Author Topic: Water temperature issues  (Read 2167 times)

Offline nightroamer

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Water temperature issues
« on: 01 August 2013, 20:05 »
Hi Guys,

Looking for a little advice about water temperature issues i have with an 8v i just brought.

The internal gauge never reads above 1/4. The car stays stable at that temperature and after a jaunt in the London traffic the fan often kicks in at low speed for a minute, or runs on for 30 seconds after i stop as i would expect.

Thing is i have changed the black sensor 3 times and they all read the same! they were all used but its odd they all ready the same. I also pinched the blue engine temp sensor off my other 8v as this one had two black ones which i am sure is wrong. Its a 1989 big bumper car (They both are).

any ideas of what to look out for? could all three sensors be faulty?
If anyone knows the correct sensor part numbers i may renew both and the slightly damaged house.

Thanks

Offline oakgreener

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Re: Water temperature issues
« Reply #1 on: 02 August 2013, 09:33 »
I would imagine it is the black sensor. You might have a wiring fault but you can check this by shorting the wiring at the sensor. The gauge should go full scale. If that's not the case you have a wiring fault that's dropping the voltage to the gauge.

Offline nightroamer

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Re: Water temperature issues
« Reply #2 on: 02 August 2013, 10:23 »
I would imagine it is the black sensor. You might have a wiring fault but you can check this by shorting the wiring at the sensor. The gauge should go full scale. If that's not the case you have a wiring fault that's dropping the voltage to the gauge.

ah ok nice simple test. I will have a look now.  thanks oakgreener

Offline nightroamer

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Re: Water temperature issues
« Reply #3 on: 02 August 2013, 13:12 »
Ok guys, i have disconnected the sensor and shorted the wiring and the gauge goes up to max.

So thats now 4 sensors i have tried all of which sit at 1/4 temp (Worth noting all are used sensors)

So i have realised the fan is always running on low when i pull up the car. It doesn't kick in when cold so im guessing it is by 1/4 temp.
I pulled the fan fuse and let the car climb to 1/2 way on the temp gauge no problem. then i reconnected the fuse and fan kicks in until temps back at 1/4.

Do i have a fault thermo switch for the rad fan?

Offline JimR

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Re: Water temperature issues
« Reply #4 on: 02 August 2013, 14:14 »
My 8v never/rarely gets above ΒΌ on the gauge either, perhaps some just run cool?
Mk2 GTi.

Offline Sgt_Lemon

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Re: Water temperature issues
« Reply #5 on: 02 August 2013, 14:20 »
Mine will always sit between 1/2 and 3/4 when at running temp. The fan will only kick in at 3/4.

Offline nightroamer

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Re: Water temperature issues
« Reply #6 on: 02 August 2013, 17:31 »
ok this gets even wierder.

Having pulled and replaced the fuse the car now get up to just a smidge over half way, fan kicks in, then cuts off just under halfway like it should.

could pulling a fuse have reset something???

Offline gazareth

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Re: Water temperature issues
« Reply #7 on: 02 August 2013, 18:04 »
maybe there was a bad connection at fuse. was there any corrosion on it? oh and the chances of 4 sensors been faulty and giving the same reading is kinda slim.

Offline nightroamer

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Re: Water temperature issues
« Reply #8 on: 03 August 2013, 20:39 »
well fan was running just to soon. maybe stat switch was faulty untill I heated it right up and now its all ok.