Slow to warm up and dodgy idle

[dransfield]

2001 V70T Auto

I've noticed recently that my car's temperature gauge doesn't climb
quickly up to "straight up" and stay there.
This winter (London, fairly mild: 2 to 10 deg C (not freezing)) it
seems to be quite sluggish to get up there. Is that normal? Or should
I replace the thermostat?

Also, and maybe this is related: Once up to temp, when sat at traffic
lights the idle sometimes drops to the point where the headlights and
dashboard lights dim a bit, then the idel kicks back up to 800-900 rpm
and stays there.
Its like a tired driver fighting to stay awake - it almost 'nodding
off', but catches itself just in time, and then stays alert for a
little while longer ('til the next stop light).

Does any of this sound familiar?

I had the throttle body module (or was it gearbox?) reprogrammed a
while ago, and that cured all its previous idling woes for about a
year.

TIA

Dz

 

[Roland Messerschmidt]

Hi,

Or should I replace the thermostat?

I'd say yes!

Same problems here on my '99 V40 just before new year's holydays. Bad
heating, temperature below normal level etc.
Thermostat changed and everything was fine - even at -15°C (+5°F)...
In retrospect the engine went hot very quickly last summer...

headlights and dashboard lights dim a bit, then the idel kicks back
up to 800-900 rpm and stays there.
Its like a tired driver fighting to stay awake -

How old is the battery?



Roland
(Austria)

 

[dransfield]

How old is the battery?

Actually, funny you should say that, but I suspect the battery is
knackered:

The car is a Feb 2001 car, and I don't know if the battery is
original, but I've had the car for 4 years and never changed it, and I
did flatten the battery recently (for the second time) - I think just
by having the boot/trunk open for a couple of hours.

Would a knackered battery affect the idle?

Dz

 

[James Sweet]

Actually, funny you should say that, but I suspect the battery is
knackered:

The car is a Feb 2001 car, and I don't know if the battery is
original, but I've had the car for 4 years and never changed it, and I
did flatten the battery recently (for the second time) - I think just
by having the boot/trunk open for a couple of hours.

Would a knackered battery affect the idle?

Dz

It would be very unusual if it did. So long as the battery is strong enough
to start the engine, it shouldn't have any effect on the running. My
experience is only with older Volvos, but they run fine even with the
battery completely flat. There were 2 days in a row where I parked my 240
facing down a hill because the battery had been run down to nothing and
wouldn't take a charge but between work and everything else I didn't have
time to pick up a new one. The car ran just the same as always.