I found a federal om617 locally for a descent price and the seller posted the results of his COLD engine compression test all cylinders test at 300psi except number 5cyl tests at 260psi. The engine is from an 85 w123 with 200k miles and includes all acc. including the turbo. I really don't want to pass on the chance to pick up a federal engine but the low pressure cylinder is a huge red flag. Buy or pass?

Could be an improperly adjusted valve causing the low compression.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

I agree. Unless he did a valve adjustment before the compression test, those results are worthless. On top of that, I believe a true compression test is done on a warm engine.

Adjust the valves to spec.
Run engine up to temp.
Pull injectors.
Test compression.

__________________
1991 F250 super-cab 7.3 IDI. (rebuilt by me) Banks Sidewinder turbo, hydroboost brakes, new IP and injectors.
2003 S430 - 107K
1983 300SD - Tanoshii - mostly restored ~400K+.
1983 300SD - Good interior. Engine finally tamed ~250K.
Monark Nozzle Install Video - http://tinyurl.com/ptd2tge

The low cylinder does not make a useless engine but it should be reflected in the purchase price.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Considering I can get any om617 at pick n pull for $250. How much would a federal with odd compression go for? I'm thinking $350 since it has all accessories. Btw he is asking $800! Lol!

We picked up a practically mint 617 turbo minus the alternator/starter/P/S pump for $550 with only 160k on it about 3 years ago. Perfect compression.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

I'd wanna be around the 350 range or find a better engine.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

In todays world you just do not buy an engine that is out of a car. Unless it is from a member on this site that is very crediable or someone else that is.

There is just too much work involved to find out later that the engine had issues. Eight hundred is also too much for the situation you describe. Best to find another car complete. This gives you a chance to check out the engine properly before even buying the car . Remove what you want from the car and sell the remains to a wrecker if the engine is good.

Our members have enough accidents that one of their smashed cars may be a good source as well. The problem with engines is the distance away sometimes.

I bought my OM601 on the sellers word, (car it came from was around, but it had been pulled). Turned out fine....I cranked it sitting on the floor in my garage at home for the first time it had run in 2 years (did an oil change first) and it fired right up once it got fuel. It now lives in my W201 and has covered over 1,700 miles so far. I did replace the injector nozzles and delivery valve seals...but thats it!

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

There is no doubt you can get a good one off the ground. There are many variables though. What is a good one to the person vending it may have unacceptable issues to a buyer. This can be based on things like the sellers level of knowledge being basically it runs so it must be good type of thing.

It will always be more of a gamble than an engine one has properly checked out. Then this can even be compounded by people selling engines that have the same ethics basically as a crook. The other issue is availability when you need it.

A mercedes rebuilt engine with perhaps fifty thousand miles on it wil usually sell for about the same dollars as a mediocre very high milage engine. That is another gamble in itself. As at a time of need what you find may be out of your control and more a luck of the draw. I always try to anticipate needs giving me some time frame to work in.

Several years ago I ran across a free mercedes rebuilt 617 turbo engine in New Jersy when picking up a car. I did not have the time or tools to pull it and had to walk away. The owner of the car I purchaed said he also owned it and the paperwork was still in the dash for the engine. It had little miles since installation. He was moving away and just wanted many things gone.

I'm assuming the engine is not in the car any longer... how are you to know the mileage?

pull the valve cover and look at the bananna rails. if there are grooves in them, pass... over 400K on them, or POOR oil change intervals...

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

That's right, it is not in the car and the CL posting doesn't claim an exact mileage. Just that it was "around 200k". I suppose 300k could be considered "around" lol! Thanks for the tip! I'll be sure to check for grooves when I check out the rest of the engine.

blow by would tell you if around 100k , 200k , 300k ,
but if you cant run it they can claim anything ....

i have 2 pull and save stores close by and neither of them ever have any diesel engines

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current fleet
Ford f350 dully 7.3L 1990 . ats turbo , zf5
Mazda 4x4 b2600 with 617 20-26 mpg
Past fleet
1983 240D w123 232k 25-30 MPG
1984 Ford f250,1979 ford 150 300-6 (sold@ 251K )
81 300D, 79 240D , 2x 76 300D ,74 240D , 2x 89 grand prix , 85 grand fury , and several other fords

Custom machine shop work ..

The lucky thing about living in the pacific northwest is that hipsters love these cars so there are plenty around my location. The yard closest to me has x4 w123's. Although, whether those still have engines and acc is not for sure.

Even then the milage is usually suspect but the general condition of the car at least can indicate what the reality might be. We are lucky in the northern rust belt as rust is a direct cause of cars going to the salvage yards or being cheap to buy with decent mechanicals still present.