Took my XK8 out last week only to see a low coolant level light about 700 miles after a flush and fill. Filled up the overflow tank. (BTW how full should it be?) Took it back out and ran fine. Noticed after I got home and parked it that there was a wet spot under the car so obviously a leak. Put it in the garage and today went about finding the leak. Drove it until it reached midway on the gage. parked it. A few drips behind the front wheel about even with the amber light. Opened the hood and it looks like the leak is coming from the seam between the halves of the overflow tank. is that a normal failure point? Wiped it down real good and the seeping out returned in little drips.

I guess it's safe to drive as long as I have water and watch level.

 

As I understand with these cars in a proper working system the level in the resivor tank should come up to the bottom of the opening of the tank when you look into it.
The over flow (resivor) tank can fail as you are describing. Easy job to replace.
If you can I would clean it all up and when cold do a pressure test on the system to make sure that is the only place.

 

Wow, that is an expensive piece of plastic. I'd guess that buying a new OEM is still worth $100 more than one from a parts car.

 

From the Driver's Handbook for your MY:


(click on the image to enlarge it)


Overheating is an engine killer - not worth the risk.

Graham

 

Yep. I see two small hoses coming off of it. Are there more connections on the bottom or is that it?

It just seemed to me that the expansion tank should have room for expansion when the coolant gets hot and then shrink as it cools. I guess the British do it differently.

 

There is another on the bottom. It's a hose about the diameter of a wine cork. Which by the way can be used to stopper it and save losing more coolant. Save the wine until the job is done.

Don't buy a used tank. New ones come with a cap and sensor, both of which might be bad on a used one. Save your old ones for spares just in case.

 

The cap is designed to do that.

 

Remember that as the engine goes from hot to cold or cold to hot the cap allows the coolant to move from the expansion tank to the coolant recovery bottle. If your leak is in the expansion tank you might want to replace the coolant expansion tank cap.

Just an FYI I have been dealing with a leak that shows up behind my front wheel and found it was coming from the thermostat tower going down the engine valley then traveling down the back side of the engine and trans. Be sure where your leak is.

 

I went out today to install my new overflow tank only to be greeted with a type of hose clamp I've never seen before and don't know how to open. Any assistance would be appreciated.



Unknown hose clamp with flash





Unknown hose clamp

 

Squeeze the two outer protrusions with vertical sides with a pair of small pliers. At the same time use a small flat blade screwdriver to gently pry up in the space between the sides you are squeezing. It will just pop open.

To re-close, just squeeze together the same sides with the pliers.

 

Got it, thanks.