I have been troubleshooting leaks in my cooling system for some time now. I have replaced most everything except the upper and lower rad hoses and some smaller return lines to the reservoir. I have also experienced a blown out reservoir tank.

This all leads me to think I have a pressure problem within the cooling system. I would expect that excessive pressure would be bled off, but not in this case. What could cause the cooling system to over pressurize, if its even possible? Or does anyone think I am just dealing with a 10 year old car.

Any thoughts, I just sealed a leak on a coolant line going back to the rear of the engine under the intake on the pass side. This was leaking up front where it connects to the crossover pipe.

 

I'd bet you are dealing with old age more than anything else.

I've heard that the reservoir tank cracking at the bottom is a typical issue.

As far as rubber hoses go...4 years is the recommended shelf life. After 10 years of service in the hostile environment of an engine bay I'd say they are due.

If all else fails put a pressure gauge on it and see if it falls in spec.

 

Your most likely issue would be the engine running too hot, possibly due to a sticky thermostat. Any kind of excessive temperature will also cause high system pressure, and make leakage more likely. How about the electric fan operation, does it seem to run as normal? There is also the possibility of a water pump impeller that is disintegrating.
The best thing to do is to check the engine temperature with a scantool and see if it rises much above 100 deg. C or not.

A few things to check, good luck!

 

Thanks to both replies.. I replaced the thermostat when I replaced the housing about 6 months ago. The Tank first cracked in Dec 2010 and I replaced it then and it cracked again two weeks ago. It runs way to good to be a head gasket.

I will check the fan operation tomorrow. I have AutoEnginuity and it works, but I don't have the Jag bundle which means I won't be able to do some diagnostics but I will see if I can get it to give me actual temperature numbers.

The other thought that crossed my mind.. All the plastic parts that I have had to replace where disintegrating, literally as in melting around the edges that had been leaking. I wondered if this mushy S#%^ would have slowly clogged the radiator passages making it less efficient. One thing is for sure, summer is right around the corner.

 

It turned out to be a couple things.. The fan fuse was fried so the fans were not working. I was able to watch the temp using AE rise above 220 to 239* F and she started leaking. Replaced the fuse and the lower fan now comes on at about 220* F, I assume the upper fan will come on when it's hotter outside.

It turns out that the water pump appears to be leaking. Now that the car has overheated the water pump seal must have started leaking. It is the OEM pump with 170k on it. When it's leaking it appears to be spraying out behind the pulley and dripping down the front of the engine as well as being sprayed all over by the belt.

I am replacing the pump today in hopes thats the leak, but I can't see anything else that could be leaking in that area.

xjrgy, sinister, Thanks for the pointer to the fan operation..

 

Look for any broken vanes on the water pump when you replace it -- they did have problems with the pumps and the vane material was changed at least three times. This can cause overheating.

You should also do a search on the proper operation of the fans -- at 220 I believe they should both be running.

Are they running with the A/C on.

How is the antifreeze concentration?

With the new water pump you should make sure you have the correct fluid concentration. Then make sure the fans are both running correctly and observe the temperature gauge to see if the thermostat looks to be operating correctly. What make of thermostat did you use?

You could have a bad relay or sensor -- coupled with a bad pressure cap.

Heat is the enemy of the system -- lots of problems start. And ........strange things do happen with a bad head gasket - but look after the simple things first. It's strange you would have two tanks fail !

 

I didn't understand where the leak is. I had a leak after having the engine replaced. I figured out that the machanice had the connections crossed up by the windshield on the driver side.

 

Thanks to all. It turned out to be a combination of a blown Fan fuse and a bad water pump. The pump seal was leaking behind the pulley and spraying coolant all over the front of the engine making it difficult to see where the leak originated.

Replaced the water pump and fuse and she's back on the road leak free and fan cooled.

 

The same symptoms I had with my car. Kept replacing cooling system parts including the reservoir. Turned out I had exhaust gases leaking into the cooling system which could only be fixed with a head gasket replacement. Car is still sitting...

 

That sucks, and could still be an issue that I may have to face. However, all the parts I have replaced are the plastic originals that are beyond corroded, they turned to mush in your hands. I watched my temps go beyond 240*F before overheating and no fan. Replaced the fuse and the lower fan comes on at 220*F and stays on until 213*F and no overheating and no leaks. Also, everything I have replaced has over 10 years/160K miles.

I have suspected the head gasket before, but keep getting proven wrong. Fingers crossed as I want 250K and I am at 175K.

 

I think both fans should be running, in my case both do in summer and in winter time.....

 

The AntiFreeze reservoir unit was just replaced on my 1993 Vanden Plas and the new unit lasted about 50 miles before it started splitting on the seam and leaking coolant. Had the mechanic send it back and got a second one from Jaguar and the SAME THING happened after running about 10 miles. Took it back again. Now, waiting on the third Reservoir Unit. Sounds like a manufacturing defect on the AntiFreeze Reservoir Unit that Jaguar should look into.

 

First, you are in the wrong section unless you are posting as general information.

Second, you may very well have some other problem that is causing the reservoir to split as soon as the engine is well warmed up.