Running temp on Vt series 1

[Griz]

Hi Guys, sorry if this is posted elsewhere, had a look but couldn't find anything.

I recently bought a VT V6 series 1 that seems to have a temp issue. It has an external gauge as well as the dash unit. Seems to run at around 90 - 110 deg and then the thermals kick in and it drops back down to around 90-95. Then it climbs back up and repeats the process. During this time the dash gauge sits where all VT's I have owned sit and doesn't go any higher until the external unit starts to creep past the 110 and then the dash one starts rising. At which point I get a strong smell of coolant until the fans manage to bring it back down.

Now I have changed the pump, flushed out the system and put in fresh coolant and thermostat. Everything seems to be tight bolt wise and there are no visible leaks, Is this normal as I remember my previous VT II had a mysterious temp spike that still happens randomly. Any ideas?

Thanks.

 

[mrknowitall]

I got 2 vt v6 series 1...autos....1 has a new Rad ...other does not...I had the vt spike like you mention happen under the following conditions....prolonged idle.....long idle post traveling ....post doing some pulling work...or post doing hilly work......even had the engine light come on......and once its gets going all goes away.....and it sits on just under the 1/2 way on the gauge........I would check the opening of the thermo new or not.....in a test condition with boiling water and a temp probe.....new or old does not mean they work right....check it...and while your at it clip the restrict or on the thermo over valve....when your convinced the thermo works replace it....if your not sure leave it out and see what happens...flush the heater water....flush the Rad...by taking it out...and make sure...rest all hoses....check the overflow and hose to it.....and replace the Rad cap....and clean the sensor and temp ....contact points into the engine....use Rad cleaner ---flush and give it a lite 20 min run....drop an flush ..then do new Rad fluid and take it for a run after bleeding any air .....often his is caused by a faulty thermo.. and a faulty Rad cap....and gunk on the temp senior and gauge..inside...

 

[The1]

that temp range is normal operating range and thermo fan range. if you want the fans to kick in earlier then get a tune done.

 

[Griz]

I got 2 vt v6 series 1...autos....1 has a new Rad ...other does not...I had the vt spike like you mention happen under the following conditions....prolonged idle.....long idle post traveling ....post doing some pulling work...or post doing hilly work......even had the engine light come on......and once its gets going all goes away.....and it sits on just under the 1/2 way on the gauge........I would check the opening of the thermo new or not.....in a test condition with boiling water and a temp probe.....new or old does not mean they work right....check it...and while your at it clip the restrict or on the thermo over valve....when your convinced the thermo works replace it....if your not sure leave it out and see what happens...flush the heater water....flush the Rad...by taking it out...and make sure...rest all hoses....check the overflow and hose to it.....and replace the Rad cap....and clean the sensor and temp ....contact points into the engine....use Rad cleaner ---flush and give it a lite 20 min run....drop an flush ..then do new Rad fluid and take it for a run after bleeding any air .....often his is caused by a faulty thermo.. and a faulty Rad cap....and gunk on the temp senior and gauge..inside...

All done. Still the same issue. Replaced the radiator cap and still gets hot. In response to The1, I do understand it is normal operating range, but it goes past the 110 mark and the fans take a while to cool it down, I get a really strong smell of coolant at this point. Seems to be fine while I am driving, but when I am in idle is the issue. ECU maybe? I noticed when I got home tonight that the gauge was saying 110, fans kicked in and I popped the bonnet to have a look and noticed the hoses were hot to touch, but the cap was stone cold. I had been driving for about 35 mins.

 

[The1]

All done. Still the same issue. Replaced the radiator cap and still gets hot. In response to The1, I do understand it is normal operating range, but it goes past the 110 mark and the fans take a while to cool it down, I get a really strong smell of coolant at this point. Seems to be fine while I am driving, but when I am in idle is the issue. ECU maybe? I noticed when I got home tonight that the gauge was saying 110, fans kicked in and I popped the bonnet to have a look and noticed the hoses were hot to touch, but the cap was stone cold. I had been driving for about 35 mins.

If both hoses are hot then thermostat is opening, if the cap is still cold then id bet there be a blockage in the radiator.

Does the low speed fan come on before 110c ? if the fan only comes on at 110c then it sounds like the low fan isn't working as there is a low and high speed, they should operate as below.

Series 1 VT V6

High Fan ON 111.50c
High Fan OFF 107.75c

Low Fan ON 104c
Low Fan OFF 99.50c

CXWL or Higher Memcal
Series 2 VT V6

High Fan ON 107c
High Fan OFF 103c

Low Fan ON 104c
Low Fan OFF 99.50c

 

[Griz]

If both hoses are hot then thermostat is opening, if the cap is still cold then id bet there be a blockage in the radiator.

Does the low speed fan come on before 110c ? if the fan only comes on at 110c then it sounds like the low fan isn't working as there is a low and high speed, they should operate as below.

Series 1 VT V6

High Fan ON 111.50c
High Fan OFF 107.75c

Low Fan ON 104c
Low Fan OFF 99.50c

CXWL or Higher Memcal
Series 2 VT V6

High Fan ON 107c
High Fan OFF 103c

Low Fan ON 104c
Low Fan OFF 99.50c

I backflushed the radiator and it came out the top of the radiator with some force. The low speed on the fan does not seem to engage. What would cause this and how to rectify. Could there be air in the system that causes the cap to stay cool. I am a bit confused as to the correct way to bleed it as I have been told several different things. One was to have the heater on when I do it, but I just removed the cap and bled it from the valve. Is there a better way to do it? Thanks.

 

[Nut Kracker]

Draining, Refilling and bleeding the cooling system.
Yes, the heater must be set to hot, to allow the water to flow through the heater core.

Start the car before you set the heater to hot, as the heater tap works off vacuum and there might not be enough vacuum left to open it if the car's been sitting a while.
I believe this could be the problem for a lot of people who have cooling problems. They have air trapped in the cooling system, but claim the heater was on, but in actual fact, it wasn't because there wasn't enough vacuum left to open the tap.

 

[The1]

you can do it as above but it's pretty piss poor to bleed air as most of the air is stuck in the radiator, i get a coke bottle or similar that fits in the hole where the cap goes on, cut the bottom off and run the engine upto temp, just keep the fluid higher than the engine and all air will come out.

 

[Griz]

Thanks to all who helped, it was a dodgy temperature sender & faulty low speed fan relay. Now however a new problem has cropped up.

I installed the sender, disconnected the battery and had to undo the alternator as I dropped a socket behind it. Put it all back together now the check engine light is coming on and the fans come on after about 1 min of driving and stay on. Car does not seem affected in any way.

Any ideas?

 

[vtcommo-owner]

Thanks to all who helped, it was a dodgy temperature sender & faulty low speed fan relay. Now however a new problem has cropped up.

I installed the sender, disconnected the battery and had to undo the alternator as I dropped a socket behind it. Put it all back together now the check engine light is coming on and the fans come on after about 1 min of driving and stay on. Car does not seem affected in any way.

Any ideas?

I also got a low speed fan relay fault, is it a matter of changing the relay? ive done it twice and still get the same problem. i had a dodgy coolant sensor is that the same thing?