ML270 CDI Loss of power

[jonny2]

My ML has a problem problem in that when driving the turbo boost is lost until the ign is off for about 5 seconds. MAF/MAS usually give these symptoms when the engine is under load and the power is suddenly lost. Like a madman I immediatley replaced the MAF sensor and guess what, I still have the problem. With my ML its fine providing you drive hard and need boost, as soon as its allowed to cruise and back of the gas all boost is lost until engine is restarted. Not had chance to code read it but now think its more to do with the boost pressure transducer,, Would love to get anyone's opinion., When getting desired boost there is quite a bit of air noise, sounds like a split or leaking hose but cant find any leaks and no loss of performance.. As long as I got boost when I want it then I'll be happy.

 

[rpe2]

Holled intercooler or split turbo pipe.

To hear the noise at standstill, you will need to rev the car in gear with the brakes firmly applied.

Make sure the assistant does not stand in front of the car.

 

[jonny2]

LOL, only if its someone I like,, The noise is there just when revving and without any load but quietens when revs are held steady. Its most apparent on the inlet manifold side of the engine and wondered about split manifold (with it being plastic) or similar but can find no evidence of a leak anywhere, bit baffling..
Regards Jon..

 

[pault8084]

the 270 does suffer blowing inlet gaskets which sound like split turbo pipe

 

[Xtractorfan]

Holled intercooler or split turbo pipe.

To hear the noise at standstill, you will need to rev the car in gear with the brakes firmly applied.

Make sure the assistant does not stand in front of the car.

Why does the car need to be in gear, this sounds dangerous

 

[television]

Why does the car need to be in gear, this sounds dangerous

I think that the turbo only works under load

 

[Stu_CDX]

If it's an auto, I wouldn't be happy revving it at all! Unless it was firmly in park.

 

[television]

If it's an auto, I wouldn't be happy revving it at all! Unless it was firmly in park.

You can do it in D for a max of 20 secs

 

[Stu_CDX]

You can do it in D for a max of 20 secs

Blimey. I still wouldn't do that. I'd think of the strain I was putting on the prop and everything.

 

[television]

Blimey. I still wouldn't do that. I'd think of the strain I was putting on the prop and everything.

This is the way that you do a stall test on the torque converter, its OK for 20secs as said, you do not need to rev it up much

 

[kebo57]

Hi have you tried swapping the transducers over this was mentioned in an earlier thread

Kevin

 

[jonny2]

Thanx guys, great to read your conversation, No need for anyone else to leave comments, I've sorted it myself...

 

[jonny2]

To Kebo57,,
Yeah, I was a bit quick off the mark in changing the MAF sensor, should have investigated further first. I've eventually discovered a leak on the backside of the intercooler. This was giving the loud air leak sound and projecting the sound under the intake side of the motor and so the sensors are correctly reading the intake pressures..
Intercooler repair fixed all,, Regards Jon..