Losing coolant.......

[Erik Estrada]

Help required please.

This eve I was on the way home, and noticed the temp gauge needle slowly starting to climb past halfway and towards two thirds, it normally sits constant at 1/3 on the gauge. Pulled over into a car park and had a look under the car, and water is leaking at a fair rate from just in front of the engine block. In terms of location and volume, it looked very simialr to when the water pump failed last June, and was subsequently replaced.

Filled the expansion tank with a mix of water and coolant, and thought I'll see how far it goes. Initially the temp gauge was hunting between just under half, and just over, but then settled to just below half. Pulled over about three miles down the road, and the coolant level is constant, and there appears to be no water leaking from under the car, or from where I pulled into the car park and the engine was under load.....

Continued home at a steady 55/60 on the M5/M42 and the needle remained constant all the way home. once on the drive I popped the hood and had a look in the expansion tank, and nearly all the coolant had gone, however when looking under the car, there was no water leaking, and even after filling the tank and letting the car run, there was still no fluid leaking...

So, anyone got any ideas? Bearing in mind the water pump was replaced last yr, it seems early for it to fail no?

Thanks in advance everyone

Jon

[Erik Estrada]

Anyone at all?

[I Am Milk]

I would place my bets on Water-pump failure.

I know you said you got it replaced last year, but how many miles has it been?

Belts over tight and knackered the bearing?

[Erik Estrada]

I Am Milk said:

I would place my bets on Water-pump failure.

I know you said you got it replaced last year, but how many miles has it been?

Belts over tight and knackered the bearing?

well, the pump was fitted by a local guy, who AKAIK is very competent in his work with MX5's. I would be surprised if it was a failure of a new pump fitted a year ago, the car has done a maximum of 4000 miles since the pump was fitted........

[DanGT]

Top the car to the correct level with water (Dont forget when finished to put the right amount of antifreze in). Run the engine until it is at normal tempriter. If water comes out as you get hot then is could be ???? the head gaskit. As the engine runs the pressure in the cilinder is pushing the water out. No garranty but worth checking.

[Erik Estrada]

But it was running at normal operating temp yesterday and not losing water?

[I Am Milk]

Leaking water from the front of the block won't be a head gasket. But saying that, if you're loosing coolant and your temp gauge is all over the shop it could be a head gasket.


Have you checked your top and bottom hoses on the radiator for splits? Or the radiator itself?

What about your thermostat is that leaking?


If you want to make sure it's not the head gasket, get it down to your mechanic and get him to do a sniff and pressure test on your cooling system.

[Erik Estrada]

I Am Milk said:

Leaking water from the front of the block won't be a head gasket. But saying that, if you're loosing coolant and your temp gauge is all over the shop it could be a head gasket.


Have you checked your top and bottom hoses on the radiator for splits? Or the radiator itself?

What about your thermostat is that leaking?


If you want to make sure it's not the head gasket, get it down to your mechanic and get him to do a sniff and pressure test on your cooling system.

Hiya,

thanks for the advice, I am gonna head out to the garage in a bit and have a dig about. If it was the head gasket, would the volume and rate of the fluid loss be similar to that when a water pump fails?

Wish I knew a bit more about cars to be honest. guess now is the time to learn though!

[DanGT]

Look for bubbles coming up throw the water in the expantion tank. There may be some when you first top up but this should quickly go away, if there is a problem the bubbles will keep coming. Be carful not to burn your self.

[Erik Estrada]

Hmm, just took it out for a drive after topping the coolant up. stop at various stages to check, but no water coming out from the bottom of the car. Any ideas why it may have done this yesterday, but not now?


The temp gauge stayed dead on 1/3 of the gauge, but on returning, and checking the coolant, it had definitely used more than normal. Car drove ok, no noticeable power loss.....


Confused!

[SJobson]

My Eunos has been randomly losing water too; outside Waitrose the other night it piddled quite a lot when parked up, and it turned out to be one of the hoses to the heater. I hadn't been using the heater until that evening when I turned it onto warm. At least I think that's it; it's currently with Only MX5ives and I haven't spoken to Mark to confirm yet.

Is the rad cap in need of replacement, as another possibility? If it's not sealing properly it allows the water to boil and escape as steam from the expansion tank so you don't necessarily see a pool of water.

[I Am Milk]

That's a good point about the heater hoses. They're located on the passenger side of the bulkhead - worth a look.

When my Head-gasket went, the rate of water loss was immense, I lost about 5 litres in 5 minutes - unfortunately, it all went into my sump resulting in a massive over heat, which dropped a valve the water spun all my bottom end bearings.

Could it be a blocked radiator? Forcing water into the expansion tank and it going out the over flow?

[Erik Estrada]

SJobson said:

My Eunos has been randomly losing water too; outside Waitrose the other night it piddled quite a lot when parked up, and it turned out to be one of the hoses to the heater. I hadn't been using the heater until that evening when I turned it onto warm. At least I think that's it; it's currently with Only MX5ives and I haven't spoken to Mark to confirm yet.

Is the rad cap in need of replacement, as another possibility? If it's not sealing properly it allows the water to boil and escape as steam from the expansion tank so you don't necessarily see a pool of water.

Thats an interesting point, about the heater part of things. I had turned the heater onto full, and hot, to try and get some of the hot air out of the engine bay, and this is when it was leaking water. I have driven it today, and it hasn't appeared to drop any water. Interestingly, on start up it sounded lovely, but on blipping the throttle, there became a graunching sound. constant and fairly loud, and sounded like bearings had gone in the water pump, as it was coming directly from that area.

However, I used a bit of WD40 on the pulleys in that area, and the sound disappeared, and during the subsequent run, it didnt return. Even when being given a little enthusiasm, all sounded ok.

I did give Mark a bell, but his phone was off. think that may need to be the next port of call though if things don't work themselves out.....

Any ideas?

Edited by Erik Estrada on Thursday 24th September 20:28

[Erik Estrada]

Update on this one:

A week later, and the car has been driven a few times, one journey 70 miles or so, with constant checking of temps, and coolant levels. It now appears to be running absolutely fine, using no water in comparsion to the last week or so....


Odd ....