Astra SRi CDTi Problem

**Tippy** · 30th January 2011, 12:43

Hi all, A couple of weeks ago I noticed when I was pulling off my Astra was struggling to pull off due to a lack of power, however the engine management light was not coming on. I just thought I had some dodgy diesel so I put some cleaner through the system which I hoped would cure it but it hasn't. Now occasionally when I am driving, the car seems to go into limp mode again without the engine management light coming on, also again occasionally when I start it from cold it has trouble starting! very frustrating! Any ideas? Cheers.

**mark_647** · 30th January 2011, 12:46

Is it the 1.9 and also, is it 120 or 150bhp mate?

Sounds like it could be the EGR valve. They become 'clogged' and can really inhibit the power and also put the car into limp mode.

**Tippy** · 30th January 2011, 12:48

Thanks mate it is the 1.9 150bhp. Big job?

**mark_647** · 30th January 2011, 12:59

No, I wouldnt say so mate. Its very easy to get too, open workspace. You could just replace it or take the valve apart, clean it all and make sure the insides work freely. Whilst your there, you could also clean the boost sensor, fragile but easy enough aswell.

This I think is the most common cause of low power on the 150bhp.

Hope this helps, im sure someone else will offer some more advice soon too

**Tippy** · 30th January 2011, 13:03

Thanks for your help Mark!

**GazVXLINE170** · 30th January 2011, 13:08

The EGR valve normally is shut on idle - so if it's open, starting will be a problem and if it manages to idle it will be lumpy and rough. EGR valves don't normally put the light on if they are jammed open as the ECU has no way of measuring valve position. So it may run like it's in limp mode but it's simply lossing pressure via the EGR valve being open. If it was stuck shut the opposite would happen - cracking repsonse and power but the EM light would come on with no limp mode as the EVU is not detecting any EGR flow. It measures EGR flow via the MAP sensor (high pressure reading). On ealier CDTI 150's I believe it measures this via the MAF - when the EGR valve is open the MAF reading drops.

Gazza4

**Tippy** · 30th January 2011, 13:18

Cheers Gaz sounds like a garage job to me!

**GazVXLINE170** · 30th January 2011, 13:20

The EGR valve on the 1.9's is very accessible. It sits at the top right of the engine - when you take the vanity cover off. Check the How2 out and make sure if you're going to do it buy new gaskets too.

Gazza4

**Tippy** · 30th January 2011, 13:39

If it was plugged in Gaz would the problem be confirmed on a diagnostic check?

**GazVXLINE170** · 30th January 2011, 13:45

Originally Posted by Tippy

If it was plugged in Gaz would the problem be confirmed on a diagnostic check?

A stuck open EGR valve usually doesn't leave any fault codes as there is no position sensing on it. The only way the EGR valve would leave a fault code is if it is jammed shut.

Like said it sounds like it is the EGR valve and probably is but EGR faults also share their symptoms with injector/fueling problems - I doubt it's these btw.

It's upto you if you want to clean it, but I say it's really only temporary measure.

Gazza4