Check the integrity of the wire to the temp sensor (on the water pump...it's just about the only wire which goes there). Mine was stretched tight (seemingly from the factory...odd!) and had had its insulation rubbed through, and was shorting intermittently to the water pump, causing the light to flicker and the gauge to read a bit high. If the short were more permanent...

Agreed that t-stats tend to fail open, but a friend recently had one clamp shut on an 850, and it's a nice easy thing to check. Not a lot can cause a car to overheat...especially one with an operating cooling fan. Having said that, the cooling fan is triggered by the sensor in the rad on the 340 (opposed to the temp sensor in the head on the 850), so if the fan is working, it's probably seeing hot coolant. Odd...

cheers

James

JPB wrote:Gizzashout if you want me to come through and help with this, I have no prior engagements for tomorrow and can combine the trip with a call to my mate who lives just around the corner.

Working early doors John, so I''ll be up at the crack, have a look at the pipes, check the level, try running to town, if it overheats I'll park it up and continue by bus and report back.

Thanks though man. Very good of you.

foggyjames wrote:Check the integrity of the wire to the temp sensor (on the water pump...it's just about the only wire which goes there). Mine was stretched tight (seemingly from the factory...odd!) and had had its insulation rubbed through, and was shorting intermittently to the water pump, causing the light to flicker and the gauge to read a bit high. If the short were more permanent...

Agreed that t-stats tend to fail open, but a friend recently had one clamp shut on an 850, and it's a nice easy thing to check. Not a lot can cause a car to overheat...especially one with an operating cooling fan. Having said that, the cooling fan is triggered by the sensor in the rad on the 340 (opposed to the temp sensor in the head on the 850), so if the fan is working, it's probably seeing hot coolant. Odd...

cheers

James

youre talking to me.
Dont just say part names.
Descrable them by shape and colour.
Water pump is a gay bathtime game to me dude. What does it look like? (the volvo component, not the gay bathtime game)

On the front of the engine at the top...lots of hoses going to it, and a pulley for the belt on the front

cheers

James

foggyjames wrote:On the front of the engine at the top...lots of hoses going to it, and a pulley for the belt on the front

cheers

James

cool, cheers man.
Ben finds this post helpfull.

Ok, had a hunt round the pipes this morning.
=Nothing untoward.

Checked coolant.
= Level stable and fine.

Drove ten miles to work.
= No issues.

Hmmmmmmm.
Blockage thats worked itself through?
Thats Liams shout.

Im flumoxed.

Just keep an eye on it and report back.

don't worry about headgasket yet.. hg on B14 can only bring the temperature up if you have a coolant leak to a piston chamber wich you would instantly notice by big white plumes out of the exhaust.

first check the thermostat for opening; run the (cold) engine on idle and keep your hand on the top radiator hose; it should get warm after a few minutes wich means the thermostate opens.

next best bet is radiator, if they are corroded they don't work sufficient..
and after that it could be the waterpump, a few broken fins on the pump also means insufficient coolant suply; you can tell this if the interior heater isn't as hot as the gauge on the clockset tells it is

volvodspec wrote:don't worry about headgasket yet.. hg on B14 can only bring the temperature up if you have a coolant leak to a piston chamber wich you would instantly notice by big white plumes out of the exhaust.

first check the thermostat for opening; run the (cold) engine on idle and keep your hand on the top radiator hose; it should get warm after a few minutes wich means the thermostate opens.

next best bet is radiator, if they are corroded they don't work sufficient..
and after that it could be the waterpump, a few broken fins on the pump also means insufficient coolant suply; you can tell this if the interior heater isn't as hot as the gauge on the clockset tells it is

Cheers Anjo.
Heater is still blowing hot.

I turned it on to try and get some heat out of the engine when the warning light was on.

in that cast it is mostlikely the thermostate or radiator

volvodspec wrote:in that cast it is mostlikely the thermostate or radiator

Cheers dude, im gonna swap the thermo and flush the system. If it happens again, I'll start hunting a new radiator.

volvodspec wrote:first check the thermostat for opening; run the (cold) engine on idle and keep your hand on the top radiator hose; it should get warm after a few minutes wich means the thermostate

that is the easiest way to check the thermo Ben, you don't have to take anything apart for it

volvodspec wrote:

volvodspec wrote:first check the thermostat for opening; run the (cold) engine on idle and keep your hand on the top radiator hose; it should get warm after a few minutes wich means the thermostate

that is the easiest way to check the thermo Ben, you don't have to take anything apart for it

Awesome.
Thanks very much for the help mate.
I'll do that first.

I should have a pretty new rad available soon, if needs be.

cheers

James

foggyjames wrote:I should have a pretty new rad available soon, if needs be.

cheers

James

cool dude, I'll see how it goes.