My '5 Went Pop
Discussion
Well, the cooling system anyway.
Basically, I'm just looking for a few opinions as to the cause. I was travelling along the motorway at a fairly high number of leptons and had been doing for some time enjoying the top down on a sunny afternoon then pop, coolant spewing everywhere and the temperature gauge off the scale.
I pulled over straight away and couldn't see anything obviously wrong. I know the coolant level in the expansion tank was fine prior to the journey, and I don't believe a hose has split as no more coolant was lost after the initial pop (what was lost exited via the expansion tank cap, and I drove another couple of miles to the next junction once it had cooled down).
The recovery guys suspected head gasket failure which I doubted and after running a 'sniff' test (blue dye in a pipet) they decided against that.
Water pump, thermostat, any ideas? Or just too fast for too long? Although, I have completed the same and similar journeys at those speeds on a number of previous occasions.
Normally I'd get to the bottom of this myself but I'm off to Israel for two weeks so was just wondering if somebody could point my very kind father (fixing it whilst I'm away) in the right direction - is this a known problem I haven't heard of?
Basically, I'm just looking for a few opinions as to the cause. I was travelling along the motorway at a fairly high number of leptons and had been doing for some time enjoying the top down on a sunny afternoon then pop, coolant spewing everywhere and the temperature gauge off the scale.
I pulled over straight away and couldn't see anything obviously wrong. I know the coolant level in the expansion tank was fine prior to the journey, and I don't believe a hose has split as no more coolant was lost after the initial pop (what was lost exited via the expansion tank cap, and I drove another couple of miles to the next junction once it had cooled down).
The recovery guys suspected head gasket failure which I doubted and after running a 'sniff' test (blue dye in a pipet) they decided against that.
Water pump, thermostat, any ideas? Or just too fast for too long? Although, I have completed the same and similar journeys at those speeds on a number of previous occasions.
Normally I'd get to the bottom of this myself but I'm off to Israel for two weeks so was just wondering if somebody could point my very kind father (fixing it whilst I'm away) in the right direction - is this a known problem I haven't heard of?
Edited by Wigeon Incognito on Friday 8th June 00:12
i would be interested in this as a very similar thing happened to me which i cant quite work out.
on a reasonably warm day (not very hot) travelling at 80 the temp started to rise and rise till i had to stop. coolant was boiling. i let it cool and topped it up, started off again, it repeated. i turned back and got my girlfriend to drive us the next day in her car.
after a lot of head scratching i couldnt find a problem anywhere. i emptied out all the coolant and replaced it with some about 20% antifreeze and since then it seems to be have been fine.
i think it is probably due to a couple of things:
-fuel consumption at just over 4k revs (80ish) is much higher than at just below 4k revs hence a lot more heat generated
-i think my radiator could do with being replaced at some point. maybe beginning to block up. quite tempted by a bigger capacity one to help on track days.
-running both fans seems to help (my aircon has no pressure in it so the aircon radiator doesnt add to the heat problem but switching the system on still gets both fans running
on a reasonably warm day (not very hot) travelling at 80 the temp started to rise and rise till i had to stop. coolant was boiling. i let it cool and topped it up, started off again, it repeated. i turned back and got my girlfriend to drive us the next day in her car.
after a lot of head scratching i couldnt find a problem anywhere. i emptied out all the coolant and replaced it with some about 20% antifreeze and since then it seems to be have been fine.
i think it is probably due to a couple of things:
-fuel consumption at just over 4k revs (80ish) is much higher than at just below 4k revs hence a lot more heat generated
-i think my radiator could do with being replaced at some point. maybe beginning to block up. quite tempted by a bigger capacity one to help on track days.
-running both fans seems to help (my aircon has no pressure in it so the aircon radiator doesnt add to the heat problem but switching the system on still gets both fans running
Both cases sound like a bocked radiator to me (emptying & refilling might have cleared your blockage but there's a good chance it'll come back soon).
Try running the car up to temp and then feeling all over the front of the rad for a cold-spot (not the rear of the rad unless you want your fingers chopped off by fans/belts etc).
Try running the car up to temp and then feeling all over the front of the rad for a cold-spot (not the rear of the rad unless you want your fingers chopped off by fans/belts etc).
Bear in mind the rad will NOT suck water out of the exp tank when hot (only when it cools) so you should ALWAYS check the water level in the rad.
First suspect is rad cap, change it and feel the rad for cold spots which would indicate a blocked rad (rare).
Other suspect is thermostat, this weather you could just run without it.
First suspect is rad cap, change it and feel the rad for cold spots which would indicate a blocked rad (rare).
Other suspect is thermostat, this weather you could just run without it.
Had similar problem, although symptoms were a steadily rising temp gauge at speed, like a blocked radiator or something.
