3800 Mystery

[94SilverSSEi]

This is our 2001 SSEi.

Lady said the engine was bad, had a knock.

Started it up and it drove but ran rough. To me it felt like there was coolant in the cylinders. But there was no knock in the engine.

Only engine code was misfire cylinder 1. Check compression on front 3 and ran out of time.
#1- 60 psi
#3- 80psi
#5- 135 psi

After compression test, I could not get the car to star either. Have spark and gas, but thinking spark plugs may be wet.

Oil had a LOT of coolant in it.


But the engine just had new aluminum intake and plugs and wires and waterpump. Previous owner had all that done but it didn't fix the problem.

Anyway this could be an intake problem or other ideas?

Think the first thing will be to tear the intake off, then probably the heads.

[00Beast]

You drained the oil, right?

[94SilverSSEi]

Yup. That was the first thing I did. I knew there was going to be coolant in the oil just from the way it was running so I drained the oil as soon as I got it home.

[FasGP]

Wonder if the person that did the intake work was because of an internal leak, and then they just never drained and changed the oil? Let's hope not.

Could be a cracked head, or a poor LIM sealing job. Do you notice the aluminum gaskets in there, or black plastic LIM gaskets?

[94SilverSSEi]

But the engine just had new aluminum intake

[bs009]

Do you know the last time the oil was changed before you got to it? If it's been in there for a long time, there could be some bottom end issues. Probably something along the lines of worn main bearings due to the coolant in the oil.

60 psi is ridiculous.

[94SilverSSEi]

BUT, there is no knock or lower end noise that's the funny part.

That's why I'm thinking its upper end, coolant related.

And it was holding good oil pressure.

[MattStrike]

Need to do a leakdown test. But if coolant gets in the oil again, it's probably a rare case of head gasket failure likely caused by overheating. But the leakdown would tell you for sure. Maybe, you can hear if air is hissing into the crankcase with the oil cap off while cranking?

[94SilverSSEi]

This is almost what I was starting to think, either the intake is very fubared, which really I can't understand because its very simple to put it back together properly.

I've heard of the leakdown test before but whats the best/easiest way?

oh, and the cooling system is mostly empty at the moment because the radiator was being repaired so...

[MattStrike]

Leakdown test is pretty simple, but the tester costs about $100. It hooks into an air compressor and plugs into the spark plug hole. And you can hear where the big leaks are (crank case, intake manifold, exhaust, or gaskets).

[94SilverSSEi]

oh ok. I think there was a trick to cobble some other parts together to make your own leak down tester.

[travisd]

I had the same thing in a 3800 in an Oldsmobile. The owner said he had replaced the intake and changed the oil, but it still wouldn't start. I ended up pulling all of the plugs and then turned it over for a couple of seconds, put it all back together and ran fine. There can still be plenty of crap up in the heads. You should've seen all the spray come out of the plug holes.

[94SilverSSEi]

yup I took the plugs out and cleaned them, put it back together and they ended up wet again

[redzmonte]

if all 3 cyl on that one side are bad... you need to pull the head and look at what you have goin on. the compression test on thoes 3 cyl are already confirming you have something failed and the wet plugs tell me coolant is blowing into the cyl which a intake would indicate a HIGH compression reading, Head gasket would show a low reading.. my guess is head gasket. which isnt the end of the world but its a little more time and a few more parts. that will also let you inspect the pistons to see if you have damage there. that is where i would go from here, you can do a leak down but you will be taking it apart after anyhow to fix what you find.

[94SilverSSEi]

I am hoping that it is the headgasket and not a hole in the piston or effed up bottom end. Soon to find out, probably tomorrow.

What is a "good" compression reading? Seems like I hear different numbers for all different kinds of engines.


I know that the cylinders SHOULD be within 5-10 psi of each other and this deemed "ok."

[redzmonte]

iirc you will see something like 145-155 for good compression.

[l67se]

Takes roughly 90# for a cylinder to fire. 60 is certainly an issue.