

I have a 94 SE with the series 1 3800 and the plastic upper intake manifold. After reading all the posts about cracking, I thought I check mine. I noticed a small pool of coolant on the lower intake next to one of the fuel injectors. Am I toast? I thought Series 1 did not have this problem or is it a leaking gasket? I don't seem to be consuming coolant. It has 125k on it.

Re: Serie I Intake leaks
 

Here's your fix......

3.8L (L) Engine Intake Reseal Series I PH93/94:
17113265 Upper Intake Gasket Kit
12338840 Lower Intake Gasket Kit
24501671 EGR Valve Gasket
88891743 Coolant By-Pass Fitting
10953472 RTV Sealant
993088 Antifreeze {2L}
992878 Engine Shampoo
88901247 Brake Kleen

It's just a lower intake leak probably.....

I agree. Probably just a leaky upper intake seal. Easy fix. When you open it up to fix it, you'll probably notice one or two ultra-clean runners in your lower intake manifold. Typical sign of leaking coolant, even small amounts.

Thanks!
 

Thought the seals could be a possibility. Is this as critical as a cracked manifold? Am wondering if I can put it off a while until I do some valve work (leaking valve seals). That brings me to another question- is it possible to replace valve stem seals without pulling the heads? I heard there a trick pressurizing the combustion chambers with compressed air to keep the valves from falling down while you have the springs off....
You guys are great.

Hi! I wish I had known about the intake manifold problems and checked for them like you are doing.That's smart. I have a 1999/ 92K with total engine failure as of Tuesday and am getting a brand new engine. I am just now finding out about the problems with the Series 3800 engines and the intake manifolds, antifreeze in the engine, etc. What an expensive auto repair lesson.

Re: Thanks!
 

Dougtful your manifold is actually "cracked". As to putting it off, here's a little bit of advice on what happens if you do......

Be prepared to get a new engine rebuilt due to coolant contamination to the crank main bearings & conn rod bearings, along with new crankshaft. Estimated cost for the 7 others I've personally quoted on in the last 6 months are about: $500 Can for Crank Kit and 16-20 Hours labour.

As about the Stem seals, well you can an adapter that screws into the spark plug hole for an air line that will keep air pressure on the bottom of the valve. :wink:

Upper Intake
 

Since I appear to have a leaking manifold gasked, is it possible to leak oil into the intake manifold? If so, is this why I'm getting a little bit of smoke?
OK, I won't put it off!

Deathrat's warning would be applicable if your coolant was mixing with the oil. After driving, how does the oil look on the dipstick? Normal? Milky brown? If normal, you're just burning it off. That would explain the smoke you're seeing. This scenario would mean your manifold vacuum while running is sucking it into the cylinders and burning it off.

Best case scenario, you'll be replacing the TB seal and intake seal, plugs and probably O2 sensor.

Worst case, what he said ;)

Upper intake
 

Oil looks fine. It still has some transparency even after a 1000 miles on it. I've had a car blow a head gasket before and I know what coolant in the oil does. How does oil get into the intake in this case, though? Are there oil passages that pass through the manifold? Why would an intake manifold carry oil?

Re: Upper intake
 

It doesn't! It just seals off the upper block from the heads itself. It the lower intake seals are leaking oil, it's 90% chance they will leak EXTERNALLY. The other 10% chance it will leak into the combustion chamber entrance into the head itself. :wink: The oil comes from the Hydrallic Lifter galleries BTW & used to lubricate them externally as well as the ballance shaft.

*EDIT: Spelling*