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Mon 1 Nov 2004 15:18

Renault Scenic DCi100 problem - PhilG

Hi all,

I'm the driver of a fairly new company car (~3 months old, 6600 miles), a 1.5l turbo-diesel Renault Scenic 2004.

This is an ongoing saga and I would appreciate any advice anyone can give!

Back on the 24th September, I was travelling to Reading when the car started losing power, hesitating and "chugging" at a certain throttle position, accompanied by clouds of smoke from the rear of the car.
The car was towed back to a Renault garage, where they diagnosed a turbo fault and two weeks (!) later a new turbo was shipped in and fitted.

I took the car home, and brought it back the next day- exactly the same fault.

The garage kept it for another two weeks, constantly telling us that because there was no fault code showing, they couldn't find the problem. Eventually I got fed up, and took the car out for an ~80 miles journey, as it only seems to do it after being on the road for about two hours minimum.

The problem re-occured, and I managed to get an "engineer" to come out with me to experience the fault. This he did, and they kept the vehicle in, and made a "Technical Report" to "Renault Technical" (sigh). *Two weeks* later, we get a call to say that the car's ready, and they've replaced the throttle potentiometer and one other item, the name of which escapes me.

Picked it up Friday just gone, took it home for the weekend, no problems. Excellent, I thought, they've finally fixed it.

Fast-forward to today, where the car does exactly the same thing again, in Hertfordshire. I was able to nurse the car home to the South (I travel a lot, mobile engineer for a computer company, so this car is our lifeblood), and, furious, demanded that someone came out from the garage with me to experience the fault again. Apparently they're all at lunch, so I logged with them that it's happening *again*, and the mileage of the vehicle.

I won't bore you with the details of what's happening with the lease company, but suffice to say that Renault UK, IMHO are being a bunch of useless idiots.

I'll summarise the problem below:

(After two hours minimum continuous driving, the speed doesn't matter)

Pushing the accelerator ever-so-slightly beyond "cruising" level results in a hesitancy in the car. Pushing the pedal a little further causes the hesitancy to worsen, and a loss of power is experienced (not a great deal, but definitely noticeable).

Gently and slowly pushing the pedal to the floor results in a large loss of power- if you're on the flat, it's okay, but anything more than that and you find yourself slowing down. At this point, clouds of what look like grey/black, sometimes blue-ish smoke appear in the rear-view mirror. It's difficult to tell what colour it is, to be honest.

Jamming your foot down hard the last inch or so causes the car to "wake up" and off it goes; turbo spools up and the power returns.

However, once the problem has occurred, it's almost impossible to get the car to stop doing it, short of pulling over for half an hour to allow it to cool down.

Can anyone offer any help? I'm at my wits' end here, and right now I'm contemplating taking a fire axe to it, and the garages "engineers"!

Many thanks,

Phil

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Mon 1 Nov 2004 15:26

Renault Scenic DCi100 problem - Altea Ego

It sounds like a sticky EGR valve.

You really have to lean on the the leasing company here. Its Their car. Your company is paying for the use of a car via the leasing company, so you will hire a car at their expense until the problem is fully resolved. The leasing company are in breach of their contract if they take the monthly lease and dont have the car availble.

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Mon 1 Nov 2004 15:32

Renault Scenic DCi100 problem - PhilG

Oh, they're providing a hire car at Renault's expense, forgot to mention :)

However, it's a crappy gutless 2004 Avensis "1.8" (scoff), and without sounding picky, I *hate* it- nothing like the Scenic.

I digress.

The AA guy did mention the EGR valve, and I have seen that this was a fairly common problem among the older Scenics, but the problem with this is that the garage won't replace anything unless they get a fault code.

However, I have the Autolease terrier on the case, and he's speaking to one of the Renault managers.

Do you know roughly how much an EGR valve is, and how much to fit? I'm seriously tempted to get it changed and bill Renault along with a stroppy letter!

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Mon 1 Nov 2004 15:48

Renault Scenic DCi100 problem - Number_Cruncher

I think RF's suggestion of EGR valve is a very good starting point.

If your current Renfault dealer won't change it without the fault code;

a) go to a better dealer

b) disconnect the EGR wiring plug, drive around 'till the light comes on, reconnect it, and drive it in to the dealer.

As EGR valves tend to accumulate sticky deposits, and deposit formation is highly temperature dependent, try to vary your driving technique to either raise or lower engine temperature. This may be enough to allow the valve to free off.

