w124 E320 intermittent power loss

[ncundy]

I have 1994 E320. Engine runs fine a smooth, but it has started to suffer intermittent power loss.

Revs start to drop about once every couple of minutes (both when at idle and under power). Unless at idle it doesn't stall, and it can be caught with the throttle.

I've done a search but can't find anything that really seems the same.

It doesn't misfire, it's as if the engine is just dying. It's had a replacement loom in its time.

Any clues as to where to look??

 

[kth286]

Does you car have EGR valve which may be getting clogged.

EGR = exhaust gas recirculation.

Ideally you need to read the fault codes stored in memory - where you based ? as some members have that facility for your generation of car.

 

[ncundy]

Thanks,

It has the charcoal filter in the wing and a small valve with MOT stamped on it that takes a feed from the filter and seems to pump it into the inlet manifold. How would I tell if it's blocked?

I'm in Derby.

 

[kth286]

Thanks,

It has the charcoal filter in the wing and a small valve with MOT stamped on it that takes a feed from the filter and seems to pump it into the inlet manifold. How would I tell if it's blocked?

I'm in Derby.

Not the same thing, but does that valve on inner wing tick/pulse when engine is fully up to temp.

Should pulse approx 2 beats per second.

It is for the fuel tank vapours.

THE EGR is near the exhaust and there will be some gubbins under the front engine top plastic cover.

This system was stopped at some point as my late 95 car does not have it, but I have seen plenty on earlier 320s.

 

[BlackC55]

It could be a faulty air mass sensor?

 

[coupe deville]

could be this, that or the other you need to blinking blink

 

[ncundy]

The problem was the MAF. New one in and everything fine.

However now have another problem! Even with the ignition off there is a whirring from the engine bay, rather like a computer fan. Seems to be coming from the inlet manifold area. This is draining the battery. Any idea on what, where and why??

Thanks

 

[carat 3.6]

Electronic throttle body?, coolant lift pump for heater?

 

[ncundy]

Yep, definitely coming from the throttle body.

What's in there that could do this ?