Vk Cooling Issue

[VK SL 3800]

My 202 with the est is having a lot of trouble holding a consistent temperature, during the winter months its fine and always holds the exact same spot on the gauge not matter how you drive. But now that its summer it can usually hold the same temp around town without the AC going but with it on it tends to run much hotter and then if you go out on the open road and hold a constant 100kp/h it gets even hotter still(about 2/3 of the way up on the gauge). It is not filling up the overflow reservoir with coolant and overflowing. The gauge is working fine and have tested all the connections. I have replaced the water pump before summer and it did have a different impeller to the original but the new impeller is the same as the early red motor types. can take a picture of another pump i have with the same impeller for clarification. I have removed and blown any crap in the radiator out, flushed the system, replaced the thermostat and blown out the condenser as well.
It seems that me that the pump just cant get enough flow to efficiently cool down the engine because the air can cool down outside to a temperature where normally will hold its engine temperature fine but take a good hour for the engine temp to co-inside with the changing outside air temp.
A good example of this was when i left home in 40 degree heat and hit a thunderstorm after being on the road for an hour with temp right up but when the ambient air temp dropped to about 25-30 degrees it took an hour or so extra until the engine temp had dropped down with it.
My HG ute can be driven fine in the heat (even if your dying) and holds its temperature pretty well, only running a couple of degrees hotter.

Any help will be appreciated.

 

[ari666]

checked that your vacuum advance is working properley? heating up at 100kmph is a prime example of it not advancing far enough at part throttle.

unfortunatly its EST so i couldnt say how the advance works on that dizzy. but yeah, id be looking further into it.

 

[whats up]

Overheating

I had the same thing with mine and I thought I'd get the radiator cleaned out and the rad guy told me it only had 5% crap in it so I reinstalled it.
The temp guage would read 3/4 on most days depending on the weather and I just accepted this as normal...Until the headlights would shut off while travelling at night at high speed and scare the living crap out of me having to drive blind until I could pull over.
I thought of a new light switch and went down and got 2 just for good measure.
The problem was still there the next time I went out into the country so I replaced the other switch while on the side of the road and continued on and eventually made it home.
It wasn't until the next day that I opened the bonnet to find out what the hell was going on and I started the engine and I could not believe it when the engine was warm I saw a very small pin hole in the top of the radiator and the water was spraying onto my regulator I had mounted on the guard for my spot lights.
So what I'mtrying to say is maybe go out and buy a NEW radiator because my cars temp guage always sits in the blue zone now no matter how hot the temperature is.

 

[VK SL 3800]

I dont really want to buy a new radiator untill im sure that its the problem. It doesnt leak and the car isnt using coolant so i think there might be another problem causing the cooling issue but i could be wrong, theres not doubt it isn't advancing enough because if you run it on 91 it will ping under light acceleration at 100 so i doubt its a timing issue.

 

[codfishface]

If you are running EST, the computer won't know/care what octane fuel you are running and you won't be able to adjust any advance/retard.

I'd look at replacing your Temp Sensor (mounted on the thermo housing). From the manual -

"The temperature sensor is used to inform the control module of the coolant temp to asses the correct timing advance during cold,normal and high temperature operations."

Also -

" The air conditioning compressor emits a signal to the control module when the compressor is operating which advances the ignition timing at IDLE speed, which raises the idle speed to prevent the engine from stalling."

I'd check/replace the temp sensor and all the wiring/joints.

Better still, dump the EST and install a HEI dissy and have control over your timing.

 

[ari666]

run it on 91 it will ping under light acceleration at 100 so i doubt its a timing issue.

ill start by saying coldfishface is spot on, but just so you are clear, you wont get any advance at light throttle. advance should only be at cruise and deceleration. the idea is to reduce your engine temps when you are on the freeway.

 

[VK SL 3800]

I have already replaced my Temp sender on the Thermo Housing abut 6 months ago so it should be all sweet, i will eventually get a HEI dizzy when i save up a bit of spare cash to buy one but till then ill just try get the best out of the EST system. I can drive at 80 and not get any pinging but 100 does in the old EST box. I have no problems with it stalling with the AC on, when it engages the idle speed will drop momentarily then the computer will advance it to get the correct idle speed again so im guessing that it knows when its on still.

This probably has already been covered in another thread but anyway, when you put on the HEI dizzy, i have been advised to connect the Vacuum advance line to the EGR system because it starts to operate once the engine is warm and provides vacuum under throttle.
About vacuum advance on HEI dizzys, does giving the Dizzy vacuum advance the timing or retard it? It seems everyone has different opinions but i always thought that vacuum rotates the the base inside and advances it is this correct? Older Red motors dizzys operate the same way dont they?
Can someone point me in the right direction.

 

[codfishface]

Vacuum advance will, oddly enough, advance the timing under load conditions.

If you incorporate the EGR valve vacuum line, you will have no vac adv at idle until the engine reaches operating temps, then the EGR thermal vacuum switch will open, giving you vacuum.

Vacuum Advance

Distributor advance

Both the above links helped me get my head around vac advance(plus some guidance from the regulars on here).

I was the same with my EST. It was functioning, but with a new carby, air filter, extractors, no air pump or EGR, it was getting all the wrong data and running like a pig. I dropped in a reconditioned HEI re-graphed for 98 ULP and whoa baby! Best $200 bucks I've spent yet on the old girl.

 

[VKCOMMO]

i'd say get a V8 radiator, or even if your feeling lucky a good one like PWR or aussie desert, have you got any cooling fans on it??

vkcommo

 

[ari666]

Vacuum advance will, oddly enough, advance the timing under load conditions.

If you incorporate the EGR valve vacuum line, you will have no vac adv at idle until the engine reaches operating temps, then the EGR thermal vacuum switch will open, giving you vacuum.

Vacuum Advance

Distributor advance

Both the above links helped me get my head around vac advance(plus some guidance from the regulars on here).

I was the same with my EST. It was functioning, but with a new carby, air filter, extractors, no air pump or EGR, it was getting all the wrong data and running like a pig. I dropped in a reconditioned HEI re-graphed for 98 ULP and whoa baby! Best $200 bucks I've spent yet on the old girl.

once again, really good post dude i got nothin to add to that.