New EGR didn't solve problem

[Liz65]

Just paid out �180 + labour to have new EGR valve fitted to 2002 Renault Scenic 1.9 Diesel (not turbo). Problem still exists - reduction in power when accelerating to get up slight incline at 60-65mph. Heat lamp also comes on. Going back in next week for further tests, but mechanic didn't sound too confident that he would find a solution. Does anyone have any idea what the problem is. Can't afford to be forking out that sort of money for no result. Many thanks.

[logic]

Hi, LIZ 65
just been reeding your earlier post, firstly, understand one thing, the EGR vave does not push air into the manifold, it merely allows some of the exhaust gas to be let in to be reburnt, so not really a performance enhancer,in fact mine is disconnected altogether, i just put it back for MOT to help with emissions,when you say heater light comes on ,are you refering to water temp, or glow plug preheat,?
I suppose you have checked the obvious,
1. fuel filter.
2.air filter, ( very important,)
also look in cars section, Marvinmoons problem,
sat. 08/08/09 19;45.
post a reply here to let me know how it goes.
Pete.

[rnchugg]

Hi, had a similar problem on another make of car, was diagnosed as being the maf or map sensor (mass air flow) simple test, disconnect it. if it improves dramatically whilst disconnected get it replaced, if not the no money lost. Most sensors are located next to the air intake box. With my car it went from being a snail to a cheetah by just disconnecting the maf sensor, They are not that expensive and its a VERY quick job to replace them. Please let me know the outcome. Good luck.

[Liz65]

Thanks Pete, I had already seen marvinmoons, but not the same problem. Mine only happens when the engine is under pressure i.e. driving along on the level at say 60mph, come to an incline, not necessarily steep, accelerate slightly, glow lamp preheat comes on at the same time as the engine loses power. Once I'm back on the level, lamp goes out and acceleration back to normal. It's alright when the road ahead is clear and I can get up enough speed to get me up the incline beforehand, but, of course, this isn't always possible. Mechanic diagnosed it as egr clogged up and gave it a good clean, which was alright for a short while, but it started again, so I said put in a new one which has not made one iota of difference. Liz.

[Liz65]

Thanks rnchugg, but as you can see from above, it's not really a performance issue as such. This only happens in specific circumstances. Liz

[logic]

hi again Liz65
sorry I can't throw any light on your problem, but am still racking what bit of brain i have,
That preheat light would bug me until i knew why it was coming on, It shoud'nt come on untill the switch is operated, thus i am half convinced that you have an electrical problem,
I know a diesel doesn't need electric for combustion, but it does need it to keep the injector pump working, thus if there is a fault it could well be interfering with fuel delivery, if that makes any sense to you, If you haven't solved it yet, I would suggest an electrical engineer to check it out for you, iether way,
Keep me informed, please,
Pete.

[Liz65]

Thanks Pete, it's going in on Monday, so here's hoping I have something to report. Liz

[hughjass]

Hello Liz, there should be some fault codes stored if your mechanic has the necessary equipment. My money is on the mass airflow sensor.

[Liz65]

Thanks everyone for all your input. Got car back on Tuesday, but, unfortunately, haven't had the chance to give it a good workout, mainly due to atrocious weather in the Borders, so I don't know if problem is fixed. Mechanic seems to think it is. He checked EGR and found it OK and did a few other things, including codes, but I got the impression that he's none the wiser as to the cause. Will keep you posted. Liz