Part #AJ85885
Friggin price dropped like a rock since I last bought it! Good for you.
John

 

I was trying to find a picture of what Truck Graphics is describing but, typically, I can't. This snip from JEPC shows the two bleed pipe arrangement:


In the early cars, (16) goes to a nipple on the LHS of the radiator, and (7) to the thermostat tower. Pipe (16) was later deleted and one of the connections on the expansion tank, together with the one on the rad., were both blocked off.
If you have the two-pipe arrangement, it's important to get them on the correct connections on the expansion tank, apparently.

Wise move to replace the coolant outlet pipe assembly as they can and do fail. If you also still have the biodegradable thermostat tower then I'd add that to you list of stuff to do.

Forum sponsor SNG Barratt has OEM at ~$72:
https://www.sngbarratt.com/English(U...&saveBranch=US

It's one of the parts that I would go with OEM.

 

Thanks for your help guys. Now that I have a part number I can call around to find one and see how long it will take to get here.
Looks easy enough to re and re even for me.

 

There’s an Old Youtube video of an AJV8 cross over pipe replacement. Link below

 

So, the data we have is that 1. the temperature gauge goes low, 2. the OBDII coolant temperature pid goes to overheat land (ignoring the possibility that the scanner is using the wrong calculation), and 3. no red light comes on. These contradictory things come from the ECM, sounds like the sensor may be wreaking havoc on the algorithms.

Added. Another thought, though unlikely considering what you've just had done, you're sure the system is full of coolant?

 

David, thank you for the video.It's a lot easier for me if I can take the laptop to the car and follow it step by step. That way I only have to do it twice.

Dale, yup that's pretty much the story. Happened once or twice last year and twice since I took it out of hibernation this spring. I took it to the mechanic the first time it happened and he changed the thermostat but couldn't really find anything wrong with it. Took it to the mechanic again the first time it happened this year and he did the a fore mentioned work and it ran fine for 2 500km+ drives. It's got lots of coolant and no fluid leaks of any sort. The sensor must be shot because I started the car this morning and checked the coolant temperature and it said 73C. The outside temperature was 7C. The car runs fine when this happens, no warning lights or restricted performance or cooking coolant smell when I open the hood. I don't trust it to drive it so If I can't get the replacement parts here by 2 weeks I'm going to bring the car home on the trailer and fix it there.

 

Hi folks, just an update and stupid question. The part came in and swapping it out took about a half hour but my new problem is where do I refill the rad? Do I fill it from the top of the thermostat tower?

 

Fill the brown container left rear of engine to the top. It has black threaded cap and is inches away from throttle body.

you'll see the fragile plastic pipes coming out of it traveling on top along the black plastic Jaguar v8 cosmetic valve cover.
John

 

I'm wondering if this temperature problem is an actual temperature control issue, or an indication problem only. The fluctuation makes me think it's indication, but if that fluctuation only occurs under specific and repeatable conditions, you may have an actual engine temperature issue. The little temp sensor doesn't know the speed of the vehicle, it only knows how hot it is, nothing else.
If the indication ever shows a ridiculous number, you probably have an indication problem, as mentioned previously. If your temperature is actually fluctuating I'd start with a thermostat no matter how recently it was changed. It's cheap and easy, and bad from stock parts do exist. Make sure it's installed correctly. It needs to sense the coolant temperature on the engine side, not the radiator side. A backwards thermostat could probably do weird things, I suppose, and you have weird things happening.
Pay attention to when your fans run because they are sensing the temperature in the radiator. If the engine is actually very hot, your thermostat will be open, your radiator will get hot, and your fans will turn on. Warm the engine and run it while parked and see what the fans do.
If the fans are working properly but they don't turn on when the temp gauge says you're 50 feet from the sun, you have an indication problem.

