OK, my '01 XJ8 has succumbed to the common slow coolant leak. I've been adding about a pint or so every week for about the past month while I've been trying to locate the source. Today I confirmed I'm getting a few drips (orange on newspaper) from the firewall area at the steering column. I've also confirmed a bit of fluid on a weld lip on the firewall (engine side) under the overflow tank where the two larger hoses (heater) disappear and go to the firewall. I'm assuming it's one of the heater hoses, and I'm assuming there is a somewhat familiar nipple on the engine side that the hose fits to (not getting any odor from inside the car). I'm not a novice to the engine, thanks in part to all of you and having completed a full timing component swap, new waterpump, upgraded thermostat housing, new crossover and new cooling tubing to the front end. However, I haven't had an opportunity or need to go digging deep at the back end. It's 110 where I am, and I'm looking for any direction (pics-schematics, been there done that's, etc.) that might make this little endeavor a little more streamlined. Anybody that's been there knows it's a birds nest between the throttle body and firewall so any input on what I do, don't need to remove or an area I might want to concentrate on, easier from above or below and any pics of that area from the pros would be greatly appreciated.

 

Its your lucky day bluerdg. I just took some pictures today of the hoses all around and below the expansion tank. Actually I am not 100% sure that all the hose routing is correct. I lost my previous pictures of when I took it apart. I have looked at the best schematic I could find and think that I have the hoses hooked up right. Was hoping to post the pictures on here and see if anyone else could tell me if I have them hooked up right. Guess its a common problem for these hoses to get mixed up and changed around when the cooling system is worked on. Hope these pictures may help you. I do not have all of the hoses in place yet. I am working on getting a couple of replacement hoses that run down through the valley. I wanted to replace these before I put the intake manifold back in and could not get to them later. There is also an electric water pump under the expansion tank that pumps water to the heater matrix (core).

 

A free rental of a pressure test kit from one of your local auto parts stores will tell you in one minute where the leak is with a cold engine.

 

Slightly off topic, but I noticed that if I fill my coolant tank 'to the brim' (above the level of the overflow hose that goes to the overflow tank), the coolant level will constantly drop down a little below the hose that leads to the overflow tank (after around 300 miles). It takes maybe a quart to fill it to the brim again.

Is this simple overflow into the overflow tank around the right front wheel, or is this losing coolant? I do not get a low coolant warning and it runs fine. I did have a slow leak before (faster, low coolant light would come on after ~ 100 miles), I took it to a dealer who did a pressure test and they said they found a broken hose clamp. The low coolant light never came on again and it seems to not drop like it did before. Is it safe to assume what I have now is normal behavior from hot, overflowing coolant or am I missing something?

Thanks, guys!
(1998 XJ8, VdP).

 

Here is a procedure for earlier cars that will have info for all 98 to 03 XJ

bob gauff

 

The pics are just what I was I was looking for. I was assuming it was heater hoses(still may be) but it looks more like one of the hoses in the mix leading out of the bottom of the expansion tank (hope so - not looking forward to having to pull the manifold to replace heater hoses) Based on the location I'm hoping now that it's just one of the hoses or connectors in the area you took pictures of.