Mercedes 190e 2.3-16V Turbo

[jeandersson]

Hi guys

Engine and transmission is coming apart for inspection shortly. Is there anything specific you would like pictures of?

[Nagilum]

Bearings/pistons cylinder walls? ;P

[Steffen102992]

Hi Jean, I wanna see, how you killed the 722.6xx....what was the weak point!

[jeandersson]

Hi Jean, I wanna see, how you killed the 722.6xx....what was the weak point!

Hi Steffen,
Believe that I overheated the transmission oil. So I would not really say that it was due to a weak point. Seems like you can kill any automatic transmission if the oil is passing a certain temperature. Have increase my cooling capacity now, but are still not fully satisfied. When pushing the car it's still possible to have the temperature in the transmission to raise slowly towards unacceptable levels. Below are some pictures of the two times when I damaged the transmission. In some cases the clutch packs got welded together. In other cases the small tooth got broken off (after the packs got welded I suppose). In one of the breakdowns the aluminum in the B1-clutch was melted, so I guess I didn't stop in when slip started to occur.

1.jpg

2.jpg

3.jpg

4.jpg

5.jpg

6.jpg

7.jpg

8.jpg

9.jpg

10.jpg

[jeandersson]

11.jpg

12.jpg

13.jpg

14.jpg

15.jpg

16.jpg

That all pictures from the transmission damages.

[Steffen102992]

Holy Moly!
Never seen that before, I repaired many of them in my career, but this is unbelievable! I thought if a 722.6xx could not resist a powerful engine, then no other tranny will do it.
I saw a 722.5 with similar damage, but this was driven without oil or less oil.
It was caused by one single run? (overheating)

[jeandersson]

Holy Moly!
Never seen that before, I repaired many of them in my career, but this is unbelievable! I thought if a 722.6xx could not resist a powerful engine, then no other tranny will do it.
I saw a 722.5 with similar damage, but this was driven without oil or less oil.
It was caused by one single run? (overheating)

Hi Steffen,

Thanks for the interest and comments. The overheating was caused by several runs with to short cool down in between. Maybe 3-5 runs on the 1/4mile. Once it started to slip the temperature raised incredibly fast. So I believe that the oil was destroyed gradually by the overheat and then all mechanical damage occurs more or less at once when oil lost the capacity to remain the oil-film. But as said before the root cause it that I continued to push it. New rule is to not pass 95 Celsius, not because I'm sure about that number. But rather just to have some number for myself to refer to. Once in a racing situation it's easy to think "just one more it will last"...

[jeandersson]

Hi again

So engine have came apart. And it seems that it was not about to fall apart this time. Only notice I have taken is that the cylinder walls seems to have some corrosion, maybe due to the long times between usage and the E85 fuel. Cylinder walls also has some wear in the area were pistons/rod is pushing the most. But nothing severe. So my plan is just to clean the cylinder walls a little with Scotch brite and reinstall it all. Didn't take any pictures of bearings but they are looking just fine. Shall see If I can remember to take a picture before assembly. Also noticed a crack in the exhaust manifold that has to be welded. It's a relief to see that the oil pump is still properly fixed, chain tension good etc. Pictures below.
Any questions, just let me know

1.jpg

2.jpg

3.jpg

4.jpg

5.jpg

6.jpg

7.jpg

8.jpg

9.jpg

10.jpg