Coolant Temperature Gauge rising to 95º and then back to 90º

[Turbo_Boss]

Hello Guys,

I already post this on the Skoda Forum but since my car has the same engine as the MK4 and place this post here to to check if any of you have experienced the same problem.

I have a 2002 Skoda Octavia 1.8T with only 56,000 kilometers ( I just use it to go from home to my work and them back to home)

I have a small problem with my coolant temperature.

Both Coolant fans are working in slow and fast speed
AC is working OK and is cooling perfectly
Fuse over battery are OK and not melted

When I am at stop light the coolant temperature rise a little bit from 90º to 95º (Please check the photo) It does not rise more than that.

When I begin to drive, the coolant temperature go back to the middle (90º)

Also, one day that I saw the temperature in 95º, I turn off the engine, wait a little and then start again the engine........ The temperature goes to 100º and a few sec later go back to 90º

I was thinking the Termo Switch was not working but I open the hood and I see both fans are working in hi speed and then they cycle to slow speed.

This problem happened after I took the car a weeks ago to the VW Dealer to fix a small leak on a coolant hose 1J0 122 109AQ that is near the coolant reservoir and when they gave me back the car, I notice they put me in a bag the damage hose part + two empty G12++ Coolant 32onz bottles.

I was curious because I am pretty sure when the replace that small hose some of the coolant loss on the floor and they need to add more but I was think that maybe one bottle plus water was enough...............So when I ask the mechanic guy, he says he put the 2 bottles and they do not mixed it with water and that this is OK

Here in my country the weather is very hot. I know the G12++ Coolant has to be mixed 50/50..............Can this be my problem that the coolant temperature rise a little........ Or this can be a symptom of a water pump that the plastic impeller is going to fail

THX

Isaac

[nightphotographer]

I've had similar problems with a mk4 golf and it turned out to be the CTS (coolant temperature sensor) which was about $15 dollars to replace, worth a shot in my opinion.

[balkanac]

Check if there is enough coolant, and if the thermostat is working properly. And replace the CTS, its cheap and they break

[grtuned]

Check your themostat operation if you have not replaced this in the past i suggest you change it there not expensive, Also have your water pump checked your flow might not be good enough for coolant to circulate!! Also if you have access to VAG com do a dash test on the needles if the needle stops halfway during test this means its centred ok!! so if your needle is over middle this means you may have coolant issue, Cheers from OZ!!!

[Turbo_Boss]

I took the car to the dealer and they check all and toll me that the problem is the water pump. Since they want to charge me $280.00 for a new water pump with plastic impeller and 150.00 for hand labor. I tell them that I don't have money to fix it right know, that I will take the car to them in January. The guy toll me that they will remove the thermostat and leave the the engine without it to help the engine not overheat. I have the thermostat with me and I bring the car home and the temperature was always on 90º

I just order a complete timing belt kit with water pump with steel impeller for $259.00

So back at home, I open the hood and notice that they move a bracket were the accelerator cable goes and they leave it like you see in the pic. I really don't understand what was they checking in that hose........Do that hose has something to do with the coolant temperature?

I am curious, what that hose do? (Red Arrow) Why they move that part?



THX

[JustCruisn]

My mechanic told me that the earlier Golfs would do this a lot. Owners would complain that there must be something wrong. VW changed things so the signal or gauge was more balanced. The gauge would indicate a firm 90 from about 88 through to 110.
I can confirm that when my fans were not working over a 6 week period the needle always indicated 90, with no air flow it must have been higher than normal.

I have no idea what is going on with that bracket, the hose looks to be a vac line, nothing to do with coolant.

[Turbo_Boss]

Hey Guys,

Just to let you know that the problem was my Water Pump. As you can see on the attached pics, the factory water pump has a plastic impeller that with the time the plastic get brittle and then it cracks

My car is a 2002 with only 55,000 kms.

I took the opportunity to install a timing kit, GEBA water pump with steel impeller, new thermostat and new G-12++ Coolant

THX,

Isaac