Hi There, Hopefully someone will be able to shed some light on the following problem. My 440 has done the following two occasions recently: After being stuck in slow moving traffic jams for about 40 minutes the engine just cuts out. The starter motor will turn over but the car won't start. After about 30 minutes (or just as the breakdown truck arrives!!) the car will turn over and start. The temperature gauge on both occasions showed just slightly above half way and the cooling fan works ok. Please Please can anyone help? The rest of the time it has run perfectly.

Hi there Madger.

Which engine & year?

BB
:beer:

Hi BB,
It's a 440SE 1794cc petrol 1984.

It sounds like you're having overheating problems. Your temperature sensor might not work properly anymore hence the seemingly normal coolant temperature. Does your fan still spin at the correct speed?

If it doesn't spin fast enough it won't be able to suck enough air in your car as it would easily be able to do when driving normal speed or fast. Check your fan as well.

Also did you check the coolant level after having pulled over? And when did you last change your coolant and did you put in the correct mixture? If you do not have the correct coolant mixture in your car the boiling point will be much lower than usual hence it will not be able to cool the engine enough.

Coolant fluid will dilute and contaminate over time. You should do a proper flush through at least every 2 years regardless of the mileage.

Lastly, something might be obstruction the coolant flow into your engine. Did you check for minor leaks (in the hoses) near the engine?

Hi Face - Thanks for your suggestions - all appears fine regarding coolant - levels ok and no leaks. Also inbetween the two occurances of cutting out the car had been serviced and coolant changed. The fan appears to be working at the same speed as normal. If the car was over-heating what would cause the engine to cut out and then start ok after a period of time? is there some sort of thermal cut out on the engine?

It does seem to be temperature related, but next time it happens, slowly release the fuel filler cap & see whether you hear a hissing noise. If you do hear it & it doesn't normally happen when you fill up, then check that the fuel vent hose isn't blocked & consider fitting a new filler cap. Could be that a vacuum is building up in the fuel tank the more fuel you burn and thus starving the engine of fuel.

If it's not that then the engine coolant temperature sensor (on end of cylinder head) is your prime suspect. There could be a blockage or air lock in the cooling system, the fan motor might be on its last legs, the cooling fan thermal switch in the radiator might be faulty & the water pump could be kaput, but these should lead to the temperature gauge climbing into the red & if it isn't then on balance of probabilities they are OK & the coolant temperature sensor (from which the ECU takes readings to adjust fuel/air mixture & ignition timing) is your main suspect.

Another possible but less likely candidate is the intake air temperature sensor - the intake air will be much warmer in a prolonged heavy traffic situation than when moving regularly.

Process of elimination, but I think you'll crack this one pretty quickly.

Good luck, please let us know how you get on.

BB
:thumbsup:

Hi, I have a very similar problem and when releasing the fuel cap the vacuum
is alot. So from my little knowlegde my cutting out is most probably the vacuum
in the tank. I broke down three time on the way home tonight and thought I will check the fuel cap, and when did the suction was alot, after the air was allowd in the car ran without any problems. So where would the valve be to allow air to be
sucked in is my question if anyone has the tech info on that please.

Much appreciated Sean

:57:

Also forgot to ask, where is the fuel filter on the volvo 44020.i CD M reg.

Regards
Sean