Intermittent coolant leak

Hi

I have an intermittent coolant leak.

Ive got a Mazda 323F GLX V6 "M" reg'95 model

It will most often occur after Ive had a long continuous drive and then slow for traffic. I see steam billowing out from the bonnet and theres a strong smell like rotton eggs,

I called out the RAC on one occasion and the guy thoroughly checked the cooling system for leaks. He pressure checked it, checked the fan etc and couldnt find anything wrong. I never get any signs of overheating.

Ive tried RadWeld and keep a check on the coolant level.

It definetly seems to be related to when the engine is very hot. Is there some sort of pressure relief valve that opens?

Any ideas?

Thanks for your time.

Ian

Reply to
Ian R
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Only a guess. I don't know the car in particular, but it sounds as if might be a coolant circulation problem. Blocked rad etc. On a run at a reasonable speed cooling might be adequate, but when you slow down with a hot engine, the temperature and pressure rises enough to overcome the pressure relief valve in the radiator cap. Hence the steam. A reverse flush of the cooling system could help, but it sounds like it might be time for a new radiator. Mike.

Reply to
Mike G

========================================= Despite the test results it might still be a tired radiator cap if it's a spring-loaded type. I had the same problem on my 306 and a new cap cured it - still perfect nearly a year after replacement.

Cic.

Reply to
Cicero

Check the fins in the radiator, you may find that a lot of them have rotted away reducing the surface area of the rad so less cooling. Trevor Smith

Reply to
Trevor Smith

Most cooling systems are pressurised and have an over pressure release in the cap. Caps should be replaced as routine maintenance every few years.

I would get some flourescent dye put in and find where it leaks, it might be the seal on the water pump for instance, or a loose hose, or a gasket on the inlet manifold, a crack in the rad that opens at high temperature only, a blowing head gasket etc. etc.

Can you not stop when it does it and have a look?

Mrcheerful

Reply to
Mrcheerful

I'd agree. First, get a new radiator cap, in case.

Then flush out and refill the cooling system.

Other than that, I'd suspect a blocked radiator. A dodgy water pump is also a possibility, but I'd go for the rad first.

Reply to
Chris Bartram

I had similar on a Toyota supra. Rust in the radiator meaning the radiator was sealed ok. But vibration from the air condition would start a leak. Water was lost and then the car over heats. Do a proper flush by removing the radiator. You may find taking things apart and clearing out may show up the problem.

Reply to
david.cawkwell

Hi Guys

Thanks to all of you for taking the time to reply.

Really appreciate your helpful suggestions and will get to work.

Cheers.

Ian I^)

Reply to
Ian R

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