So, I recently bought myself a Skoda Octavia vRS 2.0 TDI 170, CEGA engine, 2010. 

 

Car has 213000 km right now.

 

Timing has been done by the previous owner at 206000. 

 

I replaced:

- radiator

- intercooler

- airco condenser

- fan shrouds

- oil LiquiMoly TopTec 4200 5w30 alongside a Liqui engine flush + motor protect

 

- I still have ordered the DSG thermostat to replace it - because I see it takes a long time for the coolant temp to reach "90" on the dash, and sometimes it fluctuates (sometimes drops to 85, sometimes to 70), so DSG thermostat is in the plan for replacement. 

 

My issue is, and something that I can't seem to figure out, I see my oil temps on the dash spiking pretty often, even reaching 150 degrees on a 100 km/h speed cruising on the highway, that doesn't seem normal in my opinion.

 

So most of the times it just stays between 85-105. Then it spikes around 120-130, then goes back down.

 

This morning on the way to work (it was a 85 km drive), it spiked to 150 and stayed in the 130-140 degrees area for the last 15-20 min of the drive. 

 

Is there another thermostat that I should replace? 

 

Afaik the car has the coolant radiator, the dsg oil cooler and the oil cooler on the oil filter housing. And the latter 2 are also using coolant, could all these issues be caused by the dsg thermostat? 

 

Coolant level hasn't dropped at all since the replaced parts mentioned above, I have no errors on the car. 

 

Average fuel consumption is between 5-5.5 l/100km, so that seems alright also. 

 

DPF oil ash volume is around 140 ml. So that would also seem fine according to the km the car has, dpf is doing it's regens. 

 

Anyone else had issues like this? Or has any pointers?

Sounds like you need Diagnose Dan!

Can you tag him here please? 🙏

 

This is something that's really bugging me, and would like to hear some opinions before I start taking it apart to replace anything that has to do with the cooling system haha

Just search Diagnose Dan.

Morning mate,,

I'm having a similar issue with my 20tdi vrs CEGA engine 2010,, 

1st is mine doesn’t over heat stay around 90 degrees and never really moves up or down but my live data reading says whilst driving 90deg but will read drops and rises in temp,, I seem to have a lot of pressure and when cold if I remove the cap the coolant spits out the bottle,, I’m taking to a garage to do a sniff test to see if it is head gasket (if it’s possible on a diesel)

 

I did a Google search as you do haha and whilst looking I came across a YouTube video showing that in a little thin hose that comes off the top radiator hose on radiator and kinda goes back to the expansion tank has some kinda plastic thing inside and gets bunged up,, I took the pipe off and could not blow down or suck air through this pipe, so I tied flexing it where the plastic is and whacked it on the ground and some gunk came out allowing me to blow down it to make it clear,, flushed out the pipe re fitted and proceeded to run the car upto temp,, apparently the pipe allows any trapped air to then be forced into the expansion tank and not into the radiator (not sure if true but I have nothing to lose hahaha) 

anyway car got upto temp and I noticed a lot of bubbles now coming back into the tank,, got to 90deg coolant raised in the tank and spat some out then settled down, left it running until fans kicked in (98 degrees roughly) coolant again raised up and leaked out slightly so left running until fans kicked in again and that seemed to help as it didn’t spit out this time, (kept topping up coolant after spitting it out) so I put cap back on went for a quick 4 mile spin, parked up popped bonnet and checked pipes for pressure, they was pretty had to press in,,

 

just been and took dog for walk this morning and then proceeded to pop bonnet to check on pressure in system (do this ever morning to release pressure),,, I could normally not push the pipes in as it still had a lot of pressure and if I took the cap off coolant spat everywhere even though it was cold,,

but this morning I could squeeze the pipes (top and bottom radiator hoses) together and when I released the cap next to no pressure and no coolant spat out,, still need to drive to work on Monday as it’s a 37 mile journey there and back to see if it still has high pressure or next to nothing (pinkie crossed this has helped) 

This is the pipe hopefully you can just see where it bulbs out just  above the shadow of me phone hahaha,, like I said I could not blow through this pipe until I whacked it on the floor hahaha 

It goes from top radiator hose and goes behind the air intake on front and the air box 

not saying this is your issue but could be worth checking this pipe, I’m hoping it has seriously cured my issue of over pressurising due to not being able to release trapped air,,, 

Thanks for the detailed answer. 
 

but my coolant temp never went past 90.

