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After discovering the white slimy stuff on the coolant reservoir cap, I parked the new-to-me 92. On closer inspection, the entire coolant reservoir (as far as I can get my finger in) is the white slimy stuff. The oil is perfectly clear, the AOS is clear, everything there is fine. So an oil cooler gasket kit has been ordered.
However, before I tear into that, I did a compression test. First time I've ever done one, first time I've ever needed to. Borrowed a compression tester and 6 hours later, the results are in. I know, it shouldn't take 6 hours to do a compression test but when the fitting on the hose gets stuck in the spark plug hole and you have to go the Home Depot to get a shower valve tube wrench and then rig a contraption to make it long enough to reach the bottom of the spark plug hole so you can unscrew the tester hose, it manages to become a 6 hour test. And it's 91 degrees outside with 60% humidity. This didn't go as planned. In more ways than one.
To me and my research, these numbers are low. And when I do the test, the car sounds anemic. Very slow and struggling to even build compression. Even when I start it to drive it, it starts very sluggish. I don't know if this is related to compression or a faulty starter. The battery is/was fully charged. Would a faulty/dying starter cause low compression readings? These numbers were as much as the cylinders built so it got all it gave.
But with these numbers and the fact that dry to wet didn't change much am I safe to say it's probably not worn piston rings? Probably looking at a headgasket? But if it was the head gasket, wouldn't I also have coolant in the oil?
Which leads me to valves and/or valve seats. Take a look at the spark plugs below. These are new so they shouldn't look like this. Left to right is cylinder 1-4. Before I even took the spark plugs out #1 had oil in the tube. Not a lot, maybe a few drops but it was still there. It also came out wet but dried off between removal and the pic 6 hours later. This is all on a car that had either a broken timing belt or blown head gasket a few thousand miles ago. Don't know which but the whole top end was supposedly gone over with a rebuilt head but no paperwork to say one way or another so it's anybody's guess.
So where do I go from here? Start tearing it all apart and seeing what everything looks like? Give me your opinions on what's next...
The only other thing I could think of is to check the timing on the engine, what if it is off and some how you have some small overlap that shouldn't be there?
The only other thing I could think of is to check the timing on the engine, what if it is off and some how you have some small overlap that shouldn't be there?
You probably have multiple things happening. Paul asked about testing warmed up...makes a difference in results...
Doing a test of what is present in the coolant will tell you a lot.
Some observations from your photo of the spark plugs:
-The cylinder that tested the best (4) looks like plug is about to be fouled.
- The cylinder that tested the worst and had oil "in the tube" (1) looks the best.
-Spark plug gaps (may be angle of photo) don't look the same.
-Spark plug washers don't look like they have all been tightened to the same torque or that the surface of the head may be warped.
The fact that all cylinders tested similar wet vs. dry and no muck in the oil tells you that pistons/rings are probably not at fault.
Some observations from your photo of the spark plugs:
-The cylinder that tested the best (4) looks like plug is about to be fouled.
- The cylinder that tested the worst and had oil "in the tube" (1) looks the best.
This seems counter intuitive to me. What would cause the best cylinder to foul the plug but the worst to keep it good?
Originally Posted by spark1
-Spark plug gaps (may be angle of photo) don't look the same.
-Spark plug washers don't look like they have all been tightened to the same torque or that the surface of the head may be warped.
I'll have to check the gaps in the morning to verify.
And I did notice when taking the plugs out that 3 of the 4 came out nearly by hand. They were barely in there. The only one even remotely tight was #4 and even that one was loose.
the cylinders are huge so the oe plugs are triple electrode. (helps with starting). I believe aircooled dot net still has stock and is on your end of the states.
some detonation aluminum bits on the plug on the right. see if the 2k resistor on the plug end is ok.
the little dimples on the plug wire holders on my car smooshed the insulation enough to make it arc to ground on the olderish wire but those look new. open the hood and fire it up in 100% darkness. you might see the culprit.
I concur that a leak down test will tell you a lot. And with you not wanting to run the engine, a leak down test is still valuable. Most people like the engine warm for both compression and leak down tests, but it's fine to do LD cold and expect slightly higher percentage of leak. What is good about an LD test is that you can hear if you have a valve problem versus cylinder rings and even exhaust valve versus intake and head gasket. I'm guessing that you'll find the leak down to be just a little higher than the healthy range (I'm guessing 11-15% leak) and if you do, that means the low compression numbers are because the starter is slow and the engine is cold etc. But none of that is solving the original problem of the white gunky coolant. I also don't think the spark plug inconsistency is connected to the coolant issue.
I'm going to be like my wife when she plays Clue. She'll say it's Mr. Green in the library with the lead pipe without knowing all the facts. I'm going to say that the rings are fine and the valves a fine. The low compression and junk in the coolant is due to a head gasket leak or even the head not being machined well during the recent work by the prior owner. The oil runs at a higher pressure than the coolant, so coolant is not getting into the oil, but oil is forcing itself into the coolant. The spark plugs look like that because the gaps aren't set right and they were not torqued (I think it's 17ft-lbs). Not torquing the spark plugs is also the source of the oil in the spark plug cavity. That's my hypothesis, without all the facts yet.
Very interesting hypothesis and it makes total sense. I'll see what I can do to get a hold of an air compressor and leak down tester.
Based on what @thomasmryan said I went ahead and ordered a set of NGK BP6ET spark plugs since the Bosch WR7DTC plugs are no longer available. The PO also mentioned the wires and distributor were probably original to the car so need to order those as well. Noticed today when messing with it that the rubber is dry and cracked on the wire going from the coil to the distributor cap so they definitely need replaced. The other wires looked fine but if one is bad, they all are at this point.
In the mean time, the block tester kit should be arriving tomorrow so I'll see if combustion gasses are in the coolant. I hate to run the car but I put almost 400 miles on it as it is so running it another 20 minutes just to get it warm shouldn't kill it. At the same time I'll do another compression test to see what the warm numbers are.
MY 2 CENTS WORTH
Plug 4 looks to be oiled but yet its the best cylinder as far as PSI on the comp test...maybe a lead or even a crook plug.
10% variation of PSI between cylinders is the standard and you are over that on several cylinders from worst to best.
Generally they are low no matter how you look at it....how many miles on it
Valve timing could be out and needs to be checked.
but that slimy "stuff" is generally indicative of head gasket blow. Good idea to replace the oil cooler gasket set.
If you're lucky enough to have the sleeves on the old wires, they will slip on to the new ones by unscrewing the resistor ends. There should be a grey retainer on plug wire number four. Bremi sets can be a bit cheaper than OE.
One will get lower compression numbers at elevation. The phosphates in marvel oil can clean the ring lands a bit. Even more so if you have some hills for compression braking.
If you're lucky enough to have the sleeves on the old wires, they will slip on to the new ones by unscrewing the resistor ends. There should be a grey retainer on plug wire number four. Bremi sets can be a bit cheaper than OE.
One will get lower compression numbers at elevation. The phosphates in marvel oil can clean the ring lands a bit. Even more so if you have some hills for compression braking.
Yep, still have the sleeves on the wires. Thanks for the reminder to put them onto the new wires. It is NOT on the coil to dist cap wire though. Should there be one? And is that the grey clip that you're talking about that holds the #4 wire to the fuel rail cover?
Yes. I am a fan of the sleeved look and the added insulation from the heat. If you unclip the fuel rail cover, the front wire retainer was my short to ground. The clip sleeve on the front drivers will jump across the room but it's similar to the ones for the top of the radiator deflector.
07-16-2019, 05:28 PM
head gasket? piston rings? valves/valve seats?