Some manufacturers are now including EGR valve cleaning cycles in the engine management software strategy. It may be worth checking your car is running latest software.

number_cruncher

p.s. I am pleased that you put quotation marks around the word "engineer". I would be amazed if they can even claim the title of technician - they are most likely mechanics. The sloppy adoption of the title engineer by those who don't deserve it really winds me up!

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Mon 1 Nov 2004 15:54

Renault Scenic DCi100 problem - PhilG

Thanks for the suggestion- how do I find the EGR plug in the engine bay?
I'm familiar with the older types of engines, but this one's a mass of wiring and plastic covers (sigh).

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Mon 1 Nov 2004 16:10

Renault Scenic DCi100 problem - PhilG

Right, I just spoke to the garage, asking if the EGR valve was replaced or checked during the last six weeks, and apparently the computer in the car's recording that all the readings from the valve are "within tolerances", which suggests that it's working.

I did ask if they could take the valve out and physically inspect it, but was told that you can't see anything much inside them, especially at this low mileage, where it should be squeaky-clean anyway.

Any thoughts anyone?

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Mon 1 Nov 2004 16:14

Renault Scenic DCi100 problem - cheddar

NB suggestion b/ is a bit dodgy, I agree that it sounds like EGR though what if it is not, the dealer (however good) would be completely confused having been sent on a wild goose chase.

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Mon 1 Nov 2004 16:26

Renault Scenic DCi100 problem - Number_Cruncher

I agree that suggestion b is a bit dodgy, but in waiting for a fault code before any action, the dealer is being more than a bit obstructive.

In terms of confusion, if EGR valve work doesn't fix the fault, don't get confused, move on to consider other possibilities! It's not difficult!

In particular, they are being very short sighted in beleiving that for their to be a fault there *has* to be a fault code. I think some younger mechanics are over reliant upon computerised diagnosis.

It is, of course possible for a part to fail to work well enough for the engine to run properly, but not be sufficient to put on the engine management light.

number_cruncher

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Mon 1 Nov 2004 16:50

Renault Scenic DCi100 problem - PhilG

Very true number_cruncher; however, good news.

After talking to the lease company for some time, Renault UK have finally decided to "terminate" this car and provide a new one. Certainly good news, but I am still curious as to what caused the problem.

Sigh.

Thanks for all your help guys :)

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Mon 1 Nov 2004 19:06

Renault Scenic DCi100 problem - Dynamic Dave

PhilG,

I've edited this thread to remove all reference to the garage you refer to. I'd be grateful if you didn't mention their name in future, but to simply refer to them as "the garage".

Please see "The Small Print" for future clarification of our no naming / shaming policy. www.honestjohn.co.uk/credits/index.htm

DD. BR Moderator.

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Mon 1 Nov 2004 20:41

Renault Scenic DCi100 problem - cheddar

Wonder if you could wangle a 1.9 DCi 120, more punchy, almost as economical.

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Mon 1 Nov 2004 21:18

Renault Scenic DCi100 problem - Altea Ego

Yup the DCi120 is a peach of an engine, and in the scenic there is very little difference in the fule economy (the scenic being a bit brick like needs the extra punch the extra 20 horses brings, and does not need to be worked so hard)

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Tue 2 Nov 2004 09:02

Renault Scenic DCi100 problem - cheddar

It is the 50% extra torque that is the key, the 1.9 produces 300nm against the 1.5's 200nm.

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Mon 1 Nov 2004 19:49

Renault Scenic DCi100 problem - AndyT

Quote : "b) disconnect the EGR wiring plug, drive around 'till the light comes on, reconnect it, and drive it in to the dealer."

I've had the EGR unplugged on my '01 Clio dci65 since not long new, no fault codes have ever appeared.

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Mon 1 Nov 2004 20:49

Renault Scenic DCi100 problem - Number_Cruncher

Quote : "b) disconnect the EGR wiring plug, drive around 'till

the light comes on, reconnect it, and drive it in to

the dealer."

I've had the EGR unplugged on my '01 Clio dci65 since

not long new, no fault codes have ever appeared.

Lucky you!, as you may know, these valves cause quite a bit of trouble. I'd like to disconnect the one on SWMBO's Astra, but I know the light will come on. I need to make up a blanking gasket to allow the valve to move, but not to admit any exhaust gas.

number_cruncher

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