Thread: Running Hot

Is there any caked on mud* on your radiator?

*or insects or any obstructions

Are there any air pockets in your cooling? (probably not after such a long time).

Try having the radiator flushed and see what comes out.

Was your viscous fan working? I have the same problem with mine, and as near as I can tell, it's the viscous fan coupling. Been too slack to deal with it during winter, but need to get serious soon.

Ian

hi there
this all occured with me just recently &with two others i know having the same hassles straight after.
the first thing to check is get the radiator cleaned & pressure tested.
it will be full of a white/brown plaster type texture material that comes out of the engine & has blocked at least 20/30% of your rad.
the gunk comes from the heater system in your dash.
sometimes it shows up as a bit of water on the floor when you use your heater. the fins of the heater core corrode throuhg sitting with little use in our hot climate & when they corrode the aluminium residue gets into the block & thus your radiator.
once it's cleaned, either replace the heater core or disconnect the hoses from the firewall & ignore it, buy a radiator filter sock that goes on the top radiator hose where it joins the rad & make sure you check it every two days for the first fortnight.
the reason for this is the gunk continues to come out of your motor for some time & will cause a blockage in the filter instead. check & clean regularly.
the reason i suggested not replacing the heater core is you have to remove the centre console & dash bulkhead to get at it. not fun.
hope this helps & saves you some dosh.
adam

No viscous fan any more I've got twin electic ones and the heater core is only 18 months old but my guess is the radiator flush was missed out in the course of all the other problems so the radiator still has the crud in it along with that wax stuff from the new block. Tested for the head gasket and all seems well so it looks like an early worning of a blocked radiator. In thursday to get the radiator out for a clean and a jolly good back flush for the engine so I get a nice fresh start.

On a side note what sort of coolant does every one use? anyone think redline water wetter does anything or just an advertising gimic.

Er ,try it with the viscous fan refitted.
Regards philip A

Given I have continual leaks, I use 'H20', but I don't have any overheat probs, just check it daily.....

GQ

Are you sure the radiator is big enough?. I would ask a specialist if the 4.6 needs a bigger radiator. I have a 4.2 and think I do, especially for towing.
Is it on LPG?
Is the timing right?
Either of these will add to the overheating.
Are the twin fans thermostatically operated? The aircon will soon pump out warm air if the fans are not going anyway.
Cheers,

Originally Posted by Quiggers

Given I have continual leaks, I use 'H20', but I don't have any overheat probs, just check it daily.....

GQ

for this problem.....you are slowly making the leaks worse via electrolysis.....
one metal is slowly eating the other without any corrosion inhibitor in the system.....
tend to the leaks and use some corrosion inhibitor before its too late.......




for the original problem of this thread.......is the thermostat any good......?
another problem may be the waterpump......it may not be pumping the coolant around fast enough at idle.......

also......were you really close to car infront in the traffic jam.....?
this can also make a difference to airflow through the radiator.....as well as the temp of airflow.......
as the car infront gives off a fair bit of heat as well......


if you had a blockage in the cooling system......it would overheat at high revs under load......
as the coolant couldnt move around fast enough.......
but at low revs......i would be thinking more along the lines of a water pump.....
which pumps a bit faster as the revs increase and the temp drops......


however....im only guessing....as i dont have the vehicle to be able to run any tests.......