Overheating

[EG3B16]

Guys need your help on this one....

I was on the motorway just doing 100-110 KM/H today in my EG and the temp gauge started to raise.... seems like it was overheating.......

I was just driving normally and its never done it before....

Now I did some checks when I got home.....

There's plenty of coolant.... as it was only serviced last week.

The fan works..... so thats fine..

Not sure what else could be wrong....


Any help would be great!

Cheers,

[JasonGilholme]

whats your overflow bottle look like?

If it was only serviced last week, you might have an air bubble in your system and it needs to be removed.

[MWAKU]

maybe your thermostat..

[EG3B16]

whats your overflow bottle look like?

If it was only serviced last week, you might have an air bubble in your system and it needs to be removed.


My overflow bottle is fine... theres coolant in there....

BUBBLE in the system? please explain..

[JasonGilholme]

when you drain the coolant you're block fills up with air, and when you refil the coolant through the radiator theres a chance that air can get trapped in the block, and prevent coolant flowing through the system completely (causing symptoms like you mentioned)

Undo the radiator cap (when the car is cold), turn your heater on full, and let the car idle up. Keep an eye on the coolant level in the radiator as it may drop due to the water pump pumping the air bubble out of the system.

[EG3B16]

when you drain the coolant you're block fills up with air, and when you refil the coolant through the radiator theres a chance that air can get trapped in the block, and prevent coolant flowing through the system completely (causing symptoms like you mentioned)

Undo the radiator cap (when the car is cold), turn your heater on full, and let the car idle up. Keep an eye on the coolant level in the radiator as it may drop due to the water pump pumping the air bubble out of the system.

Cheers buddy.... will try that when the car cools down...

+1

[JasonGilholme]

no probs mate.

cheers :thumbsup:

[teh_mechanic]

try jasons suggestion.if that fails.

overheating at highway speeds can indicate sediment in the radiator blocking a part of it.
all the sediment falls to the bottom of the radiator, and it can block of layers of it, effectively taking away 1/3 or so of your radiators ability.
only really affects you at high speed because the engine is working and there is supposed to be heaps of air passing through the radiator but there is not enough cooling being done by the partially blocked radiator,doesnt hurt it at low speeds because there is normally enough radiator left to keep it cool and the fan helps out anyway.

to check - heat the car up, then feel the top of the radiator, it should be very hot (please dont hold your hand there and burn yourself haha).
then feel the bottom of the radiator,if it feels a fair bit cooler then chances are its blocking.
DONT PUT YOUR HAND IN WHERE THE FAN GOES,IT CAN START AT ANY TIME,EVEN WHEN THE CAR IS TURNED OFF

[EG3B16]

try jasons suggestion.if that fails.

overheating at highway speeds can indicate sediment in the radiator blocking a part of it.
all the sediment falls to the bottom of the radiator, and it can block of layers of it, effectively taking away 1/3 or so of your radiators ability.
only really affects you at high speed because the engine is working and there is supposed to be heaps of air passing through the radiator but there is not enough cooling being done by the partially blocked radiator,doesnt hurt it at low speeds because there is normally enough radiator left to keep it cool and the fan helps out anyway.

to check - heat the car up, then feel the top of the radiator, it should be very hot (please dont hold your hand there and burn yourself haha).
then feel the bottom of the radiator,if it feels a fair bit cooler then chances are its blocking.
DONT PUT YOUR HAND IN WHERE THE FAN GOES,IT CAN START AT ANY TIME,EVEN WHEN THE CAR IS TURNED OFF

Cheers mate... will definately try that.....

yeh at low speeds nothing happens.. even when i give it...

but at high speeds.. it just started to creep up on temp...

[Limbo]

is the car driving like normal? especially when you just had it serviced
I had something like that once and it turned out to be a blockage in my exhaust. The CAT died and left a piece blocking the exhuast pipe and caused it to overheat at long drives. Check if there is any leaks in the exhaust system.

The other thing i can think of if all the above don't work is that maybe the mechanic used a different coolant to mix it and bad blend? maybe new coolant (complete flush is what's needed)

[EG3B16]

is the car driving like normal? especially when you just had it serviced
I had something like that once and it turned out to be a blockage in my exhaust. The CAT died and left a piece blocking the exhuast pipe and caused it to overheat at long drives. Check if there is any leaks in the exhaust system.

The other thing i can think of if all the above don't work is that maybe the mechanic used a different coolant to mix it and bad blend? maybe new coolant (complete flush is what's needed)

Yeh the car is running sweet man... but at long drives along the motorway it just creeps up...

its nothing major at all.. but thought id get some ideas on what it could be..

I'll check out my exhaust..

If theres a leak in the exhaust, could that be the cause?

[JasonGilholme]

yeah theres a leak in your exhaust, theres a big hole in one end of your muffler :p:p

A leak should cause any major over heating problems, but a blockage is what you should be looking for.

