Is it the turbo?

[lowriderdog37]

I just bought an '86 300SD. When I start the car, there is a lot of half-burned oil smell + smoke out of the tail pipe. After warming the car up, the smell goes away at idle, but I get a good bit of smoke during higher acceleration. I can see a little smoke in my rear view when I am on the highway. When I get off the highway, I can smell burning oil at the red light. If I park and turn the car off soon after highway driving, I get smoke from what looks like the turbo. I have oil spray on the side wall, and the general area near the turbo. The spray is not in the area of the oil tube. There is also oil on the middle of the turbo on the bottom.

Well, from the searching I have been doing, I am guessing a turbo rebuild would be in order. Info I am finding is pretty spread out though. Is there one place that will sell all the rebuild parts, as well as the gaskets for remounting, EGR blockoff plate, and oil drain tube seals? Is there anything I am missing?

I am not driving the car at the moment, I want to make sure the turbo is working properly first, but I would like to do it pretty quick. Thanks for the help!

[JimFreeh]

Sounds like you may have more than one problem.

The external oil could be from the turbo oil supply lines or from a leaking cam cover gasket.

Burning oil out the tailpipe can be either turbo seals or shot valve seals/guides.

Jim

[bobodaclown]

Whats your oil consumption? Are you adding a quart every 1000 miles? Are you getting good boost? Do you have a boost gauge? Get some degreaser and clean the engine compartment that may help a bit to find your leak.

SMOKE = Not enough Air (incomplete burning)

Just some other food for thought.

Looks like you've done some research on tweaks... But you forgot the cold beer.... To enjoy with the fruits of your labor.

Bobo

[bodyart27]

Originally Posted by lowriderdog37

I get a good bit of smoke during higher acceleration. I can see a little smoke in my rear view when I am on the highway.

Some smoke under heavy acceleration is normal - it's unburnt fuel.

You might see if the little wastegate hose is still attached or even present. On my 84 300sd it deteriorated and started making a mess.

T find it, look under the big U-shaped plastic elbow that feeds air from the air cleaner (sits on top of the turbo) into the turbo inlet (held in place by a big metal band / clamp). Right below the inlet / U-shaped elbow piece should be a hose - here is the link to it on from the buy parts tab:

http://catalog.worldpac.com/mercedesshop/sophio/quote.jsp?clientid=catalog.mercedesshop&cookieid=1ZO0K1NU42AZ0KI4HN&baseurl=http://catalog.peachparts.com/&partner=mercedesshop&year=1984&product=B4034-11582&application=000005726

or just search "wastegate" and you'll find the hose.

Of course there are multiple other areas that "leak" on that side of the engine on 617 5 cylinder turbo - (1) drain from under the air cleaner that snakes down and under the turbo and then into the pan, also (2) the turbo oil drain itself (much larger tube right below the turbo going into the pan.

[lowriderdog37]

My consumption is about 2 qts for the 400 miles I have driven the car. I know this is a different motor (603), but my '85 300CD (617 motor) doesn't smoke nearly as much. I feel like I am getting boost. I have already taken it to the local trusted mechanic, and he said that there is nothing major wrong...I think he just doesn't want to work on it. He said there is a small leak in the head gasket, the rest is maybe just burning oil in the cylinder at highway speed from the added pressure of high engine speed.

Well, I am going to go work on it for a bit, start taking off random parts. I'll check back in a bit with an update.

[ConnClark]

If your getting blue smoke under heavy acceleration it sounds like the turbo seals are going to me.

I just had a turbo that the seals let go in. The following is the order in which the symptoms occurred.

First I noticed a hot oil smell.

Next I noticed my oil consumption increasing.

Then I noticed blue smoke a light amount of blue smoke starting out in the morning followed by a big puff of it when I got on the accelerator the first time. The blue smoke turned into a light trail after that and would go away as the engine warmed up.

Then I noticed heavy blue smoke under hard acceleration and a light blue haze following me every where.

[Brian Carlton]

Originally Posted by lowriderdog37

I just bought an '86 300SD.

Can you please clarify what you bought. There was no 300SD manufactured in 1986 in the USA.

Does the engine have the five cylinder OM617 or the six cylinder OM603.

Without this info, it's difficult to provide useful advice.

[Diesel911]

If you want to be sure if it is the turbo or not remove the flexable coupling between the Exhaust pipe and the turbo and take a look inside. If it is all black and shiney you have an oil leak. Here is a pic of a turbo with NO oil leak full of carbon but DRY.

[lowriderdog37]

Sorry for the confusion, I do have an '86 300SDL with the 603. That is the car in question.

I did some more looking, I haven't taken the turbo, or the exhaust off yet, I found the exhaust-to-turbo bolts were loose, as were the ones on the EGR (which looked like it was leaking). I took the EGR off, made a block plate, new gaskets and re-assembled, cleaned, drove and it's still doing the same thing.

I did find that the EGR is leaking liquid (unburned) oil out of the top. My friend (who knows much more about engines than I do) told me that it could be the exhaust valve guide. What does everybody think about that?

I have to go to work now, so I can't work any more today. I would like to take the turbo off tomorrow and see what it looks like inside.

[babymog]

Originally Posted by Brian Carlton

There was no 300SD manufactured in 1986 in the USA.

Must've been before the Alabama plant started making SDs Brian? ;~)

Sorry, couldn't resist. I'm weak.

[Brian Carlton]

Originally Posted by babymog

Must've been before the Alabama plant started making SDs Brian? ;~)

Sorry, couldn't resist. I'm weak.

..........an SD from Alabama..........now there's a scary thought..........

[Brian Carlton]

Originally Posted by lowriderdog37

My consumption is about 2 qts for the 400 miles

One quart per 200 miles is significant and the cause needs to be found. My first guess is the turbo seals are shot and the turbo is putting plenty of oil into the intake.

At that consumption level, you can prove this theory by taking the crossover pipe off the engine and looking down into the discharge area of the turbo. You'll see oil droplets all over this area if the turbo is the cuplrit. If you start the engine briefly, you'll probably be able to see the oil begin to pool in this area.

The '87 had the exact same problem when I purchased it. Be careful........the consumption can rise a bit (to one quart every 50 miles).........and you'll have quite an oil fog behind you on all accels at that point. You really need to park it and find the culprit or the engine can become hydrolocked with oil if you try to go much further than this level of consumption.

[lowriderdog37]

OK, got the turbo off, and the intake side of it was full of oil. There is no grinding, but the assy doesn't spin as freely as it should.

Now, is there a place that will sell the rebuild kit for it, as well as all the gaskets that I have stripped off the car while doing this? I would like to get all of it in one place for simplicity reasons. Also, is there a company I should stay away from when getting this kit? I mean, does any one company sell cheaper 'crap' than others?

[turbobenz]

How much oil was in the intake side. Oil in the intake side doesn't indicate a turbo seal problem, it indicates that you have oil coming into the turbo, from the re breather system. How is your blow-by on this car? Everyone here has at least a small amount of oil on thew intake side. See how much blow by your car has before you jump on the turbo, because it doesn't sound like a turbo. This could just be a case of extreme blow by and maybe just a bad gasket on the turbo somehwere that is spraying the wall. only familiar with the 617 so I really have no idea what im talking about but just my .02 cents

[Brian Carlton]

Originally Posted by turbobenz

. Oil in the intake side doesn't indicate a turbo seal problem, it indicates that you have oil coming into the turbo, from the re breather system.

This is a factually incorrect statement.