range rover 3.5 severe overheating

FurtherSouth91 · Post by **FurtherSouth91** » Tue May 20, 2014 4:24 pm

Hi guys,

This time is about cooling. A few days ago, cooling fan on my 1989 Range Rover Classic 3.5 exploded due to faulty viscous coupling and took out hood, cowl-cooling, ATF cooling hoses, radiator, which started leaking...

I had no way to stop leaks but to add some specific sealant to the cooling system through expansion tank. Leaks are actually stopped, but the car suffers severe overheating issues.

My opinion is that the sealant was rubbish and reduced cooling efficiency sticking at everything from pump, to radiator, to hoses.
I tried a complete flush with chemicals on the radiator, draining it and refilling but to no avail.

I then removed thermostat thinking it was somehow stuck closed and run the car a little bit but temp goes high anyway, near 3/4 of the indicator range.

Head gaskets are fine as the hoses stay soft, not pressurized by exhaust gases.
I'm going to try a new radiator. Hope it isn't water pump because removing it is quite tricky.
What do you think? Any advice would be appreciated.

Regards!

unstable load · Post by **unstable load** » Tue May 20, 2014 5:07 pm

Sounds like an already marginal system has finally been overwhelmed by the sealant you added.
I'd run some cooling system flusher stuff through it first, then replace the radiator. Remember the heater matrix, too when flushing.

FurtherSouth91 · Post by **FurtherSouth91** » Tue May 20, 2014 6:37 pm

I already tried a complete flush of the system using a specific chemical degreaser but had no luck.
What do you mean about heater matrix when flushing?

Thank you anyway. I will try a radiator swap as soon as possible.

DaveEFI · Post by **DaveEFI** » Tue May 20, 2014 10:57 pm

Not quite sure what you mean by the hoses staying soft. A system in good condition will be pressurised to about 15psi when hot - and hold that pressure for quite some time after the engine is stopped.

unstable load · Post by **unstable load** » Thu May 22, 2014 4:42 am

FurtherSouth91 wrote:I already tried a complete flush of the system using a specific chemical degreaser but had no luck.
What do you mean about heater matrix when flushing?

Degreasers won't work for this application. Radiator flush is specifically formulated for the gunk that collects in a cooling system.

The vehicle has a heater that is fed with hot water from the cooling system and that water flows through a mini radiator. That will also probably have your sealant stuff in it, so remember to open the heater controls if the vehicle has them to allow flow through the matrix so it will e cleaned too.