Engine taking increasingly longer to warm up at cold starts

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halfbytecode
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Drives: 2010 1.6 TDI
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Engine taking increasingly longer to warm up at cold starts

Post by halfbytecode »

Hi,

My car has clocked over 130,000 kms, and it is over 7 years old. It is a 1.6 TDI, 105 HP.

I have observed the engine seems to take longer at cold starts, to warm up. The warm up time has gradually increased over the past year or so. It feels close to half hour or so, while driving in the city. Moreover, this happens in summers too, but to a lesser extent.

During the warm up, the engine is very sluggish to rev, quite noisy, and has reduced fuel efficiency, by about 20%.

It is worth mentioning that the car never felt this way, in the initial 5 years of ownership.

Could it be the coolant temperature sensor acting up, thermostat stuck open, or something else?

The car is regularly maintained, on time, at the dealership. It has not thrown any error codes whenever it was scanned at the dealership.
joe6
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Re: Engine taking increasingly longer to warm up at cold starts

Post by joe6 »

My first check would be the thermostat. Could be stuck open and would not show up on a diagnostic scan. How quickly does the cabin heater get warm? If it is longer than usual that could also indicate a thermostat problem.
halfbytecode
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Re: Engine taking increasingly longer to warm up at cold starts

Post by halfbytecode »

joe6 wrote: Sat Feb 17, 2018 11:45 am My first check would be the thermostat. Could be stuck open and would not show up on a diagnostic scan. How quickly does the cabin heater get warm? If it is longer than usual that could also indicate a thermostat problem.
It seems to take longer than usual, with the AC on and temperature set to High. It only seemed to get warm once the engine felt a bit warmed-up.

Is there an easy way to change the thermostat, without dismantling a lot of the stuff in the engine bay?

I also had a coolant change done, a few months ago. Is the a way to avoid wasting the coolant?
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iichel
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Re: Engine taking increasingly longer to warm up at cold starts

Post by iichel »

Do you have a VCDS?
halfbytecode
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Re: Engine taking increasingly longer to warm up at cold starts

Post by halfbytecode »

iichel wrote: Tue Feb 20, 2018 8:40 am Do you have a VCDS?
I don't have it. However, it would likely be possible to do what you suggest, at the dealership.
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