7 replies to this topic

[Kam]

Mate called me over to take a look at his 998 head he removed as the plugs were getting caked in oil but on the block No1, 2 and 4 pistons had water in them.



Top hose from radiator had been removed but not the hose on the water pump, he said as he was lifting cylinder head water poured out under the head.

Would leaving the water pump hose still connected cause this??

I think he knows this aint looking good for his wallet!

[john1.2pearl]

i would put the water down to the coolant from removing the head tis normal !

[T.Harper]

Yes basically you've broken the seal on the head gasket and all the water has drained into the cylinders. No biggy - mop it up with rags. May need to drain the oil though after you whack it back together and before starting - may have water in the sump.

This is no proof that water was there before, or that the head gasket has blown. If the plugs were fouled you could try replacing guides and stem seals, but if the bores are worn there's not much you can do without hauling the block out to have a rebore. If you suspect a warped head you can have a surface skim to flat the head at your local machine shop.

Make sure the block face is clean, dry and grease free before putting the head back on. You can stick twisted up corners of rags into the water holes to make the level go down a bit which stops these making the gasket/head/block wet before you fasten everything up.

[Kam]

He said it was misfiring and not starting and then he saw the oil on the plugs so he thought he'd take the head off.

But towards the end of the day No1 and No4 pistons were almost dry so its leaked through, does this mean his piston rings are gone - Which would explain the oil on plugs and misfire?

[T.Harper]

Nope rings have a gap in them anyway especially when cold. Onlyw ay you can gauge for wear in situ is to use a dial bore gauge to measure the size of the bores.

Oil on plugs is oil being burnt either from leaking valve guides, worn rings, both or a really oily breather. Was it smokey when running (blue smoke?) if so when - idling and deceleration or when you plant your foot and accelerate?

Misfire could have been due to gasket, but could also could have been due to damp /old ignition parts or even carb/air leaks

[T.Harper]

by the way this does mean the oil will need to be drained as water is now in the sump. Or you will start this up and then think the gasket has gone again as you'll have may o in the rocker cover :s

[Kam]

Oil will be changed but I'm hoping new valve stems is all thats needed.

He dont know about the smoke it just suddenly died on him whilst driving, He's replaced the main ignition parts but it turns and if it does start it cuts out after a few seconds. He then looked at the plugs again and noticed whilst they were black from running rich they was also covered in oil - Hasn't been started since.

I'll pass this info onto him and see what he wants to do as he's mega broke at the mo!

Thanks for the help T.Harper

[L400RAS]

Hi Kam,

As everyone has said, its because he didnt drain the water. For next time tell your friend to take off the bottom hoze on your radiatior. I know this seems a waste of water, but saves this happening.

as T.Harper suggests, you need to drain some more water out before fitting, i would suggest pulling hte bottom hoze now - i find a head removal a good chance to back-flush the radiator with the hoze pipe, alos with the rad removed i always fit the bottom hoze to it, rahter than trying to connect in-car, as that is a pain of a job to do in-situ.

Ryan.