engine overheat??!


jpk88

jpk88

EM1 Coupe
Joined
Dec 2, 2010
Messages
146
hi lads,

yesterday i was driving home (about a 2 hour motorway drive) when i noticed that my engine temp had raised up to about 2 thirds up the gauge doing 80mph!!! i slowed down and it started to fall back to normal within a few seconds. when i pulled in i checked radiator coolant and it was fine, also been serviced two days ago.

Anyone any ideas??
 
Could be the water pump mate or thermostat to.

Is the fan coming on when it gets up to temperature?
 
Is your coolant color has changed?
If your coolant color turned from green to brown you maybe have a headgasket leak!
If not, you can also check your radiator for rust inside it.
 
If you've noticed any drop in coolant whilst driving, you could potentially have a blown hg.

Best way to determine this is with a leak detection dye of some sort (basically a dye you put into your coolant (after taking a samples from the radiator, if it turns say blue - it confirms the presence of hydrocarbons within the coolant and the head gasket is caput.

You'll see loads of 'milkshake' under the rocker cover where the coolant has mixed with the oil too.
 
I would say the system needs bled.
Allow the car to cool and put ur heater on hot, open the rad cap and allow the water to come up to temp, you should see any air come out of the opening. That should do it, failing that maybe a couple of blocked path ways? If so try some bg rad flush.
 
Hersh l said:
I would say the system needs bled.
Allow the car to cool and put ur heater on hot, open the rad cap and allow the water to come up to temp, you should see any air come out of the opening. That should do it, failing that maybe a couple of blocked path ways? If so try some bg rad flush.
Click to expand...

Dont mean to be rude, but Im assuming his car has been fine in the past - with no problems/symptoms of overheating (so a totally serviceable car).

All of a sudden it starts to overheat - I highly doubt it just needs to be bled - and this is just a waste of time.

Get the dye, its a yes or no test for hg. :nice: if it yields a negative for hg, best bet is on the water pump or thermostat as other have said - hope you get it sorted out mate
 
You could assume that yea, but the car has just had a service. If the coolant has been changed then it may have an air lock in the system causing a hot spot

If it was changed and any rust has been aggitated and not washed out that can also be a fault.

He could try a bleed in 10 mins tomorrow if he has the time, how long will it take to get the dye? Is it a halfords job?

If the headgasket had gone i would be worring more about the thermostat going sky high and having congealed oil in the coolant.

Easy and quick things first.

We have given him a few options to try, would be good to find out what is causing the temp rise.
 
80mph your at high revs, how was your oil quality and level? Thermostat checked or replaced recently? look at the rad fan switch too, make sure its coming on when its supposed to.
 
thanks for all the replies lads. the fan is working fine, oil is brand new. ive driven it the last two days 20min motorway runs and it has been fine, no movement from the temperature gauge at all. surely if it was to do with the HG it would be overheating constantly??

I will try bleeding any air out of it today. Im going to do the timing belt in the next couple of weeks now so will change waterpump and get thermostat checked.
 
bled the radiator and was fine. then overheated on motorway again today! this time i found a little puddle of water under the radiator which i hadnt seen before! would a leak cause overheating?
oh and coolant level was still fine.
 
Id check the thermostat, i had the same problem with my car a few months back turned out to be the thermostat! Worth a check anyway!
 
if coolant is leaking, not good. that would mean loss of pressure which then would mean it will over heat faster. not to mention that stuff is slippery when it gets on the tires.

blown hg will not always overheat also, depends on how hard you are driving it ie 80mph in 4th. as the hg gets more "blown" it will start to over heat much quicker as the breakage in the gasket opens up more, bigger hole for coolant to pass. But this may not be your issue.

I would recommend timeing belt change now over waiting, water pump, thermostat, all belts and hoses. at minimum.
 
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