Diesel engine symptoms/help!

[NTECUK]

The engine management closes the EGR when power is needed.ie acceleration test on the Mot .
You need as much O2 as possible.
Venting exhaust gas back to the intake is to slow the combustion burn ,so lower combustion temp reducing oxides of Nitrogen (NO x) that produce Smog in unique atmospheric conditions.

[Mark_h]

My old BMW 3 series 320d had 150k on it and was running like a pig when cold at low revs. Some google-fu suggested the mass air flow sensor (MAF) this is a thing that measures the volume of air coming in and effectively sets the mixture.

MAFs are not cheap but on the BMW (may be the same on the ford) the diagnostic was to disconnect it entirely, simple unplug, and see if it got better or worse or stayed the same. If it got better or stayed the same then look into your MAF. If it got worse. look elsewhere.

On the BMW the MAF connector is held in place with a security torx for which I have the correct tools to remove if you need then. else hammer and screwdriver to the little pin then a normal torx (spiky alan key) takes them out.

If the diagnostic suggests your MAF if duff, then some careful googling required as to how to clean it. Or for me I just cleaned all the soot off, put it back and full power was resumed.

Later I had issues with a flange widget thing that fed exhaust gasses back into the inlet manifold causing a huge flat-spot when cold. The fix for this was to remove the vacuum pipe that fed the valve, blank it off (golf tee works well, see Thunderputter for some) and again full power was resumed and MOTs still passed. I think it was diverting too much exhaust gas away from the turbo which stopped the turbo getting up to speed or something like that but it had variable vane turbo blades and other mystical stuff going on so who knows.

Basically just keep disconnecting emissions stuff until it either gets better or goes bang. If it goes bang chances are the problem used to be where the big hole now is.

[Fallout]

Good stuff Mark. Think it may be time I bought a Haynes for this wagon. I keep buying them for cars and never using them! Did yours produce any smoke with these issues or was it just power related?

[Mark_h]

Originally Posted by Fallout

Good stuff Mark. Think it may be time I bought a Haynes for this wagon. I keep buying them for cars and never using them! Did yours produce any smoke with these issues or was it just power related?

Never much smoke just massive flat spot. To the extent you had to rev the nuts off it for a clod hill-start. If it came off turbo was like driving a milk-float.

Haynes won't cover this sort of diagnostic as for each piece of emissions stuff you blank off another penguin bites the dust. But I hate penguins anyway so all good.

[NTECUK]

http://www.ebay.co.uk/itm/EGR-VALVE-...e2b7aac&_uhb=1

[Mark_h]

Originally Posted by NTECUK

http://www.ebay.co.uk/itm/EGR-VALVE-...e2b7aac&_uhb=1

Or if it's the same as the BMW just disconnect the vacuum pipe that opens the EGR valve with one of these blanking devices

[flymo]

I had very similar symptoms on my Transit last year. I removed the inlet manifold and it was choked full of crap from the EGR valve. Cleaned it out, blanked the EGR valve and its run beautifully since.

[NTECUK]

I don't work on Fords or BMW .
All our EGR systems are electronic.
So we blank them off . Tin snips and a drill plate fashioned in 5mins .
We had one so bad the truck wouldn't start !
We found most you can clean up and get working .
Airflow meters we have not allot fail.Only one but looking on live data it stopped at 2.6volts
VW are known to smoke caused by Airflow over reading .

Well Si I have one piece of advice when it comes to diesel fords, as you know I've recently binned mine after owning two derv mondeo's I decided (a clutch plate deciding to explode did help) to stop being tight and bought a V6 petrol! Much better...........watch this space for "oh dear I've blown my engine" type threads!

[Fallout]

Luckily, clutch in the Mondeo seems good. No noise. No weird feel. Pedal is lower than a low down low thing from the lowlands. Bites sooner than a rottweiler on fire etc etc. Exhaust is a bit corroded but not blowing. Can't think of any other probs. So really it's only this engine issue. BUT would definitely give a thumbs up to the V6 petrol.

Thanks for the EGR valve advice gents. At the cost of that blanking plate I might as well do it anyway and see what the results are.