V6 Warm-Hot Idle

Unread post by **CitroJim** » 24 Jun 2009, 18:03

Calling all the other experienced V6 owners out there please

Mine has an erratic idle when started from half-hot. The tacho wavers beteen nearly zero and about 900rpm for a bit before settling.

It seems to do it mostly if the car is restarted after say, a 30 minute stop after a good run and it seems to be worse when the weather is very hot, as it is today. It almost seems the engine is completely heat-soaked and something on the ECU is confused for a bit. Lexia shows no faults.

I know this is normal Activa behaviour so I'm not too worried but I'd be reassured to know if this too is normal V6 behaviour.

Cold starts are instant and she settles to a steady idle immediately.

f00lzz · Unread post by **f00lzz** » 24 Jun 2009, 18:13

Never happened on mine... steady as a rock!

Unread post by **CitroJim** » 24 Jun 2009, 18:55

Thanks F00lzz...

Just went out and started it half-hot and guess what?

Idle as steady as you like

Stempy · Unread post by **Stempy** » 24 Jun 2009, 20:09

Mine too, always steady at any temp. The air temp sensor can be a bit fragile so might be worth a check. (when I say fragile, I broke mine

)

Unread post by **xantia_v6** » 24 Jun 2009, 22:15

I have (very occasionally) had a similar problem. Maybe it is a Mk1 thing?

What I have found is that sometimes on a hot day, whan the engine is hot, but has been sitting for a few minutes, the engine can be difficult to start (needing a bit of throttle) or only just managing to idle for about 20 seconds.

I suspect it is the auto-adaptive software having a learned throttle position for each temperature at startup, and it somehow learns a wrong value for this particular condition.

wheeler · Unread post by **wheeler** » 24 Jun 2009, 22:31

Are all the paramiters reading ok when checked with lexia when the fault occurs ? especially the coolant & air temp sensors.

Exhume.dk · Unread post by **Exhume.dk** » 24 Jun 2009, 22:37

Had at some point a similar experience, when semi hot, on a hot day, it started instant, like always, but was somewhat destabile, just for a seccond, and stalled, then it was much more diffficult to start it up again. It wasn't me who was driving, i only stood a looked concerned, then took charge, a had a 3-5 sec. start up sequence.

Is it me or do those ES9J4 really radiate heat and build up, even with 82 C. on the water, and a 90 C. on Oil, the engine bay is really hot, and even after 3 hours it still contain some heat. New radiator, new matrix, wented, no leakage and level okay.

Can we have a reality check please

Engine oil :

Motorway at normal speed 60 mph : 90 Celsius

Excessive motorway speed 100 mph : first mark after 90 Celsius( 110 C )

All-in @ motorway speed : seccond mark after 90 Celsius( 130 C )

After that run it was hot, for a week...just kidding

Sorry for somewhat high-jack, Jim

Unread post by **CitroJim** » 25 Jun 2009, 06:27

THanks all

That's quite a picture you have posted above Christian

So they are fast then

They do generate a lot of heat but nowhere near as much as a 2.0 TCT Activa engine

Mind you, they stay hot for a long time.

xantia_v6 wrote:I have (very occasionally) had a similar problem. Maybe it is a Mk1 thing?

That's precisely it! A perfect description of what mine has been doing. Maybe it is a MK1 trait

I need to investigate further as it was apparant last evening during dad's taxi work..

I'll get the Lexia ready for monitoring a hot start. It'll tell me the sensor information (agreed Stempy, the air temperature sensor is a bit fragile) and what the ICV is up to.

It also feels a bit like a sticky ICV, a bit "iffy" when it is down in the position it normally occupies. Anyone had a go at cleaning a V6 ICV? It looks a bit sealed to me

KP · Unread post by KP » 25 Jun 2009, 08:16

I'd say possibly some sort of fuel vapourisation within the engine bay or injector rail maybe??

If i ever have to take my turbo off i'll be wrapping the exhaust in some heat wrap stuff to get the engine bay temps down as in this current hot climate its no good for power

Exhume.dk · Unread post by **Exhume.dk** » 25 Jun 2009, 09:00

CitroJim wrote:THanks all

They do generate a lot of heat but nowhere near as much as a 2.0 TCT Activa engine Mind you, they stay hot for a long time.

I can understand that, mainly because of the XU cast iron engine block and the entire turbo unit also in cast iron.

But here it's all i aluminium wich is much better at dispersing heat, and no backpressure turbo-unit.

The ICV on my MK.1 "hum" like a powergrid(barely audible) , so a good cleaning was on my to-do-list in my holidays..among other things

Anyone else got some Oiltemp readings ?

Unread post by **CitroJim** » 25 Jun 2009, 09:30

Exhume.dk wrote: The ICV on my MK.1 "hum" like a powergrid(barely audible)

Mine hums like a swarm of angry bees Christian

My oil temperature sits around 85 degress..

The oil temp gauge was only seen on the MK1 V6s in the UK as the part of the dash occupied by the oil gauge was used to house the gear indicator on MK2 models..

Exhume.dk · Unread post by **Exhume.dk** » 25 Jun 2009, 09:48

CitroJim wrote:
Mine hums like a swarm of angry bees Christian

Looked the ES9J4S up, and noticed they actually fitted a sandwich between the filter and block but still use the heat transfer plate in the oilsump.

I guess PSA didn't like the above normal oiltemp.

CitroJim wrote:
The oil temp gauge was only seen on the MK1 V6s in the UK as the part of the dash occupied by the oil gauge was used to house the gear indicator on MK2 models..

That's annother way to get rid of the horrible news..remove the gauge

Unread post by **xantia_v6** » 25 Jun 2009, 19:08

At 80MPH, my V6 oil temperature sits at about 90 degrees, +/- depending on ambient temperature. I have seen 110 on a hot day at 90MPH. At 60 MPH, it would be a below 90 degrees.

I don't think that these temperatures are anything to worry about.

Exhume.dk · Unread post by **Exhume.dk** » 25 Jun 2009, 19:27

110 @ 90 mph..okay, but above 120 C. is pushing the envelope for sure.

Running on 15W-50 or 10W-60 when i can get a fair deal.

But nice to know it's somewhat normal Citröen and finding yet annother reasson for 90 Mph-ish travel speed.( ticket and/or ban, Mpg )

vince · Unread post by **vince** » 25 Jun 2009, 22:15

Hi jim,

The ICV i presume can be cleaned with carb cleaner sprayed into the air inlet....? If not then removed and cleaned with a toothbrush and carb cleaner.

The hot start wobble is likely to be down to a temp sensor i presume