Compression results
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Lead Driver
Joined: Jun 2004
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From: Amarillo, TEXAS!
Compression results
OK, so I have 375-400 psi in all but cylinder #7, which was about 300 psi. I don't think it's a valve because of the blowby I've seen. My plan is to pull the head and inspect the cylinder wall, piston rings, etc. I'll also double check the valves at the same time. Does this sound reasonable, or am I wasting time I should be spending looking for a different engine?
Post Fiend
Joined: May 2009
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From: Pea Ridge, AR
OK, so I have 375-400 psi in all but cylinder #7, which was about 300 psi. I don't think it's a valve because of the blowby I've seen. My plan is to pull the head and inspect the cylinder wall, piston rings, etc. I'll also double check the valves at the same time. Does this sound reasonable, or am I wasting time I should be spending looking for a different engine?
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Lead Driver
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From: Amarillo, TEXAS!
I had a local (pretty highly regarded) diesel shop run the test. I can't ask them until Monday now. They said they put a borescope as far into the glow plug port as they could, and didn't see anything obviously wrong.
Hotshot
Joined: Jan 2011
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From: Puget Sound
I am no expert on this one, I just offer this up: I have seen combustion gasses go through cups and into fuel, due to loose injectors. It's relatively easy and inexpensive if you replace the O-rings/copper washer on #7 and redo the compression test on that cylinder. You can test the injector bolt torque before removing. At least you will have more information than you do now.
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Lead Driver
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From: Amarillo, TEXAS!
I suppose it could be getting by the injector. Can't hurt to investigate that, anyhow. I guess I should check the torque on that injector and check compression again. If it doesn't improve, then pull that injector and look for evidence of soot getting past the crush washer. Then if there's no soot it's time to pull the head. I'd like to rule out as many problems as possible before I decide to repair or replace, anyhow. Any thoughts?
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Lead Driver
Joined: Jun 2004
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From: Amarillo, TEXAS!
You do have a good point about the weight. It'd be a lot easier to work on too. I noticed the oil cooler and up pipes are leaking now too, so I could get all that crap done at the same time, with 75 percent less foul language and cuts on my hands.
Hotshot
Joined: Jan 2011
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From: Puget Sound
I was staring this issue in the face last fall - the question was raised about redoing the heads if I had a problem with them. While I have not yet ruled it out (noisy exhaust valve in #7 and tired seal on #2 exhaust valve), I wonder how the rest of the engine would react to this. I don't know the answer, I just wonder.
Butt-Head
Joined: Apr 2004
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From: Reed Point, MT
Also, once you find out that you have to pull the engine anyway, lifting it out of the frame with one head attached is a lot harder than with both heads on the engine.
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Lead Driver
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From: Amarillo, TEXAS!
So, I guess I'll do a leakdown on #7, then proceed from there. If the head has to come off, the engine will come out. Gawd, I hate not knowing, lol.
Lead Driver
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From: north of Minneapolis, MN
In addition, pulling only the cylinder head will show you the top of the piston and the cylinder wall.....you can't see anything else so it would be a waste of time since just about anything that's going to cause a loss of cylinder pressure will require an engine removal and total teardown/rebuild/replacement.
Also, once you find out that you have to pull the engine anyway, lifting it out of the frame with one head attached is a lot harder than with both heads on the engine.
Also, once you find out that you have to pull the engine anyway, lifting it out of the frame with one head attached is a lot harder than with both heads on the engine.
Awesome point about the difficulty of the one headed engine removal. You loose the lifting ring.
To the OP...if you are thinking oil cooler and uppies after you decide the heads or bores need work.....pull the engine, it's all easier.
Elder User
Joined: Mar 2012
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From: Quaker Hill
Kevin (pikachu) is up from TX visiting liberal land (CT), and just happens to be in my town. We're going to be working on this in my garage as soon as we figure out a plan if action, so I'm going to ask some questions, looking for a little guidance as we figure this out.
So over the last few weeks I have read both Cody (Cleatus) and Rich (Tugly) advise different people to pull the ICP and blow compressed air into the oil system. If, hypothetically, we pull the VC, blow air through the ICP, could we see air bubbles coming up from around #7 injector? Now, If we do this, see air bubbles, change orings on that injector, is it even possible to be losing that much compression due to an injector oring? Also, is it likely that 1 bad oring would cause a black fuel filter, that would be easier to check? Thanks for the input!
So over the last few weeks I have read both Cody (Cleatus) and Rich (Tugly) advise different people to pull the ICP and blow compressed air into the oil system. If, hypothetically, we pull the VC, blow air through the ICP, could we see air bubbles coming up from around #7 injector? Now, If we do this, see air bubbles, change orings on that injector, is it even possible to be losing that much compression due to an injector oring? Also, is it likely that 1 bad oring would cause a black fuel filter, that would be easier to check? Thanks for the input!
Hotshot
Joined: Jan 2011
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From: Puget Sound
I got the air idea from Cody, but it makes perfect sense - the HPO system has an oil rail, a couple of hoses with fittings, and the injectors (plus the HPOP). If 100 PSI air leaks from something designed to contain 3000 PSI of oil, the culprit should gurgle like a baby.
This is one of those "from the hip" tests not sanctioned by the Ford manual, but we're not certified Ford techs with all the tools in the book. We have to make do with what we have in our humble repair "shops".
I have one trepidation about this procedure though - if both fuel O-rings are toast, as well as the copper washer... oil could go in the cylinder from this test. On second thought... if it's that bad, the gawd-awful racket would dissuade anyone from turning the key until they found the source.
If this proves to be bad O-rings or a loose hold-down bolt on #7, don't count on your compression to come up to 375... but don't rule it out either.
This is one of those "from the hip" tests not sanctioned by the Ford manual, but we're not certified Ford techs with all the tools in the book. We have to make do with what we have in our humble repair "shops".
I have one trepidation about this procedure though - if both fuel O-rings are toast, as well as the copper washer... oil could go in the cylinder from this test. On second thought... if it's that bad, the gawd-awful racket would dissuade anyone from turning the key until they found the source.
If this proves to be bad O-rings or a loose hold-down bolt on #7, don't count on your compression to come up to 375... but don't rule it out either.