I just bought a 2001 Disco SE, As alway's when I buy a new car I replace all the fluids including brake, ps, oil, differentials etc. I was working under the hood changing to spark plugs. I was using one of those hand held work lamps with an incandesent bulb (Trouble Light) I was interrupted by son who wanted a ride somewhere nearby. I interrupted my task and obliged him. When I came home, I was horrified becasue, I had inadvertantly melted a hole in the top of the expansion tank!!! I left the trouble lamp on while it was left laying on the tank. It also melted a hole in the nearby fuse box.

The hole was small and while hot I was able to form it back together. I went to Autozone and bought some epoxy that was supposed to used to plug holes in plastic tanks. I slathered it on and it promptly dried to a very hard bond. I let it cure over night. The next day, I tested the system with a pressure tester and it held pressure. I took it out for a test drive and had no problems. However, the so called " tank epoxy" had begun to loosen around the periphery!! I used a about a 1/3 tube of Industrail Sized JB Weld and slathered the entire top of the tank with a thick layer of JB Weld. This ultimately did work. I did however order a new tank from Rock Auto for $31.00 plus shipping of $10.00.

The moral of the story is be careful using incandescent lights with modern vehicles. There are lots of plastic parts under modern hoods that can easliy be destroyed. Flourescent lights are cooler but they are not as bright and dont illuminate as quickly. The second moral is dont mess with any expoy product sans JB Weld all others wont permanently bond like JB Weld.

 

Well, working with a small piece like that that goes thru lots of heat/cold cycles, and heat at above 200F, and pressure up to 18 PSI, even JB Weld would eventually let go, just takes longer. New tank is the way to go. Fuse box lid at the salvage yard, son will have to stay outside with mom until he is 16 usually. Great tour when driving training begins....

 

LED's are the way to go, i bought this a while ago and it works well:



edit: i just noticed your user name. i also own a boston green e36

 

After watching my son burn the carpet on a beautiful Range Rover, we now use CFLs in trouble lights.

 

Good sir,
Get a new expansion tank. About $75 with shipping.
Don't even think of using a kluged expansion tank.
If you lose coolant and over heat your engine - you are simply
done.

these engines when overheated ruin the head gaskets.
And, worse - they drop cylinder liners.
For $75, get a new expansion tank.
I can't state this enough.

And, put in a new thermostat while you are at it.

 

Your right, I already ordered a new one. I dont think this one will let go though!! I think it's now stronger than the OEM tank but it looks like h_ _ l
I used a whole industrial sized tube of JB and even embedded a zip tie in their. I fully understand the importance of not loosing pressure in a cooling system. I ordered one from Rock Auto it was only $31.00!! plus $10 shipping.

Good observation "Bostongrun" is the color of my 97 328i

Smart guys out there!