Engine temp drop? then back to normal

[ibiza_95]

driving to UNI today the engine temp needle dropped as i was following a truck on a windy road at moderately low speeds, it went from half to about a quarter then 5 mins later went back to half and didnt move from half again. its never done this before is there a logical explanation? and is there any signs im missing from thjis that might need addressing ASAP.
cheers in advance

 

[Czechboy]

well when the needle is half way up, its normal. Only reason I can think of why the temperature would have dropped is because you weren't close enough to the truck to be traveling in its slip stream but just behind the slip stream(where the air from both sides joins in the middle). Therefore blowing lots of air straight towards the front of your car, therefore cooling it down.

Not too sure if you'll understand as its hard to explain.......but it somehow made sense in my head

mig

 

[ibiza_95]

but such a drop from half to quarter, the engine was hot also, id been driving 20 mins or so... i put it down to a dodgy temp sensor, but then it didnt do it again.
i can understand what your saying, dont know if it would have made such a drastic temp drop tho?

 

[Dolly_Gti]

unless the thermostat got stuck and is on its way out?.. i assume its a wax stat on a spring?

 

[sweilam]

what's the normal position for the needle during a long trip ?

mine goes to middle then the fan starts , takes it to quarter then it stoppes, making the temp. rises again to middle, fan starts ,, etc..

is this what you have guys ?

 

[ibiza_95]

nope mine usually just stays at the middle point and doesnt shift once its heated up

 

[Czechboy]

yeah same here. The fan only tends to kick in if either the car has been idling on the spot for about 10mins or if you have stopped just after ragging it for a while.

Mig

 

[sweilam]

it stays on the midle with the fan off ?!

 

[sjc59]

Yeah its never budged from the middle once warm.

 

[sweilam]

is it true that the fan got 2 different speed modes?

i tried to unplug one of the elec. wires and the fan speed got lower and less noise, i like it to be with this low speed-noise.

is this right ? or i am just messing things again ?

 

[Czechboy]

I don't think they do. My old 1.4's fan was either on, or off. No inbetweens. And no, it shouldn't kick in when the needle is in the middle, only when it starts going past it couple of mm.

Mig

 

[andyj]

I had this on my old 1.6 Cordy.... coming down a very long hill, just coasting on idle, and the engine temp dropped to between 1/4 and 1/2 position....

I just thought it was down to the decreased load on the engine, and then increased air being pushed past the radiator.....

 

[jenk]

But shouldnt the stat close off the flow of water to the rad if it cools to much

 

[ibiza_95]

its still doing it, tho not as much now, i guess as long as it doesnt go above the half way point it wont damage the engine, so ill let it carry on