ML 270Cdi limping max 3000rpm

[FenandGreyDog]

Hi,

My ML 270cd 52 plate 116K miles, will not do more than 3000 rpm which is a real pain it's 60miles to work and 60 back, 5 days a weeks (30mpg!!). Reading the forum post it looks like is the MAF or EGR. The MAF sounds the easiest thing to look, but where is it! I have not done any work on a car for sometime.. (I do know my AF's from my BA's!!) But I would like to be able to overtake again!

thanks.

 

[jurmic]

Hello FGD,

I think you can find the MAF between the airfilter and the turbo-charger. That means either on the body of the intake filter case or on the hose between this filter case and the turbocharger. But, I had the same problem, some weeks ago and it was caused by a broken hose between the turbo charger and the intercooler. The effect was that air was leaking at that point and the MAF couldn't measure the correct airpressure.
Succes,
Jurmic

 

[gtvlusso]

You will need to get it STAR diagnosed for a true indication of the problem. MAF is more than likely, cost is about £60 for the MAf and it takes 5 mins to fit.

However, take the engine cover off and have a look for a leaking injector too, black carbon deposits around injectors.....you will hear a 'chuffing' sound. Can also cause limp mode activation.

Worth a poke about before you commit the money as a few things can cause limp mode (although MAF is the most likely candidate)

 

[FenandGreyDog]

thanks, I will get under the hood and poke about a bit....

 

[Terry_]

Just an addition to above. The front front cat can get blocked as well. I done one last week for the very same issue! The maf is the first point of call though.

 

[Howard]

Don't change anything though until you have had it diagnosed , replacing parts until you find the fault is expensive.

 

[Mercedes cozy]

Try disconnecting the plug on the MAF, I have done this before and the car drove better.
The fault turned out to be a faulty MAF in my case.

 

[Bobby Dazzler]

MAF must be a likely suspect. New part from MB is less than £60 and can be fitted easily at home. If it's a few years old, even if the part hasn't yet failed it's best changed. Increasingly becoming a service items.

 

[dokalj]

If travelling at 70mph should the rpm be higher than 3000?

dokalj

 

[FenandGreyDog]

Thank for the advise, I got a MAF from EuroCarParts, as Idrive pass them on the way home from Nottingham, It takes 6 torex headed screw to replace the MAF, 4 on the engine cover and 2 on the MAF. V quick and V easy.

regards!

 

[dokalj]

Thank for the advise, I got a MAF from EuroCarParts, as Idrive pass them on the way home from Nottingham, It takes 6 torex headed screw to replace the MAF, 4 on the engine cover and 2 on the MAF. V quick and V easy.

regards!

Does the car now perform differently?