Hmm, well, I'm not sure what to add to the title...

AC not cold
With the AC on both fans behind the radiator are running yet the air is only cool when the car is in motion.

Car Overheating
I've also had an ongoing issue with the car overheating while not in motion - a few posts on this site regarding that....no coolant loss, pressure tested, thermostat replaced, fans both kicking in when expected etc yet the coolant temp often reaches 100*C/212*F and creeps up to 113*C/235*F (before I panic and stop the car).

Is there any relationship between the AC cooling efficiency and the radiator performance?

The mechanic's advice is that the next best action is to have the radiator checked/repaired at AUD$1,300 / US$1,000 (it's the original, 15 years old).

Any thoughts or advice?

Troy.

 

Radiator is probably a good bet. I'm surprised at the price though. I replaced mine for $400 -$500 USD. The A/C might just need a charge of refridge.

 

Are you sure then fans are running on high speed?

The early water pumps could also be a factor -- any information on replacement. What was the car's build date?

With normally maintenance the radiator should be fine -- does it have the correct thermostat?

 

An often overlooked problem with the poor ac and overheating is the space between the ac condenser and the radiator. Over time debris will build up between them and even though the fans are running the air isn't getting thru.
Yours has good ac moving but it is overheating so air is moving across the condenser but doesn't sound like it is getting across the radiator.
Try flushing out the space between the units and also direct water thru the radiator from the fan side. Don't use pressure washer just a good strong hose stream.

 

@jimmyl - did your cost include labour?

@yeldogt - the fans are certainly spinning fast, my mechanic has assured me that the water pump is of the metal fin variety (2001)....hmmm....should I trust him? and the thermostat was the correct Jaguar part (I checked with the a couple of the Jaguar parts databases)

@avern1 - sounds plausible. I'll check the area and see if I can see any build-up.

 

Don't trust the thermostat completely. I have one that causes the engine to run hot and another that runs so cold that I can't use it in winter. But they both appear to open at the same time in hot water. I need to evaluate the difference in the opening at 100 C one of these days.

Removing the radiator and having it cleaned and inspected should be inexpensive. Shops here charge $100 US or less.

 

Really? That cheap? It seems quite a complicated process when I looked at the notes. I might stop by a radiator specialist and see what they say.

The local Jaguar dealer, Alto Jaguar, who are very professional, if not expensive, said they don't recondition them any more but just replace them.

My alternate [authorised] Jaguar repairer was the one that quoted me approx US$1000 (AUD$1400).

Troy.

 

Hmmm, I've just noticed that after driving the car for about 40mins in medium traffic the radiator itself was hardly warm - I could hold my hand on it [lifting the little rubber flaps on the panel to the left of the top fan....should the radiator be this cool when the coolant temperature is ~97*C / ~206*F?

 

Definately not. Unless there's a record of it, how do they know the waterpump has a metal impeller? Our 00' XJ8 had the original plastic when I bought it.

Have you tried turning the heater on full blast when your car starts getting hot? If not, I'd certainly turn the A/C off and run the heater. It's better than possibly blowing a head gasket.

I suspect that you're low on freon, but until the overheating issue is resolved, having a fully functioning air conditioner should be secondary. Keeping the engine alive is top priority. I'd take the above advice and check for either excessive debris in front of the A/C condensor or between the condensor and radiator.

 

I replaced my radiator myself, so no labor cost. It wasn't as difficult as you might think. It can be done without opening the A/C system if you are careful. Also, it is not uncommon for the radiators to get clogged due to different coolant types getting mixed and forming a gel. There is a test that can be done with an IR thermometer, but the rad should be at a relatively consistent temp. Don't, don't let the engine overheat, very bad things happen.

 

If the radiator is cool to the touch when the sensor is showing 206*F suggests that the thermostat is not opening!

Also might have a bad temperature sensor: located on the crossover pipe on the NA engines (not sure where it is on the SC models).

 

I recently replaced the thermostat and tested it was opening by heating up the car.

Seems to me that the likely culprit is either:

• Radiator blocked
• Water pump fins [despite this models should be metal]

 

What makes you say the pump impeller should be metal? Last I knew, OEM was still plastic.

If you tested the thermostat by heating up the car the radiator should have become hot.

Your conclusion that the radiator is blocked or the pump is not working are worth checking. It's possible the pump impeller is no longer connected to the shaft.

 

Hi RJ, m

My car doesn't instantly overheat - it's when it's very slow moving traffic, and much worse on a hot day.

I figure that if there is some flow through the radiator the thermostat will still open as it heats up....which brings me back to either insufficient flow [pump] or insufficient cooling [blocked radiator].

I've always assumed by pump has metal impellers as it's a 2001 model, my mechanic also said these models have metal impellers...could he/we be wrong?

...Where the best place is to check on the radiator for heat?

 

Of course, it might vary on which market the car was built for, but my 2001 built in May 01 F35063 had plastic
impellers.


Does the outlet pipe get hot? If not, the problem is most likely the thermostat.

 

To the best of my knowledge, Jaguar hasn't had a metal impeller waterpump since the mid 90's. Do you think the mechanic that looked at your car meant 'metal tensioners' (referencing secondary timing chain tensioners) That's the best I can make of it.
Anyways, if the new thermostat that you tested and the radiator is new (both fans functioning properly also) and installed and you are not loosing or having to add coolant, everything points to the waterpump. Just get a new metal waterpump or remove the old one to inspect what it's made of at least.
Hope this helps.