Glycol issue on W211 gearbox

[Deleted member 11979]

I was crying into my beer as 2 Mercedes specialists had diagnosed a juddering drive at low throttle and medium revs to be the lunched gearbox and torque convertor due to the contamination issue. I had also thought the same after reading many threads on it. Both garages drove the car and put it onto Star. The second garage had agreed to give the car the once over so as I could see whether it was worth spending the £2k plus required to sort the problem out properly.

They went into all the fault codes and erased them (no current ones, just stored ones), and because the rest of the car is good I decided I would take the plunge and spend the money.

As soon as I drove away from the garage, it became obvious that the car was different, a few more miles and it hadn't juddered or done anything naughty. So now I'm wondering what they have done, after a 50 mile exploratory trip the car doesn't judder anymore, a phone call to them had them stumped too.

Now, I'm expecting the problem to reappear as soon as I drive it next because surely this can't be right.

Can anyone shed any light on this seemingly miraculous pause/cure to this problem?

 

[Ian B Walker]

This is strange. I had one in today with a similar problem although mine needs a new hydraulic plate at £856 + vat. + labour. I read the codes, cleared them and hoped that it would be ok. Advised my customer that it may only be a very short time fix, if fixed at all. Its not going to get any better being left.

 

[st4]

Did they specifically test for Glycol in the ATF?

 

[mebs]

if you`re interested in a glycol test. PM me we do testing for contamination check in ATF and coolant

 

[flt.eng]

Have you had it confirmed that you have a VALEO rad? It's not sraight forward to identify, without taking off the panel support across the top of the rad. I understand there could be a label on the bottom of the rad. The Valeo rad. has castellated crimping & the Bher (good rad.) has wavy crimping, down each side. This crimping is difficult to see in situ. But is possible. If you shine a light down the bottom rgt. hand
side of the rad. You can just see a small section of the crimping. There are some good pictures in MBworld forums. Unfortunately at the presant time I have'nt confirmed %100 what make my rad. is. As the crimping on mine is'nt one or the other.
Although it is like the Bher wavey pattern it's not a continuous wave but split.
This thread has goaded me into checking this out. Once & for all.
You suddenly realise your'e sitting on a time bomb £££££s

 

[Deleted member 11979]

Yes, the plot thickens, today after driving for 200 miles with all behaving well, I attempted to reverse up a steep hill and there was no drive backward or forward. I stopped the engine and restarted it and all was fine again.
The problem with this is that I was all set up for a new gearbox and torque converter etc, and now it seems that it might be some other fault which might not be rectified with these items. I'm wondering if it is an electrical fault, although the gearbox is showing no faults on the star system.
I'm going to take it back and have it put on star again and see if the loss of drive has logged as a fault somewhere.

F@**ing Mercedes!!!!!

 

[flt.eng]

Have you been able to identify the make of radiator yet.

 

[Deleted member 11979]

With regard to the Valeo, no not yet, I can see a Behr sticker on one of the rads, but it's not the main engine coolant one. Today the car was perfect again, as if nothing had ever happened, so the next step is to bottom out this Valeo issue and if the rad is Valeo get it changed, then see how the gearbox goes.

I'm keeping my fingers crossed!

What else could it be I wonder? Any ideas?

 

[flt.eng]

Where did you see the Behr sticker.

 

[timskemp]

Mine had a Behr intercooler and a Valeo rad, at 150k ish miles the rad failed. Total cost (including a service) at an independant who had my existing torque converter refurbished was about 1500 quid plus vat (breakdown here) or about a penny a mile. However if you don't do many miles it does appear to be a time not a mileage related failure so it cold be quite a big running cost chunk of the car!

 

[flt.eng]

This seems to be the general mis-diagnosis, that the intercooler sticker relates to the radiator.

 

[Deleted member 11979]

No one has been able/bothered to diagnose the radiator so I am assuming it's a Valeo given the build date of my car in mid '03.

The fluid is going to have a glycol test this week.

Does anyone know if the Glycol problem can disappear overnight though, this is what i confusing me, I really don't want to have a rebuilt box and convertor if it's not the problem, regardless of how the glycol test comes back. Help!!!!! I'm wondering if it's an electronic issue although there were no gearbox faults on the car when it was put on the star machine, but when all the old faults were erased the car immediately started to behave itself.

 

[Deleted member 11979]

One more thing, all the gearbox/Mercedes specilaists say that the glycol problem cannot be sent away with a Star machine, but then in the next breath tell me I need a new box and convertor as it's the glycol problem. I'm really confused and am thinking this car is going to become a money pit!

 

[Deleted member 11979]

Mine had a Behr intercooler and a Valeo rad, at 150k ish miles the rad failed. Total cost (including a service) at an independant who had my existing torque converter refurbished was about 1500 quid plus vat (breakdown here) or about a penny a mile. However if you don't do many miles it does appear to be a time not a mileage related failure so it cold be quite a big running cost chunk of the car!

Thanks for that,

It's not the cost that is the main concern here, but the certainty of it being fixed by throwing £2400 at it.

 

[Deleted member 11979]

No Glycol in the transmission fluid apparently, so what now? No faults on Star? Everyone stumped.

Anyone got any ideas

 

[markjay]

Did all this fault diagnosis processes involve at any time simply replacing the ATF and filter to see what happens?

 

[Deleted member 11979]

No, it didn't as I was told it "seemed" ok, could that cause this intermittent fault?

 

[markjay]

Don't know, but I was always told that any auto box issues should be treated first with fresh ATF and filter as it seems to cure around 50% of the faults....

 

[paris2463]

See post 2

This is strange. I had one in today with a similar problem although mine needs a new hydraulic plate at £856 + vat. + labour. I read the codes, cleared them and hoped that it would be ok. Advised my customer that it may only be a very short time fix, if fixed at all. Its not going to get any better being left.

Think IAN may have answer as not constant fault

 

[flt.eng]

This does'nt solve the basic problem though. A change of ATF & filter could relieve things if the T.C. had'nt been too contaminated. But we get back to the cause. In your case I would suggest, an ATF glygol test first & take it from there. If this is positive, we get back to the cause. Firstly the rad. is it a Valeo? If yes. Change the rad. carry out an ATF/filter change. & hope the G.Box/T/C. had'nt been too contaminated. If it turns out not to be a Valeo problem. There are other reasons which have been discussed, in these & other threads. But I have no experiance of them.
Good Luck.