Wierd Coolant Loss !

Dave Burns · Unread post by **Dave Burns** » 05 Mar 2003, 00:27

The maximum acceptable pressure difference between cylinders (according to the good book) is something like 75psi, and depending on the general condition of the engine, a compression test may not be conclusive in the search for gasket failure.
Dave

sooty · Unread post by **sooty** » 05 Mar 2003, 01:10

Hi Mat,
I might be wrong, but every faulty H/G that I have seen pressurising the water system, has blown the water out through the overflow pipe(using a bottle at the end of the o/flow pipe to check). Otherwise the H/G is blowing water out to an external part around the H/G edging, this then should be visible.
Dave is right if you over pressurise, you could blow your Radiator, Matrix, W/pump and hoses and if you do have blown gasket to the cylinders and fill one of them, sods law you will be better off getting another engine( it could be as bad as that) if you try and turn it over on the key or any other method.
Good Luck
Sooty

wingrattg · Unread post by **wingrattg** » 05 Mar 2003, 03:48

I also had water leakage, slowly at first the one day it just dumped over the drive. I eventually found the problem to be a dodgy hose clip at te bottom of the rad (drivers side). Its a bit of a bastard to get too but I replaced with jubile clip...it worked...

Unread post by **alan s** » 05 Mar 2003, 07:09

wingrattg has good point. I had a similar leak on my BX that was an intermittent leaker. It had the added problem of also due to being on the bottom hose it would leak often a while after the engine had stopped with the result that as it cooled it drew in air which also gave the similar symptoms as air in the system. Eventually it blew completely due to an elbow being contaminated & made porous due to a neglected CV boot that was torn.
It could be an idea to spend some time with a good spotlight paying close attention to clips & elbows particularly around areas of the plumbing in out of the way places.
Alan S

mbunting · Unread post by **mbunting** » 05 Mar 2003, 15:05

Well, funnily enough, last night, I started the engine and looked around. Nothing.
I opened the cap, and took the bleed cap off, and there was a significant dripping from under the radiator area.
Went to the car this morning, and it was already dripping - it had lost 1.5l since leaving work last night ( approx 40 miles ).
So it looks like I have a leak in the radiator, or top/bottom hose, that only shows itself under certain coolant and atmospheric pressure conditions !
Now I know what's happening, I can plan my weekend project !!

tomsheppard · Unread post by **tomsheppard** » 05 Mar 2003, 15:38

If the cap is on, then there will be a partial vacuum beneath it when the engine has cooled. This is what is keeping the water in. If you did not get dripping before releasing the bleed screw/cap then there is a partial vacuum there which has been caused by steam build up while the engine was getting hot due to inefficient circulation in the rad. This pressure has (quite likely) burst the radiator. I strongly suspect that it has become blocked and would regard it with the gravest suspicion. I would be looking to see if any of the lower cross tubes of the rad appear to be swollen or distorted this confirms a blockage. I have seen this before on BXs and this may have caused the radiator to burst. Either way, take it out and flush it thoroughly. This in itself is usually an education- where did all that muck come from!? If you are lucky then it is only silt but the head gasket problems on these engines often are caused by a duff rad.

mbunting · Unread post by **mbunting** » 31 Mar 2003, 21:18

Just a quick reply to say that I changed the radiator. The original was well green at the bottom, and after much effort ( and sliced skin ! ), I've got a new one in, and after three weeks, it hasn't lost a drop.
Mat.