Author Topic: Low Coolant Temperature and Low Oil Temperature  (Read 6891 times)

Offline Carbon VW

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Low Coolant Temperature and Low Oil Temperature
« on: 11 January 2018, 19:32 »
I noticed driving home yesterday that my coolant temp gauge was jumping between 80-90 degrees C. One time I would look it would be 80, the next sat in the middle at 90c. It never budged from 90 before this. I also noticed at the same time that the oil temp is running very low. It usually settles at around 102-105 degrees C but it is now between 77-80 max. The car is fully up to temperature with these readings. Economy has not suffered according to the MFD. car seems to be running fine. All levels and fluids checked and all ok. I suspected thermostat/water pump but I’m confused as to why the oil temperature is also very low.
Any thoughts would be interested. Car is August 2013 Mk7 GTi with 50,000km on the clock.
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Offline a9wyn

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Re: Low Coolant Temperature and Low Oil Temperature
« Reply #1 on: 11 January 2018, 20:20 »
I don't know if this is the same thing, but over on the TT forum, this issue raises its head all the time, especially on MK1 TTs. and its either the  coolant temp. sensor, which on a MK1 TT is straight forward to change, or if that doesn't work, it's the thermostat. Is the car still under warranty? If so take into the dealers and get them to sought it out.

Offline Carbon VW

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Re: Low Coolant Temperature and Low Oil Temperature
« Reply #2 on: 11 January 2018, 20:26 »
Thanks for that. Yes I’m hoping it’s a temp sensor. Would that explain the low oil temp also? The car is out of warranty.
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Offline itavaltalainen

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Re: Low Coolant Temperature and Low Oil Temperature
« Reply #3 on: 12 January 2018, 08:00 »
Does it throw any faults?

Oil temp would have its own sensor, so looks like it really does not warm up fully.
You say kilometers..... where are you based?
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Offline I wanted a GTi

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Re: Low Coolant Temperature and Low Oil Temperature
« Reply #4 on: 12 January 2018, 10:17 »
Does it throw any faults?

Oil temp would have its own sensor, so looks like it really does not warm up fully.
You say kilometers..... where are you based?

Ireland.
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Offline Carbon VW

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Re: Low Coolant Temperature and Low Oil Temperature
« Reply #5 on: 12 January 2018, 13:34 »
Hi yes Ireland. Haven’t scanned with VCDS yet. Heating inside car (blower) is working fine so that would tell me the thermostat is not to blame ? It’s just very strange that the oil temp is reading so low also. I will update once I know more.
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Offline GloriaGTI

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Re: Low Coolant Temperature and Low Oil Temperature
« Reply #6 on: 14 January 2018, 16:58 »
I have been having these exact symptoms for the past two weeks. The water temp fluctuating between 75-90, oil running cool and the heater blowing hot air in the cabin as usual.

I have noticed a big increase in fuel consumption on mine though. My average mpg has dropped from 29 to 26.5 with no changes to my driving style/distances covered, just more stops at Shell than to usual.

Car is showing no fault codes when I scan it either.

I've had the water pump off and inspected but the garage said it was fine. They have replaced the coolant and I topped it up the following day after it had all settled overnight. Being family friends, they were against just going ahead and replacing the thermostat as they weren't sure it would resolve the problem for me.

Mine is also a 2013 model, out of warranty but with more miles under her belt than yours - 76k! Which is why I thought it could be the water pump.

Today I did the 16 miles journey back from my girlfriends without the heating on and it seemed to be fine. I then turned the heating on a couple miles from home and it started to drop in temperature again.

Not sure what to do, so as you said, let us know how you get on
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Offline Carbon VW

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Re: Low Coolant Temperature and Low Oil Temperature
« Reply #7 on: 14 January 2018, 23:25 »
Yes that is the exact same symptoms as I am experiencing. It’s disappointing really from a 4.5year old car. Whatever the mileage covered. I have my car booked into my local Indy VW expert tomorrow night . He has already said over the phone he suspects coolant temp sensor. I will let you know what happens.
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Offline naxcars

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Re: Low Coolant Temperature and Low Oil Temperature
« Reply #8 on: 15 January 2018, 16:26 »
Notice my coolant was low and had to top up 100ml yesterday.  Took it into the dealer and the Service Manager (different dealer from my last service) did notice though that the expansion tank filler cap hadn't been screwed on correctly.  On my Mk7 it gets tight and you think you're going to cross thread it but you keep tightening until you get the audible click. The Service Manager put some grease on the nylon thread of the cap and refitted.  I mentioned about the discoloration of the expansion tank compared to my 67 plate Golf, but he said it was down to coolant gases over last 4  yrs and the coolant and tank looked all OK.
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Offline GloriaGTI

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Re: Low Coolant Temperature and Low Oil Temperature
« Reply #9 on: 16 January 2018, 19:06 »
Yes that is the exact same symptoms as I am experiencing. It’s disappointing really from a 4.5year old car. Whatever the mileage covered. I have my car booked into my local Indy VW expert tomorrow night . He has already said over the phone he suspects coolant temp sensor. I will let you know what happens.

How did you get on?

Mine is still dropping off but not as frequently as before now that the coolant has been changed.

If I don't use the heater inside (fortunately I have heated leather) it sits at 90 just fine. Then when I turn the climate control on, hot air comes in as expected but then the water temp dips again.
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