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Old 18th June 2022, 16:48   #1
Mogwyth
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Default V6 high idle,

Mk1 190.

Tick-over is high at 1300 on cold start dropping slowly to 1000. Temperate is very slow to rise to normal. Can sit 30 minute idling and only reach 65c from cold. Occasionally is hesitant to start when hot. Not sure if they are all related but ....

Today managed 66c and overheated, not sure rad fan is working tried the air con trick and nothing. But I checked the coolant earlier so may have not tightened it fully.
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Old 18th June 2022, 20:14   #2
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Today managed 66c and overheated, not sure rad fan is working tried the air con trick and nothing.
Hello Bill,

Can I begin by checking a few details with you please.

When you say "66c and overheated", how are you measuring the coolant temperature? What is happening to lead you to believe that the engine is overheating?

When you say "tried the air con trick" do you mean pressing the windscreen demist button then checking that the radiator fan is running?

Simon
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Old 18th June 2022, 20:27   #3
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Temperature via live data from both Torque and PScan and thinking about I did check the water level before starting so numpty may not have tightened the cap as its was water and steam out of the cap


When you say "tried the air con trick" do you mean pressing the windscreen demist button then checking that the radiator fan is running? Yes
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Old 18th June 2022, 20:35   #4
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Thanks very much for the extra information Bill.

From experience I would not rely on what Torque and PScan is telling you, particularly as a temperature of 66˚C would not result in steam from the expansion tank. I'd recommend that you use the instrument pack diagnostics test no. 7.0.

You say that your radiator fan is not working when you press the windscreen demist button with the engine running. Is your air conditioning fully charged with refrigerant?

Simon
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Old 18th June 2022, 21:18   #5
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Found PSCan to be pretty good on my TF but will take your advice and try the diagnostics.

And I know the temperature gauge isn't perfect but it always used to get up to 9 o'clock pretty quickly pretty quickly but not anymore. Which seemed to coincide with the idle issue.

To be honest, I don't know as I never use the air con, hot weather is what the TF is for.
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Old 18th June 2022, 22:38   #6
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Is your air conditioning fully charged with refrigerant?
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... I don't know as I never use the air con, hot weather is what the TF is for.
The reason for my question is that we've recently confirmed that on a KV6 the "demist test" for the radiator fan won't work if there's no refrigerant gas in the air con. system. As you say you never use yours, it's virtually certain that there will be no gas and so you cannot easily test that your fan is operational.

Please let me know the temperature showing on the built-in diagnostics whilst driving. The engine must be under load to obtain a meaningful reading which won't happen when idling.

Simon
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Old 19th June 2022, 09:47   #7
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Thanks Simon

Ok got into diagnostics

Drove mile down our track@10mph temp reached 44c

4 miles 50-60 on the main road temp actually dropped to 42c

Drove mile up our track@10mph temp reached 55c

FWIW Torque temperatures matched the diagnostics
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Old 19th June 2022, 10:09   #8
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For me i think Bill and Simon are nearly there. Stat not working (opening early). ECU compensating with high tick over (and im guessing its using more fuel) And yes AC/fan as issues.. My philosaphy. Start at cheap end.. Air lock/vent it. New stat. Go to Jules in North Wales for AC overhaul if needs be.
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Old 19th June 2022, 10:28   #9
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Thanks for the excellent data Bill. As Phil says your thermostat is the suspect; failing to close properly or opening early and the only cure for that is a new one unless you've had work done on the cooling system recently and it hasn't been refilled and bled properly. No-one has put K-Seal in it I hope?

Simon
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Old 19th June 2022, 10:56   #10
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Thanks guys, no not had any work done on the cooling and wouldn't let K seal near any of my vehicles!

Will order a thermostat kit for DMGR and hope my fat hands can fit in the gap

Phil, I do need to get up to Jules as I got a new key for it just before covid and spoke to him about codeing it and then never actually got up there.
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