Blowby information on 617 engine

[DSLVO]

I have found very little practical information on causes, diagnostics and possible repair for blowby on a 617 engine. Many mechanics see this as a fatal problem but it's common on this engine. Can we gather information on this thread for future reference?

[kerry]

Search on it, there's tons of info here. I believe I summarize the general sentiment of the forum when I say that nobody here thinks its a fatal problem. There are accounts of lots of heavy blowby engines that continue to run fine. Without the existence of other symptoms, just drive it.

[pleiades]

Drive it, and check/fill the engine oil regularly.

[JimmyL]

Originally Posted by DSLVO

I have found very little practical information on causes, diagnostics and possible repair for blowby on a 617 engine.

It ain't rocket science, rings and cylinders wear thus creating blowby.
All 3 of mine have some blowby. I'd venture most do. It is funny, my old smoking wagon had the least amount of blowby of all of em.......

[habraken]

so why do 603 engines have so much less blowby than the 617? or any other diesel? do they wear less then?

[Jordan G]

Originally Posted by JimmyL

It ain't rocket science, rings and cylinders wear thus creating blowby.
All 3 of mine have some blowby. I'd venture most do. It is funny, my old smoking wagon had the least amount of blowby of all of em.......

X2 what Jimmy and Kerry said. Most old diesels have it, short of rebuilding, I don't think you can do much, nor should you. Obviously, if you are buying a used car -stay away from severe cases because it's indicative of a worn engine...but if it's already yours, just keep driving.

Search away (it's been discussed at great length here, so I'm not sure where you are searching) - my own personal favorite was a fellow member trying to quantify the "amount" of blow-by by taping a garbage bag to his oil cap.

By the way, I giggle everytime I see "blowby" - I have no idea the correct way to spell it either, but I always split it up into "blow-by". Why? Otherwise, my little immature little mind thinks of cute little sexual favors (pronounced similar to blowbee, as in, "hey hon, it's been awhile since you've given me a blowby".)

EVERY engine has blowby, even brand new 20xx model year engines. It is a natural part of the reciprocating piston design and can never be eliminated.

pleiades got it right. If it runs well then keep on driving it and keep the oil level correct.

Your "mechanics" probably see you as an easy money source by giving you a big doom and gloom story about evil blow-by and how its a plague to old engines.

[turbobenz]

Blow by is a perfectly normal condition. It happens, every mile you drive your engine the blow by increases. I'm sure every Mercedes diesel on this forum has at least a small amount of blow by when the engines hot. Hell, even my engine with only 121k on it has some blow by, and its the fastest mb diesel Ive driven. Dont worry about blow by gasses. If it starts up easy on the coldest of morning dont worry about it