Thread: Overheating - Blown Head?

Originally Posted by Frizz

Head checked and all looked good (no cracks).

What was done to the head in preparation to refitting

Was it just "visually" checked at the mechanics and refitted ....
OR .... was it taken to a head shop / crack tested / hardness checked / straightened / surface faced

Mike

As I say, I don't know. To my way of thinking if you take a suspect head off, it gets pressure tested by a head 'shop and shaved if there is any warp.
But I don't know. I am wondering if I should look further into buying this car or not.
I also would like to find out how hot it got when it blew the hose.

I am thinking that it could be an air pocket from not being bled properly when the heater hose was replaced.

I will try and obtain some more info from the seller.

Originally Posted by Frizz

To my way of thinking if you take a suspect head off, it gets pressure tested by a head 'shop and shaved if there is any warp.

But I don't know.

I am thinking that it could be an air pocket from not being bled properly

and there you have the answer ....

If the head was checked properly ... why does the mechanic blame the head??
If the motor has a air pocket ... why can't the mechanic bleed it properly??

So throw in a block that is not straight and requires decking ... or might be simple as a blocked radiator, thermostat or a bung radiator cap

Because the seller is not prepared to fix the problem, but rather sell and transfer it to someone else to sort out .... Work on the theory that it's got a shagged motor and pay the $$ accordantly ... if simple / you win, if replace, then you end up with something new .... but not out of pocket

Have a look at this current thread, pictures show this head is totally shagged

http://www.aulro.com/afvb/discovery-...jectors-3.html

Mike

The head only had a visual inspection when it was removed.

It looked good down the bores with the head removed.

The Disco wasn't driven once the temp gauge came up to red. They pulled over and topped up with water.

He says that there mechanic has checked the temp of various parts with a laser gun. He says that they are all normal.

He says that it is just pressurising and overflowing the system.

The compression readings were all in order, would this not be the case with a warped head?

I don't understand why you would remove a head; and without ruling it as a good unit refitting to vehicle.

Originally Posted by Frizz

... I am thinking that it could be an air pocket from not being bled properly when the heater hose was replaced.

I tend to agree.

Definite possibility.

Mongrel things if they get air locks. Lots of points for it to happen.

If you have a service manual (RAVE, Gregory's, etc.) just do a normal bleed as per (Don't forget to 'open' the heater valve).

If not there are several threads on here about the process.