Merc Turbo Not Working?

Vita · 21 Jul 2007 at 11:51

Hello all,

Have a Y Plate C220 CDI Auto Estate,

This has been going on for quite a while now. Seem's like the Turbo in the car isn't working. I'll floor it and it's just redline and no pull/torque? Gear changes are sluggish and tthe whole car feels slow.

Someone told me it could be because the MAF (Mass Air Flow) Sensor is buggerd, could this be the problem?

Thanks.

[huzeeee] · 21 Jul 2007 at 12:36

If the MAF is buggered then it should run on "limp home mode" where the car feels slower and less smooth but the engine internals are safe on this setting. Are huge plooms of black smoke pouring out, thats usually a pretty surefire way of seing if your turbo has gone/loss of pressure.

Vita · 21 Jul 2007 at 12:39

[huzeeee] said:
If the MAF is buggered then it should run on "limp home mode" where the car feels slower and less smooth but the engine internals are safe on this setting. Are huge plooms of black smoke pouring out, thats usually a pretty surefire way of seing if your turbo has gone/loss of pressure.

Yeah that's what I think it is in, feel a lot lot slower. Even when you put your foot down, it takes ages for it to pick up speed. Black smoke does come out quite a lot actually, just seems there is a huge loss of pressure.

divine` · 21 Jul 2007 at 12:46

I know on VAG cars if you disconnect the MAF it runs better (only a bit, but noticeably so) than with it should that be the problem. Not sure if the same applies to the mercs.

[huzeeee] · 21 Jul 2007 at 13:05

Lots of black smoke means loss of pressure and the smoke is the diesel not burning. This could be as bad a knackerd turbo or as simple as a loose hose. I would get it checked out if i were you asap

Vita · 21 Jul 2007 at 14:00

It's not too much, when the car revs doesn't come out, when you release the pedal then some does.

MagicBoy · 21 Jul 2007 at 15:57

Surely if it's buggered then the ECU will trip some sort of warning. The VWs tend to give an emissions warning when the MAF is stuffed. No nasty flashing lights on the dash?

Vita · 21 Jul 2007 at 19:54

MagicBoy said:
Surely if it's buggered then the ECU will trip some sort of warning. The VWs tend to give an emissions warning when the MAF is stuffed. No nasty flashing lights on the dash?

Nah no warning from the ECU. I'll have to get it hooked up to a STAR and see the outcome. Read a couple of forums saying most likley MAF and needs cleaning/replacing.

bmh.01 · 21 Jul 2007 at 20:07

Can you hear the turbo spool up?

Vita · 21 Jul 2007 at 20:09

Faintly yes, only when reving, it's really faint but you can hear it. At high revs when driving, all you can hear is the diesel engien being noisy lol.

MAF's buggerd, so don't think it's allowing much air to go in, if that's how a turbo works?

5tephen · 21 Jul 2007 at 21:26

My dad has a C270CDI, same model as yours, and the exact same thing happened with him. Air flow sensor.

Vita · 21 Jul 2007 at 21:27

5tephen said:
My dad has a C270CDI, same model as yours, and the exact same thing happened with him. Air flow sensor.

Cheers, I'll have to sort that out then.

MagicBoy · 21 Jul 2007 at 23:59

Vita said:
Faintly yes, only when reving, it's really faint but you can hear it. At high revs when driving, all you can hear is the diesel engien being noisy lol.

MAF's buggerd, so don't think it's allowing much air to go in, if that's how a turbo works?

The MAF doesn't let the air in, just measure's how much air is going into the engine and the temperature of it so the ECU can give the optimum combustion.