Hi Guys

Since replacing the water pump, thermostat housing, thermostat, water hoses and coolant temperature sensor, I still occassionally get the fans on high speed when going up long hills or sat in traffic on hot days. The next thing to be checked was the Radiator, and I am not surprised this big V8 is running warm in the Australian heat.Has anyone had their radiator out or looked at it from the top with the trim cover off ? Do you see what I see, or is mine just - not right.

The end tanks are about 3" thick and obviously designed for a double or triple core matrix. So why then has mine got a single, 1" wide matrix in there ? I will be pulling this out and having it recored very soon, has anyone got any tips on removing it from the car. It looks like it is attached to the air-con condensor with a couple of bolts, but other than that it looks like it might just lift out ?

here's a photo, see how the tank shown is way bigger than the very thin single core........

 

Have a look at these photos, I think your radiator is correct.

https://www.jaguarforums.com/forum/x...61/#post814907

From your description, could you still have any air in the system?, or perhaps the radiator does need flushing.

 

I flushed it when changing other parts, and water flows freely through the core, no blockage. Also no air trapped as far as I can tell. It just seems strange to have tanks and end plates for a 3 core radiator and only have one core. That's not much heat transfer for a 4 litre engine.

This car is a UK import so I wondered if the cooler weather there warrants a single core but maybe export models have more ?

 

My 06 XKR only has a one row core, it works fine in 100 deg heat. It is normal for the fans to go to high speed sitting in traffic or pulling a grade, thats what high speed is for. If it didn't go to high speed, that would be a problem. One thing I did find was a lot of debris clogging the area between the radiator and the AC condenser. I had to hose it out.

 

+1 on all points.

It routinely hits triple digits here in the summer and mine runs fine. Temp stays around 198F - 202F on average. High speed fans kick on mostly during stop and go, but not a lot of uphill grades here.

I have 3 radiators in my garage right now (don't ask) and all are narrow one row core units.

 

Ok, maybe I am worrying for no reason. I keep reading that if the high speed fan comes on, it's a sign of problems. The temp seems to be around 195f on average and the high speed kicks in at around 205f according to my infrared thermometer.

I tried a new temp sensor a while ago, but it must have been the wrong type as the gauge in the car never got above a quarter, and the high speed fan didn't kick in and the water started bubbling out into the overflow tank. Changed it back again pretty quick and no damage done.

I always use the air on, so the low speed fans are on all the time as expected. The area between the rad and ac condensor is very clean , no debris and the fins are all clean too.

Thanks for your replies.

 

Mike,
I understand your frustrations with finding the right radiator for your car.
My XKR radiator seems to have become very scarce.
What parts numbers do yours have?
Maybe you are sitting on Mine.
I need 4190BB or BC
Niessen seems to have two for the XK8 male and female TOC fittings and none for the XKR. Yet the parts locator indicate there is a Niessen for it.
Crazy
What have you found out?

 

The two new ones are Nissens 61700 (which replaces MJA4190AF) and 61701 (which replaces MJB4190AF). I was told by Graham (GGG) that the suffix is often just an indicator of supplier changes. Two different Jag dealers say I need the MJB4190AF for my XK8 based on VIN#.

It appears that the two radiators I have are identical except that one has an adaptor fitted to the TOC connection (see pictures). I haven't had a chance yet to try the adaptor against the transmission line on my car, but the eyeball method says it should work.

Pictures are below. Sorry, they keep coming up sideways. I can get pictures of the entire unit(s) if you need.