Temp gauge paranoia??

Car has had lots of fun over the Xmas period but it seems that frequent glances down at the stack to check the temp is something I do subconsiously now…

Car always runs at 86-87 during normal running. However, never noticed it before but under hard acceleration the temp sharply drops to 74-76. Have I just never noticed this before or could it be something more sinister Coolant level seems normal, and thankfully despite it being the turkey season, no hellman’s is evident…

Don’t worry, when you have HGF temp shoots UP, not down.
Many cars do what yours, if you want to get rid of that symptom, install a remote thermostat.

I’m pretty sure this is a case of TADTS.


in this weather it will be more noticable and is due to cold water in radiator being let thru’ to cylinder head when your stat opens at 89deg. Its more visible when you accelerate hard because the 87deg water in your cylinder head heats and opens the stat more quickly than it would at gentle throttle openings.

Remote 82deg stat cures it… i believe.


what exactly is TADTS ?? never been able to suss that one out yet…

OK makes sense, and just a TADTS symptom cheers guys.

They All Do That Sir …

Can confirm mine does it as well, its best to really get the temp stable as much as possible in these situations - next to impossible when not on a track though …

cheers Andy

in fact it came to me in a Eureka moment today when i was out looking at new sofas with Gillian

Amazing how the mind wanders when shopping huh

Shopping! I’m too worried. Noticed temperature shot up from 87ish to 93is when heater fan turned on one notch, Went up to over 100c when turned a couple more notches. Temp returned to normal when fan turned off. Anyone noticed this? Shd I be worried?

That sounds to me like you’ve got a dodgy earth connection somewhere.

Here ya go… there is a description of your ‘feature’ under the earthing section in the middle somewhere…


Maybe a bit obvious but very very important… have you got enough coolant in the system ? is the header tank at correct level ? If you leave the car idling does the radiator fan come on for a while then cut off?

assuming this is all good… then you are then looking for an earth fault possibly as described in the FAQ (Benja’s link above) or possibly in the temperature sender return path.

Thanks to all for guidance on temp guage. Temp does go up when lights switched on so earthing looks like the problem.Coolant level just above min so will monitor closely.If there’s a leak somewhere, I presume undertray disguises it and prevents drips on to garage floor.