Dashboard Temp Rises Too Quickly

[TaffyTim 6]

For a while my water temp gauge has been paying up, it'll go from cold to operating temp within a couple of mins and after 5 mins it'll be maxed out. This happens even if the car is not driven and left ticking over.

 

The oil temp acts normally and does not follow suit and the water temp warning light does not come on so I'm happy to think it's just an electrical gremlin.

 

I thought I would need to change the sensor as I presumed that this had failed so did this yesterday. I ran the car for a few mins to get the temp gauge pointing north, whipped the sensor out, got covered in Iuke warn water and put a new sensor in. Unfortunately it gave the same reading, I then left the car on tick over on my drive the gauge got maxed out in a couple of mins.

 

What should be my next port of call?

[welshpug 1,666]

Guessing the fan is working fine?

 

Check the wiring, though typically you would get a permanent high reading or no readimg with a damaged wire.

[TaffyTim 6]

Yes he fan is working, no issues there.

 

its very strange how it just creeps up and stays high.

 

How long does the needle normally take to point north? I know the oil temp takes an age but ive forgotten how long the water one takes.

[Slo 283 1 Cars]

Anyone possibly had the binnacle cover off at some point? The needles could have been pulled off to replace a faulty guage and not put back right.

 

They are VERY temperamental when putting the needles back on to get it in the right place.

[TaffyTim 6]

Im not 100% sure what you call the binnacle. Are you referring to the dash display? If so, no, its not been off for years and was working fine and sure for all the time since then.

 

It really is strange.

[luggy 13]

2 first thoughts are baring in mind you havent touched the dash:-

1. Is there enough coolant in the system

 

Yes he fan is working, no issues there.

 

its very strange how it just creeps up and stays high.

 

How long does the needle normally take to point north? I know the oil temp takes an age but ive forgotten how long the water one takes.

 

2. How old is the thermostat? maybe worth testing/replacing?

[Tom Fenton 1,548]

I would also check the thermostat.

[TaffyTim 6]

2 first thoughts are baring in mind you havent touched the dash:-

1. Is there enough coolant in the system

 

 

2. How old is the thermostat? maybe worth testing/replacing?

 

 

 

 

1 This was my first thought too and i filled the system to the brim as my first port of call, although (stupidly )I haven't brimmed it up since i put the new sensor in, I'll do that tomorrow.

 

2 Ive just seen how cheap they are so I'll get a replacement and pop it in rather than testing http://www.carparts4less.co.uk/cp4l/p/car-parts////?209745121&1&3ecffef39cc4cbb1f31bcbb558f8e6b6f1202604&000325

Edited November 18, 2013 by TaffyTim

[MikeC 10]

Make sure you get the right stat to suit the fan temp switch.

A search will bring up a few threads that i found very useful when i had a similar issue

[luggy 13]

 

 

 

 

1 This was my first thought too and i filled the system to the brim as my first port of call, although (stupidly )I haven't brimmed it up since i put the new sensor in, I'll do that tomorrow.

 

2 Ive just seen how cheap they are so I'll get a replacement and pop it in rather than testing http://www.carparts4less.co.uk/cp4l/p/car-parts////?209745121&1&3ecffef39cc4cbb1f31bcbb558f8e6b6f1202604&000325

There's no need to physically remove it to confirm the fault

Just follow these steps.

 

1.Get the car to running temp.

2. Check if the hose from the thermostat housing to the rad isn't hot to the touch

3. Turn heater on full with max heat, if this reduces the temp reading then the fault is confirmed as the thermostat.

[TaffyTim 6]

Ive had the thermostat valve out and replaced with a new unit and the problem persists, on starting the car the gage steadily increases to max over a 5 min period

 

I then tested the old unit in a cup of hot water and it functions perfectly.

So i pulled the temp sensor out and dropped it in the cup of 75C water with a thermometer and a route to earth and the temp gauge on the dash was showing max straight away. So the fault appears to be electrical, unless im missing something.

 

What could i have done to the loom to be giving these readings? Its not as if the gauge jumps straight to max so Im left scratching my head?

 

PS

 

After the above I thought there might be a blockage, so i ran water from a garden hose through the pipe that attaches to the offside of the expansion bottle when the thermostat housing was open. Water found its way out of the thermostat opening, this appears to show that the radiator is unblocked. Although saying this could the water just have been dropping down the offside of the rad and not flowing through the rad itself? I believe my plumbing is set up the same as surferkid205s post 13th11/08 @0955 in this thread: http://forum.205gtidrivers.com/index.php?showtopic=97614

Edited April 22, 2014 by TaffyTim

[welshpug 1,666]

From your test of the sender it sounds like your coolinh is fine and you have a duff sender.

[TaffyTim 6]

From your test of the sender it sounds like your coolinh is fine and you have a duff sender.

Do you mean the sensor (sorry I need simple talk, lol)? This was changed for a new one but still has the same results.