New to diesel. Engine question. Thanks - PeachParts Mercedes-Benz Forum

aeonflux · #1 02-01-2006, 07:00 PM

Any advice on what to look out for when buying a diesel? I am looking to buy a 300td. Some things I have read about are:

Blow-by(what exactly is this?)
Smoke(do different colors make a difference? One wagon I am looking at smokes consistently a dark grey)
Oil use(what is acceptable)

Do Merc. diesels have their own quirks, or are diesel problems pretty generic among all makes?
Also a wagon I am looking at slips a bit when shifting up and down into 2nd gear. Am I asking for trouble buying a into a transmission like this?

Thanks for any info out there! Dave.

kip Foss · #2 02-01-2006, 07:29 PM

You might start out by using the search to look up some of these questions.

t walgamuth · #3 02-01-2006, 10:28 PM

here are some things

first, blue smoke can mean oil or fuel. if it is oil it can be valve seals or rings. it can be other things too occassionaly, like a leaking vacuum pump i think. it it smells like diesel it may be a leaking injector. if it starts up roughly and smokes blue for a little while it can be a glow plug problem. this is the easiest to solve. dark gray smoke is probably normal. maybe running a little richly, but not a problem.

oil use is a problem if it is so much that it is hard to keep track of it and you end up running it low and ruining the bearings. anything above a qt every 1000 miles is prob ok on an older benz with a couple of hundred thou miles on it. if it has had good care though it may have that many miles and use essentially no oil.

slipping on the shifting is not a good thing. but often if it locks up solidly eventually it can be adjusted out of it. tranny repairs are pricey.

good luck with your search. feel free to come back and give more specific info and get ideas.

tom w

kerry · #4 02-01-2006, 10:31 PM

Couple of points. Blue smoke could also be coming from bad seals on the turbo. You may already know this, but in looked for an MB, be aware that 'TD' refers to the wagon. The turbo sedan is a 300d (but people often refer to them as 300dt's)

t walgamuth · #5 02-01-2006, 10:38 PM

and a car advertised as a 300td is often a sedan wrongly identified, so i always ask what model it is. and i ask a million questions before taking time to go look at one. sellers sometimes get irritated but i dont mind. why waste my time looking at something i can tell over the phone i dont want?

tom w