Hey folks,

So I've been chasing a mild, summertime overtemp problem for some time and working my way through things. I was getting ready to recore the radiator (I had it cleaned and painted, it was plugged up (why the heck don't these things have a drain plug?)) and when it was sitting draining the residual coolant I noticed a chalky substance in the coolant and then noticed that all the coolant was an opaque green.

My first thought was blown head gasket as that would explain both the overtemp and the cloudy coolant. The oil is clear so it's maybe just combustion gasses getting through.

Question: Could this be something else?

Question: Looks like I need a couple of special tools to keep the cams in place when reinstalling and insure TDC on everything. Anyone have a good source for those or care to lend me yours when I get everything apart? (I'm working on a 4.0 straight 6)

Question: Do I really need to remove the darn hood?

 

Sounds like your coolant is fast becoming "mayonnaise", and is a clear sign of head gasket failure and oil in the coolant. This is not unknown on AJ6 and AJ16 engines, but not a common problem. You say the oil is clean, but remember oil floats over water, so any coolant in the oil will be lying at the bottom of the sump. So it might be prudent to release a bit of "oil" out of the sump via the drain plug for a check.

I assume your question about removing the hood is because that is what Jaguar say you need to do. It is probably possible to remove the head without taking the hood off, but you will have more room to move around with it off.

 

You will be much happier if you remove the hood.

Tool:

http://www.motorcarsltd.com/18G1433-A.html

 

Where are you buying your head bolts from? I'm in your shoes, my Indy said jaguar used cheap composite head gaskets in the xk8 and xkr. What's weird,he mentions weather changes flood his shops with head gasket repairs. He made his own locking tools for the cams.He says the flat spots on the cam stays up, and a mark on the tranny lines to a hole to time the unit.