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Having trouble with the ever tough leak detection kit used for checking leaks in coolant system of 2000 XK8 convertible. The car is new to me and drivability/reliability has been a serious issue from the very beginning. Our ownership started at the end of January this year. A variety of codes have been logged each time we use it. Haven’t gotten more than 30 miles away without an engine light or limited performance notice on dash. Each dealt with and cleared but new codes thrown on next attempt to use it. About 9 attempts so far. Most recent sent car into limp mode. P0121 Code indicates coolant leak affecting throttle position sensor. Coolant level has been low and coolant added so this makes sense. I Rented the Ever tough 67085 model testing kit with Adapter 67086-A from Parts house but can’t get pressure to build up in system at all regardless of multiple efforts/ Adapter is identical in diameter with O-ring at correct level to seal off overflow in plastic tank EverTough kit
attempts. Some pictures attached. Any ideas?
I also had leak issues with my 2000 XK8.The PSI for the system is 15 I believe. Why you are unable to build pressure in the system seems odd. With the engine running you should be able to feel pressure in the radiator hoses. If so then I suspect the tester you are using is not compatible. Advanced Auto has a test kit that you can borrow that has a much better selection of pressure caps, i believe No 7 was the one that worked for me. You could also use a little dye to make the leak more obvious.
As far as codes and issues first make sure your alternator is charging the battery and that the battery is in good shape. One of the codes you mentioned was thrown by my car and I had to have the thottle body rebuilt. To make life easier I think getting a copy of the workshop manual is a must. Takes the guess work out of the steps to diagnose code issues.
Put a bunch of white paper under the car and run it for a while and see what drops. From there look and see if you can follow the leaking coolant. It's either a hose, seal or O-Ring. For me it was an O-Ring that had parished and was dripping intermitantly. That's the cheapest way to do it. The paper makes it easy to see even the smallest amount of coolant leaking.
I also had leak issues with my 2000 XK8.The PSI for the system is 15 I believe. Why you are unable to build pressure in the system seems odd. With the engine running you should be able to feel pressure in the radiator hoses. If so then I suspect the tester you are using is not compatible. Advanced Auto has a test kit that you can borrow that has a much better selection of pressure caps, i believe No 7 was the one that worked for me. You could also use a little dye to make the leak more obvious.
***David, I will try the Advanced Auto tester and the dye is a great idea...
As far as codes and issues first make sure your alternator is charging the battery and that the battery is in good shape.
**On advice of others, I replaced the battery with best AGM available and have tested alternator.
of the codes you mentioned was thrown by my car and I had to have the thottle body rebuilt.
**throttle position sensor was replaced by former owner...I will put a throttle body rebuild in my list of possible fixes.
To make life easier I think getting a copy of the workshop manual is a must. Takes the guess work out of the steps to diagnose code issues.
Good luck.
Go to automotive stop and rent their pressure tester. It will be the green cap in the assortment in the case.
First place to look is the back of the throttle body, next, under the thermostat housing and lastly the norma connections on both sides of the engine bay. Mostly it's the one on the passenger side.
Come back here if that is the one, a not so Jaguar fix is simple.
I found a crack in the thermostat housing at the outlet for small hose which is connected to the plastic reservoir with radiator cap. I plan to replace the housing with the aluminum one available. Also will replace thermostat. Should the water pump be done as well? Should any other connections or hoses be replaced while I am doing this?
Good move to replace with aluminum housing and couple of things to be aware of.
The rear bolts are difficult to get at and bending a 8MM wrench is the answer I came up with. A crow foot wrench will work, just hard to find on in that size.
Water pumps are not bad for on price and you are right there, so yes, good idea.
Get the gaskets for the crossover pipe, two of them.
Be careful with the two plugs on each side of the housing, they are your knock sensor connections.
Lots of write ups on how to and I used Allen head bolts to install the new housing, easy to get the rear ones in with a 6 inch extension.