[EG3B16]

^^^^^ hahaha lolz..

yeh ill get it checked out..

[aaronng]

Check if you have an aftermarket thermostat. Some aftermarket brands tend to fail shut!

[Limbo]

yeah theres a leak in your exhaust, theres a big hole in one end of your muffler :p:p

A leak should cause any major over heating problems, but a blockage is what you should be looking for.

Yeah your looking for blockages, but the way you do that is look for leaks. The reason is that where its blocked it usually leaks just before that, cos the exhaust will push its way out somewhere else.

My old car it leaked at the cat join & on the header. We worked it out by putting the car up on a hoist and hitting the piping, but just see if there is a leak first as its the first sign of actually blocking. Also see if there is alot of air coming out of the back exhaust or if it seems to be restricted.

[BigWillieStyles]

sounds like a new radiator is needed or give it a good flush.

[EG3B16]

sounds like a new radiator is needed or give it a good flush.

i already done a coolant flush..

[JasonGilholme]

sounds like a new radiator is needed or give it a good flush.

his radiator will be fine. Unless its got obvious cracks or is leaking fluid it won't need to be replaced.

How did you go with the air bubble trick??

[EG3B16]

his radiator will be fine. Unless its got obvious cracks or is leaking fluid it won't need to be replaced.

How did you go with the air bubble trick??

yeh theres no leaks from the radiator...

i did the air bubble trick.... but i havent had the chance to test on the motorway....

Normal driving its sweet...

[JohnL]

i already done a coolant flush..

Have you checked the rad externally for debris that may be impairing air flow through the core?

Worst case scenario might be the first signs of a blown head gasket (sorry to mention this possibility). Have you got any signs of creamy froth on the underside of the oil filler cap, or any excessive pressurisation of the rad hoses?

[EG3B16]

Have you checked the rad externally for debris that may be impairing air flow through the core?

Worst case scenario might be the first signs of a blown head gasket (sorry to mention this possibility). Have you got any signs of creamy froth on the underside of the oil filler cap, or any excessive pressurisation of the rad hoses?


not a blown head gasket either.. the car was just serviced last week..

All of these thigns got checked.... thats y im abit suprised when the temp gauge went up..

It didnt exactly overheat... the temp gauge just went up past halfway when I was doing high speeds..

But when i turned the heater on.... the temp gauge went straight back to normal....

its only happening on high speeds...

[cvicek]

i am having overheating issue too...

it is normal when doing highway driving or normal driving. but when i stuck in the traffic for a long time, i can see the temp started to rise.

i idle my car for more than 10 min the other day, the fan didn't even kick in, is there somethign wrong with the fan? but the temp still stay normal( could be because its a cold day that day

[EG3B16]

i am having overheating issue too...

it is normal when doing highway driving or normal driving. but when i stuck in the traffic for a long time, i can see the temp started to rise.

i idle my car for more than 10 min the other day, the fan didn't even kick in, is there somethign wrong with the fan?


yeh mate... my old EG use to do that... u may need to check ur fan...

Sounds like its not cooling the radiator when ur in traffic..

Its ok when ur driving because the radiator is getting AIR COOLED.

but no air while on idle...

Check out the plugs or even maybe the fuse for ur radiator..

[cvicek]

will give that a go tonite... .thanks EG3B16

[EG3B16]

will give that a go tonite... .thanks EG3B16

no worries mate.. :thumbsup:

[JohnL]

Have you pulled the rad out and had a good look at the radiating fins? These can corrode which reduces the ability of the rad to exchange heat (coolant to air). Sometimes the black paint holds the fins in their original shape even if under the paint they are nothing but crumbly oxide, but at a glance they can look fine.

It's not uncommon for substantial areas of the finning to be either corroded completely or to the point where the only remaining metal is very very thin (which doesn't help heat transfer). Try running your fingers firmly (but not too hard!) over the finning, if it crumbles or easily collapses (due to being thin metal), then the rad might be the problem.

[cvicek]

check the fuse. . Its fine. . I let the car running idle for about 10-20 min but the fan didn't come on. . But the temp is only half way. . Not over heat. . Any idea at what stage will the fan run?

[teh_mechanic]

on some cars the fan wont even come on when the car is just sitting there idling, it needs a little drive to get some heat in it then maybe if you sit at the lights for 30 secs (so the air going through your now quite hot radiator stops) so the fan comes on.

If it doesnt come on at idle after 20 mins (long time)..... then go for a lil drive until it heats up,then idle in your garage and hold the revs at 3000rpm or so to give it more heat,then see if the fan comes on.

pretty sure your fan will be fine though, or it would be a low speed or standstill problem,because thats the only time the radiator relies on the fan allow for cooling, all the other time the air passing through it does the job

[cvicek]

will give that a try when i got time ... thanks for the advise teh_mechanic