Shuddering issue and overheating

[Chamelion]

Hello all,

I've had a few problems with my 2002 AU3 I6 wagon lately..

3 times in the last couple of months I've been driving along and the car has started to shudder like it is being starved of fuel. I've looked down to notice the temp gauage at 3/4 the way to the red zone. I've stopped the car each time, checked under the bonnet and noticed nothing amiss.. well, I think one radiator fan it not working come to think of it.
As soon as I have turned on the cars cabin heater the temp guage drops at a very visible rate taking only seconds to return to normal. After that I have been able to turn the heater back off and then drive like normal. It's weeks between each time.

I've also had issues with the idle being eratic (worse on LPG) and then I'm going slow she often shudders and shakes (idle drops and again, worse on lpg) and it's even more pronounced if I'm turning and/or running the airconditioning.

Any thoughts or suggestions greatfully appreciated.

Matt.

PS: LPG was serviced less than a month ago, oil was changed at the same time, plugs could be getting old, leads are 15 months or so old, O2 sensor is of an unknown age, throttle body and ICS were last cleaned around a year ago and the air filter is a month old.

[Whoosha]

Sounds like a over heating issue. dont the I6 have the over heating protection ? if so I would give the thermostat the flick and try another one

[mik]

if the coolant level was down.... or too hot(turning to steam)the gas mixer might be freezing up, but probably more likely what Whoosha has said...... over heat protection, one fan not working..... perhaps the other is intermittent, i would be getting them checked out post haste, plugs are cheap, throw a set in as well see how it goes, the thermostat sounds like a good idea too.

[Chamelion]

Cheers lads... How would I test the fans? Just throw in a new set from the wreckers and see what happens? :P

I'll do the plugs and thermostat at any rate.. I assume changing the thermostat isn't hard.

Matt.

[au2sw]

thermo is easy as, if you want, come round to my place with a new thremostat amd coolant, and we'll do a coolant flush and thermostat change. and ill have a look see to make sure everything else is ok for you matt. PM me if your interested

[EvilChief]

idling rough: tighten intake manifold bolts