isbeinside,

Regarding the 642 rebuild you mention above, was the cause of failure determined?

Is there any instructive guidance you'd care to impart about 642 engines?

-Jon

 

Monty, could this be the reason they're bringing out gasser engines?

 

I doubt it. I think they are just trying to play both markets. The V6 diesel seems to be alot better than the 642 and the 612's. However, they are still pretty new.

Jon, the only thing that I see on a daily basis with the 642 engines is the turbo resonator leaking. About a 50 dollar part. If you look at the turbo and the outlet of it where it goes into the CAC. You will see a black box. That is the turbo resonator. Around the front of the seam they are very prone to leaking out boost and setting a code and/or derating. So, if you every derate down to say 45mph tops and chk eng. light comes on. Take some soap solution and spray down the resonator. If it is leaking, there will be bubbles around the seam.

 

This information is from a German MB tech that saw the picture of the cabon build up and broken cams:
"Those cams were broken when valves contacted piston crowns-likely caused by mistimed chain drive due to chain/sprocket/tensioner failure."
"The camshaft breakage could have been caused by a sudden catastrophic failure of the chain sprocket or a jump in timing due to high mileage chain wear. The driver may have had long term gradual increase in audible clatter or a sudden failure without symptoms. Regarding fuel-I assume you are referring to the photos of leakage from the injector bores. Failure of the injector hold-down clamping force resulting in leakage from the injector seal rings in the cyl head could well have been caused by fuel quality related combustion anomalies."

 

Thanks for the info.

He is right about the chain sprocket. As that is what caused the failure on this particular engine.

As for the combustion leakage. I agree that it was probably due to a hold down clamp or hold down bolt. Since the injectors had been changed at sometime in the 130k miles, the tech may not have replaced the hold down bolts like you should.

 

Wow - there are alot of 'Wow's' in these replies...

 

hope this in not too common... my brother has a sprinter too

 

I had a first gen sprinter, at 95,000 km's I kissed it goodbye and traded it in on a 2nd gen sprinter.. The 1st gen sprinter was as the dealer for repair every week, the odd time it made 2 weeks between break downs, one time it was there for 8 weeks straight when it dropped the transmission.
The summary on the first gen sprinter:
Who in their right mind sells a 2005 with a cassette deck, maybe in Germany to play David hassellhoff tapes.
They should ship a few hundred spare egr valves with the vehicle.
Pneumatic seat supports with handpumps are duds..
The powerloss instead of a check engine lamp is nuts, a good way to get your sprinter buying customers killed when it goes into limp on the middle of pass.
The 138 km speed cut makes mountain passing hard.
The body is to flexible, work truck shelving gets torn apart from body flex.
Mercedes needs to go back to Edison to learn about headlight bulbs.
The turbo resonator made of plastic is idiotic.
The door hinges rust shut in a week in a Canadian winter.
No standard block heater in a Diesel in Canada, hmm....
Include a free tow truck with every sprinter, Mine never made it to an oil change interval without breaking down.
The blower for the heater/a/c was horribly weak, below -10C you end up scraping the windshield on the inside.

The upside , great power for small motor, great mileage

I have a 2nd gen sprinter now. Interior and optioning is far better than 1st gen, I find the 3.0 v-6 weak compared to the inline 5, the down low torque is not there. The shifter is to short, and I have longer than average arms. The headlights are waaayyy better, being projector HID. The door lock system is better, and the seats are way more padded.The hvac controls and blower are vastly improved.. The guages and assyst system is now driver instead of just dodge tech friendly..
I just finished basically the same round trip that I do in all of my vehicles.
Mixed hill/flat, highway cruise at 110 km/hr with tool load. All are automatics.
1 st gen sprinter 34 mpg.
2 nd gen sprinter 17.8 mpg
1994 2wd reg cab cummins 2500 27.3 mpg
The sprinter is a great work truck for room and standing up in the back. But if I would do it all again, it would be a older plain cummins with a stand up work canopy on the back.
If the 2nd sprinter does anything like the 1st gen, I am gonna go postal..

 

Thank G*D my wife cancelled the order for one last year. I found a stepvan at auction with a B3.9 in it that I use as a work truck on the farm. Carries everything a farm/ranch needs in the field from barbed wire to tools to pvc pipes to extra saddles and lariats and still carry six people safely. I won't be giving up this one quite so soon.