VP V8 runs hot under load

[dans_vz]

My V8 is running too hot under load usually around halfway when driving around town or even on the freeway (sometimes up to 3/4 on a hot day).
I think this is too hot, as the thermos come on just after half way...

And as I mentioned I can be doing 110 on the freeway on a hot day and it will have the thermos running after it gets past half way and it wont get back down to even half way, it wants to stay at near 3/4! I know on hot days the car will run hotter, but I dont think it should be this hot, soon as I pull over and stop and just let it idle it will start cooling down.

When im just idling I can get it down to a quarter with thermos on, or when rolling down a hill you can see the temperature starting to drop
So im assuming it could be timing or spark related?
The cooling system is in pretty good nick, got a fairly new cooling system less than two years old with a thick alloy radiator, nulon coolant, no coolant leaks, new coolant hoses, etc

I have a greenfoam tune, what should the base timing be set at for the tune?

Thanks guys

[dans_vz]

Oh also could it be possibly coolant temp sensor issues?

[mr calais 5.0]

How long since you flushed the cooling system or changed the coolant?

[dans_vz]

About a month ago

[dans_vz]

Anyone any ideas?

[IBLOWN]

It could be anything. Blown head gasket, temp sensor, water pump, radiator, thermostat. Start with the easy and cheap ones first then work your way up.

My 5L NEVER moves from just under the halfway mark no matter what driving condition.

[DANNY8]

How well do ur thermo's seal up around ur radiator? Maybe try a clutch fan and shroud on there? Whatever fan u use, it has to be sealed up good around the radiator otherwise the fan will suck air from the gaps. A mate's car has a 20c size broken piece in his shroud and it ran hot around town. Told him to chuck some dusct tape over and hole and it fixed it.

But.....as urs is still running hot on the highway, I don't think it would be fan related as the wind should be more then sufficient. If the radiator isn't to old....I'd go with the thermostat.

Base timing should be 10 degrees. Remember to short the pins out on the ALDL connector to check/adjust it.

Another thing to look at would be the timing cover. If it has corrosion behind the waterpump it won't pump properly.

[Not_An_Abba_Fan]

I'd be checking the timing as well, if it is running too much advance it will run hot. Check for vacuum leaks as well, could be running lean.

[HoZy]

Put a cooler thermostat in.

Cheers
Mat

[dans_vz]

Adjusted the timing to 10 deg.. It was near 14 deg.. The thermostat is new still..

[VR38]

If it heats up on the express way and cools off when you slow down I would be thinking a blocked radiator or colapsing bottom hose.

[Circlotron]

VR38 beat me to it.
Check and see if the bottom radiator hose is not being sucked flat by the water pump when you give it a rev up when it is hot. Or alternatively, see if you can flatten it with your hand. There should be a spring inside the hose that stops this happening.

[dans_vz]

Hmmm I dont think it could be blocked radiator I did do a flush a month or two ago, and replaced the coolant even though it was still clean with no crap in it and about a year old... I can squeeze the bottom hose with my hand when its cold I will have to give it a rev when its hot and see what it does. Doesnt feel like there is a spring in it... I can do the same thing with the top hose.. thought this was normal..

[Not_An_Abba_Fan]

It is. You can squeeze them when cold, but they should be pressurised when hot.

[VR38]

A flush will not clear a blocked radiator. Regular flushing will help prevent it tho.

[dans_vz]

The radiator would be about two years old, but I will check when it's hot later and touch the side tanks to see if it's all hot or if there is any cold sections in them.. I checked the bottom radiator hose when it was hot, I could squeeze it but not to the point that it was completely flat.

[dans_vz]

Also the was a new water pump on the motor when I bought it a year ago I wonder if it's a cheapie one and I should maybe replace it? Could it be possibly struggling to keep up with higher revs ?

[Brian47]

just sounds like a dicky fan relay to me. Had a similar prob recently. another relay and now the prob is in the other car