Jerky driving at slow speed in D3/D4 - C5 X7

[steveclv]

I improved the drivability of my C5 X7 138 FAP with the new engine mounts but on my daily drive through a 20mph town over speed bumps, the engine seems quite jerky - usually when it's in D3 or D4 (auto). I have been reading about the EGR valve and wondering if this might be misbehaving? It's got 166,000 miles and no evidence in the servicing records that it has ever been touched.
I'm tempted to get a blanking plate to test if that fixes the problem before I dig around trying to remove it for cleaning.

Does this sound like the symptoms of a faulty EGR - acceleration, economy and idle all seem to be good.

[GiveMeABreak]

That would not affect the vehicle going over bumps. If the EGR was blocked or faulty you'd have a warning lamp being triggered most likely. The EGR has a self-clean test every time the engine is stopped to help prevent sticking, but there would probably be some other symptoms if this was faulty that would cause the vehicle to go into limp mode at some point.

I'd be running a diagnostic to see what is coming up, but it may be something to do with the gearbox - when was the auto gearbox oil last changed?

[steveclv]

Nothing coming up in Diagbox - it's not the bump itself causing the problem, it's the feathering of the throttle in D3 as you approach the bump - it just seems jerky when going on/off light throttle. It might be just the way they are as I have been used to automatics in the USA which seem to have much more use of the torque converter in lower gears to smooth things out. On a manual you would be using the clutch to do the same thing.
If the EGR is monitored by the ECU then I can probably tick that off the list of culprits - thanks

No evidence in the service records of the autobox oil ever having been touched.

[GiveMeABreak]

That's the first place I would start then - a complete auto box oil change. Despite being 'sealed for life' they are not and will deteriorate over time if the oil is not changed. You can only do a partial change as 4 of the 7 litres remain in the box, so you can only change about 3 litres at a time. So best practise is to change once, allow the oil to circulate for a few weeks. then do another change and repeat a third time after another few weeks to get as near a complete change as possible.

The Oil wear counter has to be reset each time, so the gearbox can reset it's auto adaptives each time.

This chap gets more oil out by removing the other part of the grain sump, which means he's done it more or less after a few attempts in situ. It's the same gearbox on the Volvo if you have the AM6 gearbox:

[steveclv]

Thanks - sounds like a plan - do you know offhand which fluid I need - 2009 C5 X7 138 FAP

I've watched a video of the C5 partial change previously so it's not too scary
I also watched a french guy using an adaptor that screwed onto the autobox oil cooler and used the internal pump to pump fluid out but I'm not going anywhere near that

[GiveMeABreak]

I'll need your VIN - the oil is specific to the Euro level.

[steveclv]

It's on my thread below - otherwise I'll have to go to the car to get it and it's raining cats and dogs and a major thunderstorm atm

Re: C5 X7 fault codes - can anyone advise plz?
Post by steveclv » 06 Jun 2024, 22:23

[GiveMeABreak]

Ok, got it.

Your vehicle is actually Euro 4, so in this case you need JWS 3309 oil.

[steveclv]

Thanks - now to see how much it's gonna cost me

[steveclv]

OK, not so bad - about €11 a litre but can you cast your eye over this as it looks to be JWS 3309 but that's cheap and 20L would be enough for several changes to clear it all out. Thanks!

https://www.auto-doc.fr/chempioil/15769407

[steveclv]

Now I am even more confused - started looking at more expensive fluids such as https://www.mobil.fr/fr-fr/products/con ... ti-vehicle

In the spec sheet where it lists the manufacturer and the quality level it says

Aisin Warner :- JWS 3309 (T-IV) & ??JWS 3324 (WS), AW-1

So does that mean that this can be used in both Euro 4 and Euro 5 autoboxes?

Now I really don't know what to put in there - the cheap stuff or the expensive stuff

[GiveMeABreak]

You can't use JWS 3309 oil in a Euro 5 Engine vehicle. JWS3324 should be ok though.

[steveclv]

We already agreed that mine was Euro 4 so the choices were the cheap JWS 3309 oil at €4 a litre but then I found the Mobil one at €17 a litre which says that it is JWS 3309 AND JWS 3324 compatible.
That's what confused me.
So should I use the cheapest one or the more expensive Mobil one?