I would expect oil and water to separate out over time, but perhaps not. The dipstick, last I checked, actually looked ok... clean, brown oil...Quote:
Originally Posted by Citizen
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I would expect oil and water to separate out over time, but perhaps not. The dipstick, last I checked, actually looked ok... clean, brown oil...Quote:
Originally Posted by Citizen
If you have a leaking head gasket, a compression test will show lower compression in that cylinder and maybe the one next to it. Cold, you should get around 120 psi in the good cylinders and the one with a leaky head gasket about 90 psi. I think everyone is waiting for you to do some of the tests we have all been recommending and report back with the results.
Roger, thanks for the specific values.Quote:
Originally Posted by cdrusn
Fair 'nough - I'm out of town this weekend but have next week off, so plan to do some of these diagnostic tests then, assuming I can sort out the parts/tools I need... Thanks all for patience & guidance thus far!Quote:
Originally Posted by cdrusn
OK, I have an engine compression tester, coolant pressure tester, and torque wrench from O'Reilly's. I took the air filter box off today to start getting at the plugs, and drained the oil, installed the EZ-drain, and refilled with O'Reilly 20W50 - I plan to change the oil again after it's run it's course a bit, and replace the oil filter then as well.
The oil itself looked normal - mid to dark brown (not black) and clear, maybe small bubbles near the top but not foamy or milky.
I was able to loosen all the plugs without removing the intake manifold, and it looks like it *may* be possible to do the test as-is (ran out of time today). However, I could see that there was debris (looks like nut pieces left by mice or something) on the intake manifold, and I can only assume the VoD is awful... the engine's overheated before and it's all covered in a film as it is...
Should I remove the intake manifold to do the compression test & clean out VoD, or just remove the plugs carefully and do the compression test and see where that puts me?
Don't overcomplicate this; pull the plugs, stick the compression tester into the hole, and crank the engine.Quote:
Originally Posted by JCochrane
OK, I finally got around to taking the plugs all the way out and inspecting.
Attachment 66636
I think they look pretty dark/bad, but not sure how old they are - I'm thinking they should be replaced either way, yes?
Now to the compression test. I gather from the workshop manual that the cylinders are numbered 1-3 on the 'L.H. bank' (which I think is on the right of the engine looking from the back?) and 4-6 on the 'R.H. bank' - with '1' being closes to the front of the car. If that's wrong, I'll edit this post to compensate ;)
I started 1/2/3 and everything looked fine, being careful to hand-start the adapter so as to not cross-thread. Then 6, after hand-starting, was super hard to get fully seated. Ran the compression test and like 40psi... pulled it back out to test and there's no rubber ring gasket on the adapter anymore - pretty sure there was one before, at least for #3 - so either dropped in/after #3, or borked it up during install to #6... pulled out boroscope and poked it around the block a bit but didn't see anything. Down #6... sad day - there it was crumpled and broken along the edge... put the hook on and fished it out, then tested compression again without the deepsocket adapter - just twisting the rubber hose in to get it seated - got higher but still significantly lower than the others.
(front of engine here; do tables not work? I tried with formatter but it's not showing... will reproduce below...)
PSI | Cyl# | PSI
160 | 4 | 1 | 155
150 | 5 | 2 | 165
105 | 6 | 3 | 160
Here's a look inside cylinder #6, when I had the boroscope down there - there's some discoloration on the wall... I also have video of the extraction and turning over a bit, if either of those would be interesting/helpful to see
Attachment 66637
So does that confirm a busted head gasket? Or should I run the combustion gas test as well?
Low compression does NOT confirm a low cylinder, it only indicates further testing. Low compression could be a bad valve or a cracked ring. A coolant combustion gas tester is a definitive test for a blown head gasket. Either way it looks like that head is coming off!
You have a ways to go before taking anything apart. The plugs look quite rich, they should be tan in color, put new ones in, make sure to use anti sieze on the threads. A reading of 105 does not in itself make it a headgasket problem. Given the history of the engine I would more likely suspect a "stuck" compression ring. I've run engines with less than 90 lbs. and they run o.k. so your readings except for the one cylinder at 105 is healthy so you need to concentrate on that cylinder. Get some Marvel mystery oil, use a clear tube hose (available at ACE Hardware) and put in enough to cover the top of the piston. Check it after 24 hrs. to make sure the level is going down. Keep doing this until you've gone through the bottle. Don't worry when it drains into the oil it's still o.k. to run it and will actually help free up the other piston rings. Run the engine for 15 minutes with the water pressure tester on the overflow cap. While running check for a blip from when that suspect cylinder would fire. If the engine will run without overheating I would run it around for awhile. Yes, the combustion gas test is the ultimate test for a blown head gasket. :race:
Change the filter now! (Both times.)Quote:
Originally Posted by JCochrane
+1Quote:
Originally Posted by cdrusn
...I would add, bring your pressure tester up to 2-3 lbs before you start the engine (dead cold). Then see if the pressure begins to rise right after you start it. Normally it takes a while for the engine to heat the coolant enough to make it expand and raise the pressure. ...Then watch for the blips and/or the pressure raising well above the cap's rate faster than normal....
If I understand correctly, there is no coolant going on the ground or into the oil, so it would have to be 'burning' it. If that's the case, the coolant will usually leave the spark plug noticeably cleaner than other plugs. (Hard to say looking at the pics and seeing how rich it has been running -- fingers crossed!.)
This isn't clear to me; are you saying you tested cylinder 6 with no o-ring on the compression tester?Quote:
Originally Posted by JCochrane