325i Touring head, it's ruining me!

[Stu_D]

right, my cylinder head cracked on the way home from failing it's mot, awesome! so set about getting hold of another head (thanks tom) replaced my viscous coupling as i thought it had died. now replaced the cylinder head, renewing the head bolts but not skimming before putting a new one on (now i know, but money is a killer) so car's back together, but wont keep any water down, she runs a little rough, but nothing drastic, and as soon as she comes up to temp out comes the water, i've bled the cooling system, both and the thermostat (which i removed after the first coupla times to double check) and at the heater. still no luck, have i just wasted my time, and got to take the head off again and get it skimmed?

She doesn't seem to be throwing any oil into the water or puffing out too much white smoke as the first time, am i missing something or what?

Any help appreciated i'm getting annoyed with it now, it's great to drive, and it's been a while

Cheers

Stu

[gcorky]

oh man....allways pressure test and skim if required before fitting.

[Stu_D]

fair comment, mind you there's only one way to learn, but is there any way i can narrow down what's screwed?

[Brianmoooore]

Pressurise each cylinder in turn with a leak down tester, and you'll probably find air bubbles coming through the coolant tank on one or more cylinders.

[Stu_D]

not sure i get how to do that!!

[Brianmoooore]

Compressed air into each cylinder through the spark plug hole.

[Stu_D]

now that's a cunning plan, i'll let you know! cheers

[Stu_D]

right, done that, and there were no bubbles! which i'm not sure is a good thing or not! there a bubbles in the expansion tank every now and again, but not related to when i was putting compressed air into the spark holes, unless there is some nifty trick to it!

any other ideas? i'm all out i'm afraid!

[Globulator]

as soon as she comes up to temp out comes the water

Where?

If it's not going out of the exhaust pipe then it's dripping out somewhere!
Temperature == Pressure, so look for the lleak when warm!!

[Stu_D]

it comes out the expansion tank, with or without the cap on! i've looked over whilst warm and can't see any leaks!

[Brianmoooore]

It'll come out of the expansion tank at working temp with the cap off - it's supposed to.
Are the two 'O' rings on the pressure cap OK? Does thye system pressurise properly?

[Brianmoooore]

i was putting compressed air into the spark holes, unless there is some nifty trick to it!

This doesn't mean just blowing air in the hole from an air gun; It means pressurising each cylinder to a few bar and keeping it there.

[Templ8e30]

You did fit a new head gasket didn't you ? you only mentioned new head bolts !

The 325i heads seem to be pretty fragile , pretty much essential to pressure test it and have it re-faced before fitting.

I know some people on here bang on about them not being fragile but there seems to be a hell of a lot of cracked 325i head posts and a lack of good 325i heads at the dismantlers.

Cheers,

Iain T

[Stu_D]

ok, well i've decided to do this properly, it's booked in to get skimmed, tested and tappets replaced, i've ordered another head gasket, and with any luck, i'll have it runnning after the weekend! anything else i should be doing?

[Morat]

buying a new cambelt? (unless you changed it last time)

[Stu_D]

good plan, but if i'm honest it scares me cuz i don't understand it!!

new cambelt?