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overheating still

Greggles_VS

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So I've changed my radiator, top and bottom hose, water pump and heater tap. Bled the system correctly as far ask know, losing little amounts of coolant still but can't see any leaks, hoping its not going to be heater hoses or heater core, but why else would my car hit almost full hot? Only really happens when sitting at lights etc. Could it be my trans oil? Should I bypass straight to my trans oil cooler?
 

Brett_jjj

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Are the cooling fans switching on when sitting with the engine idling for 5 or 10 minutes? The cooling fan should switch on around the half way mark on the temp gauge on most VSV6's. You can test the cooling fan system by removing the temp sensor wiring connector from the temp sensor on the engine, starting the engine, and after around 12 seconds, the cooling fan should switch on at low speed, then after a further 6 seconds, the cooling fan should switch to high speed.
Remember that theres 2 temp sensors used on VSV6, ones for the temp gauge on the dash, and ones for the ECU. The temp gauge sensor has one wire, this is not the one to remove, you want to remove the other sensor wiring, the one with 2 or so wires.
Let us know how it goes.
 

Greggles_VS

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Don't even need to test, need to check my relay wiring, low far doesn't kick in, high fan not til 110 degrees from memory. Always gotta put ac on to keep coolish. Presumably my main problem?
 

Brett_jjj

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What do you mean theres no need to test?? This simple quick test will tell you if everythings working correctly or not. . Anyway, Ive have some problems over the years with the LOW speed cooling fan relay failing on my VSV6. This relay overheats when the A/C is on for long periods and the cooling fan is running for long periods, and the relay ends up failing from getting hot .. Ive had to replace this relay probably once every 12 months during the 9 or so years Ive had the car.. Ive also seen this problem occur on a few other VS's too, so its worth trying a brand new relay in there and see if the cooling fan comes on low speed then..
Another way to check the relay for this overheating damage is - if you look at the 5 relay pins, the plastic melts slightly around the base of one of the inner pins. Its hard to notice it unless you look very closely for it. All the ones Ive seen fail have gone like this. I always use genuine replacement relays from my local dealer, around $10 each. I tried to get different brand aftermarket ones once before, but the auto place didnt have them in stock so I never got them, I might have to get some different ones and try them this summer actually...
 
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Wozza

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What do you mean theres no need to test?? This simple quick test will tell you if everythings working correctly or not. . Anyway, Ive have some problems over the years with the LOW speed cooling fan relay failing on my VSV6. This relay overheats when the A/C is on for long periods and the cooling fan is running for long periods, and the relay ends up failing from getting hot .. Ive had to replace this relay probably once every 12 months during the 9 or so years Ive had the car.. Ive also seen this problem occur on a few other VS's too, so its worth trying a brand new relay in there and see if the cooling fan comes on low speed then..
Another way to check the relay for this overheating damage is - if you look at the 5 relay pins, the plastic melts slightly around the base of one of the inner pins. Its hard to notice it unless you look very closely for it. All the ones Ive seen fail have gone like this. I always use genuine replacement relays from my local dealer, around $10 each. I tried to get different brand aftermarket ones once before, but the auto place didnt have them in stock so I never got them, I might have to get some different ones and try them this summer actually...
Hi
You might want to check your fan motors not on the way out...as they get older they tend to pull more amps even more so as they get hot...I pull mine out once a year and clean all the dead bugs ect and oil it up were I can using a pin oilier...If you can remember which relay pin is getting hot and its one of the contact pins rather than the coil pins, then the fan might be pulling to many amps for the contacts to handle
 

Brett_jjj

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Hi
You might want to check your fan motors not on the way out...as they get older they tend to pull more amps even more so as they get hot...I pull mine out once a year and clean all the dead bugs ect and oil it up were I can using a pin oilier...If you can remember which relay pin is getting hot and its one of the contact pins rather than the coil pins, then the fan might be pulling to many amps for the contacts to handle

Na, I looked into all this years ago when it first started happening, I tried a couple of different fan motors etc, they all did the same thing. All the wiring etc is all 100% original and the fan wiring connections and relay connectors are all clean and tight etc. Ive also seen a couple of other VS commys have this exact same problem...The fan motor must overload the relay over long periods of running on low speed, and this eventually fries it. It only happens on mine over summer when the A/C is running for long periods of time.
I also had the ECU burn out once, which only stopped the cooling fans from coming on. That problem took some tracking down, as the ECU is usually the last thing thats thought of with problems like these, so I replaced the ECU and shes all good again, but it still burns out the relays though. Also Ive really gotta try another brand of relay. Ive only ever used the genuine relays, as I mentioned before, and these always end up cooked. The genuine holden relay is a siemens brand, its got it stamped on the side of them.
 
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Wozza

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Maybe pop down to jaycar or online at RS components and see if you can find a higher spec relay....If you can find out what pin is heating up that will tell you what you need to look for
 

Brett_jjj

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Ive got 2 old relays sitting in front of me now, the pin that overheats is pin 5, its one of the inner pins. The VS wiring diagrams I have dont show the relay pin numbers, so its hard to tell which pin goes to which wire. The relay has 3 smaller terminals and 2 bigger terminals, and its one of the bigger ones that gets hot. Id say the 2 bigger terminals carry the main power supply for the cooling fan motor, and the smaller ones carry the relay switching power.
 

Not_An_Abba_Fan

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Maybe upgrade the supply wire to larger guage so it doesn't have as much resistance.
 

tavrin

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Maybe pop down to jaycar or online at RS components and see if you can find a higher spec relay....If you can find out what pin is heating up that will tell you what you need to look for

You could convert the low thermofan relay to use a 30a 4 pin Bosch relay instead if the relay keeps crapping out.
Go to the wreckers and grab the high thermofan relay (4 pin 30a relay) holder & cut the wires off and connect the control + switch wires up to it and you're ready to go.
 
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