Compression test results OVER 220psi!?!?!??!?!

[Pet2002aluma]

Long story short. I've had the car for only a few months. Its a stock 2002 (expt weber 32/36) 1974 with 70,000 miles. This is my weekend project car and I have relatively little real mechanical experience, but manage to get by with the help of the forum.

I noticed the other day that i had water/coolant in my oil. Brown/whitish junk under the valve cover cap and the oil is starting to turn cloudy brownish. Thought blown head gasket, but i have NO smoke (black, blue, or white) coming from the rear end. So to check out whats going on, I started with a compression test. This was my first time doing this test on this car.

My results were 225-230psi on all four cylinders. I am pretty sure i am doing it right (warmed up, all plugs removed, turned over 7-10 times until it wouldn't go up anymore), but those numbers seem WAY too high. What should they be? Why would they be so high? Also any ideas how my coolant is getting in the oil? Still worn head gasket?

Thanks.

Neal

[ray_]

Well, the head has to come off anyway. I'm 90% certain the gasket is bad, or you cracked the head.

Best not to drive it if you are swapping fluids.

Pull the head, have it checked for cracks, replace the valve guide seals, take a good look at the valves and do what's necessary and button it back up.

GL,

Ray

[dubois]

Brown milkshake is sometimes normal due to water condensation under the valve cover. I've seen numbers that high, usually 10:1 compression pistons or higher. If you had a big differential among cylinders, then I would be worried. If you are not loosing coolant, overheating, or running crappy, change the oil and run it like you stole it.

There is another reason for the higher compression numbers, carbon deposits in the combustion chamber. You probably would have noticed when you pull out the plugs.

[PSloan]

Do 2 more tests. Run a leakdown test. Also, pressurixe the cooling system and see what happens.

[TobyB]

High compression and a conservative cam can do that to you.

Are you losing coolant? If so, park it.

Coolant will kill the bearings in pretty short order.

If not, change the oil, go on a nice, long drive and then check it.

An oil testing service can tell you for sure.

Yes, it's completely possible to have a bad head gasket,

water in teh oil and no other symptoms.

t

[JsnPpp]

I agree - having high-compression pistons and a modest/stock cam will result in very high compression in the cylinders. Change the oil and drive the thing for a bit. Change the oil again and see what what it looks like.

You might just be ok.

Jason

[Arshloch]

I figure 10:1 might give you 200-210 psi on a fresh rebuild. There must be some carbon build up for sure or your gage is off.

Does it ping or diesel at all?

[Pet2002aluma]

wow, thanks for the great replies.

ray_koke: i agree with you about having to pull the head anyway. you also have a good point about the head might be cracked, ill make sure to keep a close eye on it. When its off, it will be getting a good valve job as well.

dubois: I highly doubt the amount of water under the cap is from normal condensation (o how i wish it was). I am also in agreement that the fact the results are all very similar is a good sign.

PSloan: I did the test 3 times yesterday. all the exact same results. The leak down is next on the list, but it might be several days before i can get my hands on one.

TobyB: I don't think im loosing coolant, but were else could it be coming from? its parked in a garage all day, and its certainly not just condensation.

Jason_Pappalexis, Arshloch, and everyone else: I thought factory compression was only around 8:1? I am 90% sure it still has the factory cams and pistons (not high compression). As far as i know, this car has never seen any real mods or rebuilds, if it had it might be running a little better! HA! But i guess the PO was kinda shady, so who really knows.

BTW, I very recently changed the oil (before i noticed any problems, so the oil had fewer than 50 miles on it before milkshake symptoms). the old oil was very dirty, but no signs of water/coolant. The plugs are clean (a little rich but not bad).

I guess the consensus is the high #'s aren't as bad as the milkshake oil coolant issue. thats what i was kinda thinking anyway. Guess ill be pulling the head and crossing fingers (after a quick oil change and maybe a leak down).[/img]

[TobyB]

Yeah, it doesn't take much coolant to give you brown oil,

BUT

I'm always surprised how much moisture builds up in Jenn's car's

motor when she doesn't drive it regularly. Then, when it's been her d-d

for a couple of weeks, everything's clean and fine.

Before you tear it all down, though, I'd spend the money for an oil analysis.

Like you said, if the water's not coolant, then it's not the head gasket.

And if it's not the head gasket, then, honestly, once you get rid of the

sludgy oil, the problem shouldn't recur.

t

[alp]

compression may be high because of water siting on the pistons. If the gasket is gone and water has leaked into the combustion chamber it would account for high compression.