Low Compression

greyford1979

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Well I did a cold compression test on the engine today. All cylinders read between 280-300 psi. Does the truck have to be warmed up and then do the test, or was it fine the way I did it? Sounds like it's time for a rebuild or new engine? :doh: Truck is right at 312,000 miles. Runs well except for a bit of blue smoke that clears up. Heads were rebuilt about a year and a half ago. This sucks!
 

DieselDC

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Them numbers are low. Losing oil btwn changes?


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co04cobra

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Should be cold on the test with all GPs out is best. Your numbers aren't "perfect" but I have seen trucks run, and I have ran trucks with same numbers or less for a long time.

If the balance across the board is close I would run it for awhile. Age on injectors and turbo?
 

greyford1979

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Should be cold on the test with all GPs out is best. Your numbers aren't "perfect" but I have seen trucks run, and I have ran trucks with same numbers or less for a long time.

If the balance across the board is close I would run it for awhile. Age on injectors and turbo?

Yep that's how I did the test. Injectors are around 4 years old, PIS. Turbo about 1.5 years old from KCTurbos.

That's not horrid. Send it!
I plan on it lol. Like I said she drives damn well that's why I'm surprised.
 

greyford1979

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One thing that still has me stumped, is how the truck didn't puff any blue smoke, and then a little over 3 weeks ago the blue smoke just started one night after work. I would assume that the low compression didn't just happen over night on all cylinders. Wouldn't have there been blue smoke quite some time ago at the psi? Just wondering if there is something else going on?
 

greyford1979

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My brother and I were both thinking this as well. I ran the truck with valve covers off nut couldn't tell much. They all made a difference in how the truck ran when I unplugged each one individually. Gonna hook the laptop up to it tomorrow. Gonna be pissed if I have issues with my 4 year old injectors already lol. Although this was pretty much how it started with my factory injectors when they were bad. Except that they had closer to 270,000 miles on them.
 
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greyford1979

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Low fuel pressure could be bad for injectors.

Yeah I know, one of the main reasons I decided to do the complete fuel system. I might have waited a little too long. Fuel pressure is good now. But of course my radiator decided to spring a leak. Looks like that will be this weekend's project lol. I'm sure I could go a bit, real small leak, but I would rather just get it done and out of the way for piece of mind. It is the original radiator with 312,000 miles on it.
 

greyford1979

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Well now that the cold is here, truck runs fine but occasionally while sitting in traffic it idles rough for a sec and puffs some blue smoke out. Once I start driving again the blue smoke goes away and runs like a champ. Only goes through about a quart of oil between changes, and some of that is from my dipstick tube oring leaking lol. Yeah I know I gotta take care of that too. Forgot to mention, have had the laptop hooked up to it and so far not much. Did have a P1271 injector high low side open code. Only other thing was one day leaving work got on it a bit too much and the CEL came on but no code.
 
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lincolnlocker

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Well now that the cold is here, truck runs fine but occasionally while sitting in traffic it idles rough for a sec and puffs some blue smoke out. Once I start driving again the blue smoke goes away and runs like a champ. Only goes through about a quart of oil between changes, and some of that is from my dipstick tube oring leaking lol. Yeah I know I gotta take care of that too. Forgot to mention, have had the laptop hooked up to it and so far not much. Did have a P1271 injector high low side open code. Only other thing was one day leaving work got on it a bit too much and the CEL came on but no code.
Uvch conectors good? Inside and out?

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