Hi, I recently bought an S Type R (had an S Type 3.0L Sport for 7 years before that)- so it may a case on “new car paranoia but ....
I have a strange clunking/knocking sound coming from behind the dashboard (sounds like it is low down somewhere between the centre console and the glove box).
The noise itself sounds a bit like “bad plumbing” so I am wondering if it could be the Air Con (maybe the fluid needs topping up and has air in it making a clunking noise) or could it be one of the Stepper Motors that control the flaps to open close the different channels for the Air Con?
Does anyone else have experience of something similar?
Best regards
Cas

 

Search the forum using "faulty servo motor issue" as your search phrase. You'll find plenty of reading that will probably point directly to your current issue....

 

Thanks Jon I will give that a try (I did a search for "Stepper Motor" but did not find much).

Regards

Cas

 

It's not a common problem on the STR. Try this-Turn the climate control system to off. Then stop and start the car. In off no doors or flappers should be moving. Maybe this would give some hints if the noise is any different. The S Type is known for some gurgling type noises that we think is the refrigerant moving thru the pipes as the A/C system pressure equalizes after shutdown.

One thing you did not mention: Was the car moving when this noise happens?

You should still be at the tail end of the factory 4 year warranty? Or did it end in June of 2011? Maybe you can get an AWA? (After Warranty Adjustment). The AWA is at the dealers choice but I did get one last repair here in the US after my warranty was gone.
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Hi, I just did a search for "faulty servo motor issue" and the only result returned was my original post- hopefully someone can shed some light on this noise.

 

Hi tbird, yes the cluncking noise stops if I trun off the air con and also if I change the A/C settings from Auto to manual and select face level vents. There is always another noise when I shut off the engine- lots of gurgling/wiring which last about 2 minutes then stops dead- I assumed this other noise was a circulation pump running (I guess to cool things down under the bonnet).

 

No warranty left??

You will need a dealer scan tool to check the positions of the A/C flappers and such. It's really a shame Jaguar did not build in more self-test routines in the S Type.

My wife’s Lincoln LS has a climate control self-test that cycles everything in order and then displays 888 if everything is OK. Otherwise it spits out trouble codes. Very handy to make sure where the problem is!!
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It does sound like it's probably a (stepper) motor for a vent / other flap.

The dealer tool can command each one individually I think, but is it worth the cost.....

I never tried AE to see if it can!

 

Hi tbird6 and JagV8, thanks for the replies.
Unfortunately in the UK we only get a 3 year warranty on Jaguars so I am well out of that now.
I found a document about fixing a servo motor issue on the X-Type which although a very different car gave me the confidence to get my toolbox out to investigate further. I took the glove box out and had a look around with the A/C running in different settings and all seemed well except for some black wire that was running through the space and fouling the linkage (seems the last owner had a phone kit removed but they just cut the wires and pushed them behind the dashboard). I have removed these and the tapping/clunking seems to have stopped (hopefully for good).

There is still a “plumbing” noise once I shut the engine off which sounds like the A/C pressure stabilising as suggested. I am planning to get the car serviced in the next few weeks so will have the air-con checked and topped up if necessary.
Regards
Cas