Coolant loss

YAKmobil

Hi all,

I think my Zaffi has a bit of a coolant leak problem that i would like to fix before the summer road trip, fully laiden + family, to Cornwall. Z22SE, 2004, 45k miles.

Basically, i have to top up the coolant expansion bottle about every month or so - the coolant always drops about half an inch from the full line. I have checked all of the hoses and these all seem fine. The leak must be so slight that any water passing onto a hot engine will quickly evaporate. That said, there is none of the salt-staining around the hose connections indicating that coolant has been evaporating. This leads me to believe that none of the hoses are leaking - is this a reasonable assumption?

There is no oil in the expansion tank (i.e. i think the head gasket is ok).

The expansion cap seems to hold pressure as this hisses when removed after a journey. The leak must be very slight for some residual pressure to remain, and obviously, i'm not loosing much coolant.

There is commonly very very slight mayo on the underside of the oil cap. I have been changing the oil reasonable regularly since i bought the car to give the engine a gradual clean-out (had been neglected a bit by previous owners), thus little chance of significant moisture contamination and fully fledged mayo on oil cap and dipper. Benny tells me (he did the chain a few months back) that a bit of mayo is to be expected.

Having looked on the forum, i fear that some coolant may be passing the water-pump shaft seal thus moisture entering crankcase (but not oil going other way, hence clear expansion tank).

Does anyone else have or had similar problems? How can i test for a defective water-pump, or is it a trial and error type thing (replace and hope for the best). Are there any other areas worth checking for leaks? Radiator seems ok and carpets dry etc, leading me to believe the heater matrix is ok.

I know a little coolant loss is not a big issue, but i am concerned that the problem may escalate and cause overheating/gasket failure.

Any advice would be much appreciated.

jwalker

I know my water pump is leaking because I have puddles under my car every morning :oops:

If it's that small a leak maybe try something like K-Seal to block it off?

Gary14

Have you changed the spark plugs recently? if so remove your coil pack and check each plug hole for coolant. Plugs being overtightened or very tight on removal can cause damage to the cylinder head :shock:

YAKmobil

Thanks for the suggestion. Yes - plugs have been changed, but the old ones came out without incident and i tightened the new ones to 25nm. Checked the plug recesses for any signs of coolant and dry as a bone + nice and shiney leading me to think that this is not the source of the problem.

The leak seems to be a 1 way street though - no oil in coolant, but coolant in oil...

Any other ideas? notsure.gif

colin002

is there any chance that the water pump could be leaking into the timing chain area . running into sump ..

or pressure test your bores could be head gasket

YAKmobil

Well i suspect that it probably is the water pump, although i don't want to run to the expense of replacing the pump if it's something else. Is there any way to test the seal? Is it feasaible to remove the access plate on the end of the chain cover and pump up the pressure in the cooling system to see if water passes the shaft seal??

I'm not 100% about the head gasket - wouldn't oil have made it into the expansion tank if the HG has gone, or is it possible that coolant could pass 1 way, but not oil the other? notsure.gif

Any suggestions would be appreciated.

Chris

colin002

no a head gasket can go in many ways ... like a water port going next to your exhaust port causing massive pressure in your coolant system /

i know on all the internal water pumps ive fixed on cam belt engines. when the bearing was on its way out water would pass threw a hole in the outer part of the pump where the sprocket was attacted..

chances are if you take the chain cover of you will probably spot the leak streight away
or signs of a leak ..

Haukkeli

I have changed waterpump once to my -01 vectra z22se. First, i didn't reconise the leak. But my mate said it's coming somewhere around pump, and I spotted a leak from the waterpump seal.

Replaced pump and problem solved, but i can say it... It's shitty to replace ! If you don't have tool to keep the balancer chains on line, it's impossible without it. I maked it myself, but it worked fine. It took hole day to replace.