W209 CLK240 strange "jerking" @ 30-40 mph

[Raff]

Dear All,

I have a strange jerking at 30-40 mph while driving on a even road or up the hill, sometimes accompanied with slight vibration in the back and a resonating heat screen (probably???). My first impression: this happens when auto box shifts from 3rd into 4th or 4th into 5th, however I was driving the other day and even with setting the gearbox to 3rd or 4th gear only (no gear changes), same thing happened and revs were going up and down (+/- 300 rpm). This must mean (I think),that it only happens at certain prop shaft speed. Need to add I have the box oil and filter changed quite recently along with battery.

Any ideas please

 

[television]

Is there a humming and or droning sound at say from 1600 rpm to 2000 rpm, and what year is the car please

 

[jibcl500]

Mal

Are you thinking Glycol?

jib

 

[television]

Mal

Are you thinking Glycol?

jib

Yes but I did not want to think it

 

[Raff]

Television, yes I would say humming and or droning sound gets from the back,however in regard with rpm range cannot tell,couse it can happen on 3rd @ say 3000 rpm and on the 4th @ say 2000 rpm. It is a 02 reg CLK [2.6 V6]
Do you think it is Glycol problem?

 

[rpe2]

W209, 112 engine.

Eeek!

 

[television]

It does look that way, and they quote up to 2500 rpm on this car.

I have found a revised paper now for this, it says that for a glycol content above 100mg/L it is sufficient to replace the rad and flush out the torque converter and cooler lines

 

[Raff]

What to do now?
Is it possible for a good indi to obtain an oil sample and send it to a lab to verify if this is the case?

 

[television]

MB dealers charge £80 to do the test, and that is disgusting in my view, if a good indie has the glycol stick then they can do it. Do you have a good indie near you

 

[Raff]

Last time I used Prestige Car Repairs Ltd in Ipswich (recomended by a friend of mine).They did B service and a bit later that oil change, after pointing out autobox problem.Good/bad indi?Cannot tell. :neutral:

 

[television]

I have heard of them, but little feedback, if they could have done the test, they should have done so when changing the fluid. If all the fluid was changed, and the car was no better and the fault is still there it does look like a new converter and rad

Is it worth having a go for help from MB UK

 

[Raff]

I will contact them or pay them a visit tomorow and ask about their proceedings when doing that job and update this thread.
Just last few questions (today): can I keep on using my clk or it is not advisable?And if them parts need replaceing, what would be the damage?

 

[television]

I know that you must feel rotten about this, I would.

When MB have offered to help out the bill has been around £1300 but there are many indies that will fit a new rad and converter for that same price.

Re driving the car, what happens is the glycol raises the surfaces of the clutches inside the converter, so that has gone now and no further damage can take place

 

[Raff]

So here we go...
My indi said they are going to order sample test kit (£5+P&P) and will do the test next thursday.There were no errors within the box itself,so all the signs in the sky indicate glicol in ATF.Will see next week.
When that is the case,then they gave me two options:
A.[considerably cheaper] To change the rad, ATF and filter (with having the old one opend to look for any metal particles), and it will be circa £400.
B.[yes,much more expensive] To change the rad, ATF, filter and torque converter and overhauling the auto box for circa £2200
I reccon option B is applicable when they will find something in the filter.

Is it high time to say farewell to my beloved 209 I've owned for two months???

 

[television]

Do bare in mind that some debris always comes out, we have never had a car where the box itself needed any thing doing to it,, if the test figure comes out in line with the modified worksheet, then just the rad.

The indie will always have a difficult task in doing the right thing has he has to look after you and protect himself, and I hate such jobs

 

[Raff]

Just a quick update,
I had the "glycol content" test in the morning and the results are: glycol in ATF content is between 30 and 75 ppm, which indicates rad problem, however by my reckoning it might be the early stage and I have decided to have the rad, oil and filter changed tomorrow.I am just hoping that the torque converter (water based adhesive and friction elements) has not been affected yet and changing those parts is going to solve this malfunction.
We'll see

 

[television]

Well we know that the glycol raises the surfaces of the clutches in the converter, and MB say with that amount that you have, change the rad first and see, this is my thinking as well,good luck

 

[Raff]

Dear Malcolm,

Looks like my "problem" is very stubborn and wont go away,or my indie plays the ball with me.I picked up the car after they changed rad and the rest.I was told that due to the "nature" of the box they were unable to drain ATF completly and another ATF change should be done in the near future.Now at this point I thought fair enough,however after going threw the report (at home) I found that they have managed to change only 4 ltrs! How f%$&£@g furious was I when I read that!I felt I have been coned!Half a grand that costed me and after few miles car behaves the same!How is it possible that indie called this an ATF change!I'm afraid I'm gonna have to pay them a visit on monday and demand FULL/COMPLETE ATF change!Do you think they are unaware what a "ppm" is and that partial ATF change is not going to solve glycol problem?

 

[television]

That is very bad and not by the book,,in the first place all indies can and do change all of the fluid be removing one fluid cooling pipe and spinning the engine, so it all come out.

MB say undo the pipe and pour 4 liters through with the engine running till the new fluid has passed through and it comes out red, and this flushes all of the pipes.

Indies charge around £165 for a 7 liter change including filter

 

[Raff]

So it looks like "good engineering practice" has been forgotten in this case. Do you think by going there on Monday I will be able to achieve anything,or should I just find someone else?