I posted the same in the water pump thread, but thought that I'll take my chances here too.

 

My heating issue is a little different than earlier mentioned here.

 

The car is Octavia 4x4 DSG (not RS), 135 kW, 2016, 108000 km, diesel.

 

It only happens when the engine is heating up pretty fast (warmer ambient temperature and driving style dependent) and the oil temperature is not yet about 90 degrees celsius. Then it goes up to 110-120 degrees. But didn't have once the message on my dash to stop. When the oil temperature reaches about 90 degrees everything goes right. Then it holds still the coolant temp at about 90-95 degrees (readout with diagnostics). In these situations, it does not depends on driving style. And never happened on longer drives when the engine is on work temperature.

 

I'm almost certain that most of the time this is happening when the car is in DPF regen mode.

 

Do you think that this is the same water pump issue or does somebody have any clue what can I do or check?

 

When you talk about solenoid, does it mean the solenoid which is the actuator for the sleeve? Does anyone have the wiring diagram for that?
I thought that I can test it manually, but I'm not sure that it's 0-12 V (the connection to the water pump). Can anyone confirm that?

 

Does the sleeve only goes on-off or have middle positions?

 

Thx.

OP here. Garage confirm timing is good. The only error code is indicating a possible low current from battery. Guy doesn't think that is likely to be causing low MPG but slight possibility that if the alternator is overworking it could have a slight effect - but he certainly wasn't suggesting that a nailed on certain culprit.

 

Top marks to the garage for not charging me for this (they took cover off to check timing and possibly replaced coolant (?) as well as hooking up diagnostic equipment. and checking emissions).

 

Only thing I can do is accurately monitor MPG (difficult at the moment obviously).

 

One other thought: could a tank of "bad" diesel have an effect? Not sure what bad diesel could be but just clutching at straws really.

3 hours ago, reg091 said:

OP here. Garage confirm timing is good. The only error code is indicating a possible low current from battery. Guy doesn't think that is likely to be causing low MPG but slight possibility that if the alternator is overworking it could have a slight effect - but he certainly wasn't suggesting that a nailed on certain culprit.

 

Top marks to the garage for not charging me for this (they took cover off to check timing and possibly replaced coolant (?) as well as hooking up diagnostic equipment. and checking emissions).

 

Only thing I can do is accurately monitor MPG (difficult at the moment obviously).

 

One other thought: could a tank of "bad" diesel have an effect? Not sure what bad diesel could be but just clutching at straws really.

I would swap cars for a week and monitor how it runs.

On 04/04/2020 at 18:58, reg091 said:

UPDATE: the missus tells me that since this work was done she has noticed her MPG drastically reduced.

 

3 hours ago, reg091 said:

Guy doesn't think that is likely to be causing low MPG

 

PICNIC:

Problem In Chair Not In Car? 😆

21 minutes ago, IamGaz said:

 

 

PICNIC:

Problem In Chair Not In Car? 😆

Not sure what you are saying but putting those two quotes together is creating a different context. He was saying that a low battery isn't likely to be causing low MPG (no argument from me there).

26 minutes ago, Ecomatt said:

I would swap cars for a week and monitor how it runs.

In a normal world yes, but of course neither of us are going anywhere at the moment. Taking her car in was the first time outside the house for nine days!

40 minutes ago, reg091 said:

Not sure what you are saying but putting those two quotes together is creating a different context. He was saying that a low battery isn't likely to be causing low MPG (no argument from me there).

 

Sorry Reg, it was just a light heated suggestion that if there isn't a problem with the car, maybe it's a change in driving style?

 

I can more than halve my fuel economy by driving like the GTI my car is, rather than just a vehicle for commuting.

 

Gaz

LOL. All the driving is hers so unlikely she has changed.  When we are moving again I will get her to fill the tank and note the mileage and take it from there. She reckons she gets "about 440" on a tank (surprised that she knows that!) and that on her last tank she got "about half" that. Too much conjecture for my liking so I will try and get a bit more scientific.

late update on this:

 

About a week after my last post I noticed a stain on the drive under the car. Inspection suggested to me that it was diesel. Not a "puddle" by any means more of a wet stain probably from slow dripping as the car had been sitting for a week.

Back to the indie. He confirmed strong smell of diesel under the bonnet and found a small wet spot on top of the fuel pump. He trimmed the hose back a bit and refitted it.

 

Top man still refused payment (I convinced him to take a four pack of Stella!).

 

Been on the drive for several weeks since and no more dripping so looks like problem solved. I am guessing that when driving the fuel was being leaked out at a bit more pressure than just dripping, explaining the missus reckoning fuel gauge needle was moving.