Hi

My car - Jaguar S-Type 2003, 109,000km

The members here gave me great support and advice on a problem I had last year - so here I am again with a new problem....

A couple of days ago, I noticed that my A/C was blowing warm (even hot) air, so I dropped the temp and nice cold air started to blow.

After a while, it started to blow warm/hot again!

I dropped the temp again, and cold air returned.

A weird note - I let it blow hot for a while, then it started to blow cold again all on its own, but the cold air doesn't always return without me dropping the temp. Then it may cycle again and blow hot again.

Doesn't matter if I adjust manually or have it set to auto - same effect.

Last May, I replaced the heater control valve because I was getting cold air on the driver side and hot air on the passenger side - all has been fine since then.

Any advice would be appreciated!

Thanks

 

Two things I would look at. First, the compressor has been known to act up on these every now and then. Not real common, but can happen. Do a search on compressor and read through the threads that come up.

Also, the climate control module usually goes soon after the DCCV, so that too may be your culprit. Again, search that here, many threads.

If you don't have the tools but have the ability to replicate the problem, I would get it to a garage that has the tools to test it. But go armed with knowledge of what to look for and work with them. Realize that many garage staff don't know the ins and outs of these cars. That said, a decent mechanic with the correct data should be able to diagnose it.

 

Inside cabin temperature sensors can fail too.

 

Could easily be a DCCV that's progressively failing and boy do they fail often by the age of our cars!

 

Thanks for your responses.

My wonky A/C is working partly. As I stated above, it blows cold then hot and then after a while cold again with no changes/adjustments by me.

I will check out the inside temp sensor later today if I have time.

From what I've read here, this sensor is just above the key behind a small plastic grille.

Any suggestions for removing the plastic grille without breaking it?

Also, I noticed what seems to be another plastic grille/sensor on the dash just below the middle vents and above the A/C controls.

Can you tell me what this is and if I need to remove it to clean it as well?

Thanks for all the help!

 

Take a look at post #68 here https://www.jaguarforums.com/forum/s...e-27185/page4/
I think the sensor you mention may be one of the motion sensors for the passenger airbag.

 

Thanks again for the suggestions.

I am pretty sure that I changed the DCCV last year but I can't find my garage receipt, and my garage is closed for vacation for another week, so I will wait until then to confirm with them, but I guess no part has a 2 year warranty today.....

I had the common problem of heat on one side and cold on the other - but after the repair all has been fine for over a year - until now!

I think the garage called it a heater control valve - Is this is the same as the DCCV?

Thanks

 

Yes it is, did you look at the link? despite the title the post I referred to shows the sensor positions.

As an aid to troubleshooting you could clamp off the output hoses from the DCCV and eliminate it from the equation. (Or otherwise)

 

Hummm, I'm gonna have to do some more reading as well..

I recently took a trip, 20hrs one way, and about 12-14hrs into it the Auto AC got warm, I'd switch it to AC Off then it'd get cold again. After about 30min I could go back to Auto for about an hr before the cycle would repeat.

The month I was up in WI I had no issues. On my way back to VA again about 12 hrs or so into it. Symptoms returned.