MKii Overheating
Discussion
I've already had some help on Nutz for this but was hoping someone on here might have heard of this problem before.
I have a mkii 1.8, 103k miles on the clock.
It has started to overheat, but only when being driven above a certain speed, once I slow back down to 60mph the temp drops and stay stable. I took it to someone to look at today and drove on quiet roads so didn't go above 40, was driving for 20 minutes, then let the car idle for another 20 but it wouldn't over heat whilst he was watching! I then drove for another 25 minutes, and only when I'd been going at motorway speeds for a few miles did the temperature rise, as soon as I slowed down it dropped again, and was fine driving slowly for another 20 minutes, and idling for a bit.
I have replaced the coolant, replaced the thermostat and replaced the radiator cap.
I am not losing any coolant at all, the fan is working properly.
The mechanic who I spoke to thought it could be the water pump, does anybody have any ideas?
I have a mkii 1.8, 103k miles on the clock.
It has started to overheat, but only when being driven above a certain speed, once I slow back down to 60mph the temp drops and stay stable. I took it to someone to look at today and drove on quiet roads so didn't go above 40, was driving for 20 minutes, then let the car idle for another 20 but it wouldn't over heat whilst he was watching! I then drove for another 25 minutes, and only when I'd been going at motorway speeds for a few miles did the temperature rise, as soon as I slowed down it dropped again, and was fine driving slowly for another 20 minutes, and idling for a bit.
I have replaced the coolant, replaced the thermostat and replaced the radiator cap.
I am not losing any coolant at all, the fan is working properly.
The mechanic who I spoke to thought it could be the water pump, does anybody have any ideas?
I do have a grill but I've had it since I got the car and it's never been a problem before.
I did check there was nothing in the grill blocking anything.
I emptied the radiator and ran a bit of water through it but haven't used a flusher, ony thing is would that not affect it all the time rather than just at speed?
I did check there was nothing in the grill blocking anything.
I emptied the radiator and ran a bit of water through it but haven't used a flusher, ony thing is would that not affect it all the time rather than just at speed?
Classic symptoms of a blocked rad. Once it's up to temp, carefully feel all over the front of the rad (you'll have to remove the grille to do this) for a cold spot.
You might be able to get away with a flush or you might have to remove the rad and back-flush it but once they have been blocked they usually don't last much longer. It's not a big problem as a new replacement is only about £90 and they are easy to change.
You might be able to get away with a flush or you might have to remove the rad and back-flush it but once they have been blocked they usually don't last much longer. It's not a big problem as a new replacement is only about £90 and they are easy to change.
One good thing is that I now feel I could change it myself, wouldn't have risked it before.
I must say I couldn't feel any cold spots, although I didn't remove the fan so I wasn't able to feel the whole thing, plus I'm not used to checking that so if it wasn't really obvious I could have missed it.
Can I ask why you think it is the rad rather than waterpump?
I must say I couldn't feel any cold spots, although I didn't remove the fan so I wasn't able to feel the whole thing, plus I'm not used to checking that so if it wasn't really obvious I could have missed it.
Can I ask why you think it is the rad rather than waterpump?
A chap on the OC (Passell) has had this exact problem on a mark one and you're correct Lazza, was the radiator. Thanks very much for the info.
So looks like I will be fitting a new radiator in the near future.
Would it be foolish to buy a second hand one from Autolink? I know they're very reputable but I assume it will be untested as it wouldn't really make financial sense to fit and test something so cheap, OTOH this problem sems qute rare so I could be OK, and I could have a radiator delivered tomorrow for about £60.
A new one would be about double the price but maybe better off spending that bit more.
So looks like I will be fitting a new radiator in the near future.
Would it be foolish to buy a second hand one from Autolink? I know they're very reputable but I assume it will be untested as it wouldn't really make financial sense to fit and test something so cheap, OTOH this problem sems qute rare so I could be OK, and I could have a radiator delivered tomorrow for about £60.
A new one would be about double the price but maybe better off spending that bit more.
I'd get a new one. It's not that uncommon for old rads to clog up and people have in the past delayed the purchase of new rads by removing some of the more restrictive grills. But if that works it's another indication the rad is probably due a change.
You could try a flush...but shiny new things always get my vote!
You could try a flush...but shiny new things always get my vote!
Bit annoyed with MX5 parts atm, bought a part I needed on Sunday and they only shipped it on Tuesday, I realise this isn't horrendously late but it was a real pain.
Plus MKii is more expensive.
I have now ordered one from Autolink, and it will be with me tomorrow, also spoke to them and they agreed 100% it would be a blocked rad.
Now I've just got to fit it without disaster!
Plus MKii is more expensive.
I have now ordered one from Autolink, and it will be with me tomorrow, also spoke to them and they agreed 100% it would be a blocked rad.
Now I've just got to fit it without disaster!
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