Near Catastrophic Oil Loss 240D & Rust Proofing Job
 

This evening I was helping W Hunter retrieve a 190D (W201) from a customer that had broken the alternator pulley and had popped off the serpentine belt. The trip was about 50 miles from home. I picked up W Hunter on the way and my 240D worked really great (kiss of death to ever say that about a car) all the way to our destination. W Hunter patched up the 190D and we were returning to his place so he could finish the repair and do other things with that car.

About 4 blocks from his house I noticed the 240D oil pressure gauge dipping below 3 and then it dropped to ZERO!!! I turned off the engine and coasted (manual 4 speed) about 2 blocks. I turned on the engine and had a little oil pressure and got up to speed and turned it off again... coasting to a stop in front of his house. (I always watch the oil gauge!)

We opened the hood and everything in the entire engine compartment is covered in black engine oil. We pulled the dip stick and there was nothing on it. We put in 2 quarts... still nothing on the dip stick. We put in 4 more quarts and it was now over filled enough to put the car in his garage.

The diagnosis is that there was a small pin hole leak of one of the oil cooler lines (original equipment on the 32 yr old car) that was spraying on the power steering pump pulley. This allowed the oil to be equally distributed all over the place! (see the pictures) The whole engine compartment is slimed! The underbody probably won't need any rust protection for a while either! The pin hole leak seemed to be from when a power steering belt had been rubbing against the oil pressure line. (don't know when that happened) We could see the line where the belt or something in that direct line had been rubbing previously on the oil line.

We estimated that the leak probably had been going on for at least 20 minutes / miles. And that it would only register zero on the oil pressure gauge when only about 2 quarts of oil were left in the sump. W Hunter said that the engine is OK because it ran OK after we filled it and that I had not run it for long after discovering the issue. He will install new oil cooler lines in the next day or so.

I needed an oil and filter change... but this was just ridiculous! I had just power washed the engine bay for a potential customer last Saturday... Darn!

Whew! Caught that just in time... Lucky!!!

Hood picture, then engine bay. The next post will show where the pin hole leak is.

Near catastrophic oil leak 240D & Rust Proofing 2
 

Here are more pictures...

Oh yes... you should have seen the puddle of oil on the street where the old Benz marked it's spot!

See spot... see spot not run without oil. Run spot run... Nope!

Near Catastrophic Oil Loss 240D & Rust Proofing Job 3
 

Point of screw driver is where the leak is located.

Nice story - it sounds like you stopped the engine just in time.

good catch!

very lucky,,
 

Good catch, if my wife had been driving your car the engine would be junk.
most drivers would not have saved the engine,, they need bells and audio alarms !!!

I think you missed a spot in that second picture.

You're one in a hundred. In most cases that engine would have been toast.

Ick
 

We prepared the shop floor with a bag of oil dry, before driving the car in.

FYI: Part numbers.

Oil Line - to Top of Oil Cooler
MB# 616 187 06 82

Oil Line - to Bottom of Oil Cooler
MB# 617 187 12 82


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Good subject for a "Heads Up!"
 

Nice save. A little bit of distraction while driving could have led to a catastrophe.

My 240D is on jackstands, still, as I catch up on the deferred maintenance of years long gone. New oil lines have been added to the list of "things that must be done before we hit the road together." There is certainly enough good information on this forum to keep one from posting messages here that should go on FailBlog! Although I will probably do the same myself somewhere down the road.......


snapped_bolt

Update
 

I used a Sawzall to cut the old lines roughly eight inches from the unions.

"Houston" we have a problem!!

The oil cooler was removed from the car with the union stubs attached.

The oil cooler union stubs required three hours delicate application of (propane torch) heat, PB Blaster, and torque to achieve separation. :D

FYI: The oil cooler is a folded path, tube and fin unit = gravity draining requires unreasonable time (days).
I prefer to use an air blow gun to gently force the oil out of the cooler, and zip tie a contractor trash bag to the output line.
Cleanup takes minutes. :)


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The word that comes to mind when I see the oil coating on everything under your hood is: "Thorough" I do not think I could have done a better job with a spray bottle.

Wow - now there's dedication.

Another testament for Kroil. Many independent tests prove its about the best commercial one out there.

X2 on that. I used PB Blaster to get mine off but I also soaked them daily for a week before I attempted to remove them.