AC Clutch and rising temps problem

[slackboy72]

I have a 2007 Lib GT Spec B, 2.5T with Auto box

So I was driving along in 30c heat this afternoon and the AC stopped working.
I looked for warning lights but nothing. The engine temp gauge was rising though. It got to high without going in to red.
I then heard a squeel and the AC started again and the temps dropped rapidly back to normal.

This was all over about 2 mins. It did it again later.
Any idea what this could be? Is it the AC clutch? Would that stop the water pump somehow?
Please someone help.

[bigBADbenny]

That’s troubling.
Basically any time your temp gauge goes into the red, it’s not good.
Are your rad fans working?
Eg car up to temperature, turn it off, key on to acc position, fans should come on, engine not yet started.

I use Btssm to monitor coolant temperature, much more accurate being in actual degrees.
I see around 100c on 40’ days, stopped in traffic.

A squeal on ac startup? Replace both accessory belts if they’re cracked and worn, otherwise adjust the tensioners, rule of thumb being they’re tight if you can turn the belt 90’, otherwise refer to FSM for actual spec.

Broken accessory belts can lunch your engine if they break, no joke.

[Tonic]

I reckon it is your main (serpentine) alternator belt. It powers the ac and a host of other things like steering pump. Easy to replace but if it goes you will lose battery power soon after...like late on a Sunday night at New Italy....
I also replaced a couple of the smaller pulleys as their bearings were worn which probably added to the belt going...

[slackboy72]

Well the belts look good and seemed to be within handbook tolerances for tension (9-10mm).

I think I have an air pocket in my coolant though.
I'll absolutely have to burp that.

But how could that stop the ac clutch from engaging?

[BillyCorgi]

What comes first, the chicken or the egg?

Most ECU will cut out the A/C on high coolant temperatures to protect the powertrain.

Did the A?C cause the high coolant temperature or did the high coolant temperature lead to the ECU cutting out the a/c?

[bigBADbenny]

Yep indeed an incomplete coolant bleed will cause issues.

Luckily for me I made a note on the correct procedure.

Bleed coolant

Since it was just serviced...
Check its been bled properly:
Raise front of car on slope or ramps.
Jam a funnel into the turbo coolant tank, support with a wire from bonnet, fill up funnel with coolant.
Idle car with heater on full blast.
Get up to temperature and massage top hose, then rev engine.
Repeat till no bubbles in funnel.
Remove funnel, replace cap and wash off excess coolant.

I use 2 SCA funnels, the inexpensive two piece type, one unit complete, and the flexible section of the second jammed into the first for extra length/volume.

Take your time and be patient, I use a welding glove or oven mitt as the coolant comes up to temperature.

Otherwise a pressure bleeder is a good tool to have for the job.