Fast Idle At Start Up?

[Guest Ross]

Yesterday morning I started that car to get teh famed auxillary heater in action to take the chill off, I stopped the engine to put the kids is their car seats (TDI owners will know the lovely smell of diesel fumes that fill the car with the door open!).

On re-starting the car it instantly revved to around 2,000 rpm and coughed and spluttered for a few seconds before settling to a normal idle speed, this has happed a few times before but with no dictinct pattern ie it happened before after starting the car full warm after a normal run?

 

Any ideas?

[seatkid]

My guess is that its a sensor problem (maybe crankshaft or cam position sensor or even accelerator pedal sensor). If it bothers you then next time you're at your Ford dealer ask him to check the PCM diagnostics to see if a sensor fault has been logged.

 

I recall that similar happened once to me, but it never reoccured.

[sniper]

My '98 Galaxy (2.3 petrol) is currently exhibiting and idling speed problem. I've looked around here for any similar topics, but not found anything as yet.

 

The car starts ok, but is idling lumpily, occasionally revving up to around 2000rpm before then settling back to around 1000, but with irregular idle.

 

It drives ok at higher revs - but when coming to a stop at a junction, it'll sit at around 2000rpm - if I wait long enough (about 20 seconds) it will then drop to around 1000 with irregular idle.

 

I've been assuming this was a vacuum leak, but I can't find anything atm. There is a 'hissing' noise coming from the engine bay (sounds like it's coming from the area next to the alternator - i.e. where the exhaust manifold is - but it doesn't sound like it's coming from behind the metal cover over the manifold) - maybe it's a rubbing noise rather than a hissing noise - but it takes a second or so after I turn the key off to stop.

 

I thought I'd post a question here while I'm waiting for the car to cool down again - I can't do anything without burning my hands atm.

 

Thanks.

[mk2vr6]

most idle faults are due to a gummed upped ISV! you could start looking there? then if that doent cure the problem delve deeper!

[sniper]

most idle faults are due to a gummed upped ISV! you could start looking there? then if that doent cure the problem delve deeper!

I've just had the idle control valve off the top of the throttle body, sprayed it clean with carb cleaner and refitted it. Still the same :lol:

 

Idle is irregular, coming from high revs it'll stick at around 2000 rpm for a few (10-30) seconds then drops down to around 1000 rpm again, idle still irregular.

 

I checked operation of the MAF sensor - disconnecting it makes very little difference, but some, so I can't assume it's not working.

 

Not sure what to try next...

[mk2vr6]

make sure it's really clean!

[sniper]

make sure it's really clean!

It is. Certainly MUCH cleaner than it was a week ago when it was still working...

[sniper]

OK, I decided to look for the source of the 'hissing' sound, and I'm pretty sure it's the 'crankcase emission control valve' - situated just behind the exhaust manifold on the front of the block.

 

The pipe running from the top seems loose - not sure what to do, though. (Right now it's very hot - again)

 

Anyone have any thoughts?

[sniper]

Is it possible to replace the rubber hose at the top of the emission control valve (on the front of the block, behind the exhaust manifold) with the manifold in place?

 

Also, should the valve be replaced as well, or just the hose? The hose is very sloppy, so it seems it's collapsed/split/perished - the least I expect to do is replace it (presumably need to get this from the fraud dealer) but if I do have to remove the manifold to do that, I want to know whether it's worth considering replacing the valve as well. As it is, I can't even see how it's fixed in the block.

[sniper]

Is it possible to replace the rubber hose at the top of the emission control valve (on the front of the block, behind the exhaust manifold) with the manifold in place?

Further to the above, I went to the dealer today to check out the diagrams, and it seems this is probably the PCV (crankcase ventilation) 'oil separator', rathe than as the Haynes book describes it. It connects to the intake manifold through a rubber hose at each end - the end by the block (just behind the very hot exhaust manifold) is the one that's gone.

 

I think it's probably a good idea to clean the PCV valve/oil separator too, while I'm there - I guess they can become gummed up.

 

Has anyone else had trouble with this part of the system? I'm not looking forward to having to remove the exhaust manifold etc. - seems there's rather a lot of other things - e.g. dipstick, alternator - that are also attached - that'll be a right royal pain.

[sponger]

Can you let us know how you cure this problem my 2.3 gal is showing exactly the same symptoms. Thanks.

[sniper]

Can you let us know how you cure this problem my 2.3 gal is showing exactly the same symptoms. Thanks.

I ordered the new tube today, and I'll be fitting it on Saturday - weather permitting.

 

I'll probably start by removing the tube coming from the inlet manifold and then if/when I can actually see the PCV valve I'll decide whether the exhaust manifold needs to come off.

[sniper]

OK, today I got the new tube and fitted it. Result? The car is again running normally.

 

Anyway, I started by trying to remove the exhaust manifold. I got all but one of the nuts/studs removed - the one behind the alternator is a real b*st*rd - I think I'd have to remove the alternator to get at it!

 

So I tried having a go without going further. The tube that runs from the inlet manifold is held by a single bolt on the r/h side of the block. Once I'd removed that, I could disconnect at the inlet manifold, and then I pulled the other end (at the PCV valve) free.

 

First of all I found that I could move the tube so I could reach it from below (see pictures) which allowed me to refit the new tube and the PCV valve before refitting into the block. Note - the PCV valve will pull from the block quite easily, so forget about removing the exhaust manifold! (In fact, I managed to snap 2 of the studs putting it all back, so now I've got an even bigger job to do! - but for now it'll do.)

 

Anyway, enough said, it was a pretty straightforward job, in the end - I just wish someone could have told me to leave the exhaust manifold alone!

 

The pics attached show the tube/PCV valve location behind the dipstick tube, and the view of the new rubber tube with the PCV valve attached, sitting just behind the front downpipe - in this position I could just about get to it.

[niallsan]

I had the same problem. Turned out to be a defective coolant temperature sensor.

 

 

 

 

 

 

 

 

OK, today I got the new tube and fitted it. Result? The car is again running normally.

 

Anyway, I started by trying to remove the exhaust manifold. I got all but one of the nuts/studs removed - the one behind the alternator is a real b*st*rd - I think I'd have to remove the alternator to get at it!

 

So I tried having a go without going further. The tube that runs from the inlet manifold is held by a single bolt on the r/h side of the block. Once I'd removed that, I could disconnect at the inlet manifold, and then I pulled the other end (at the PCV valve) free.

 

First of all I found that I could move the tube so I could reach it from below (see pictures) which allowed me to refit the new tube and the PCV valve before refitting into the block. Note - the PCV valve will pull from the block quite easily, so forget about removing the exhaust manifold! (In fact, I managed to snap 2 of the studs putting it all back, so now I've got an even bigger job to do! - but for now it'll do.)

 

Anyway, enough said, it was a pretty straightforward job, in the end - I just wish someone could have told me to leave the exhaust manifold alone!

 

The pics attached show the tube/PCV valve location behind the dipstick tube, and the view of the new rubber tube with the PCV valve attached, sitting just behind the front downpipe - in this position I could just about get to it.