w203 juddering

[tonygardner]

hi all have just got back from cornwall have spent the week there , lots of driving etc etc , the car has developed a judder almost like a miss fire just not as bad when pulling away up a hill accelerating up steep hills and some times accelerating from speeds say 30 to 45 mph , does not seem to do this when cold , its a cdi 220 2004 auto ,its been slowly getting worse over the last 9 months or so , accelerates fine when flooring it gear change seems fine no slip, happens more so when drived slow to moderate ,i know is over due a autobox fluid change . just can`t find anyone local to do it , or is it the injectors ? thanks tony

 

[Stratman]

You may have the dreaded Valeo radiator problem. Do a search on here and the interwebs, there's loads of worrying information.

 

[tonygardner]

You may have the dreaded Valeo radiator problem. Do a search on here and the interwebs, there's loads of worrying information.

thats what i was thinking but its been very slowly getting worse over about a year , is fine when its cold/warm ,only happens when under labour at lower speeds

 

[miro]

You may have the dreaded Valeo radiator problem. Do a search on here and the interwebs, there's loads of worrying information.

I thought the radiator problem affected 112 engines.

 

[brucemillar]

Had the same in my C55. ATF and filter change solved the problem. It is worth having a look at the prop shaft donuts for wear. Just had the rear break up on mine and that also caused juddering only under load but was getting noticeably worse by the day.

 

[Auto-mobile]

If it does it pretty much around 1500rpm then possibly oil contamination with coolant, get a glycol test and then maybe a transmission service if the test is ok.

 

[tonygardner]

thanks for the replys , ok ive do a few tests etc this morning empty car no judder , loaded car inc roof box im emptying out my lock up , judder , not as bad as when i was in cornwall but then the hills are not as bad , i think a full fluid and filter change to do first , any idea on the cost of the donuts for the prop , or some diagrams many thanks tony

 

[tonygardner]

If it does it pretty much around 1500rpm then possibly oil contamination with coolant, get a glycol test and then maybe a transmission service if the test is ok.

can do it at any rpm, more so when under load carrying weight found that out to day

 

[tonygardner]

ok lets say it may be oil contamination with coolant ive had the car 2 1/2 years and covered over 30000 miles , i have noticed this over the last year may be longer ? slowly getting worse , would the antifreeze contamination course total faliure of the box , or is it something that happends over a long period of time over many thousnds of miles , say possable 2 years 20000 miles ? , i have no idea when or if the atf and filter has been changed the car has now done 150000 miles , has service history some mb but no record of it being done

 

[LexCorp]

I have the exact same car and exact same problem as you describe. Only does it once engine has warmed up and only at part load low revs. If I floor it it would accelerate fine. I have had this problem for six year which is how long I have owned the car for and the problem has not got any worse. I do all work on my car myself and it has been very well maintained but cannot find the cause even after carrying out a lot of self diagnostics to check the operation of all engine management sensors. I would be interested to know it anyone finds the cause for this problem.

 

[tonygardner]

I have the exact same car and exact same problem as you describe. Only does it once engine has warmed up and only at part load low revs. If I floor it it would accelerate fine. I have had this problem for six year which is how long I have owned the car for and the problem has not got any worse. I do all work on my car myself and it has been very well maintained but cannot find the cause even after carrying out a lot of self diagnostics to check the operation of all engine management sensors. I would be interested to know it anyone finds the cause for this problem.

thanks for the info have you had the atf and filter changed ?

 

[LexCorp]

I have not had the ATF changed before. Not sure if it has ever been done by previous owner either. I have checked ATF level with dipstick and it seem at the correct level and clean red fluid. I have changed all other engine fluids and have not found any sign of fluid contamination.

 

[brucemillar]

The ATF is worth doing if you are at all unsure if it has been done previously.

The prop donuts are easily visible from under the cat. You want a pit or ramps and you will spot visible damage.

While underneath have a good heave at the gearbox mount for excessive play.

Rear donut is available on here via ECP. They ordered up some spares when they got mine.

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[Auto-mobile]

Get the fluid tested before you change it.

 

[LexCorp]

I just checked my ATF fluid level this weekend using the correct dipstick which I purchased from ebay and found that the fluid level is low. When I checked it previously which was years ago I used an improvised dipstick so maybe I did not check it accurately.

This time I drove the car until the transmission fluid reached 80C which I checked with a scan tool and the fluid level was half way between the 80C and 20C marks on the dipstick when the engine was running and gear selector in park. This is obviously low and I will need to perform a fluid change.

I don't know for sure if this is the cause of the jerky acceleration or not as the car can drive perfectly fine when cold and gear changes are always clean but I will have to wait to see if it makes a difference.

I may not perform a full filter change by dropping the sump as I do not have a drive or garage and I always like to do all the work on my car myself. I may simply suck the old fluid out by using a fluid extractor then top up with new. I don't plane on keeping the car for long anyway so don't want waist money by paying incompetent mechanics to do the work.

 

[Twistedmind]

If your not keeping the car, just top the oil up and see if things are better

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[LexCorp]

Just wanted to provide an update. I changed the transmission fluid today. I dropped the sump replaced transmission fluid filter and filter to the correct level. However I am still experiencing the same issue, jerky acceleration when the engine has reached temperature. It does not do it all the time but only when there is a high load on the engine and am at mid engine revs.

 

[Twistedmind]

Check your drive shaft and rubber donut couplers. One of them might have failed.

Get the car on some ramps and have a good inspection

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