Help diagnosing possible head gasket?
 

Hi guys. I have not ceased to learn from this forum and am asking for input on a possible head gasket job. The car is a 1985/2 944 NA A/T. I bought the car from a guy who had it less than 30 days and sold it to me telling me that the head gasket is blown. Said it was overheating and milky oil. I want nothing else to do with him so have only that much info. He removed the DME/ECU before I picked it up or I didn't notice it was not installed - towed it home.
Anyways, I have this information:
There was a little moisture on the dipstick and no oil in the engine when I first looked at it.
I put oil in and it started up right away and whined pretty significantly until I topped off the coolant. I saw no white smoke and the exhaust seems normal; not sweet.
Normal oil pressure - 5 bars at start, 2 bars at operating temp.
Did compression test - 1:145psi, 2:152psi, 3:148psi, 4:150 psi
Did leakdown test - 1:18%, 2:18%, 3:9%, 4:14%
I haven't driven it except to take it around the block, so have no significant mileage on the engine to see if the coolant is decreasing significantly. I have a friend who says "Just do it!" to the head gasket job. Trying to decide if I should just take the plunge.
Picture of the plugs below (Order left to right is 4,3,2,1):

http://forums.pelicanparts.com/uploa...1375233899.jpg

#2 is suspiciously clean. As you say, probably bad HG. However, change your oil cooler seals first as a test. There's a ton of info floating around here, so have a good read about oil coolers and OPRVs. Oil Pressure Releif Valves.

HG isn't so bad but it means a timing belt job, and for some that's a scary proposition. Then again, if you're good with tools, curious and fearless, go for it!

From experience, I can tell you that it's pretty easy to get to the oil cooler seals if the head and exhaust manifolds are out of the way. You might consider just jumping in and doing everything - take the head off, send it out for machining, and while it's out you can do the oil cooler seals and waterpump. When you get it all back together, you know where you stand.

With water in the oil, I'd be concerned about how far the car was driven in this condition. Water on the rod and crankshaft bearings is damaging to the bearing surfaces, as well as the cylinder walls. Getting the head milled and then after putting it back on for a compression check is only 1/2 the problem. If there's broken rings in #4 that's another issue. I guess it all depends on how deep you plan to chase this. After the head is on and the engine is running, the tailpipe will will tell you if you have ring or valve seal issues. Good luck on this project.

I suspect that the seller was not experienced with the 944 and misdiagnosed the problem as a bad head gasket. With many other cars, it would be a logical conclusion and it may be true. When a car overheats, the head can warp and the HG can blow. However, with the 944, we know that oil cooler seals are a problem and this is most likely what occurred.

At this point, the only thing we know (based on PO input) is that you have overheating and milkshake in the oil. This usually points to the oil cooler seals. I would suggest that you attack this first, then see if you have solved the problem before going deeper. replacing the OC seals is a PIA the first time you do it, but it's relatively cheap (if DIY) and can be done in one day. Flush you cooling system, get your radiator flow tested, and ensure your cooling system is up to par. Make sure your oil is not contaminated with water. Run it and see if the problem repeats.

+1 on the oil cooler seals.

Your leak down and compression numbers are good. Unless there was some other obvious sign (white exhaust smoke) I'd rule out the head gasket.

No sense in creating more work than necessary. Just do the cooler seals.

Do flush the engine well to get out all the contaminants. Both oil and coolant systems.

Thanks for the input guys! I just started and got the fuel rail off. I will clean those up and reinstall. Then transition to checking the oil cooler. Will I need a special tool for the OPRV when checking and replacing those gaskets? Is there a way to confirm that it was indeed the oil cooler seals except for checking for repeat issues? If it is an iffy thing, I might just do both HG and OC. We have a limited time to drive these cars in Alaska, so I always feel up against the clock and hate garage time in the summer! Thanks!

You put oil in it and it was running. Do you see any coolant in the oil?

One common thing on these cars is white milky crap forming on the under side of the oil filler cap - which looks really bad but doesn't mean anything at all - just condensation.

Have you observed the car overheating? If so, do the fans work? Is there proper coolant in it, etc?

Like Slam said, your #2 plug does look awful clean, but if there is no cross contamination (water in oil, etc), and it's not over heating or blowing white smoke, I'd write it off to the PO boing a moron and just drive it.

If you're gonna do the OPRV, yes you should have a special tool to align the OPRV.

Although when I did mine, I just found a deep-dish socket that was the right size and used that and an extension and it worked great. Just depends on your level of expertise. My worry was if the socket came off the extension - I woulda had to take everything off and start over. Fortunately, that didn't happen. Your mileage may vary.

#2 obviously looks cleaner, but does not look steam cleaned to me. . .might have been installed at a different time? I would pressure test the cooling system and make sure you aren't losing anything on the ground.

Why does #1 look so funky?

^ Good question.

One other thing: after you do get the car running, do a compression test with the engine warm. I'd be interested to see the results then. I mention this cause my 83 had a bad HG as a result of overheating - no cross-contamination and no issues cold. Hot, it would blow into the jacket and pressurize the cooling system. Believe it or not, it went like this for a LONG time before I fixed it.

Akron:

Suggest running 1 range cooler spark plugs like Iridium BPR7-EIX and lowering your thermostat by 15 or more degrees..

later...

Akron:

Plug #1 Electrode Cereamic Damage
***Lean fuel or excessive high temperatures ***

later...

Did compression test and leakdown after it ran for 5-10 minutes or so. Didn't drive it a few miles or so before those tests. Trying to get back to it with a vengeance! Life, life, life! I will post results of OC gasket replacement and pictures as soon as I get into it.

You mean you have a life AND a 944!?

;>}

I didn't notice that the first times I looked but you're right. Good chunk of insulation missing from the electrode. That is weird.

Haha! Noooooo, something of a life and two 944's! Now if I could get ONE of them on the road!
On a different note, a progress report.
Got as far as removing exhaust manifold. Drained oil and coolant. I had put new oil in to run it up after I purchased it and PO had sold it to me and diagnosed a head gasket. Oil was a milky brownish mess again. This is after I ran it a couple short times to warm it up and once around the block. So, I am anxious to see if the oil cooler gasket replacement fixes this. Parts are ordered and delayed for OPRV tool. Hope to have OC out tonight.

Okay, OC is out and looks like some breakdown of the gasket. I will post pics soon. Need sleep first. Had to remove stabilizer bar bracket and some other brackets that hold oil lines in place in order to get it out. What a pain! The good thing is that most of the parts seem to be original installation and are not goobered up.

I hope you don't read this until after you get a good night's sleep but WSM states that rod bearings must be replaced in the event mixing of oil and coolant occurs. There's a lot of info on this and it's not hard to do. First things first though, and congrats getting the oil cooler removed.

BTW, what were your compression numbers warm? I re-read your first post and those numbers look okay. Maybe #2 is carboned up a bit. Then why the clean plug? A little coolant in the cylinder would bump compression...

Yep, I let the engine warm up before I did the compression test. I did see discussion on rod bearings in another forum. Very strong advice for changing them. I actually bought an engine support for the possibility that I would need to access the bottom of one of my engines. Not looking forward to that.
Question here: anybody willing to admit they did NOT do the bearing change after oil cooler/head gasket maintenance? Oh, that's gonna get er goin'!
I haven't ordered bearings yet and would really wanna see if I get a repeat oil/coolant mix before changing them. But, after seeing the OC gasket, I might just have it. Pictures in my next post.