L200 revs high on startup

Bear83

Just looking for abit of advice on what may be causing an 09 L200 to rev high when 1st started in the morning. The problem is more obvious in cold weather.
It'll start fine but the revs will jump to 2000rpm and may stay there for up to 10 seconds depending on how cold it is. They will then just immediately drop back to normal.
I know cars tend to rev abit higher when it's cold but I don't remember this happening before and I think reving up to 2000rpm seems high.
Any help or advice would be greatly appreciated
Thanks

biko

Yes, cars do rev a bit higher as they run a richer mix initially.
There used to be a "choke" for this on old cars but is now automatic.

It sounds as if it's just the car responding to the cold. Is there any other issues or lights on the dash to signify something else?

How is idling, general power etc?

Bear83

Thanks for the reply

Everything else is spot on as far as I can see.
The only issue is that it has only started doing it recently whereas it never used too. It's as if you have your foot on the accelerator when you start it but after 10 seconds or so, it returns to normal idle

I was just googling it and I saw some related posts which were saying a vacuum leak or leaking injector, which then got me somewhat concerned.

punisher5112

When was it last serviced?

Air filter & fuel filter changed?

Lot of new stuff does this at times due to dpf and regen.

Bear83

It should be up to date on the servicing. There's one due in April. So the filters should be ok.
If it were a filter, would I not be getting other symptoms too?
Funnily enough, it was only 1 degree this morning and it didn't rev high when it was started but it is definitely linked to the cold weather or if it hasn't been driven in a few days.
Perhaps it is due to the DPF. I haven't heard of that being mentioned before.

The one other issue it has is that it's gone into limp mode a couple of times when it's been driven hard on the motor way. But if you turn if off and start it again, it runs fine again. And that hasn't happened in months. I presume this isn't connected to the other issue

biko

Do you have a diagnostic scanner? Even if there are no lights on dash it could be worth it to scan car for codes anyway.

Bear83

I don't have a scanner but I'll get it checked when it's in for it's service if you don't think it's a serious problem. Also, I'm waiting to see will it stop doing it when the weather gets abit milder

biko

It's "a bit"

Yeah, just mention it to them and they will check it for you.

Bear83

Thank you for pointing that out

If it gets any worse, I'll get it checked prior to the service.

Thanks for your help!

Gravelly

Check the intercooler pipes - an air leak could cause these symptoms.

Bear83

Ok, thanks. I'll look into that.
Is that a serious issue or can it cause any damage in the long term?

Gravelly

Bear83 wrote: »

Ok, thanks. I'll look into that.
Is that a serious issue or can it cause any damage in the long term?

Other than poor fuel economy, no. It does sometimes cause the ECU to go into limp-home mode I believe, but that's not going to do any harm other than annoyance.

cournioni

Sometimes can be suction control valve related.

Bear83

The twice it went into limp mode, I did have the codes checked and both times it was a Turbo Over-Boost. It happened in July and in October and hasn't happened since.

The high rev at cold start has only been happening since just before Christmas

traco

Could be fuel shut of valve/solenoid or something that does that is leaking.

Basically when you shut the engine off it closes and stops the fuel supply to the engine. As fuel seeps through over the time if off when you start it there is an excess of fuel supplied and the engine revs up, this can confuse ECU with the readings its seeing as its not expecting that and go into limp mode.

If you drive it a little bit stop it and restart is it OK? I spent weeks chasing such a faulty on an VW and multiple mechanics. Eventually convinced a guy to change the valve for a second hand one I found and all sorted.

Worth a look.

Bear83

Thanks for the reply but I'm fairly certain the high revving on cold start and it going into limp mode aren't related.

It only went into limp mode twice and that was months ago. Code both times said Turbo Over-Boost

The high revving may be still be down to what you are saying though. It's like as if there is excess fuel and it's being burned up. It will only happen when the engine is very cold i.e on a frosty morning. Once it warms up, it doesn't happen. But if it were a fuel leak, should it not happen every time?

traco

Bear83 wrote: »

Thanks for the reply but I'm fairly certain the high revving on cold start and it going into limp mode aren't related.

It only went into limp mode twice and that was months ago. Code both times said Turbo Over-Boost

The high revving may be still be down to what you are saying though. It's like as if there is excess fuel and it's being burned up. It will only happen when the engine is very cold i.e on a frosty morning. Once it warms up, it doesn't happen. But if it were a fuel leak, should it not happen every time?

Don't know to be honest - mine would do it when hot (VW), it was fine from cold but the high revs were the excess fuel. Might be a totally different problem on yours but as I said it was a simple fix so thought I'd mention it.