OH, get a new short pipe, most are swollen, you might get away for less the $100.
Sorry to hear about your woes in terms of reliability since Jan 2021. Reminds me of myself when I first got the car. It took me a while to get the car up "on the road" with similar issues to you. But, once fixed, my XK8 has been a reliable daily driver ever since.
+1 to David Dougherty's suggestions - check battery and alternator and consider the Throttle Body - maybe it's just a dodgey throttle position sensor. The Workshop manual is available here on this forum under the Sticky's threads. It has saved me countless hours and bruised knuckles.
I'm not saying you don't have a coolant leak, as your thread title says, but deal with the problems one at a time. We've all been there.
I recently did the overhaul of the front coolant system of my XK8. Nothing unusual and well documented here by Fellow Forum Members here. Totally agree that the Aluminium Thermostat tower upgrade is a must, plus while you're there, it makes sense to change the water pump. It's a cheap part and if you're disassembling the area, it makes sense to put a new pump in there. Hope you've a new cross over pipe, plus coolant temp sensor - be careful of the electrical connector to the sensor as it may be old and crumbly. I would also mention that you should flush out the system using a chemical radiator cleaner - you'll be surprised the amount of crud that builds up in the system. Also the Coolant expansion tank has baffles in the bottom that catch sediment. It's worth washing the tank out out too.
FWIW just behind the Thermostat tower, in the AJ-V8 engine's Vee, are two knock sensors, which will probably get wet while you're working. You'll get the restricted performance message when you fire the car up but the heat of the engine burns the coolant off and hopefully it should be fine.
Good move to replace with aluminum housing and couple of things to be aware of.
The rear bolts are difficult to get at and bending a 8MM wrench is the answer I came up with. A crow foot wrench will work, just hard to find on in that size.
Water pumps are not bad for on price and you are right there, so yes, good idea.
Get the gaskets for the crossover pipe, two of them.
Be careful with the two plugs on each side of the housing, they are your knock sensor connections.
Lots of write ups on how to and I used Allen head bolts to install the new housing, easy to get the rear ones in with a 6 inch extension.
OH, get a new short pipe, most are swollen, you might get away for less the $100.
Cjd777...thanks for your help. I am in Orange Beach Alabama and typically get parts shipped to me as nothing local but the most generic of part. I found water pump ok, but crossover pipe, gaskets, rear bolts not available there. Where did you find crossover pipe and the gaskets for it? Barrett has but delivery time puts them here in mid July! Hoping to get the car back on the road much sooner.
Ken, if the crossover pipe is OK and you are careful, don't see the need for one. The later models had the sending unit in theirs and was a issue.
Just the gaskets because so much easier to get that out of the way to replace the parts right behind it, and that short pipe. Then again, if you know how to make gasket, that will solve that.
Be aware the thermostat has a orientation with the hole in it. I think it goes down, but check that out, it's been a while since I did one.
As mentioned, a flush would be good and the fans come out of the way very easy, just be careful with any plastic plugs.
Ken, if the crossover pipe is OK and you are careful, don't see the need for one. The later models had the sending unit in theirs and was a issue.
Just the gaskets because so much easier to get that out of the way to replace the parts right behind it, and that short pipe. Then again, if you know how to make gasket, that will solve that.
Be aware the thermostat has a orientation with the hole in it. I think it goes down, but check that out, it's been a while since I did one.
As mentioned, a flush would be good and the fans come out of the way very easy, just be careful with any plastic plugs.
Wayne,
Thanks for the prompt response and help with this!!
I will certainly flush the system as you recommend.
Looking forward to getting this car road worthy!
There are 2 "issues" to using the pressure tester on the cooling system. (Never used the tester on the pressure cap). You have to have the correct adapter for the pressure tester. The pressure tester kit shown in the image from your original post looks like the same one I rented. The parts store provided a test adapter that was supposed to work for the XK8 but it didn't fit. (It was close, but I couldn't thread the adapter down onto the expansion tank to make a seal).
