Coolant leak

mrscalex

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I had the engine running on the project 1.9 while I was doing some work elsewhere on it. It's not on the road yet so I thought it would do no harm.

When I bought it home it ran fine but the temp needle never made it to the normal half way position. It got to maybe one third of the way. So I assumed it needed a new thermostat. It would have got that and a new water pump anyway as it's a new to me car. In fact the new parts are already in the boot.

Initially I noticed a drip of water. I didn't think too much of it as I thought it was just rain water running off where it got moved.

But I kept an eye on it as the temp needle was now reaching half way which I thought was weird as it didn't do it on the way home or when I've had it idling on the drive previously.

On the next check the drip had become a steady stream. I checked the temp gauge and it was still in the middle before switching off.

It was getting dark so I didn't have the opportunity to check for the source of the leak. And as the car is in Swansea and I'm back to Swindon on the weekly schedule I shall remain curious.

Obvious possibilities are a split bottom hose or shot radiator. Is there anywhere else it would leak from?

I'm a little concerned about possible damage to the engine from overheating but I guess that would only be the case if part of the problem is a faulty temp gauge and no real reason to think that.

There was no steam. In fact the water was stone cold despite the temp gauge being half way. I guess that should be a clue what's going on but I don't know what it means.

Any thoughts about what might be going on?
 

raymond

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Don't think you have done any damage. Plastic thermostat housing can leak. Radiator leaks are usually not noticed in the early stages. If the car has service history see what has been replaced in the past.
 

Vince

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British Zeds
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It's worth checking the expansion bottle on the side of th radiator, these do deform with age and leak from the bottom around the seals.
It took awhile on mine to find the leak and I had to cover the area with talc.

It's not a a hard job and takes about 15 minutes to fit a new one and I think I paid about £15 for a NOS genuine item on eBay.

Also it's worth taking a look at the waterpump.
 

duckhunt

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Just a FYI,
A few years ago I was investigating a leak similar on a 318i, bonnet open engine running when something just gave way out of the blue (no pun intended) and I got sprayed with hot Coolant. Trip to hospital ensued to treat minor burns.
Please be careful, if a pipe or seal could be on its way out. it's nasty stuff.
 

Cooper

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Any hose, water pump, thermostat, radiator, return etc can leak. You must identify where it is coming from and replace the part. Spend the time to locate it. :) As stated above be safe and wear glasses and keep all skin covered if you cannot locate the issue when the coolant is cold. I think there is a product that you can put in the coolant that glows which can be helpful?????
 

jonco

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A number of possibilities, but if you remove the front undercover then you get a good view of potential leak points from underneath the car. If the car has been standing for a week then look for blue/green deposits where leaked coolant has dried out.
If the leak is from thermostat/pump seals then there is usually a tell-tale spray pattern under the bonnet where the fan/pulleys whip it up.
A leak on the M44 side expansion tank/seal or actual drain valve seal will run out via the undertray. As @Vince says it is a cheap job to replace with new OEM quality tank and a quick job if the old tank pulls out from the top. If it's stuck, then you will need to take radiator out and knock old expansion tank out - again not a massive job.
 

mrscalex

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A number of possibilities, but if you remove the front undercover then you get a good view of potential leak points from underneath the car. If the car has been standing for a week then look for blue/green deposits where leaked coolant has dried out.
If the leak is from thermostat/pump seals then there is usually a tell-tale spray pattern under the bonnet where the fan/pulleys whip it up.
A leak on the M44 side expansion tank/seal or actual drain valve seal will run out via the undertray. As @Vince says it is a cheap job to replace with new OEM quality tank and a quick job if the old tank pulls out from the top. If it's stuck, then you will need to take radiator out and knock old expansion tank out - again not a massive job.
Thanks @jonco and for the other responses. Without a doubt it was running down off the undertray. I've got no fears about finding the leak and fixing it as such. And the thermostat and water pump were about to be done anyway. I'll also be replacing the seals inside the top and bottom hoses - I've previously sourced the correct vitron high temp o-rings for my 2.2 And I'll buy a pressuriser if required too.

I was more worried about any possibility of damage to the engine and in particular why the temp gauge registered normal (having not done it before) and the water ran out cold!
 

raymond

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Z3M
I am sure it will be fine. Worry when steam is coming out or there is no water!
 

mrscalex

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I should be able to investigate Sunday. I have a slightly bizarre life living half the week in Swindon with the kids and half in Swansea with my other half.

This car is in Swansea being a project for her son.
 
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