RA7 Rodeo intermittent rough idle

Kevin, does it feel like it's a bit of a fuel issue...running rough, slight surges as if your fuel filter was blocked.

It may be the suction control valve in the fuel system. I've had the same issue for six months now and it throws some very different fault codes. It's been a bastard to nail down due to its intermittent nature. It may also be a slight fault somewhere in a fuel line or an injector casing that allows it to suck air. This may throw a "Large Fuel leak" fault code.

I'm not familiar with the Rodeo. Does it have twin tanks. Does it run roughly on just one tank or on either? Does it play up more regularly if the tanks are low?

I'm thinking something in the fuel system,

The best bet is to have it to a mechanic and leave it with them for a few days. They can start the vehicle several times a day until the problem occurs and then slip the computer onto the OBD port to analyse any fault code. That's the surest way.

Cheers and good luck with it.

Mick

RUK 42

Problem maybe a crook injector
Got to love CRD .

Cheers

Thanks guys
Well - maybe I'll be on the baked beans too. I've just had it in for it's 100000 service that included things like cleaning airflow sensor and valve clearances but they were unable to replicate my problem (maybe they didn't have it long enough). I was able to get video of the gear stick shake when the idle was both good and bad so I was able to at least show them that I wasn't dreamin'. It's due back in the workshop again next week. If they can't find anything then perhaps I take it to a diesel injector specialist. Might even give one a ring tomorrow and see what they say anyway.
Thanks again for the opinions guys - very helpful.
cheers
Kevin

Looks like I messed up with my first post!!
Hi RUK42,
I have the same or a very similar problem with my 2007 Rodeo common rail diesel, 120000Ks. The knock appears to be only on one cylinder and persists while ever the engine is running but magically disappears if I stop and restart after 20 minutes or so and it mightn't return again for days or weeks. I can tell if it's there when I start it even with the radio turned up just by looking at the gear stick shaking. This apparent miss isn't noticeable at the exhaust. If the noise isn't present at start up then it doesn't occur again unless I stop the engine and restart, or that's been the case so far. I can't find anyone who knows anything about it and being intermittent doesn't help.

This noise is very alarming and restricts how far I'm willing to travel from home. Please let me know if you figure it out because I'm at my wits end.

Thanks,
Rob.

Hi Robert
I reckon you have nailed it in one. That's exactly what I'm experiencing. My history thus far.
Originally (12 months ago) the problem was that the car would not idle - start - idle for a bit - stop. Keep the revs up and it would sort itself out. This was "diagnosed" as a fuel pressure regulator which was replaced. This seemed to fix the problem.
Now (and for the past few months) the problem is as you describe it. I have had the car to a 4x4 diesel place here on the north side of Brisbane and they have not been able to replicate the problem. I did call in one afternoon when it was happening but - they heard it and saw it but they didn't put the gauge on it - just booked it in. Of course it didn't happen in the three days they had it.
The guys there are pointing to a "flow control valve" as the culprit.
However - some contributors to forums seem to think these two parts are one and the same - I hope not.
One of the previous contributors to this thread opined about the possibility of injector problems.
I just wonder whether a knock in one cylinder is caused by rail pressure problems. Perhaps someone can enlighten both of us.
I have purchased a CReader in the hopes that if it happens again I will be able to connect it up and perhaps it will give some indication (error code) about what it might be.
Other than that I might:
- talk to a diesel injection specialist
- ring the local Holden dealer and try to talk to their service dept
- try to get onto GMH and see if they can be of any help.

so ... if anyone out there has anything to add in the way of expert opinion I reckon Robert and I are all ears.

cheers everyone
Kevin

Hi Kevin,
I've never had problems with it being hard to start or cutting out, it actually runs sweet when the noise isn't present !!!

If it's a "flow control valve" or rail pressure problems then it would be nice if someone would explain why it only affects one cylinder?

Having your own reader sounds good, I might have to look into that.

Like you say, if anyone out there has anything to add in the way of expert opinion, we are all ears.

Rob.

Hi Kevin,
$70 seems a bit cheap, do you have a link and have you tested it by introducing a fault?
My dash lights etc don't indicate a fault so I wonder if the reader would?

Thanks for the info,
Rob.