230SLK won't high rev :(

[David Caple]

Hi, this is my first post so I hope I'm following protocol.

I bought a 1998 230SLK just over a year ago, picked it up very reasonably with a fault but 99.9% driveable so have lived with it but on finding this forum thought I would see if I can get any pointers.

Basically the engine will not go past 'middle' revs. 4,000 in neutral but only 3,000 under load. So I can't use kick-down and have learned to accelerate up to 3,000 ... ease off to force an up-change and then accelerate again! Has anyone else come across this problem? Frankly the car is not worth taking to a dealer, their bill will be more than the car's value but I don't want to chuck it, it's a lovely car in (almost) all other respects.

 

[Blobcat]

Hello and welcome,

Mercedes won't rev past 4,000 in neutral as an engine safety

If it's not revving when in drive then you're in limp home mode, you really need to get the codes read to ascertain what the issue is rather than throwing parts at it.

Post up where you are as there's some very good indies on here that can fix and repair for much less than a dealer and go straight to the issue.

 

[David Caple]

I'm in Heathfield, East Sussex. Note I said "only 3,000 under load" ... if I coax it up and not force it it will go over the 3,000 revs to 4,000 and it will still reach nearly ***mph so I would consider it "limp mode"!

 

[Uncle Benz]

I’m in Billingshurst. I’ll plug the Star on it if you want to pop over sometime

 

[00slk]

We had the exact same issues with our 2000 SLK, it was put on star and came back with MAF senor fault.
We replaced the said MAF sensor and this fixed the problem.

 

[Blobcat]

I’m in Billingshurst. I’ll plug the Star on it if you want to pop over sometime

This

 

[bembo449]

cant you unplug the MAF on MB cars like you can other makes to diagnose ?, it should rectify the problem and confirm a new MAF required without plugging in

 

[moosehead]

We had this on the wife's 1999 SLK230 several years ago. No faults shown even when on STAR. I tried disconnecting the connector, cleaning MAF, etc. but no difference. They don't seem to last for ever / possibly go out of spec. I had to replace the one on my C230 4 years ago so 10 years seems to be about their life. It really makes a difference to performance and economy when replaced as they seem to get progressively worse over a period of time. Make sure you get a Bosch one. Probably half the price of the same unit in a MB box!