my 350SD smokes a lot when under boost. it smokes really bad. has a factory rebuilt engine with only 20k on it. puts out a huge cloud and i can't see the cars behind me. but when they pass me i sure get a funny look. i have also followed the car a few times, and it smokes while just going around town. looks bluish, and i know it is hard to tell by sight and by smell, but i swear i smell some burned oil. the EGR system has been rebuilt. mileage has actually increased, and oil consumption is 1000-1500 miles/quart. i am pretty sure that is what it is, but of course Mercedes says that is fine. they say 900 miles/quart is unacceptable and my dad has never had any other mercedes diesel use oil. so we both think that any oil consumption is unacceptable. the car also has a lot of diesel knock, and it misses bad too. start it up and it misses for a good minute. that could be glow plugs. it has been into the dealer repeatedly to no avail. although they have done a lot of warranty work. besides the rebuild of the EGR system, it has had 3 or 4 sets of new injectors, a new injection pump, new chain tensioner, and the injection pump was also timed. this is a hassle. any help with this would be appreciated.

Boy, it sure sounds like you have had you share of troubles with this one. Although a rebuild on the 350sd is not uncommon, I think continual engine related issues after the rebuid is.

The kind of smoke you are refering to is unacceptable to anyone with a brain - as is the oil consumption, especially on a factory rebuild. It sounds to me like it could be a timing issue, or a headgasket. Whatever it is, after 20k I am sure that the rebuild is still under warrentee. I'd take it back.

__________________
1996 (W210) E300D 86K - Traded in for a Lexus
1992 (W124) 300D 2.5 Turbo 202K - Sold
1983 (W123) 300D, 146K - Sold
1970 280S, 263K - Sold - Beginning of addiction

this engine is a factory caged engine. i talked to my dad last night and he said it is using 1 quart of oil for every 1000 mi. Mercedes limit is 1 quart/600 mi.

the engine has chain stretch and we have been told by the Mercedes dealer that this in "normal" for this engine. the engine gets retimed pretty frequently.

we think that there is a pretty good probability that the valve guides and/or valve seals are bad. we did a test with the car coasting down a hill in 1st gear. when we got to the bottom of the hill i stepped on the throttle and oil smoke came out the tail-pipe. my uncle is a very experienced auto-mechanic and he was following me when we did the test. so that is also a possibility.

thanks for the input.

1: Chain stretch is almost unheard of in this engine. I suspect smoke in more than the exhaust. Try another mechanic. A factory rebuild should run just like brand new, and that means no smoke or chain stretch.

2: Oil smoke on acceleration is much more likely to be oil from a bad turbo than from the engine. Oil consumption is on par for a bad turbo. Could be valve seals, but on a rebuild? Huh? Or was this just a rebuilt long block?

3: You are not getting good service from you dealer (big surprise). Look around for a good indie mechanic and find out just what the hell is going on. This engine is VERY quiet -- if you are getting "diesel" noise, something is wrong. Could be flat tappets (they are hydraulic), but again, if this was a complete engine, they should be new!

4: A stuck EGR valve will give you huge clouds of inky smoke and a funny, muffled rattle from poor combustion at low speed and high load. Car behind vanishes in the smoke, right? Unplug the EGR line.

Keep us posted -- I think there is more here than meets the eye.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Just curious, what does this mean?

no, the engine doesn't come in a crate, but came in a cage from the MB factory. and yes, so that means factory rebuild. i saw the engine in the cage since my dad and i put it in the car. fun job.

i don't think that there should be any chain stretch at all unless something is really wrong with the engine. and why would the chain tensioner have to be replaced? perhaps #1 rod bent?
and i also agree that it should run like new.

The sound that i hear is a metal to metal sound. it is so noisy when it starts cold. it is aweful. i have no idea what it could be. i know what a lifter that has leaked down sounds like in an in-block cam, but i don't know if it sound the same on an OHC engine. but the sound that i am hearing doesn't sound like the clicking of a leaky lifter.

The diesel tech at the dealership i think is good and knows the engine. he was at the MB factory helping to develop this engine. he knows something is wrong and is trying to help us.

like i said this engine has had a lot of work, and goes in frequently for warranty work. and has had the rebuilt EGR system about 1000 miles ago.

oh, could this be glow-plugs causing the sound? since the noise always happens when the car starts up for the first time. is the oil leaking out of the lifters? also it misses when it is stone cold and when it is warm, but not when it is at operating temperature.

we think that maybe we got a bum engine from Mercedes. it is very possible. my dad wants Mercedes to give him another engine because this one basically SUCKS!!! they are not budging, well i should say the dealer isn't budging on that. we are really fed up with this thing.

thanks for the input. i appreciate it.

