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Discussion Starter #1 (Edited)
(This was also posted in the electronics as I'm not too sure whether it's engine related or the electronics.)

I've had my car off the road for a couple of months and I've just got it running and going again, however, the temperature gauge is fluctuating a lot so sometimes it'll be at the normal running temps (which it should be at) and then drop all of a sudden to cold or near it. Any help would be really good. Thanks!
 

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You need to post whatever diagnostics/checking you've done so far, in order to avoid wasting everyone's time.
 

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Discussion Starter #3
Well, I haven't been able to do much testing, as I stated, I only just found this issue and wasn't able to find a solution from anywhere else.
 

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You didn't state anything about testing. But if you haven't done anything, then start by checking the coolant level.
 

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Discussion Starter #5
Well, I did say that I have only just got it going so I haven't had a chance to do any checks. Either way, I will start testing tomorrow. The front radiator was changed recently and the system was filled back up and the levels so far have been where they should.
 

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Discussion Starter #6
After some small tests. I've figured out that the coolant levels are good. However, I have also noticed that when the car is stationary, the temperature gauge will go up to normal running temps, but if I then go for a drive, it falls all the way back down to cold again.
 

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When the gauge drops down, have you stopped the vehicle and checked the temp of the upper and lower radiator hoses? (i.e. cold, warm, hot) Also (again when the gauge drops down) how does the heat feel when you turn it all the way up?
 

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Discussion Starter #8
So recently, my car has yet another issue (possibly a dodgy starter motor), and I can't test it at the moment, however, yes when I was driving the car, the heater fans were consistent and stayed hot like usual and didn't change when the thermostat did. I plugged in an obd reader and saw the live coolant temp readings, it was getting around 70.c when warm, but then as soon as I moved off going not much faster than 30mph it came back down to cold again which dropped down to around 55-60.c in a matter of seconds.
 

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Someone should fix the title of this thread. It's a thermostat.

Based on your latest post, I'm wondering if the thermostat has failed and is locked open. This would allow coolant to freely flow and prevent it from absorbing heat.
 

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Discussion Starter #11
I've changed the title back to thermostat. Not sure how that happened but I think my auto spelling didn't like that word. Can I fix a stuck thermostat or should I just look for a new part?
 

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You should just replace it, not an expensive part. Be sure to get OEM or comparable quality because if it gets stuck closed that can be a much worse problem.

I think I recall..VWandDodge actually posted a step by step of how to get the thermostat out. If you like doing everything at once, I'd do the water pump and hoses as well if over roughly 120k/15 years
 

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You should just replace it, not an expensive part. Be sure to get OEM or comparable quality because if it gets stuck closed that can be a much worse problem.

I think I recall..VWandDodge actually posted a step by step of how to get the thermostat out. If you like doing everything at once, I'd do the water pump and hoses as well if over roughly 120k/15 years
Yep, here you go: Thermostat Gasket Replacement

I have 182K miles on my car with the original water pump. I wouldn't recommend replacing it. Hoses are another story. I replaced all of the hoses in my car at just over 150K(?) miles. Now that I think about it, I'm wondering if the thermostat gasket on your car is sucking in air as it's cooling which is resulting in the OP's issues. Anyway, check out my above DIY and let us know what happened.
 
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