top end overheat??

conway00 · Post by **conway00** » Tue Jul 30, 2013 11:56 am

Hey guys. car is running all good when driving around for hours but when i get to high speeds at about 100mph plus (on a private road of course) in vtec the temp creeps up.

any ideas on what it could be. i realise it may be alot of things. rad, thermo, etc but anyone had same thing happen?

fan working fine and think next thing to check may be air in rad? but like i say as long as i keep to limits its fine and if i vtec through lowers gears it fine.

just top end........?

Cheers guys.

Chris

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Tue Jul 30, 2013 12:07 pm

When you say temp creeps up, where does it creep up to?
Normall running temp is with the gauge half way up. The fan should cut in without the temp going any higher (nb: I've not done sustained running at that speed so I don't know if the engine does run hotter like that, but conceivably it could).

Basics would be;

Check coolant level is correct and the coolant is clean/not scummy (could indicate sludged/scaled up cooling system)
Check the cooling system has no air in it (bleed from rad filler neck and thermostat housing)
Check there are no leaks/bulging hoses anywhere
Check the correct concentration of anti-freeze (too high or too little has quite an effect on cooling efficiency)
Check the rad gets evenly warm all over as it warms up/immediately after a hot run (no 'cold' spots that would indicate blockages/scaling inside)
Check physical condition of the rad (all fins present/not missing)

It doesn't take much of the last 2 in particular, to have a BIG impact on how efficiently the rad cools the coolant.

kris_aka_edu · Post by **kris_aka_edu** » Tue Jul 30, 2013 12:48 pm

I've had loads of problem at over heating, and especially with the thermostat I'm a professional now ay @wurlycorner! Haha At high speed I've never had it over heat. When your sat in traffic and it over heats its because the radiator is not getting air so it won't cool down, so mine has over heated then and as soon as I got up to high speed it cooled down naturally because of the air getting to it. So I'd say its pretty impossible to over heat at high speed personally.

mercutio · Post by **mercutio** » Tue Jul 30, 2013 1:48 pm

low water level???

conway00 · Post by **conway00** » Tue Jul 30, 2013 6:36 pm

ill do all the levels. thanks guys. its fine in traffic and fan kicks in. maybe it is low on water i just havent been arsed to check. mong that i am lol.

thanks guys.

kris_aka_edu · Post by **kris_aka_edu** » Tue Jul 30, 2013 9:33 pm

mercutio wrote:low water level???

Good shout!