I have an 83 240d with no compression in the #3 cylinder. I've tried marvel mystery oil and brake fluid. but no luck.

When I remove the injector and squirt some oil into the cylinder, the compression jumps to 380. This tells me it's not a stuck valve or something in the top end.

Is this a correct assumption?

I ran the engine until it warmed up, removed the air cleaner and sprayed some water mist into the intake. I read a few post about water injection and wanted to see if this would help with the compression.

Would it make sense to remove the intake and spray the mist directly into the #3 intake so I target the cylinder with no compression?

Has anyone done this?

I'd rather not do a complete rebuild but may have to if I can't get compression in the #3 cylinder.

Thanks for any advice/input.

Pete

Squirting oil into the cylinder and compression increases means rings (worn or cracked).

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92 300D 2.5L OM602 OBK #59

The other cylinders are in the 350 compression range. I don't know if the previous owner ran veggie oil or not.

Is there any way to know if the rings are stuck vs cracked/worn?

Pete,
Best you assume they are stuck for now. There was a post about some one who used the washer bottle & pump for water injection. If you can find it, give it a try. You have nothing to loose at this point.
You may wish to keep your eye out for a good 617 turbo motor as a replacement, may be cheaper than a re-build.

Good Luck !!

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Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving

Quick and dirty water injection?

Post #8

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

On my 87 TD . Also #3 was low. 100 psi , 300psi with oil squirted. I did two runs of it on separate days but i still have the blow by. I did it post turbo while idling. Maybe i need to spray pre turbo. But i was worried about turbo. I may try that one last time .

My engine uses 1 quart every 500 miles about. Thats the real annoying part. Plenty of power still since its a 6 cyl 603 engine. I also bought a gallon of Lucas oil additive and have been feeding it that. I am going to try Marvel Mystery oil soak next and then drive it till it quits.

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What Would Rudolph Do?
1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius

I thought about putting in a 300d turbo but I'd rather keep the simple 240d motor. Not as much power but I don't have to hassle with mating up the 240d manual tranny to the 617 engine.

If you have very low compression on one cylinder and its not valve related its best to get it fixed soon. If you have a broken ring it may be scratching the cylinder walls. A rebuild is much cheaper if you don't have to resleeve a cylinder.

Water injection is good for cleaning crud out of an engine but it won't help with a ring compression problem.

When is the last time you adjusted your valves?

From what I have read I don't think mating a 300 turbo engine to a 240 transmission is a big deal.

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green 85 300SD 200K miles "Das Schlepper Frog" With a OM603 TBO360 turbo ( To be intercooled someday )( Kalifornistani emissons )
white 79 300SD 200K'ish miles "Farfegnugen" (RIP - cracked crank)
desert storm primer 63 T-bird "The Undead" (long term hibernation)

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