Typical signs of engine wear.low compression - Diesel Forum - TheDieselStop.com
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post #1 of 5 (permalink) Old 05-27-2010, 10:26 AM Thread Starter
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Typical signs of engine wear.low compression

My bus was rough starting, blowing smoke for a little while, someone said it was due to low compression. The smoke was white but smelles like diesel, not coolant. I got the glow plugs replaced, and the relay. Some of the wiring on the realy was so bad it basically was doing nothing. Starts like a dream, like my girlfriends corolla! Runs great, great power, never overheats, infact it runs a little cool which i need to get checked out, but better than runninghot! What are the typical signs of engine wear/low compression? Collant out the tailpipe on start, hard start, runs rough? anything else. I have none of those right now. Checked the oil, no foamy bubbles, checked the radiator, no oil bubbles at the top!
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post #2 of 5 (permalink) Old 05-27-2010, 10:48 AM
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hard start. excessive engine blowby.

who old are your injectors/injection pump? how many miles on engine?

1986 F250 6.9,ATS turbo, np435, BW1356, hp 60,welded up sterling 10.25.
converted from 2wd to 4x4
sittin on 36x12.5 goodyears

2002 gmc 2500hd 6.6 duramax 5 speed allison
4x4 extened cab.

2000 F550 Lube Truck (Work Truck)

Certified PA Inspection Mechanic

i'd rather be 6.9'n than cummin or strokin'!
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post #3 of 5 (permalink) Old 05-27-2010, 11:03 AM
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Take off the oil filler cap, and see how much it smokes. My last 6.9 had a lot of blow by, and it would smoke like crazy.
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post #4 of 5 (permalink) Old 05-27-2010, 12:29 PM
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Take off the oil filler cap, and see how much it smokes. My last 6.9 had a lot of blow by, and it would smoke like crazy.
That's not going to tell you much unless you block off the CDR and then check blowby with a manometer to see if the reading is within specs.

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'91 F-250 SC 4X4, 5spd. ATS Turbo, 3:55 diff.
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post #5 of 5 (permalink) Old 05-27-2010, 11:57 PM
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Ive seen both 7.3's and 6.9's with 8-900,000km on the clock, even with a lot of blowby they will still run well, maybe slower to start when cold due to lower compression, but nothing to be overly concerned about. You can always switch to a thicker oil to slow oil consumption.
Valve guide wear and cavitation is my biggest concern with the 7.3l

1984 F-250 6.9, T-19, BW1345, BB code injectors, low mileage, manual Beru Glow Plugs, D70 rear end. solid truck.

1985 Toyota Landcruiser BJ60, 5 bearing cam 3B 4cyl diesel, H55F trans. Best rig I have ever owned.

1981 Honda Trail 110.
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