It also wasn't appreciably losing coolant. But what had gone was the water pump, when the cambelt cover was removed the staining of water loss was evident, the overheating came not from the actual amount of fluid loss but the air lock that this causes.
Might be worth a look, and of course at the classic thermostat bypass hose issue.
It also wasn't appreciably losing coolant. But what had gone was the water pump, when the cambelt cover was removed the staining of water loss was evident, the overheating came not from the actual amount of fluid loss but the air lock that this causes.
Might be worth a look, and of course at the classic thermostat bypass hose issue.
Regarding a blocked rad.
Somebody above said this was rare. Well, from reading on the oc site and from personal experiance this is very common on MX-5 / eunos' of a certain age.
The symptoms mine displayed were as follows. (Had owned car for 2-3 weeks and was on first long schleep)
Going down M4 at 70ish, top down on a warm sunny day, very smug with myself. (£2000 grand soft top motoring...... life can't get better)
Look at dash to find the temp guage needle trying to do a 360 on the dial.
Swiftly pull over to find coolant in expansion tank boiling.
At this point I called the RAC. (while glower at car hoping it will catch fire so I can claim on insurance, and muttering darkly to myself)
Get car home and research symptoms. All point to blocked rad.
One call to MX5 parts results in them getting £80 and me a new rad. Car has run as sweet as ever since. (I have appologized to it profusly for wanting it to self combust many times since)
Somebody above said this was rare. Well, from reading on the oc site and from personal experiance this is very common on MX-5 / eunos' of a certain age.
The symptoms mine displayed were as follows. (Had owned car for 2-3 weeks and was on first long schleep)
Going down M4 at 70ish, top down on a warm sunny day, very smug with myself. (£2000 grand soft top motoring...... life can't get better)
Look at dash to find the temp guage needle trying to do a 360 on the dial.
Swiftly pull over to find coolant in expansion tank boiling.
At this point I called the RAC. (while glower at car hoping it will catch fire so I can claim on insurance, and muttering darkly to myself)
Get car home and research symptoms. All point to blocked rad.
One call to MX5 parts results in them getting £80 and me a new rad. Car has run as sweet as ever since. (I have appologized to it profusly for wanting it to self combust many times since)
Sorry but whilst many have said they need them, I think 90% are still checking the exp tank, not the rad.
Then swapping the rad, filling it up... oh look , no problem !
No because now you've filled it !
How exactly are all these rads getting blocked ?
My dad deals in classic cars and they rarely suffer and are 20+ years older !
If parts of your rad are cold and other parts hot, fair enough, otherwise look elsewhere.
Then swapping the rad, filling it up... oh look , no problem !
No because now you've filled it !
How exactly are all these rads getting blocked ?
My dad deals in classic cars and they rarely suffer and are 20+ years older !
If parts of your rad are cold and other parts hot, fair enough, otherwise look elsewhere.
Yep, blocked rad IMHO. Apparently they're prone to it if you don't use distilled water with the coolant. Dunno if this is true, but it happened to mine. Flushed it twice but the problem was still there. Changed the rad and everything is A-OK. Only ever use distilled/de-ionized water, as does the guy that services it.
Maybe some of us are just unlucky but, although I've only owned one, in my 8 years with the OC I've heard about it a fair bit.
Nice and simple to sort out though.
Maybe some of us are just unlucky but, although I've only owned one, in my 8 years with the OC I've heard about it a fair bit.
Nice and simple to sort out though.
mine has started to overheat again now - it's fine in the winter but the summer heat takes it just over the edge. there's always water in the *rad* and in the expansion tank. flushed last year and filled with pink coolant and de-ionised water with new stat and rad cap after i lost a load when it boiled and pissed out the expansion tank.
i'll try the grill first, if not looks like a new rad. struggling to find an ally rad at a sensible price tho...
i'll try the grill first, if not looks like a new rad. struggling to find an ally rad at a sensible price tho...
ginettajoe said:
If you have fitted one of the alloy grilles that are sold on e-bay, you will find that is the problem, ..... it restricts the airflow to the radiator. Some of the MaX5 race cars had them fitted, they overheated, but the problem was solved when they were removed!!
I find this hard to believe as cars with aircon have a big rad far more restrictive than some mesh placed infront of the coolant rad (unless your taking about mesh in front of aircon rad infront of coolant rad). Also turbo cars have big intercoolers in the way too. Admittedly I played it safe and got a koyo alloy rad to sit behind my intercooler but i've had no overheating problems.steve bowen said:
speedychrissie said:
-fuel consumption at just over 4k revs (80ish) is much higher than at just below 4k revs hence a lot more heat generated
Doesn't work like that more fuel = lower cylinder temps thats why you add fuel to prevent detGassing Station | Mazda MX5/Roadster/Miata | Top of Page | What's New | My Stuff