Model 617 warning signs of failure?
 

My brother recently purchased a 85 300SD with the 617 in it. What are signs that this engine may be singing its death song? The air filter and surrounding area was BLACK with motor oil and the engine has blow-by. The engine seems to run strong though and it doesnt seem to have too much smoke in the exhaust. Plenty of pep! What are some tests I can do at home without the use of a mercedes tech.

It sounds like you need to adjust your valves. Oil in the air filter is normal for these engines. It works like a Pcv Valve on a gasser. Blow by can be adjusted down on a healthy engine.

You can't stay up nights worrying about blow-by on these engines. Clean it up, adjust the valves if you don't know the last time it was done, then just enjoy the pep you speak of.......;)

I am relatively new at this, but I would not say that oil in the air filter is normal. It may be common, but I don't think it is normal. I found oil in and dripping out of my air filter assembly and also found that the air filter (K&N) was quite dirty. I cleaned it up and the oil problem stopped. I also had a lot more zip. I concluded that I was starving the engine for air and it was sucking it up the oil return tube, along with oil.

I also read an excellent article on this forum about changing the oil check valve at the bottom of the tube (accessed by taking off the oil pan). I will be doing this as well.

Richard

k&ns' are pretty stupid designs arent they? On newer engines the oil used on the filter will contaminate and fry your MAF.

The K&N I have came with the car. I have read good and bad things about them. I have not used any of the recommended oil on it. I inquired at my local auto parts store where they sell K&N's about the oil they refer to on the K&N web site. They don't carry it and the guy said to just clean it with some detergent like 409. Not knowing any better, when I discovered the problem, I dunked mine in a bucket of Kero. It cleaned it up really well. I hope this was not detrimental in some way.

Excuse my ignorance, but what is my MAF?

I'm guessing its a mass air flow sensor.

Oiling the K&N (or similar high flow filters) is critical for trapping the smaller particulate matter. The high flow filters have larger pores so the oil is used to trap the particles. Most horror stories about K&N's are a result of neglect and lack of filter maintenance (cleaning and oiling). If they never get cleaned they get clogged and if they never get routinely oiled they don't filter well, especially if they dry out completely.

I don't know enough about the filter oil to say one way or the other if Kero would be a suitable for the filtering aspect (I don't see why not, just check it ocassionally to see if the filter is still oily) but as a cleaner it should be fine.

turbo sucks air. any oil inside any part of the air intake tract is residual from the crank case gasses. which is NORMAL and common on 10,000km engines and 500,000km engines.

dripping BLACK oil from the drain holes on the air cleaner could be an indication of something. Since you mentioned that there was a K&N filter in there, I'll bet some one over oiled it and it bled out.

Also if you have a leaking intake manifold gasket, that could put oil in unusual places.

When its 20 degrees out, and it just cranks, and cranks and cranks. Until you either it or plug it in. Thats on deaths doorstep.

Back when I had the SD either was my best friend!:D

....I've found WD-40 to be a better starting fluid for diesels.. I carry a can in my car at all times, in the winter.. :)

..oh, and I think you meant "ether"

http://en.wikipedia.org/wiki/Diethyl_ether

For the record, ether kills maggots dead.. Don't ask me how I know.. :P

AJ RN

Just curious--how would an intake gasket put oil where it's not supposed to be? And where exactly would those places be? I have some oil in unusual places.

K&N filters should not be used on these cars. You want WIX or Mahle.

i would not suggest using a starting fluid of any type, allthough WD-40 is the best kind of fluid to use if you are going to use it. instead of highly flameable either, it uses Propane.