Off throttle - the car seems to continue to fuel itself

[minke]

Resetting the ECU doesn't do anything to the instruments.

You could only see it by checking the fuel trims with VCDS.

Does the oil temp stay up on the highway too?

Gavin

Gavin - Thank you for your input.

I assumed that resetting ECU would reset all values.

I assume the dealers checked the fuel trims. It's interesting to note that when I have instant fuel economy displayed and get out of the throttle it takes a long time before it displays 0.0L/100. My friend's GTI did not exhibit this delay .

I can think of two examples on high (what I think is high) oil temp.

* Sydney to Wollongong with an ambient temp of 13 degrees the oil was reading 106-107 at 110 in 6th gear cruise control
* Inner Sydney to Parramatta (lunch with a friend) then Parramatta (via M4) back to inner west. Great traffic flow, no lights run. 108 degrees. I think ambient that day was 15.

I wonder if the 'oil temp' is related somehow. Modern cars will fuel the cylinders to aid cooling. If the car thinks it is hot, it might be dumping extra fuel for cooling. I know many a modern car does this now so I would assume the Golf has that programmed into its ECU

[h100vw]

Gavin - Thank you for your input.

I assumed that resetting ECU would reset all values.

I assume the dealers checked the fuel trims. It's interesting to note that when I have instant fuel economy displayed and get out of the throttle it takes a long time before it displays 0.0L/100. My friend's GTI did not exhibit this delay .

I can think of two examples on high (what I think is high) oil temp.

* Sydney to Wollongong with an ambient temp of 13 degrees the oil was reading 106-107 at 110 in 6th gear cruise control
* Inner Sydney to Parramatta (lunch with a friend) then Parramatta (via M4) back to inner west. Great traffic flow, no lights run. 108 degrees. I think ambient that day was 15.

I wonder if the 'oil temp' is related somehow. Modern cars will fuel the cylinders to aid cooling. If the car thinks it is hot, it might be dumping extra fuel for cooling. I know many a modern car does this now so I would assume the Golf has that programmed into its ECU

There's probably over 10 ECU in the car. So you can assume nothing to be the case.

I doubt that VW would look at trims. The ECU would show a code if it was outside the limits it has been taught.

I have an AFR gauge on my Polo and it takes a lazy count to 2 to have the fuel shut off completely.

Modern cars have heavy flywheels which hold lots of inertia. My S3 will roll for ever compared to my Polo.

There's no way they inject fuel to aid cooling, it is often done during high loads to reduce cylinder temps but not for cooling. Why would they bother with water if that were the case. I think you have 2 concepts confused there.

IMO you are over thinking the Oil temp thing. They have taken nearly all instrumentation out of aircraft cockpits to reduce pilot workload. Only when something is outside of normal parameters will it be displayed as a caution.

Not sure where the oil temperature is sensed but if it's in the sump, then it makes sense that it is hotter than the water. As the pump would pass it around the heat exchanger afterwards reducing the temp before it lubricates most of the engine.

Gavin

[Snail Style]

Did you check the clutch switch yet? :S

[Lucas_R]

I have. Two dealers. All operating as normal. I disagree but I've nothing to argue. I was able to demonstrate the issue with the QA advisor at Barloworld Mascot. He himself said it seemed odd but wanted to compare another GTI Mark 6. Two days later I get the car back (supposedly reset ECU values - however I note that all the values relating to fuel usage and time since last reset and the number of km was still in there)

Meanwhile, I note that my engine oil always seems to run hot. As per below. After 14km of driving to/from shops. I left it idling for a few minutes (3?) and it dropped to 107. Oil is 2160.7km old and the approved Castrol oil as per what the deal would use.

Frustrating. If anyone has an idea and access to VAGCOM that might know what to look for I'm happy to pay beer.

No doubt there are some variances from car to car, but my Mk6 GTI's engine oil temp rarely sees above the mid to high 90's. Im going to Sydney this weekend and will be around the Camden area, so if that's close to where you live we could meet up and compare cars etc. I could bring my VCDS cable and laptop. I will have a bit of free time in the mid/late afternoon.

We could check fault codes (if any) and look at your fuel trims.

Not sure where the oil temperature is sensed but if it's in the sump, then it makes sense that it is hotter than the water.

Gavin

Yes Gavin its in the sump

[Lucas_R]

Did you check the clutch switch yet? :S

Listening to ^^^ this guy might be a good idea too. He is a VW tech.

Snail Style - do you know where in VCDS you can check the clutch switch operation? What module?

[h100vw]

Listening to ^^^ this guy might be a good idea too. He is a VW tech.

Snail Style - do you know the are in VCDS where you can check the clutch switch operation?

I poke around until I find a row of binary and then dip the clutch and brake pedals. You see the 1s and 0s change.

[Snail Style]

Should be a mvb in the engine module somewhere, or as h100vw said just look for some binary that changes.

Was a common issue back at audi on the 8L A/S3's to have them fail, no fault codes thrown but revs would flare up on shifting. As there was no codes thrown generally technicians just scratch their heads with it.

Sent from my HTC_PN071 using Tapatalk

[Lucas_R]

Just for reference regarding your comments on engine oil temp, here are a few pics i took this morning on a 25 minute commute. All open road so speeds between 70-110kph for 95% of the trip.

I was in a hurry so i wasnt babying the car this morning - temp didnt exceed 95.

[AdamD]

My GTI would sit around 95 degrees in general 60km/h driving in average conditions (say 22 degrees). If I was stuck in traffic, driving quickly or the ambient temp was higher, it'd regularly get as high as 102-103. And if I was driving hard on country roads it'd get as high as 110 occasionally - but it would need proper pushing to get that hot.

Between 95-105 degrees the oil cooling is limited apparently (as this is the normal operating range); only above 105 degrees is the oil cooling unrestricted.

Engine oil temps can be affected by many factors, not least of which was the engine run-in technique. An engine that was overly babied may never have bedded in properly and may always run hot and consume some oil.

If it's any consolation, the latest-gen EA888 in the Mk7 (and in my S3) sits at about 107-109 degrees on a cold night when driven gently!

[minke]

I've attached two screen grabs from VCDS. One where the car behaves as expected, the other where it is obvious there is a delay before fuel stops being delivered to the engine.

Any thoughts?