The 603 engine is a noisy bastard on cold startup (below 50F). Give it a few revvs to clear it's throat, and with a ride around the block it should sound normal. I wouldn't be too concerned with this alone.

i know that it is noisy on cold startup as is every diesel engine that i have encountered. although this is louder then normal. i remember that i would coast down our hill and then put a little throttle into it and you could hear it clack a little. that too me seems normal. this sounds like there is absolutely no oil in the head. totally different sound then diesel knock.

thanks fo all the input so far

Sounds like you need to get the MB zone rep involved..my car burns about 1/2 quart in 5000 miles...and the factory MB rebuilt longblock in my car has about 45000 miles on it
there is no reason why you should had to had the injection pump repeatedly timed.....was it don't correctly the first time?
and yes the car will be noisy at cold startup...especially in temps below 40 degrees
get someone who knows this engine involved...ask the zone rep who the best tech for this engine is in your area..he should be able to tell you

Trust me you are not the first guy who has had problems in your area with this engine ..someone at a dealer near you has torn one of these cars apart before

Warren
1992 300SD 150K
Columbus Ohio

Attached Thumbnails

 

i totally agree with you. 1/2 quart on 5000 K is not bad at all. i think we change the oil at 3500 or 4000 miles. either way, both my dad and i are not satisfied with this engine at all. i will see what i can do about calling a zone rep.

the car actually lives in Seattle, and the diesel tech at Phil Smart (the Mercedes dealer in Seattle) like i said really knows this engine. he thinks there is something wrong too. but since Mercedes says quart for every 600 miles he really can't do anything.

again, that noise sounds like no oil up in the lifters. not a cold diesel engine because the sound goes away after the lifter if that is what it is pumps up. sounds metal to metal. not the sound of a cold diesel engine. we have had lots of diesel. my dad has a 78 300 CD, 50 something 190 D, and other diesel mercedes, diesel Excursion, VW dasher and rabbit, and this diesel 350. so we aren't at all new to the diesel thing. also, my dad is going on past experience with his older diesel MB and he has never had an engine that has had so much work done to it. i will try to contact or have my dad contact the zone rep for seattle and ask him some questions.

also, could that chain stetch be caused by a rod bending? therefore it moves the crank a little? seems like we would be having major problems by now because the bearings would be getting worn out very fast. also, that sound could possibly be part be rod knock? i doubt that. crank hitting the mains? i kinda doubt that too. maybe piston slap? i know a diesel will have some of that when it is cold, thus making it kinda clanky, but this is excessive clankiness.

also, has anyone had problems with the serpentine belt tensioner going bad? we have replaced ours 3-5 times. again all under warranty. they just keep going bad. is this another sign? the belt is not loose at all. since the belt is run from the crankshaft, is it going bad because the crank can move up and down in the mains? i am just throwing out possible problems. they make sense to me. i think the tech at Phil Smart needs to tear this thing apart and figure out what is going on. i know that we want to get this thing resolved before the warranty ends. i will definitely try to get a hold of the zone rep.

thanks for all the help.

I have had my serpentine belt tensioner replaced once...and the fan clutch also

who installed the engine in your car?...sounds like there are some major issues that need to be worked out

in regard to the 600 miles per quart thing...I would stand on my head and yell at the zone rep over that one...I think 1000 is the problem zone...any more than that and you probably have some issues

Attached Thumbnails

 

My dad and i installed the engine. major problems. but Phil Smart is doing all the warranty work. long story about how we destroyed the first engine. if you all want to know i will get into it. let me know and i will give the full story.

I think 1000 miles/quart i think is more then excessive. i will definitely try and get ahold of the zone rep on Mon.

thanks for the input.

also does anyone else have a MB factory rebuilt 3.5 turbo diesel engine? if so, what kind of oil comsumption does it have? my dad is making another trip to the dealer either this week or next. missing again, and it misses bad. whole car shakes like there is an earthquake or something. the thing just ricks back and forth. we'll see what comes about.

Did your fuel milage drop as well?

no it didn't. that is what i find odd. on the highway it is around 30 MPG, and around town i really don't know. the car is usually used for city driving and has been getting almost 500 miles per tank. i think between 450-480. this is what i find odd because it sounds like crap when it starts. it is going in to most likely get new glow-plugs sometime this week. and see if that cured the missing problem. my dad was driving the car and was going about 50 MPH on highway 9 headed towards I-5 in arlington. when he got to the I-5 he really stepped on it and the cars vanished behind him in a cloud of thick smoke. seems odd that so much soot build-up would occur driving at 50 MPH. and the smoke is really heavy cause it just sits there like a cloud and doesn't rise up. something is wrong for sure. i talked to him last night and told him to contact the mercedes zone rep. he said he would. we want this thing fixed.

also is anyone here a mercedes tech that is very familiar with a the factory rebuilt 3.5L turbo diesel engines? if so, could you help out too. thanks.