I recently purchased a 1982 300CD. Ran smooth but very slowly. After using Diesel Kleen, car began idling roughly, excessive exhaust, greater loss of power and poor fuel economy. I had injectors checked which were fine; compression on cylinders was good with the exception of #1 which has zero compression. Since that test, car has very good power but exhaust still excessive (although improved), and still idles roughly. My thought is the diesel cleaner knocked some carbon loose and one of the valves is hanging open. As such, I put some 44k in the tank last night. Anybody have similar experience or advice? Thanks in advance.

 

Thanks for the reply. Zero compression in Cylinder 1 and it not hitting is what concerns me. Mechanic(s) telling me fuel filters won't help-they want to take valve cover off, see if valves burnt, bad piston, etc. Hard to believe that using Diesel Kleen caused this. Do u suggest I still go ahead and replace fuel filters before having valve cover removed? Will replacement cause Cylinder 1 to hit? Thanks in advance for any advice.

 

Thank you so much ForcedInduction. I had mechanic replace fuel filters and air filter and do a valve adjustment. He said couple valves were very tight. Car runs awesome now- still shifts with a bit of jerk but no vibration, excessive exhaust is gone and vehicle has plenty of power. Mercedes mechanic who sold me car two months ago told me Friday that I had probably hurt valves/pistons and car would need a new engine-really unbelievable. Again, my deepest gratitude to you.

 

I am thrilled. However, now my 300td wagon is acting up. Seems to rev before engaging when at a standstill-whether going into reverse or first. On road, does the same going into 2nd unless I am really gentle. Two shops (including the one that adjusted valves on CD) think new transmission needed. Shop that sold me the CD says he wants to see it and run 3-4 tests on it first. I've had a lot of work done on td wagon recently and, excluding the aforementioned, runs great. Do u believe I need new transmission? If so, any idea where to get one? Should I have mine re-built of buy a re-built one? Thanks in advance for any advice you may have.

 

Mechanic drained/replaced transmission fluid. Still slips going into reverse, first and second. Three mechanics now recommending replace transmission. Should I put in rebuilt transmission or go with a used one with 100K miles on it at a significant discount to a rebuilt? Thanks asa always.

 

Transmission Vacuum and adjustments
Mercedes-Benz Transmission, Steve Brotherton, ImportCar, February 2002

 

Of course installing a re-built Transsmission would cure the problem assuming your Vacuum System is OK to start with and the Mechanic knows how to setup the Transmission after it is installed.
So that would cost you $1200-$1600 for ther re-built Trans and ?Costo for the labor.

Also when the Mechanic exchanges the Transmission He is going to be looking for other work to do while it is out like changing the Flex Discs and the Drive Shaft Bearing Carrier/Bearing (all Rubber Parts).
Maybe even the U-joint that is not easily replacable because it is staked into the Drive Shaft.

 

Thanks for the advice. Can anybody point me in the right direction to get a re-built transmission in that 1200-1500 price range? The qotes i"ve received have all been at least $1000 north of that. Its my understanding that approx 30 modifications hae been made to the original engine and that, therefore, a re-built would probably offer superior performance to that of a used one. Thanks.