2004 Mercedes Benz C240 with 69,000 miles needs new Transmission should I repair or sell Auto

2004 MB with 69,000 miles. Purchased auto new form MB dealer. Had all services performed by dealer. Car was shifting rough (automatic or 4-matic). Took to dealer. Dealer reported that radiator fluid was found in transmission fluid. Replaced fluids and new radiator was installed all for the tune of $800.00 dollars. Auto still shiftsrough (surges) when I spend heavily on gas. Dealership will do nothing about cutting any kind of deal on new transmission or a transmission from wrecked MB. Need advise on keeping auto or selling. Hoping someone can help. Thanks

As with another recent thread the question is - who would want to buy a vehicle with a bad transmission and who knows what else. Best bet- fix it and than trade.

Dealership will do nothing about cutting any kind of deal on new transmission or a transmission from wrecked MB.

And why should they? I think your best bet would be to find an independent shop that either specializes in or regularly works on European Imports. They will more likely work with you than the dealer. In my opinion dealers are only for warranty and emergency work.

My best guess is radiator coolant fluid leaked into trans fluid cooler, thus the new radiator, and fluids. Assuming trans fluid changed also. Sure trans is probably toast, and worth replacing with a different unit, but since you have nothing to loose, another fluid flush and trying some can remedy is worth a shot.


Did they at least drain the pan, clean it and replace the filter?

If they drop the pan, at least they can inspect the fluid and whatever else is in there . . .

This is one of the very few times where I think a trans flush . . . with the CORRECT fluid, not some generic junk . . . might be worth a shot, before condemning the transmission

By the way, I’m hoping the dealer guys readapted all of the gears with the factory scan tool. it should only take 1 hour tops, depending on traffic, usually much less time

But let’s cut to the chase . . . I think the transmission is probably damaged. It’s up to you if you want to pay a few bucks to rule everything else out

I sure hope this isn’t really a 4matic, as you mentioned . . . because that’s going to require mega-bucks to repair/replace. Because the transmission will be quite a bit more expensive, and there’s more labor involve

I would think twice about getting a junkyard transmission. Odds are it has even more miles than yours. Odds are the fluid has NEVER been serviced. Meaning it may already be on borrowed time

I would think you would be better off keeping the car since it really doesn’t have much mileage on it. As a last effort to help the transmission I would try adding a product called Trans_X into the tranny fluid to see if that helps. If that solves the issue you will have saved a lot of money over replacing the transmission.

There’s a chance all that’s wrong is you have some coolant remaining in the transmission from the transmission cooler/radiator mishap. It’s very difficult to get all the coolant out, but it can be done with enough persistence. If you feel lucky, you might want to try that before making the fix/junk decision. Best of luck.

I hope the mechanics also drained the torque converter. It has a drain plug, and actually holds quite a bit of fluid. If they didn’t drain it, there could still be quite a bit of coolant mixed with the atf

See below comment for additional repair bills that may help answer some of the questions posted above.

Here is more information that my help in making the decision to keep or trade in MB… Car is a 4 matic transmission. Thanks for the insightful comments from above. Some are beyond my understanding so hopefully attached images will be helpful…

I tried to open my attachments. They are to small to read in all the ways I tried to open. I will leave on board for a few days… Perhaps someone else knows how to enlarge jpg files in order to read the scanned documents. Thanks

@Jkulp360 In MB nomenclature. “4Matic” means the car is all wheel drive. It does not refer to the kind of transmission it has.

If warning lights are off I’d consider trading it in. They may not pick up on issues and will low ball you anyway on a 10+ year old trade in anwyay. Selling this will be very difficult as your market is limited to those who have the means or skill to fix the issue.

Alternatively find an independent transmission shop or foreign/german repair shop to give an estimate/assessment.

#2 page 2 of 2 says they removed the trans pan and drained all the ATF. If it doesn’t shift well enough when not in sport mode, you probably need additional work. As another poster mentioned, you will not get good value on a trade or sale because the transmission needs work. Get it fixed and then decide if you want to keep it. If you like it otherwise, I’d keep it. You will have a newly refurb end transmission, new radiator, and presumably the leaky trans cooler issue will be resolved.

As db said, I don’t know how they could get all of the fluid out by draining it. The only way would be a flush. I guess that needs to be clarified what they did. General advice though for MB and BMW is to trade as soon as the warranty is off.

This may sound very mean . . .

But I believe the dealer mechanic who worked on the car wasn’t very resourceful or efficient

He did NOT initially suspect the radiator . . . the trans cooler, actually, which is inside the radiator . . . until spending a lot of the customer’s money on diagnosis and a flush. I say flush, because he mentioned the word, and there were 15 quarts of atf charged out on one of those 4 pages

On the following pages, he said he found moisture in the atf, found the TSB, which concerns the valeo radiators, and thereafter suspected the transmission cooler was leaking. Aka . . . the radiator needs to be replaced

I haven’t even worked at the Benz dealer in about 6-1/2 years, and I knew about the Valeo radiators.

I hadn’t mentioned it earlier, because OP said the radiator was replaced, because the internal trans cooler was leaking

The advantage of working at the dealership, is that the guys have access to ALL of the factory information. In my opinion, when you have a “problem vehicle” the very first thing you should do, after verifying fluid level, fuses, etc., is spend a few minutes looking for information. There is some really good information out there, which will save the mechanic time and frustration, and will save the customer money in the end, because the repair will be more efficient

Apparently, this guy only looked for factory information, when he became frustrated and didn’t know what was going on, anymore

This may be of interest to some, or not . . . the “good” radiators, which replaced the Valeo, are made by Behr