Water leak - but where from?

[PaulTVR]

Hi
My Chimaera 450 has developed a water leak and I can't find the source. It only leaks when running and warmed up. Then there is a very visible dripping down the front, off side of the block. From underneath I can see a steady trickle coming from somewhere above the earthing bolt below the alternator mounting. I have removed the alternator and its mounting bracket but can see no signs of where the leak is coming from. My thoughts are that it may be the seal between the water pump and block or the front of the head gasket. I would like to be able to run the engine with the alternator removed but not sure if I can or should, and that would mean no serpentine belt to drive the water pump!
Any suggestions would be very welcome. Thanks.

[Steve_D]

If it leaked from cold then a start/run for a minute or two would not be a problem but if it only happens when hot then I would not be happy running it as it will overheat too quickly.

Couple of options.
1. Get a trace chemical as used in aircon systems to trace leaks using UV light.
2. A cooling system pressure tester. http://www.ebay.co.uk/itm/New-14PCS-Cooling-System...

Steve

[ChilliWhizz]

Paul, I don't want to sound like the voice of doom, and you probably have something simple there that needs fixing... but... I had a leak that showed in the vicinity of the water pump, only when the engine was up to temp... not a big leak, but just enough to notice... Turned out it was the end result of a porous block pressurising the cooling system and forcing a leak...

Seriously hope you don't have this, but I would get it checked sooner rather than later...

Good luck,

Chilli..

Edited to add, just noticed Steve suggested a cooling system pressure tester.....

Edited by ChilliWhizz on Sunday 4th June 16:57

[Classic Chim]

Have you looked at the weep hole on the water pump shaft. Often only shows itself when hot and is a trickle rather than a gush.

[PaulTVR]

Thanks all for quick responses. Will investigate further when I have time in a few days. I don't like the sound of a porous block! Might try the pressure tester.

[s p a c e m a n]

If you want to pressurise the system without running the engine then one of these hose ends can be screwed into the top of the swirl pot with a bit of force, water will obviously leak out of the cap on the overflow bottle so just put a pair of grips on the pipe to the bottle to stop the water flow (You can just bung an air line on this pipe if you've got a compressor, but I guess you haven't if you're planning on buying a kit). If you need more pressure then you can make a deeper thread on the hose end by cutting out the marks made with a hot knife.

Using the hose end on the swirl pot makes it much easier to bleed the system when the time comes too (If you're going to use tap water anyway and not deionized stuff). Pour in your antifreeze first, fill with water until the system is warm enough to open the thermostat and turn the engine off. Take out the bleed screw on the pipe above the rocker cover and then screw the hose into the top of the swirl pot and turn it on. Once water is streaming out of rocker cover pipe seal it up again, then when water is coming out of the radiator cap the entire system should be bled. Obviously the thermostat will close if you're doing this for too long as you're just pouring cold water in without it being warmed up.

This method has worked for me the last few times that I've had to bleed mine, saves me getting a headache from having the engine running on the spot for half an hour and makes a lot less mess from hot water spraying out of the top of the swirl pot, onto the alternator belt and then all over the engine. Bleeds the system in 10 minutes from when you've opened the bonnet

[PaulTVR]

Hi All. Made my own pressure tester by fitting a bike valve into hole drilled in expansion tank cap and using a bike pump. Soon found the leak - coming from the gasket between the front chest and the block. As the car hadn't been used much for a couple of years before I bought it I guess there might well be other gaskets and seals that could go soon. Some work needs to be done to the outriggers and suspension so I have decided to bite the bullet and do a body off job. Wish me luck!