azbenze

Hello everyone, I am now the proud owner of a '98 E320 sedan with 97k miles. Purchased the car last Sunday. On returning home on Tuesday, pulling into the driveway the check engine light came on and drive was lost. Turned the engine off right away and to my horror there was oil pouring out from underneath the engine.

The oil was the same colour as the engine oil. I looked under the hood and found what looked like a high presure hose disconnected at the front bottom part of the engine resting on the lower engine cover. I had the car towed (flat bed truck) to the independent Mercedes service garage that the previous owner had the car serviced at. Here they identified the problem as a failed transmission oil cooler line. They replaced two hoses and refilled the transmission back to the correct level. They stated they used factory MB synthetic ATF.

The service history for the car shows there is a receipt for a transmission flush. This was done for the previous owner 3000 miles ago by this same independent shop. My concern is whether the transmission oil should be the same color as the engine oil? Comparing the leaked oil with the engine oil they seemed to be the same. Is the ATF supposed to be red? The car is back on the road now but I am worried they did not fill with the correct oil in the first place, and maybe topped it up with the incorrect oil also. Not the best start as a new owner but I love the car. Any advice would be greatly appreciated.

Thanks

tirona

tranny fluid is red. used tranny fluid is not neccessarily red. my guess is that the shop didn't fully drain the old fluid last time they serviced the car, they probably didn't know there is a torque converter drain plug on your transmission so they just drained 3-4L instead of 8.5L. old tranny fluid is dark in color, and when old fluid is mixed with new fluid it will still be brownish and not red, that's why you thought it was engine oil. next time (after around 30k miles) you replace the tranny fluid/filter make sure they drain all the oil fluid since your car has two drain plugs, one from the pan and one from the torque converter. cars with only one drain plug can have all the old fluid drained via the cooler lines.
nothing to worry about.

RichardM98

You are correct that fresh transmission fluid for the 722.6 transmission is red in color. However, in time it fades to a brown color which is very much like motor oil in appearance. There are two approved MB transmission fluids for your car. MB Part No. A001 989 21 03 10 for your 5sp 722.6 transmission and MB Part No. A001 989 45 03 13 which is for the 722.9 7sp transmission but is approved for use in the 5sp.

You could go to this shop and ask for the Part No. of the fluid they used. You might also compare the price per liter they charged. 5sp fluid from autohausaz is about $15/l and about $19/l from dealer.

Good luck.

01BlackE320

In most American made cars the fluid stays red forever but I've found that it is normal for the fluid to get darker in our cars. I believe graphite from the torque converter darkens the fluid over time.
A reputable shop would know what fluid to use. You should be fine

ohlord

not have the ***** to charge you for the repair and refill since they were the ones that left the hose loose after the flush.

azbenze

I did think it a bit suspicious that the last work done to the car was a transmission flush just 3000 miles ago....I didn't like the feel of the garage so will be finding another shop for future work! Not too worried about the oil color anymore based on comments above - they did also charge $15/liter for the oil. Thanks for all the advice.

saintz

3,000 miles ago, did they flush it or drain it? Flush would require them to disconnect that hose and use around 8 to 10 liters of fluid. Drain would use about 5 liters. If they drained it, then that line probably just popped by itself. If they flushed it, they probably didn't reattach the line correctly.

azbenze

Looking at the receipt, it specifically states that they flushed the transmission....So it looks like it was the shop that left the hose loose. Thanks for all all the advice everyone.

azbenze

Hi everyone, Since the transmission cooler line issue above, I have noticed in the past few months only when cold the transmission is a bit jerky from 1st to second and 2nd to 3rd. This only seems to last for the first mile or so in the morning. After that it is perfectly smooth, changes gear flawlessly.
I am a bit paranoid that something is still up with the transmission. Does anybody else have this behaviour? Is it worth going to the reputable shop and having the transmission fluid flushed again? Sorry for the repost, but I thought it was the best way to capture the history of the issue. Thanks for any help/advice

RichardM98

I think you have a couple of choices:

One - Get a competent MB mechanic to carefully measure and set the transmission fluid level. At least eliminate that possibility since past service attempts have been less than perfect. An incorrect level can eventually lead to transmission damage.

Two - Skip one and have a dealer scan the transmission for diagnostic codes. These electronic transmissions are complicated and difficult to diagnose by shifting behavior alone. If you opt for 2 they can/will check the fluid level as part of the diagnostics.

Good luck.

01BlackE320

a couple of things. First off you need to check that the fluid has been filled to the proper level. If your car does not have a dipstick, you can order one online. If fluid is low or high, that could cause rough shifting. Also if your car is equipped with the W/S (winter summer switch) on the shift console, make sure it is in summer. Winter mode skips first gear and in my opinion, make the transmission feel a little clunky.

Secondy, if the really flushed the fluid 3k miles ago I would have expected the fluid to be Red. When I changed my fluid at 95k miles, it was clear to dark and could have been confused with motor oil, but the new fluid is definitely red. It sounds strange that it would not appear red at all only 3k miles after a flush.

Disconnecting the hose and flushing is really not the best way to change fluid on your car. Your car has a drain plug in the pan and torque converter that would allow you to remove and replace fluid quite easily.

azbenze

Thank you for the advice. It is time for an oil change so I will have my independent mechanic check the transmission level. The previous garage put 5 liters of oil in when the cooler line fell off. That was 4 months, 4000 miles ago now.
I am also contemplating having the garage drain and refill with correct spec oil. What price would you expect pay for a competent shop to do this?
It's strange in that after the first mile or so when it is warm the shifting is perfect.

ejrooney

My owner's manual says the transmission is supposed to do that until the catalytic converter is warmed up. For the first few blocks, it refuses to shift until about 3000 rpm, after that, all is good. My independent mechanic has also reassured me this is normal. I actually got a deal on the car from an estate, because they thought there was something wrong with the transmission!