(My car is a 2002 4.0L if you have the 4.2L you might need a different adapter). There's also a compatible adapter from Rock Auto from a different manufacturer. It will work with the rental tester kit shown above.
The second "issue" is the overflow tube from the expansion tank. It's not easy to see but at the bottom of the expansion tank pressure cap "neck" is a rectangular hole that leads to the overflow tube. Since the overflow tube/tank are open to the atmosphere the tester won't hold pressure unless you block/clamp the overflow tube. Once you have the proper adapter and the overflow tube blocked off the pressure tester should operate properly. After I got these 2 things sorted out I was able to find the first leak in my cooling system.
FYI I also had a high temp/high pressure leak at the coolant level sensor in the bottom of the expansion tank. I wasn't able to locate it until after I fixed the leak at the Norma connector on the 'Spider/Octopus' heater hose behind the passenger side head.
Tropic Cat,
Thanks for the great information!!
I am awaiting the parts to repair. I will be replacing the thermostat housing with aluminum option; crossover pipe connecting to each side of engine with coolant temperature sensor pre-installed; water pump and short pipe.
All should be delivered by Tuesday next. Will replace any hoses that look in the least bit tired. I will do a chemical flush and renew coolant.
I have been tempted to order the octapus hose setup and do that as well but previous owner had a lot of work done on this car and wouldn't be surprised if this was done. Sadly, I can't contact him and don't have documentation to know for sure.
I replaced all the heater hoses and the radiator hoses on my car. It was the first thing I did. A lot more work than it should be but I was sure all the hoses were 20 years old so they were way overdue. I also replaced the plastic "distribution pipe" (the plastic pipe w/ the coolant temp sensor). The thermostat housing was aluminum so I didn't have to replace it. I haven't replaced the water pump yet and hope I can still say that ten years from now.
Be CAREFUL with the temp sensor connector. Mine was missing the retaining clip and the entire connector housing (on the engine harness) was very brittle. I had to buy a new connector since the retaining clip was broken off. I could have put a cable tie around it and held it in place but the connector housing was so brittle it would have disintegrated if I put too much pressure on the cable tie. The connector is easy to replace but you'll be happier if you don't have to replace it.
Jagvert - can relate to the reliability issue of your car. Mine was basically unmaintained by the previous owner. Finding out repairs done only when they had to be. I'm working thru the list of typical things to repair. Hope your project is going well.
I need to replace the expansion tank. Suggests on a good source for parts? Moss looks good. SNG Barratt looks good altho shipping time is a concern. Amazon offers no brand products. I'm hesitant about using Parts Geeks. They sell garbage no name ignition coils for XK's which doesn't inspire confidence.
OBD/Bluetooth/smart phone looks like a great way to get real time data. Very helpful (particularly cooling system temp!). I've ordered a generic Bluetooth connect and have OBD Fusion ($10) which works on a Mac. I see Torque mentioned in here but I think that's Android only.
I need to replace the expansion tank. Suggests on a good source for parts?
I like. Barrett. They always get the parts to me quickly. Before the estimated time. I have also ordered from vendors on Amazon and have been mostly pleased with them but the thermostat housing in aluminum was not delivered and apparently lost so had to reorder which has delayed this repair. We had lots of rain and some flooding with the recent tropical storm which may have played a role.
Good luck with your expansion tank replacement. I haven’t done that yet.
Well, I don't mean to sound heretical, but they have the expansion tank at Rock Auto. I got one there a couple of years back. They all seem to develop weeping joints after a while, but fortunately, they're not real expensive.
The rockauto.com coolant reservoirs are decent. Been running one since September 2017 with no issues, and I have a new spare one ordered earlier this year for when my current one begins to fail....
06-13-2021, 12:04 PM
Check for coolant leak-help
