Delivery valve internal leak as a cause of nailing? Yes? No? Maybe??? - Page 16 - PeachParts Mercedes-Benz Forum

Diseasel300 · #**226** 01-02-2018, 01:52 PM

Certainly sounds better than it did before. What color is the smoke and how long after you start it does it go away (if it ever goes away)?

If it's really cold, it's not unusual to have a bit of grey or whitish smoke for up to a minute or two after starting. The engine needs sufficient heat in it to vaporize all the fuel and on a really cold day that's a struggle until the engine warms up a bit.

Typically white smoke is fuel or timing. Grey smoke is typically timing or compression. Blue smoke is oil consumption. Black smoke is a rich mixture. You should NEVER see black smoke at idle.

If your ALDA is working properly, you can get a hint of black smoke under acceleration and a bit of a haze under hard acceleration. If you're leaving a black cloud, the mixture is way too rich, possibly due to turbo problems if the ALDA is still sealed.

phlfly · #**227** 01-02-2018, 08:30 PM

it's more blue smoke. I guess you are right my tech said too turbo is more likely leaking oil, it smells like diesel. There is only solution is to re-build.

Diseasel300 · #**228** 01-02-2018, 08:36 PM

Blue smoke is oil. You can also smell it on the exhaust, makes a sort of funky "plastic" smell to the exhaust (oil burning diesels have a fairly nasty exhaust smell). My turbo leaks on the compressor side (intake), it has the faintest smoke when running, but will blow blue when you get it up in RPM. No idea about the exhaust side, guess I'll find that out when it gets pulled off next. Rebuilding the turbo is one of the many things "on the table".

phlfly · #**229** 01-02-2018, 08:45 PM

I will do video later, and see if you have same.

OM617YOTA · #**230** 01-02-2018, 10:49 PM

Quote:

Originally Posted by Diseasel300

Blue smoke is oil. You can also smell it on the exhaust, makes a sort of funky "plastic" smell to the exhaust (oil burning diesels have a fairly nasty exhaust smell). My turbo leaks on the compressor side (intake), it has the faintest smoke when running, but will blow blue when you get it up in RPM. No idea about the exhaust side, guess I'll find that out when it gets pulled off next. Rebuilding the turbo is one of the many things "on the table".

Thank you for posting this. I knew it was burning oil and that the turbo was the culprit, but your post exactly describes my engine, down to the burning plastic smell. I had attributed this to poor fuel, which may still be a contributor as it does get better or worse sometimes, seems connected with tanks of fuel. Giving me motivation to take on a weekend project, I have a spare turbo I can swap in.

Diseasel300 · #**231** 01-03-2018, 10:10 AM

Fuel smoke will generally have a very acrid smell that makes you wince. If you're close enough, it can sting your eyes too. Burning oil smell can vary with what kind of oil you're running. When on synthetic, mine smells like burning shopping bags, almost a burning crayon smell. When on conventional oil, it has a more generic "plastic" smell to it. Since mine does burn a bit of oil, one brand I do NOT run is Delo 400. It may be a great oil, but whatever the additive package they use is, it smells HORRIBLE when burned - almost like gear oil!

OM617YOTA · #**232** 01-03-2018, 02:13 PM

It smells pretty gnarly, will definitely make you wince. It is fuel dependent too, this latest tank of B20 is good stuff and makes it smell pretty sweet.

Diseasel300 · #**233** 01-03-2018, 02:17 PM

Fuel quality can certainly have an effect on how well the engine runs - especially if the engine isn't the world's healthiest example. The last tank of fuel I had made my SDL run like crap. Cold starts usually had it buck and skip a few times in the first few seconds of running, and once warm, the idle sounded like a tractor. At the last fillup, it was an almost immediate change, the tractor rattle went away and it hasn't so much as coughed on cold starts since. Amazing and kind of sad what difference a tank of fuel can make.

phlfly · #**234** 01-06-2018, 01:55 PM

Finally be able to get make video for the smoking at idle and little with pedal to the floor. As you see I have both blue and than black but then it's all good. I don't think it's turbo leaking a lot oil, I think my valve seals are worn a enough to leak oil into cylinder, since it's "blue smoking " at idle.

https://youtu.be/MxlpORUNu-k

Diseasel300 · #**235** 01-06-2018, 07:55 PM

The valve seals could be a contributor at idle, but when the turbo spools, they will no longer leak due to higher pressure in the intake manifold and exhaust manifold. You're likely in the same boat I am - leaky turbo seals. Mine doesn't smoke objectionably, so I don't give it too much thought. I'll eventually get around to sending my turbo off for a proper rebuild when it's in the budget.

Light17 · #**236** 12-06-2018, 03:34 PM

Hi there, about to give this a go on my 201 N/A OM602 diesel. What part am I actually polishing? I've attached a parts diagram of my injection pump, anyone pointing out which part and which face would be gratefully received. I think it's the top beveled edge on part 86, but I'd appreciate some clarification.

Light17 · #**237** 12-24-2018, 10:21 AM

Well, it was very easy to figure out once I'd gotten in there. The delivery valves are actually two separate bits held in by gravity only. I polished the whole lot and there's a marked improvement, I might get new ones from Bosch and replace them all.