Changing KV6 head gaskets. Advice on skimming and head bolts etc
 

Got the engine out my ZT to replace cambelts and clutch etc.

I want to change the head gaskets while its out. Is there anything particular I need to know about with the KV6? Such as different thickness gaskets etc.

Do KV6 heads need skimming when changing the head gaskets, and can the head bolts be re-used?

Why do you want to change the head gaskets?

Do you have a problem?

As above , why do you want to change them ? They are not known to suffer problems on the KV6 so unless you are doing other head work like valves or valve stem oil seals i would leave them alone .
If you are suffering oil smoke on startup then it is worth renewing the valve stem oil seals whilst you have the engine out .At just over 100k miles my seals were rock hard and not sealing much at all :eek:
The heads do not necessarily need skimming unless a straight-edge check reveals them to be warped ; this is unlikely . Mine were fine :} After the gaskets are removed however you are likely to be faced with a very dirty face which will take some cleaning . I used a piece of 4x2 timber which had been machined flat , wrapped in a sheet of fine grade wet and dry paper lubricated with soapy water , to polish up the face . Made a very nice job .
You can reuse the bolts .

Basically I don't know if the gaskets are ok or not. Car was bought cheap with problem of coolant rising out of expansion tank.
I found and replaced dead fan, and flushed and bled the cooling system. Seemed to behave itself after this with exception of temp gauge would sit a fraction over half way, and with the cap off the coolant would rise to top within seconds of starting engine. There was a noise at higher revs from belt area so I suspected water pump. So engine is out to change belts and water pump and clutch. Makes sense to change the gaskets.

Have a look at the liners while everything is off, I have found liners to be more of an issue than head gaskets on the KV6

:wot: :iagree:
Hi Ash,

From your description I would suspect that Mr. Previous Owner has put K-seal in your engine but can I ask first whether you followed the MGR procedure exactly when refilling and bleeding (notably raising the expansion tank and not running the engine with the bleed screw removed)?

When you renew the cambelts make sure that you replace the tensioner and idler pulleys as well. The noise you've heard could well be a sign of bearing wear but you'll find out when you inspect them and spin them by hand.

Also, beware of changing the water pump if there is no sign of leakage. More than one owner has found the replacements to fail after a short period of time. "If it ain't broke, don't fix it". :D

Simon

Done same job , was putting everything new including head bolts give attention to front head my one skimmed 100 micron at least.was raf.. same problem as you have.Good luck.

Remove all liners and check carefully for cracks in the block.

That sounds like way more work than I was intending!

Pretty sure it hasn't got any cracks. I could leave it running for an hour stationary and it wouldn't overheat etc. I was monitoring the temp via the dash and via obd. Cant remember the figures but when it got to the right temp the fan would kick in and bring it down.

Yep followed procedure. With engine running (after new rad and bleeding system) etc) it seemed fine. I had it running several times and kept it running for an hour or so after it had got to temp. Fans would kick in at the right temperature according to OBD and bring the temp down.
The only slight oddity was the gauge sat a fraction over half - literally a tiny bit.