300TD Turbo Problems - PeachParts Mercedes-Benz Forum

PJJ707 · #1 08-02-2006, 01:07 PM

Whoever can help...

I have a 1987 W124 300TD Turbo Diesel (wagon). It has about 40K milage on it. I just had the diesel pumps re-calibrated about 2 months ago and it was working fine. Then i noticed that there was oil seeping out through the intake manifold from the turbo. (from the gasket connecting the turbo pressure to the intake manifold. The gasket is small and rectagular, about 2.5 inches high and about 4 inches long.) Sad really...

It performs quite well and the turbo kicks in fine at about 2500 rpm. Is my suspission right that the turbo has already given way and needs replacement? or is it only the oil seal inside the turbine?

Also, if anyone knows what Mercedes Benz uses for its turbine? Brand and model? (particularly for the 1987 300TD) is there a turbo repair kit available for my car?

Any help would be appreciated. Thanks!

Lostyankee · #2 08-02-2006, 06:29 PM

I do not have experience with this model but a question comes to mind. Can this oil be consumed by the engine? If so you could have a run away diesel waiting for the worst possible time to happen.

PJJ707 · #3 08-28-2006, 03:16 PM

Quote:

Originally Posted by Lostyankee

I do not have experience with this model but a question comes to mind. Can this oil be consumed by the engine? If so you could have a run away diesel waiting for the worst possible time to happen.

Thanks for replying... but would you happen to know anyone that can help me with this problem?

Johnhef · #4 08-28-2006, 03:20 PM

Just replace that gasket and enjoy your oilburner

sixto · #5 08-28-2006, 03:45 PM

Mark, there are two sources of oil into the the crossover pipe. One is the turbo, the other is blow-by. Here are some things to try -

1) Clean the crossover pipe and see how oily it gets after a long drive.

2) There is a hose that leads from the valve cover (behind the oil filler cap) to the turbo air intake hose. Remove this hose from the turbo hose and leave it hanging or stick it in a bottle. Cap the fitting in the turbo hose. Go for a long drive and see how oily the crossover pipe is. If you used a bottle, see how much oil you collected.

3) If the crossover pipe is clean, oil is coming from blow-by. Otherwise it must be coming from the turbo.

4) Remove the turbo air intake hose. Hold the end of the turbo shaft with your fingers. Move the shaft up and down and side to side. If there is more than just perceptible play the turbo bearings are worn. But it might not be the end of the world.

5) Now move the shaft in and out. If there is any play whatsoever the bearings are worn beyond serviceability.

On the compressor housing you might see the word AirResearch. If so, you have a Garrett turbo. $3-400 to have it rebuilt in the US or you can get a rebuild kit from www.turbocity.com. If you don't see AirResearch in big bold letters or if you see KKK (I think in a triangle) then you have a KKK turbo. Perfectly good turbo but more expensive to have rebuilt and I'm not aware of any DIY rebuild kits. AFAIK, you can put a Garrett in place of a KKK and vice versa with no other modifications. Don't quote me on that.

If you feel boost at 2500rpm, that might be a little late. The true test is to have max boost by 4000rpm with the pedal to the floor. Max boost spec is 0.85 - 0.95 bar (roughly 12.5 - 13.5 psi).

If your only concern is oil leaking past the crossover pipe gasket then as Johnhef says, change the gasket and enjoy the car.

By chance did you go to Xavier School?

Sixto
93 300SD

gsxr · #6 08-28-2006, 04:16 PM

One last thing... oil in the intake is not abnormal, although it's not really desirable either. I get oil in the intake on my car, too. If your oil consumption is normal (quart per 4000 miles or better), replace the gasket and ignore the oil in the intake.

Johnhef · #7 08-28-2006, 09:06 PM

almost forgot EGR, that nifty little thing lets all kinds of nastiness back into the intake.

markg612 · #8 08-28-2006, 11:23 PM

Sixto hit just about everything.

Did you ever see Fight Club?

The first rule of fight club, is don't talk about fight club.

If this is your first mercedes diesel, you need to get use to the first rule of Mercedes diesel ownership.

Don't over think the problem, because all you will do is spend grotesque amounts of money on what you THINK is a problem, and you will still have the problem.

These 60x engines as Sixto mentioned have re-breathers and EGRs. They are designed to re-ingest the uglies that spew out of crankcase and the exhaust. Kind of crude but they are designed to eat their own waste. Something important to understand about the design, the crankcase breather is hooked directly to the turbo inlet line, a highly efficient vacuum generator. There is an elaborate labyrinth of passageway built into the top of the valve cover that is suppose to prevent oil vapor from departing the crank case via the breather. Needless to say it is impossible keep 100% if the oil vapor from being drawn into the intake along with combustion blow-by. Diesels all have blow by, even brand new. (617 owners of higher mileage engines will tell you that if you plug the breather, remove the oil cap, and cover the hole with your hand, a week engine will eventually quick as the crank case pressure builds to a point that kills the engine. I have never seen a 60x charge tube that was dry of oil.

The ten cent check for the turbo is if it is kicking in like you mentioned and continues to pull as you accelerate, and it doesn't grind or make any noise, there is a high likely hood it's just fine. They either work or don't work except on rare occasions. If they leak oil, you will notice the consumption. At 40K, the engine should be like new. At 40K, the turbo should be like new. Its a tough little unit as well, unless a trap oxidizer has caused them an early death. Mine was crack to hell and leaking oil and boost pressure at 101K and work just fine. The turbo can go inop from something so simple as a weather checked and dried vacuum line in the control plumbing. Less than 2 cents of tubular rubber and the $3000 spinning marvel and all its ancillaries become little more than an a very expensive exhaust restriction.

If you are unfamiliar with the drivability of the model, a 124.133/193 with an non-functioning turbo the car couldn't get out of the way of a charging turtle. A moped could beat it to 60MPH. If your turbo is functioning, break away acceleration is/was a point of negative concern to new owners 19 years back due mainly to transmission gearing and shift points. This issue continues to be a bane of owners today. A functioning turbo is unmistakable and will zip this 4500 pound ship to 80 MPH in short order.

After 10 years and 200K miles of use and ownership between three variants of this engine, you can chase all sorts of perceived problems with copious amounts of cash and still have the same car you started with the same perceived problem They're great fun to drive and fun to own, but repair and upkeep without knowledge will turn a large fortune into a small one in a quick hurry. This is more sad.

With 40K, this should be a cream puff in the $8000-$12000 range--something to consider if you came by it for less.

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