Corsa heater problem

My daughter's 52 reg 1.2 SXI Corsa's heater seems very ineffectual, producing only lukewarm air.

There's plenty of antifreeze in the system and if you feel the pipes leading to and from the heater matrix there is a temperature differential so some water is going through.

What's the likely cause?

Tim

Reply to
Tim+
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stuck cold air flap probably. get under the dash , find the control flap links, operate the controls to establish which operates which wire and ensure that when it is turned to hot the flap goes to the end of its travel. it may also be that the wire has moved in its clamp or come off the flap.

Reply to
Mrcheerful

How long does the temp gauge take to reach operating, and does it stay there when on a fast run , or does it drop?

Tim.

Reply to
Tim..

It gets up to 90 pretty quickly and then stays there so I think the thermostat is okay.

Tim

Reply to
Tim+

That sounds plausible (and a pain to get at). Do you know offhand what the easiest way of accessing the linkages is? Remove the glovebox maybe?

TIA

Tim

Reply to
Tim+

It may depend on the year, but on the Corsa early models that I have done this job on: I don't remember having to take any dash off to get to the linkage, so it may well be that they are by the drivers feet.

Blocked pollen filter makes the heater pretty useless, but the air should still be hot, just less of it, so my money is still on the linkages (mainly because of experience of just that.)

Reply to
Mrcheerful

Well I took the glove box out this morning and had a feel around behind. As far as I can tell, the control knob end of the linkage is okay. I

*think* the other end is okay too as when I turn the temperature knob, I can hear the air flap hitting its stops at each end of its travel. Not conclusive I know but I don't get the feeling that it's failing to move through it's full range.

I don't know whether it's significant but we noticed yesterday, that when we stopped to refuel, the heater was briefly producing hotter air when we restarted although this only lasted a minute.

Any other suggestions?

Tim

Reply to
Tim+
[...]

Partially blocked heater core?

Chris

Reply to
Chris Whelan

if the flap sounds/feels as though it is getting to the hot end of its travel then that is probably ok. Unfortunately, the next most common heater fault on those, after thermostat, pollen filter and flaps is caused by head gasket failure. Do you ever hear gurgling in the dashboard usually first start of the day? HG failure puts 'air' into the system which slows the water flow through the heater. To diagnose for sure you need to get a test done which checks for combustion gas in the coolant. Possibility of heater rad blockage, but afaik it is not common on that model, and I have never changed one, unlike escorts, cortinas and sierras where it was a very common fault due to inadequate passage sizes.

Reply to
Mrcheerful
[snip]

If the head gasket leaks you will usually lose coolant by boiling - albeit slowly. You might also see an emulsion (mayonnaise) on the underside of the water filler cap.

Reply to
Graham J

one of my customers ran her corsa for several years with hg failure, short journeys and an occasional top up kept it going till she pxed it.

Reply to
Mrcheerful

Pretty sure the head gasket is okay. No gurgling, no overheating, nothing odd in the oil and expansion bottle clean.

Maybe the system just needs a good flush? I suspect I'll hand the job to our local garage now as most of the hose connectors look beyond my ability to break/remake.

Tim

Reply to
Tim+

please let us know the outcome.

Reply to
Mrcheerful

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