Coolant loss on FD - noticed on car viewed today

[lockwood77]

Hi all.

I\'ve just been reading some threads on coolant loss/low coolant and am at a bit of a loss on this one.

I went to see a car today, all seemed fine - just a puff of smoke on startup, no more. Ran fine, boost showed stable at idle (had big aftermarket gauge on the dash). Boosting was smooth.

However, when the guy went to start the car first time, he got the low coolant buzzer and went off to fill it up with (tap) water. He made reference to "these cars drinking coolant and oil", which slightly passed me by as I understand the oil usage of these engines. We then went on the test drive and all seemed fine as above (started fine hot or cold).

I did think I noticed a slight leak on the front radiator (are there two parallel to each other!?), could this be the problem?

I couldn\'t see any leak from the AST tank and the oil filler and dipstick didn\'t show any milky residue.

I\'ve left a deposit of £100 with the chap, subject to HPI check, but I am now worried about this issue and will walk away if it\'s likely to be serious. What would be the best method of testing when I see the car again - running without the main coolant filler cap on to see if air bubbles appear?

Thanks,
Ian

[Martiny]

If there is a coolant leak outside the engine, that easy to repair. It when we cant see a leak, and coolant is leaking inside the engine, then ----->>>> ££££££££   !!!!!  :-((((

[lockwood77]

Hmm, that\'s what I read mate. Quite concerned so will be looking for all the signs possible!

Is the filler cap off/check for air bubbles a sure-fire test?

[deanflowers]

the plastic screw in the bottom of the rad was the reason for my coolant loss may be worth checking

[lockwood77]

Cheers, will check that out too.

The engine was rebuilt by Rotechniks just over 22,000 miles ago (end of 2005), but I don\'t suppose that has any bearing.

It still has a plastic AST, so that is a suspicious area, but I couldn\'t see any leakage.

[alexb]

Hi,

Mine was leaking from the coolant level sensor below the filler cap & thermostat cos the plastic thread had cracked. Was fixed with a £20 replacement from my local Mazda dealer

Hope that helps,

Alex

[lockwood77]

OK Alex, cheers.

I\'ve spoken to the chap selling the car and he suggested a compression test to check the seals - presumably this will give me a pretty good idea if it\'s the water seals or an external leak?

New thread here trying to locate a compression test in Loughborough/Nottingham!

[RobbieRX-7]

nah, a compression test isnt gonna test the water seals. A pressure test would do this, but you need the right equipment to do it. You should get the chap to take it to wgt in your company..they should be able to do this test. Another way youy could test for an external leak would be to look out for steam in the engine bay..if you can seem steam then maybe it is not all bad

[nikp]

A pressure test needs to be done when the engine is cold. And any garage should be able to perform this test, as long as they have the coolant pressure testing equipment.

[Adriansturgess]

It still has a plastic AST, so that is a suspicious area, but I couldn\'t see any leakage.

When I got my Rex it had an aftermarket alloy AST fitted. When I took it in for service at Rotechniks they identified that the cap wasn\'t sealing properly and advised I replaced the AST with a standard plastic one. They have stopped fitting alloy ones due to continued problems with ill fitting caps, (where the alloy body doesn\'t having a perfectly flat seating area for the cap to bed on to). They reckon that plastic ones should last several years before, eventually, the high underbonnet temperatures will potentially split them. On that basis probably sensible to change it every 3 years or so.  :chat

[GerbilStuntFarm]

All this being said.. it seems a tad funny for the chap to say \'these cars drinking coolant ..\' if that was how it was actually worded, almost dismissing it as a feature rather than an actual problem. If you can\'t identify exactly the problem yourself then I would personally only buy it on the condition of it being looked at by a garage first as it reeeally will be a kick in the teeth if it\'s not just the rad, ast etc. Perhaps see if he\'ll meet you halfway on the cost as it\'s in his interest?

[lockwood77]

Good points one and all, thanks chaps.

Even with my limited knowledge, I should have known a comp test would indicate rotor tip wear, not water seal condition (I think!?)  :Hammer

Problem is, I would dearly love to have WGT etc. check it over, but there doesn\'t seem to be anyone remotely nearby who has the skills.

There was no steam (bits of the bonnet are vented so this should have been evident, plus we popped the bonnet as soon as we pulled up after the test drive), but no white exhaust smoke either. Really put off now and without said tests/vehicle check I don\'t think I can go ahead.

I feel bad, cos the guy seems very genuine and if the problem isn\'t serious it\'s a very good price for the spec, even with the few cosmetic issues. But a rebuild-ready car for £5k is somewhat less appealing.

Hopefully I can agree at least the partial return of my £100 deposit, unless someone knows of an easier way to get to the bottom of this!?

[Adriansturgess]

It would be useful to know how often he has to top the coolant up and how much he has to put in! I\'m wondering if (on a nice dry day) you could actually see any evidence of dripping under the car - if it\'s something like a perforated hose or loose jubilee clip for instance. The fact that he is using tap water could suggest that either he did that just for speed on the occasion, or that it needs so much water that he\'s given up and is just pooring tap water down it all the time. It could be something so simple but then its also possible he knows something you don\'t and that\'s why he\'s trying to shift it. Trouble is with these cars you can never be totaly sure what you\'re buying and this might be a perfectly sound car with a loose hose. It\'s a tough one.  

[lockwood77]

Trouble is with these cars you can never be totally sure what you\'re buying and this might be a perfectly sound car with a loose hose. It\'s a tough one.  

Yeah, that\'s the real problem. As I said, I think there may be a rad leak, but it\'s tricky to tell unless the weather\'s bone dry. It was before we left that we saw the suspected rad leak, it was dry after the run out.

I will ask the question as to how often he tops up and what he (normally) uses.

[lockwood77]

Just spoken to the chap (Jamie), what a nice and genuine guy. So good to find people selling cars who aren\'t just trying to offload something regardless!

He says that the coolant buzzer had never gone off before, but he does top it up every three weeks or so. Bearing in mind it\'s a weekend car, that\'s probably not that many miles. He\'s never noticed any steam or water/coolant on the floor when he parks up, but has occasionally noticed the smell of coolant in the cabin. That sounds like a possible good thing to me - if it was entering the engine via the water seals, I\'m guessing it would be evaporating and flying out the exhaust rather than into the engine bay and through the cabin air vents? :confused:

He has agreed to take the car to a Mazda garage tomorrow morning for a coolant system pressure check and compression test (assuming they are capable...), so depending what that shows, my mind will be at rest.

The liquids used to fill up the radiator have been a mixture of anti-freeze and mainly deionised water. So not tap water! Phew.