Vauxhall Zafira B 2004 Engine Management Light Query

jmt12345

Hi there, wondering if anyone might help shed some light on a recent problem with our 2000 litre turbo 2004 diesel zafira.
The EML has started to come on intermittently and causes the car to go into limp home mode. I have noticed that this only happens when the car drops down to idling and occasionally seems to kick itself out of the mode, suddenly going off and full power back. It seems fine on motorways - I drove for several hours down the motorway without a single incident, yet as soon as I pulled off and sat at a roundabout, it came back on again.
I can temporarily 'fix' it by switching off the engine and immediately back on.

Last time we had an EML problem, it resulted in an expensive EGR replacement (about 2 years ago). That time, the light stayed on and the fault 'feels' a bit different - or is that me wishing it will be a cheaper/simpler fault?! The mechanic was great, despite the cost, but is no longer working so can't take it back to the same chap.

My husband checked the codes with an electronic reader but nothing showed up. I understand not all faults can be read.
Any advice what to do/try next will be greatly appreciated.

n217970

Sounds like a sticky EGR valve - I used to have this all the time on a 2006 Focus - except mine used to manifest itself during overtaking manoeuveurs, but rather then replace the valve I removed it, cleaned the insides using petrol (not recommended) and it was good for another 30k miles.

jmt12345

Thanks for your quick reply, much appreciated.
I was so hoping you would say it was something a little more simple! As it has a fairly new EGR valve, I think your advice to consider cleaning it first sounds very sensible. Will look into locating, removing and cleaning it.

n217970

If its still fairly new (less then 30k miles on it) then you would hope it is not clogged up yet...

Edit: just seen 2 years ago - quite possible then.

Strider590

The primary causes of EGR problems (the sooty/oily deposits) are not servicing to schedule, using cheap/nasty engine oil, driving like an old fart, short journeys or a combination of any of these.

Poor engine oil quality (either old or cheap) in particular causes excessive oil vapour to be passed into the engine inlet manifold to be burnt in the combustion cycle (a requirement for emissions), the more dense this oil vapour, the faster it cakes up important components in the inlet (throttle valves etc) and exhaust system (EGR valve and lambda sensors).

jmt12345

Thanks for the info. The car has been regularly serviced but has done almost 150k miles so is 'well loved'.
We plan to dismantle and clean the EGR fully tomorrow to see if that does the trick - numerous youtube videos have provided some guidance and boosted my confidence in having a go ourselves. I think a complete oil change at the same time might well be in order as I have no idea of the quality of the last batch of oil in the previous service.
Thanks again.

jmt12345

Quick question if anyone with any relevant knowledge is about:
We have taken out the EGR valve and cleaned it up. It is now ready to be refitted.
Should it have some kind of sealant gasket?
There was no gasket there but we did see some gooey yellow sticky residue and now wondering if there was a 'liquid gasket' sealant type stuff there (sorry not very technical terms there). My husband was a little surprised no metal gasket and I am just in the dark.
Don't want to refit it if there needs to be some kind of sealant in place. I have looked all over the net and not found any reference to refitting one with or without and worried that we might make the situation worse if we refit it badly.
Any advice would be greatly received so that I can get my car bonnet down, hands cleaned up and go and do my shopping!

unforeseen

I had a Savita that did that. Never got to the bottom of it so got shot of it.

n217970

You would indeed expect there to be a metal gasket, are you sure it has not been left in the hole the valve sits in? It does sound like your mechanic may have used a liquid gasket when he fit the new valve.

jmt12345

Thanks for the confirmation of the liquid gasket - relieved to hear that my presumption wasn't completely off the mark.
After much searching and squinting at online images of old EGR valves, it looks like many of the zafira EGR valves are fitted with an O ring rather than a metal gasket - although if anyone knows differently, please let me know.
Quick update: cleaned up nicely (although it wasn't as bad as I had expected), cleaned up the hole the valve sits in, removed all the sticky gunk, cleaned up the contact points, changed oil etc.
Nervous switch on - success! No EML!! Drove around, deliberately picking a route with plenty of low rev stop/start points and not even a flicker. So far so good.
Anyone reading this thread wondering if it is worth having a go at cleaning up an EGR valve or just taking to the garage: have a go yourself. It really is worth the effort and cheaper than a garage fitting a new one on spec.
Thanks for your advice,n2127970, much appreciated