 

my OIL temps are going haywire 

2 minutes ago, lucideresu said:

Thanks for the detailed answer. 
 

but my coolant temp never went past 90.

 

my OIL temps are going haywire 

My VRs doesn’t show me oil pressure just coolant temp,, I just wondered if your coolant wasn’t circulating or you had air stuck in system if this would maybe cause issue with high oil temperature readings,, mine never went above 90 whilst driving according to dash gauge only when sat stationary and only on my live data reading, the dash gauge never moved ever but like I said mine seems to have excessive pressure and not circulating properly due to air in system,, just wondering if you have air stuck in oil cooler rad thus showing high temperature,, maybe 

I’ll try cleaning that pipe and see what happens. Thx a lot!

9 hours ago, lucideresu said:

Thanks for the detailed answer. 
 

but my coolant temp never went past 90.

 

my OIL temps are going haywire 

Reading through your post and the use of a flush and seeing those oil temps I suspect some blockage, probably oil pickup would be first look, although bit surprised oil pressure not showing as well. As a second option,  maybe check the main oil cooler for blockage.  150c at 85 or 100kph is very high I'd say. 

The oil temps were fluctuating like that before the oil change and flush. 
 

i did the oil change and flush because O thought it’s old/bad oil in the car. 

8 minutes ago, lucideresu said:

The oil temps were fluctuating like that before the oil change and flush. 
 

i did the oil change and flush because O thought it’s old/bad oil in the car. 

I'd still start looking as I outlined. There must be a blockage. What else could it be. 150c driving normally is not normal. And not normal for it to spike in same sedate driving conditions. 

 

Edit. You could replace the oil temp sender I suppose. Or test is somehow by using a control temp and see if it is varying / spiking. Seems unlikely but could be I suppose. 

Edited 29 September, 20232 yr by TheClient

The use of the word "spikes" indicates that the oil temperature suddenly shoots up to 150°c which is implausible, my money is on the temperature/level sensor being faulty, I believe that they are quite exposed and prone to failure.

It jumps from 105 to 135, then back to 9x, then jumps again. It does this for a while, then stays steady between 85-9x. Then jumps again. It’s very unsteady.

 

I also don’t really think it actually reaches 150x, the oil at those temps doesn’t really offer lubrication/cooling anywhere. Turbo would die instantly 😂

Sensor sounds likely now following @J.R. post. 

 

Edit. If temp sensor is bottom of sump. Whole volume of oil would need to fluctuate and spike like that and it seems unlikely in a moment of time as per explanation @J.R.

 

See for example.

 

 

Edited 29 September, 20232 yr by TheClient

It's possible the sensor wiring/connector is bad and warrants testing.

 

Ordinarily a resistance check whilst wiggling the wires would be the test but having someone watch the gauge or live diagnostic data while you wiggled things should suffice.

Awesome, I’ll look into it. Thx guys! 

So I had some time today to get the car up on the lift and check some things:

 

- oil level sensor wiring seems fine

- I checked with VCDS - no errors.

- I checked with Launch diagnose - intermittent error on the oil level/temp sensor - which brand do you recommend I should buy? 
- apparently my octavia 2 vrs CEGA engine doesn’t have a dsg thermostat, so I can’t replace that

- I will buy the main thermostat and replace that one instead - hopefully it solves the slow heating up

 

- besides these - would you advise on some preemptive maintenance I should do on the car? (It’s my first skoda) 😁

 

On 07/10/2023 at 23:00, lucideresu said:

So I had some time today to get the car up on the lift and check some things:

 

- oil level sensor wiring seems fine

- I checked with VCDS - no errors.

- I checked with Launch diagnose - intermittent error on the oil level/temp sensor - which brand do you recommend I should buy? 
- apparently my octavia 2 vrs CEGA engine doesn’t have a dsg thermostat, so I can’t replace that

- I will buy the main thermostat and replace that one instead - hopefully it solves the slow heating up

 

- besides these - would you advise on some preemptive maintenance I should do on the car? (It’s my first skoda) 😁

 

Hi,

Did you solve the high temp problem?