[nicknack]

Took the car out last night for a quick trip to the Chinese take away (I thought I'd treat it to some crispy duck) and all seemed fine until parking up and the car was idling roughly.

It had started fine and was running pefectly whilst driving.

Idle speed was normal, but I did notice the rev counter fluctuating ever so slightly.

When I started it back up after collecting dinner I let it idle for a few seconds and it wasn't as bad but was still a bit rough.

The drive home was fine, no loss of power and silky smooth, but when we got home and I let it idle it was rough again.

It's had it's 100k service & new Denso Iridium plugs 6k ago, which I took out and checked a couple of weeks ago and they all looked fine.

It doesn't get used much these days; unfortunately it's become my better half's shopping trolley and mostly gets those horrible short journeys down to the supermarket once a week...

Any ideas?

Cheers,

Nick

 

[paulyoung666]

it might just want a good blast down the road or maybe the idle control valve is playing up :sad:

 

[mondeo.man662]

I have disconnected my Maf sensor , and this has done the same, idle is variable n sounds like its gonna cut out at any time. Check the MAF Mate might be that but if its not then at least it's something to knock off your list :L

Jamie

 

[nicknack]

Thanks lads, I'll have a poke about today.

 

[nicknack]

OK Paul, I unplugged the IACV whilst the engine was idling and it just stalled, so I'm assuming that it works fine; I removed it and cleaned it out though and it's made no difference.

Jamie, there's no MAF! It's a MK3, sorry I should have mentioned that.

I've checked around the engine bay and nothing seems to be loose or damaged.

The only thing that's been changed of late is the interior temperature sensor for the climate control, and since then I've not been running the climate control on Auto with the AC running all the time.

When I do switch the AC on, the idle speed picks up slightly and it's not so rough.

Last night when we went out, I let it idle in a car park for a few seconds and it started to hunt (if that makes any sense).

I'm stumped.

 

[James_McHattie]

Have you gone for a blast down the motorway in 4th?
Kick out some of the poo.

You might have a vacuum leak somewhere, or maybe one of your temperature sensors isnt well. You could save time and put it on a diagnostic machine if there is nothing obviously wrong.

 

[nicknack]

Hi James,

It's not had a really good run of late, however it's going to get some long journeys put on it over the Christmas break.

I'll make sure I rag it a bit once it's fully warmed up.

If that doesn't sort it I'll get it put on the diagnostics (once we've recovered from Christmas outgoings) as everything looks sound underneath the bonnet.

Cheers,

Nick

 

[thelongmile]

i have to agree a good rag is what some ford engines need to kick the shite out of them, failing that a bottle of redex helps

 

[PPP]

what about thermostat?

 

[nicknack]

The thermostat housing was replaced earlier this year, along with complete inlet manifold and EGR valve...

I'll have another look tomorrow and spray some WD40 around the place to see if there are any air leaks.

The only other thing I can think of (and forgot about) is when I first got the car the throttle would stick closed in really cold weather, like a magnet was holding it closed and it needed a bit of a heavy foot to open it. I wonder if the butterfly could be loose?

 

[Micky]

Any fault codes? IACV must be favourite. Is there an EGR on a Mk3 petrol?

 

[nicknack]

It's not been on the diagnostics so don't know of any fault codes as yet.

The IACV obviously works because if I disconnect it when the car is idling it stalls.

According to the garage, they replaced the EGR.

At the moment I don't really care about it, I just want to get rid of the :BEEP: thing...

 

[James_McHattie]

I once had mine in for a new head gasket, and on returning it they had left one of the vacuum pipes off the throttle body. It would drive ok, but hunt at idle.

Have you changed the rubber Tpiece? and looked over the vacuum pipes?

 

[SDR]

t-piece in mk3?
mine's got vibration when idling along with a kick when i start the engine.
the maf is making the idle even rougher prone to stall. last weekend checked the spark plugs and they looked fine but i am still thinking of something like leads, coilpack or timing.

 

[nicknack]

It seems to be a bit smoother today.

I gave it a good thrashing yesterday & we're going up to my parents tomorrow, so will use the motorway to give it a proper clearout.

The one downer to yesterday was that I wasn't watching my speed and may have been caught by a mobile camera. Well if I was it's my own fault and have to face the consequences...

Cheers,

Nick

 

[Bin_Man]

Sounds like the swirl plates if its a mark 3 and only afecting idle.

There are adjustable baffles in the inlet manifold to aid fuel/air mixing. controlled by a rod sytem with a ball and socket coupling that is known to wear and come appart. Search for other posts on this.

I understand that one possible soluiton is to wrap the ball joint in PTFE tape before pushing bakc together if it is too worn to hold. Also understand that you can't get the joint seperately and official answer is to change the manifold, but I'm a mark 2 man so this isn't really my field...

 

[nicknack]

That's all been dealt with...

I had the inlet manifold replaced earlier this year because the swirl plates were so loose I just couldn't put up with the noise!

The ball and socket are secure.

Cheers anyway,

Nick