 

Hi Folks, I replaced the pipe and sensor assembly and refilled the rad, filled the reservoir, burped the lines to get the air out and took it for a short drive. The temperature reading on the OBDII reader said 96C at start up and 116C after a spin around the block, slow speed. Checked the coolant level and started the car in the driveway tonight and the temperature was 98C at start up and climbed to 125C when the temperature gauge in the car was midway, about 5 min. The fans did not come on and the engine was still cool enough that I could put my hand on the covers although the hoses were hot, I had the hood up for the whole procedure. No warning lights came on, the car runs normally, idling at 660rpm and the OBDII reader said no faults when I ran the diagnostics while the car was running. Could this be a problem with the ECM or would that through up a fault code of some sort? I'm going to replace the thermostat again on Saturday and I hope this solves the problem. I'm pretty much clueless but I do have an Icarsoft OBDII reader if you folks think there is something I should look at. AT least it's never a waste to put a new part on the car. Thanks again for your help.

 

Did a full R&R of cooling system recently. Taking cap off top of the cooling tower makes it easier to squeeze radiator hoses and burp air out of system.




Put lots of rags around it to stop any coolant leaking down to the knock sensors underneath/behind. Otherwise you’ll get a Restricted performance message.

 

Those temperature readings can't possibly be correct - at start up the temp should be whatever your ambient temperature is. 125C would have the temperature gauge pegged at the top. Are you looking at Farenheit rather than Centigrade?

 

There's something dreadfully wrong. The temperature cannot be 98C (or 98F) at start in BC, correct? Then, at the midpoint, it cannot be 125C (or 125F). The ambient to hot change in temperature should be something like 55C (or 100-110F) depending on your ambient temperature. But bottom line, not possible to have 98C ambient. And at 125C, the car should have taken notice. So, those readings do not correspond with the behavior of the engine/ECM. So, the readings, themselves, are wrong?

 

Good morning guys and thanks for your responses. The more info I get the more I'm thinking that there is something wrong with my OBDII scanner or I'm getting the temperature from the wrong place with the scanner. I sent an email to Icarsoft with the details and I'll see what they think, maybe I somehow need to calibrate it. The temperature was around 15C when I tested it last night after sitting for the 6 hours so I figured that should be around the coolant temperature. I'm going to change the thermostat on Saturday as Greg suggested and see if that makes any difference and I'm also going to make sure the fans are working by putting 12v directly to them. My mechanic will be back in town the week after next and I'll let him look at it again since he's the only guy in town that works on foreign cars. The joys of living in a small northern town. Since the car runs great even with all this and I'm heading back to work on Sunday, a 450km drive and I'm going to take the car keeping it around 110 - 120kph and see what happens. The back hoe trailer is going up with us so if something bad happens I'll put the car on the trailer and send it home. I've never been one to let fear and common sense hold me back and if I blow the engine I'll either have it fixed or replaced.

 

Unless iCarsoft has actually created a customer tech support team within the past couple of years, forget about getting any assistance whatsoever from them. On the couple of occasions I attempted to contact iCarsoft several years ago, all they ever responded with was "we will ask our field engineer to take a look at your issue". Never heard anything else from them. And note that I typed "field engineer", not "field engineers". Just one guy. Probably the same guy who was packing boxes and shipping orders out to customers....

 

That sounds encouraging. I'll wait for a week or 2 and if I get no answer I'll see what else I can do. I'm going to take the car to the parts store on Saturday when I get the thermostat and see if they have a scanner that works on Jaguars to compare the temperature readings. At least I'll know if it's my scanner or something else.

 

Get a spare ELM327. Dirt cheap, goes everywhere, great primary or backup reader. Basic OBDII is still very useful.

Other question: does your iCarSoft come with a basic OBDII mode (as opposed to Jaguar mode)? The water temp is standard OBDII...

 

Just a quick thought... have you tried holding a cooking thermometer against a cooling hose? It won't be 100% accurate but should at least give you a ballpark idea of what the actual temps are. If the actual water temp was 100 then I'd expect to see the hose fairly close to that.

 

Hi fmertz, yes the iCarsoft reader I got is Jaguar and Landrover specific. I will get the ELM327 reader as I've read a lot of good things about them here.
Are they Jaguar specific?

Hi brobin, great idea about the cooking thermometer. I never thought of that. Now if I can sneak it out of the house without the old lady finding out.....
I might as well just go and buy one. Also, nice car. Looks familiar but mine has 92000+ miles.

 

Looks like they could be twins. The ELM is great unit and not specific to any car. There are a number of good apps you can use. I use Torque Lite.