I'm planning to replace the radiator on my 87 XJ-SC. Does anyone have any recommendations on whether I should record, replace or replace with something better?

Also, I currently have an issue where the car runs fine, the charge remains in the healthy position on the gauge. I shut the car off and within an hour (sometimes immediately) the battery is dead. Could it be the cooling fan??

Any suggestions greatly appreciated

 

Renewing or re-coreing is a very sensible idea. No need to go to anything else uinless you specially want to. Good idea to change the hoses at the same time and also take a good look at the fan belts as they are easier to get at and renew rad out. Also ensure you clean out the fins of the aircon rad and oil cooler in front of the water radiator.

Does the cooling fan run on for an hour? If not, are you sure the battery is OK? If you really are sure it is OK, you have a large current drain. I think, repeat think, the only way to find it is to remove the positive battery lead and put a meter between it and the battery, and see what the discharge size is. Then fuse by fuse, remove each fuse one at a time and check for when the drain stops. This identifies the circuit with the problem.

Of course, a failing alternator can (again I think) cause a drain too, so maybe having checked the size of the discharge, disconnect the alternator as your first test.

Greg

 

Could also be a bad battery??? If you have the stock electric cooling fan, I'd think it could run for quite a while w/o draining the battery to zilch. Any idea how old the battery is? Terminals are clean, cables tightly attached?

I thought about an aluminum radiator, but I ended up just getting the original re-cored, since that option was considerably cheaper than replacing it.

Let us know,

John
1987 XJ-S V12
64,000 miles

 

Thanks for all your help. It turns out the battery was bad. Given I just bought it last year I kind of ruled that out. I'll also do some of the testing you guys mentioned in case there is something draining it as well

I'm going to try taking the rad out and then get it refurbished.....wish me luck!

 

Taking the radiator out is not a big deal at all. Just remember it's a great time to change hoses.

Once it's drained, you can easily lift it out yourself, no need to remove the bonnet.

Of course at this same time it would be worth considering ditching the engine driven fan, installing electric fans, ditching the engine driven water pump and installing an electric one...it goes on and on doesn't it :-)

Good luck with it!

John
1987 XJ-S V12
64,000 miles