Over heating vs v6

Philhermit

New Member
Hi all.... vs v6 Olympic edition ute over heats under load.
It first started very infrequently, car would run as it should and then, only sometimes, if I turned off the engine and then soon after started it again it would suddenly spike temp very high and sometimes would all of a sudden drop back down. Or if I turned off the engine and started again it would just run as normal.
I checked and changed everything, everything..... to my surprise when I finally got to the water pump, I found it had no blades left all corroded..... but the cat still ran normally temp sat where it should almost all of the time until this infrequent spike that would go away ad quick as it came.

Now the car seems to run fine if I am driving it like I stole it..... but if left to idle for a while will get a little hot. But if I have a load in the back like a tonne or if I'm towing a trailer WITH a load on it.... then the car just gets hot.

When I check, everything seems to work maybe when ac isn't on the fan turns on a little later then I think it should.... but ac on will make no difference, still just gets hot under load.

Any thoughts
 

immortality

Can't live without smoky bacon!
Staff member
Flush the radiator?
 

Philhermit

New Member
Flush the radiator?
Yeah.... I have done it all..... used radiator flush, did it again with hot water, again with hot water and thermostat out engine running, and again just to make sure, I don't think theres an engine that has been flushed more....? I collected the water that came out and did end up with more than enough rusted metal and stuff. I flushed it so much I created many leaks which I then had to fix..... replaced everything I could think of that might or could be a reason. Why does it over heat under load
 

immortality

Can't live without smoky bacon!
Staff member
Have you tried reverse flushing the radiator?
 

losh1971

Well-Known Member
By a new rad they are only about 50 bucks.
 

Trevor loves holden.

Well-Known Member
Replace the temp sensor maybe its not sending the right info to the fan to switch on, or try swapping fan relay over, replacing everything doesn't explain much. Are the fan's coming on, is your thermostat opening and closing, did you use anti freeze / boil, do you have a trans cooler, is there anything in front of the car like bull bar blocking airflow. Maybe get a twin trans radiator cooler.
 

Philhermit

New Member
Replace the temp sensor maybe its not sending the right info to the fan to switch on, or try swapping fan relay over, replacing everything doesn't explain much. Are the fan's coming on, is your thermostat opening and closing, did you use anti freeze / boil, do you have a trans cooler, is there anything in front of the car like bull bar blocking airflow. Maybe get a twin trans radiator cooler.
I've changed everything, as I said fan comes on speed increases when ac is on.

Let's just assume I'm not an idiot..... to avoid replies like have you put coolant, not being rude.... as I appreciate anyone trying to help.

I can drive the car hard, I have many roads around me that are crazy and 100km/h I can drive hard like I'm racing it car runs great..... driving hard not fast. No problems...... but if I drive it easy with a load it instantly starts to overheat...?
Answer that
 

immortality

Can't live without smoky bacon!
Staff member
There is a plastic strip that covers the gap between the top of the radiator and radiator support panel. There is also supposed to a plastic strip under the radiator with a 90 degree turned down edge. These are there to help airflow through the radiator and without em fitted can have heat issues. Does it have AC? Is the AC core not blocked reducing airflow?

Next. Is the maf clean? If these get dirty they can cause a lean condition which creates extra heat.
 

Philhermit

New Member
There is a plastic strip that covers the gap between the top of the radiator and radiator support panel. There is also supposed to a plastic strip under the radiator with a 90 degree turned down edge. These are there to help airflow through the radiator and without em fitted can have heat issues. Does it have AC? Is the AC core not blocked reducing airflow?

Next. Is the maf clean? If these get dirty they can cause a lean condition which creates extra heat.
Thanks for the reply..... the top plastic strip is there, I cant say I've noticed the bottom one but will check tomorrow and also the maf. I have checked the plugs and they all looked healthy no signs of excessive heat.
 

Old_School

New Member
Hi all.... vs v6 Olympic edition ute over heats under load.
It first started very infrequently, car would run as it should and then, only sometimes, if I turned off the engine and then soon after started it again it would suddenly spike temp very high and sometimes would all of a sudden drop back down. Or if I turned off the engine and started again it would just run as normal.
I checked and changed everything, everything..... to my surprise when I finally got to the water pump, I found it had no blades left all corroded..... but the cat still ran normally temp sat where it should almost all of the time until this infrequent spike that would go away ad quick as it came.

Now the car seems to run fine if I am driving it like I stole it..... but if left to idle for a while will get a little hot. But if I have a load in the back like a tonne or if I'm towing a trailer WITH a load on it.... then the car just gets hot.

When I check, everything seems to work maybe when ac isn't on the fan turns on a little later then I think it should.... but ac on will make no difference, still just gets hot under load.

