Now I am fed up with this car!

[jazzdude]

I have been toiling all summer to get this damned a/c to work, and it has gone backwards and forwards to the a/c shop like a yoyo. Although it gives me nice cold air when it works, the compressor keeps cutting out after 15 mins on the road, coming back on again 5 minutes later by which time I am boiling again. Doesn't do this sitting outside the garage with the engine running, only when it is driven and the garage is too scared to drive it, so I get there and they say it is fixed and it is not once out on the road.

Changed the clutch, changed the pulley wheel and shim, changed the belt, shorted heater-box thermostat to keep it on, and it still shuts itself off. We now think to try a completely new compressor as my one must be 'overheating' and getting shut off from the overheat cut-out switch on the side of the unit. The bit of exhaust under it is wrapped in three layers of heat-wrap, so not sure how much more heat protection it needs if that is indeed the problem.

On top of that, today someone at the garage left the wiper stalk up and driving it home, the wiper motor must have been on full without moving the blades and the motor nearly caught fire so have that to bloody fix (not sure how yet), and to top that, all of a sudden the oil pressure gauge decided to intermittently drop to zero while on the move. Checked the oil level when I got home and it has oil in it.

Feel like putting it away for a while now as I have hardly used it this summer as it has spent most of it at the a/c shop. Too hot to drive here without a/c until October.

I think I love this car but right now I bloody well hate it!

[QBee]

The oil pressure fault is the pressure sender connection. It is under the front of the car, by the bottom chassis rail, below the crankshaft pulley I think. I will go outside and see if I can photograph it for you. Single cable, connector can come loose. You just need to make a better connection.

Mine chose 5 minutes after the end of a track day to come loose. Gave me a fright until someone who knew what was wrong came along and told me it was safe to drive.

[QBee]

I think the car kept idling outside the workshop would get hotter than the car being driven, I suspect a loose wire somewhere is your problem.

[QBee]

Too far underneath to photograph - so here is the picture of the location from the bible. Taken from underneath of course.
Ignore the comments about faulty senders - the connection is usually the problem. Simpler to fix with the car on a 2/4 post lift.

[jazzdude]

QBee said:

I think the car kept idling outside the workshop would get hotter than the car being driven, I suspect a loose wire somewhere is your problem.

Agreed but then when the car moves, more hot air is driven over the compressor from the radiators that are pulling it through the front radiator and condenser and out through the top vents, which are next to the compressor. When it stops, the clutch disengages and but there is still power going to the clutch, meaning the rest of the system is telling it to stay on.

Short of a new compressor, I can't think what else it can be unless the super hot TVR engine bay is giving an otherwise good compressor problems.

Is there such thing as an insulation 'bag' that can go over the compressor, and has anyone else seen these on TVR's as none of the a/c'd engine bays I have seen have anything other than an asbestos heat shield over the exhaust, something that the heat wrap I have already fitted is also doing.,

[jazzdude]

QBee said:

Too far underneath to photograph - so here is the picture of the location from the bible. Taken from underneath of course.
Ignore the comments about faulty senders - the connection is usually the problem. Simpler to fix with the car on a 2/4 post lift.

Yes, I know where that it, perhaps they knocked it when pushing a jack under the car at some point.

I'll get under and check it tomorrow and give it a little pinch if it is loose

[N7GTX]

If you Google the fault most manufacturers come up with typically failing after 15 mins or 30 mins.
This is from the Volvo site but the answer by the aircon bloke is the same in many other forums - Honda, Hyundai, Jaguar etc.


https://www.thevolvoforums.com/threads/ac-stops-wo...

http://www.jaguarforum.com/showthread.php?t=70911

Might help especially if there is a temp sensor in the compressor?

[jazzdude]

QBee said:

Gave me a fright until someone who knew what was wrong came along and told me it was safe to drive.

They bloody do that don't they, I think I spend more time looking at the gauges than the road, even though I consider my car 'fully sorted'

[andy43]

Maybe a daft idea but if you can't link the compressor overtemp sensor out how about taking the bonnet off, drive it for a bit then see if the a/c still cuts out to prove whether it's temperature/hot air flow related. Does the manifold below it have a metal heatshield between it and the belt? Might help.
Or maybe short the otter switch so the rad fans are constantly running to give it a bit of (admittedly warm) airflow.

[jazzdude]

N7GTX said:

If you Google the fault most manufacturers come up with typically failing after 15 mins or 30 mins.
This is from the Volvo site but the answer by the aircon bloke is the same in many other forums - Honda, Hyundai, Jaguar etc.


https://www.thevolvoforums.com/threads/ac-stops-wo...

http://www.jaguarforum.com/showthread.php?t=70911

Might help especially if there is a temp sensor in the compressor?

Thanks, interesting reading.

Am tempted to wire out the heat cutoff switch, which is there on the side of the compressor, and see if that makes a difference.

With the shim gap, put on a new pulley wheel and clutch on the existing compressor that he had lying around, and that made no difference, although I am also suspicious that when the heat from the radiators are pumped over the compressor when moving that perhaps the gap may open with expansion and might be causing the problem. The fact though that it pulls it back on again say 5 mins later, even though the engine is still running and is still hot (albeit without the condenser heat) means it is still hot there.

[jazzdude]

andy43 said:

Maybe a daft idea but if you can't link the compressor overtemp sensor out how about taking the bonnet off, drive it for a bit then see if the a/c still cuts out to prove whether it's temperature/hot air flow related. Does the manifold below it have a metal heatshield between it and the belt? Might help.
Or maybe short the otter switch so the rad fans are constantly running to give it a bit of (admittedly warm) airflow.

I can link the over temp wire, that is quite easy. As I said there are also 3 layers of titanium type heat wrap over the manifolds, up to say 20cm either side of the compressor.

The fans are wired up to be on all the time when the a/c is on and they don't turn off at all, even when the compressor turns off. The work as normal when the a/c is turned off completely.

[jazzdude]

Disconnected the overheat cut out switch on the side of the compressor today and it seems that the compressor is now working continuously, so under bonnet temperatures must be the reason I was having problems.

Even though I have wrapped the manifold directly under the compressor, there must be more heat being thrown back from the front of the car from the radiators over the compressor, hence the cut-out.

The cutout switch must be there for a reason though so I am nervous about running the compressor without it, but I am also wondering if a metal heat shield as per TVR a/c specced cars would help keep temps down or even to fabricate a small insulated pouch to put over the compressor. I know they make them for turbos but haven't come across one for a compressor.

[QBee]

What is the daytime temperature in Cyprus now?

[Belle427]

This stuff is easy to cut and wrap around things, should be quite easy to make a sleeve. Ive seen it cheaper on ebay but cant seem to find it.
https://www.carbuildersolutions.com/uk/heatmat-ref...

[jazzdude]

QBee said:

What is the daytime temperature in Cyprus now?

Around 36 degrees Anthony

[jazzdude]

Belle427 said:

This stuff is easy to cut and wrap around things, should be quite easy to make a sleeve. Ive seen it cheaper on ebay but cant seem to find it.
https://www.carbuildersolutions.com/uk/heatmat-ref...

That's perfect thanks

[N7GTX]

Yes, lots of options here

https://www.ebay.co.uk/sch/Car-Exhaust-Heat-Shield...

[jazzdude]

I think I will go with a belt and braces solution, form an aluminium shield over the manifold and stick the fibreglass matting to the underside, and also wrap the compressor with a blanket, that should keep it cooler I think.

[QBee]

The compressor surely generates heat when operating - not allowing it to cool will cause it to overheat? Discuss.

[Classic Chim]

Possibly a red herring but do you have your front splitter fitted.