c250 td slow to pull away..

[porka968]

Hi guys, just bought a 98 c250 td. Being silly I got it without ever driving one of these before so I took the guys word for it that the way it drives is how its meant to be. Pulling away with my foot planted to the floor it takes off very slowly and then only from about 3k rpm it starts to move.

I have been doing some research and at first thought that the switch was stuck in the winter mode so pulling away in second, but its not that as I took the whole thing appart yesterday, cleaned it up and its fine and working as it should.

I have timed the car 0-60 and its taking about 14 seconds which is quite a way off the 9.6 its supposed to be.

I took the under tray off to have a look and there are no obvious loose hoses.

From a stop, when you floor it, at what rpm should it start to move ? Im guessing 1800 as thats where the peak torque is supposed to be ?

Any advice would be much appreciated. Thanks, Paul

 

[GazCaff]

They do suffer from a bit of lag on the throttle but yours does sound slow, 0-60 should take just under 10 seconds. Don't really know what else to suggest at the moment (probably because I really should be in bed when I type this!)

I'll see what a nights sleep comes up with and get back to you.

 

[Doodle]

Paul,

When you floor the throttle, there should be a bit of lag as the turbo spools up, and then at 1800-2k an almighty thump as everything wakes up.

It's very entertaining to watch, gives boy racers in their Saxos and Corsa's hope...

 

[jaymanek]

Mate these 250's are very slow to take off, you will get used to it in time though!

 

[KLP 92]

Mate these 250's are very slow to take off, you will get used to it in time though!

Not 14 seconds slow!

I would check all the turbo hoses first, they can start coming away from the jubilee clips. I have changed all the original Merc jubilee clips on mine for heavier duty ones as mine used to come off time to time.

There is a lag till 2000 revs but after then there is enough power. If you superchip the car it does help with the lag.

 

[porka968]

Thanks for the info guys. Like I thought, 2k and it should move, mine only starts at 3k. Ill examine all the hoses again to make sure everything is on tight.

Where is the MAP sensor located ? I had a look at the temperature sensor, and it was a bit oily :S

 

[KLP 92]

Thanks for the info guys. Like I thought, 2k and it should move, mine only starts at 3k. Ill examine all the hoses again to make sure everything is on tight.

Where is the MAP sensor located ? I had a look at the temperature sensor, and it was a bit oily :S

There is a pipe coming form the inlet manifold (black tube) going to a small sensor located on the bulkhead on the passenger side of the car.

the most common place the pipe for the turbo comes off is the pipe that goes across the top of the engine bay, or the base of the radiator, bottom passenger corner. There are a few hoses only accesible from underneath the car. Even id the hoses look like they are on, run your hand around the jubilee clip as the pipe can half come out.

The best way to check is wind your window down and accelerate. At 2000 revs you should hear leaking air, like a hoover type of noise if your hoses are leaking.

 

[KLP 92]

Otherwise i would look at the turbo actuator. Its located on the side of the air filter box.

 

[GazCaff]

Paul,

When you floor the throttle, there should be a bit of lag as the turbo spools up, and then at 1800-2k an almighty thump as everything wakes up.

It's very entertaining to watch, gives boy racers in their Saxos and Corsa's hope...

Yep, lol

 

[Dieselman]

Check the injection timing and the boost pressure.

 

[GazCaff]

Don't want to patronise you, porka. But are you positive it's a Turbo model and not a n/a model?

 

[porka968]

lol, I can clearly see the letters GARRETT on the tubocharger Admittedly my other car is a 911 so of course it will feel slow to me, but Im sure its supposed to be faster than what it currently is !

 

[GazCaff]

lol, I can clearly see the letters GARRETT on the tubocharger Admittedly my other car is a 911 so of course it will feel slow to me, but Im sure its supposed to be faster than what it currently is !

Sorry about that, I didn't know how clued up you were. I would follow KLP 92 advice and look for a blown off pipe on the inlet tract. A blown off pipe will cause a big power loss.

 

[Glenn Smith]

Well i drove one of these and, ok it wasn't a real scorcher, but i was impressed with the performance they shoul have plenty of torque and 150bhp, there could be various causes ie blocked intake or exhaust, faulty turbo, leak on intake side, fuelling problem, egr fault (if it has one). You're best bet may be to take to an MB shop, they have the experience and tools to check everything. (after checking all the obvious things, hoses etc.)

 

[mark.t]

Hi guys, just bought a 98 c250 td. Being silly I got it without ever driving one of these before so I took the guys word for it that the way it drives is how its meant to be. Pulling away with my foot planted to the floor it takes off very slowly and then only from about 3k rpm it starts to move.

I have been doing some research and at first thought that the switch was stuck in the winter mode so pulling away in second, but its not that as I took the whole thing appart yesterday, cleaned it up and its fine and working as it should.

I have timed the car 0-60 and its taking about 14 seconds which is quite a way off the 9.6 its supposed to be.

I took the under tray off to have a look and there are no obvious loose hoses.

From a stop, when you floor it, at what rpm should it start to move ? Im guessing 1800 as thats where the peak torque is supposed to be ?

Any advice would be much appreciated. Thanks, Paul

when you say floor it do you take it to the kick down button (i take its auto?)

also check your S/W is not in W mode ..........press the peddle right down till you feel like you pressed a button.......mine winds up about 1800 then she flys not bad for a nearly 2 ton lump with a roof box e 300 td....the looks i get as i fly past em

and some times with my caravan on .how there jaws drop

 

[porka968]

when you say floor it do you take it to the kick down button (i take its auto?)

also check your S/W is not in W mode ..........press the peddle right down till you feel like you pressed a button.......mine winds up about 1800 then she flys not bad for a nearly 2 ton lump with a roof box e 300 td....the looks i get as i fly past em

and some times with my caravan on .how there jaws drop

It is auto, and yes, I do mean kick down.. Ive already checked the s/w switch, and its working fine. Im tempted to change the MAP sensor to see if it might be the cause, but at over £50 I dunno if its worth the chance..