Any thoughts
Was this in hot weather or cooler? Have You pressure tested the cooling system? & cap? & did you remove the thermostat when you reverse flushed? Only takes a pin hole to lose pressure & overheat & towing slows the airflow especially , did you bleed all the coolant bleeders? & check for any tiny leaks near the 2 'O 'rings that are in the tensioner area , sneaky culprits sometimes, look for any tell tale discoloration or corrosion , & weakened heater plastic component & softened hose, under clamp, it's a pain finding the issue a lot of the time, I had a VT Calais with an L67 engine & It did my head in for awhile too, good luck
 

Not_An_Abba_Fan

Exhaust Guru
What water pump did you use? Some cheap aftermarket ones have very small blades and don't work too well, this will cause heat under load as it doesn't move the coolant efficiently. What thermostat did you use? Too cold and it will stay open almost all the time not allowing the coolant in the radiator to actually cool down.

When you say "gets hot", what is hot? Half on the gauge? 3/4? The VS gauge is not terribly accurate, fit a proper temp gauge and see what the actual temperature is. The VS gauge can be only a few degrees between half and 3/4 and maybe as much as 15 deg between 1/4 and half. A big movement in the top end of the gauge is a small amount of temperature increase. The gauge is only a guide, just because it's reading high may not necessarily mean it's overheating.
 

gtrboyy

Well-Known Member
Yep as above can read 3/4 on gauge yet not be overheating.Think that is when fans turn on & v6 fan turns on higher + higher pressure radiator cap iirc.

Can get new radiators dirt cheap nowadays...no point flushing ol' crusty single core.

Usually if overheats at idle or slow speed look at fan or waterpump...also fan has 2 speeds normal for engine temp & high speed for ac on
 

Philhermit

New Member
Was this in hot weather or cooler? Have You pressure tested the cooling system? & cap? & did you remove the thermostat when you reverse flushed? Only takes a pin hole to lose pressure & overheat & towing slows the airflow especially , did you bleed all the coolant bleeders? & check for any tiny leaks near the 2 'O 'rings that are in the tensioner area , sneaky culprits sometimes, look for any tell tale discoloration or corrosion , & weakened heater plastic component & softened hose, under clamp, it's a pain finding the issue a lot of the time, I had a VT Calais with an L67 engine & It did my head in for awhile too, good luck
Hot or cold, raining or dry, drives fine but as soon as I have a load it wants to overheat. I often carry a 1000ltr water tank, no problems whilst its empty but then on the way back tank filled car overheats especially when I start to climb the mountain home. Ears pop kinda mountain.... and yes I shouldn't be carrying a tonne.

Thermostat was out when I flushed, as I mentioned b4 all the flushing did create some small leaks.... those o"ring were one and the only thing I didn't change. Changed everything else, heater valve hoses ring clamps water pump thermostat sensor radiator coolant.
I took care of the leak and potential future leaks with an additive which also helps condition the coolant to help with heat exchange.

Car just seems to overheat when it's under load.
 

losh1971

Well-Known Member
They do get warm under load and going up hill. 1000kg will do it. To help you could try reducing the ratio of glycol in the cooling system. More water will help remove heat better than high ratios of glycol. Redline Water Wetter I think it's called will help too.
 

losh1971

Well-Known Member
Do you have the VS auto tow pack fitted? That will help too.
 

Not_An_Abba_Fan

Exhaust Guru
Considering the payload is 710kg, take your weight and the weight of your fuel, and then add 1000kg....you would be more than 400kg overloaded. That would certainly get it warm going up a mountain. The mitigating factor is the GCM, if you were towing a trailer the tow capacity would be factored in and your theoretical GCM is ~2850kg, so you are still ~300kg under that. The car should cope. Just take it easy going up the mountain.
 

Philhermit

New Member
They do get warm under load and going up hill. 1000kg will do it. To help you could try reducing the ratio of glycol in the cooling system. More water will help remove heat better than high ratios of glycol. Redline Water Wetter I think it's called will help too.
Thanks for the rep..... my car always ran like a trooper, bought it new and has served me well for 20 years.
It all started soon after I decided to give it a little TLC plugs new leads oil coolant even painted the top of the engine cover.....there wasn't even anything wrong. Doing a chemical radiator flush actually started the issues, revealing a few leaks then the minute you touch one thing something else shows its age.
I've actually put kw fiber lock which has a conditioning agent to help with heat transfer even moved the license plate.
Might have to give it to an expert.
 

Not_An_Abba_Fan

Exhaust Guru
I'd be inclined to say that what ever the flush has released has partially blocked the flow of the coolant. Could be a heads off job to manually clear out the coolant galleries.

You could have said that in your first post...
 
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