1.5 tsi reliability

Tester01

Active Member
Oct 24, 2022
91
10
Does your coolant temperature/ambient temperature and fuel pressure look 'sensible'?

I would try a motorway test - pick a nice dry day, avoid rush hour and avoid hills, reset your MPG trip for the journey (not long term trip), and cruise control on at 55-60mph for something like 30 miles and see what the MPG is? this should guarantee a good MPG, if still poor then you definitely know something isn't right.
regarding the motorway test, would that be from cold?

Took it to a ‘specialist last Friday, but tbh was a waste of time didn’t tell me anything I couldn’t have seen myself with obdeleven
Usual no fault codes and drives fine etc.
I mean I do get it…As I guess they can’t sit around spending hours searching for an issue. But yeah £100 down the drain again.

Guy said fuel economy is fine and normal.
Basically what they’d done is took the car after I’ve warmed it up a bit, reset the since start and took it on a 3mile journey down a back road.
47mpg lol
But don’t feel that’s a fair and accurate test?

Will try get some fuel pressure figures this week…
Did have a look early last week couldn’t see any thing about a Low fuel pressure pump, could only see High fuel pressure pump in obd11

Do these cars typically have both?
 

SuperV8

Active Member
May 30, 2019
1,354
600
regarding the motorway test, would that be from cold?

Took it to a ‘specialist last Friday, but tbh was a waste of time didn’t tell me anything I couldn’t have seen myself with obdeleven
Usual no fault codes and drives fine etc.
I mean I do get it…As I guess they can’t sit around spending hours searching for an issue. But yeah £100 down the drain again.

Guy said fuel economy is fine and normal.
Basically what they’d done is took the car after I’ve warmed it up a bit, reset the since start and took it on a 3mile journey down a back road.
47mpg lol
But don’t feel that’s a fair and accurate test?

Will try get some fuel pressure figures this week…
Did have a look early last week couldn’t see any thing about a Low fuel pressure pump, could only see High fuel pressure pump in obd11

Do these cars typically have both?
Yes from cold, my thoughts were to do a drive which is optimal for getting a decent mpg - just to see if the car is able to get a reasonable mpg - to be honest that 47mpg for a 3 mile journey is good - and shows that the car is 'capable' of decent mpg.

The 150 Leon real world mpg figures are between 34 & 52.
Anecdotally I find these honest john real world figures quite accurate for the various cars I have used.
1700555121114.png


Yes, your low pressure pump is your in tank pump of fuel module.
I think I would try and log your engine temperatures (coolant & oil) - as the 47mpg when hot on a short run is good. Could be its taking too long to get upto temperature?
 

Tester01

Active Member
Oct 24, 2022
91
10
Yes from cold, my thoughts were to do a drive which is optimal for getting a decent mpg - just to see if the car is able to get a reasonable mpg - to be honest that 47mpg for a 3 mile journey is good - and shows that the car is 'capable' of decent mpg.

The 150 Leon real world mpg figures are between 34 & 52.
Anecdotally I find these honest john real world figures quite accurate for the various cars I have used.
View attachment 39319

Yes, your low pressure pump is your in tank pump of fuel module.
I think I would try and log your engine temperatures (coolant & oil) - as the 47mpg when hot on a short run is good. Could be its taking too long to get upto temperature?
Going to try that cold run one night this week, if I get chance.

It seems capable but seems to never average out, can play around and get figure like that by resetting my since start mid journey. But if I just left it alone and let it do its thing on a journey it’s not even touching that by time I take my key out, even on a clear motorway trip

As far as I can tell temperatures for oil and coolant rise within a normal time range.
Haven’t noticed anything abnormal the coolant gauge seems to hit 90 in decent time.
Unsure how fast generally coolant and oil should reach 90 for example.

But I’ll try track this tomorrow on way to work - although my journey to work is generally city driving with some a road stretch. So probably not the most optimal
Conditions for getting up to temp.

Feel like the only way I’m going to be able to tell clearly if there’s something is by finding a car show room near me, that has an identical model.
Pretending I’m interested in buying and taking it for a test drive, to see what MPG figure I pull after test driving and comparing to what I’d get under similar conditions.

Don’t really wanna do that as it's wasting a dealers time obviously and my time tbh.
But feel like that’s the only way to really have something to compare my car too, where I know I’ve driven identically too etc

Otherwise I’m absolutely stumped at what could be causing issues here, seeing as due to no fault codes or anything to investigate, I’m probably not gonna get far with any garage.
 

Tester01

Active Member
Oct 24, 2022
91
10
The 1.4 has a low pressure fuel system; "during normal operation between 2 and 5 bar. when cold or hot start is made the pressure is briefly raised to 5 to 6 bar depending on the engine temperature.
High pressure of between 140 and 200 bar."

The 1.5 has high pressure between 170 to 350 bar. Can't see anywhere confirming the low pressure system pressure - but would guess similar to the 1.4?
Sorry not had chance to take a proper look at things again.

Does any of attached screenshots mean much to you, what a captured this evening when nipping out, car was at idle btw regarding fuel pressure

Coolant seems to reach temp when driving, will try and time. I hate that obd11 doesn’t allow you create charts on iOS app.

Although noticed that when idle the temp seems to exceed 90 and go into 100-110. Is that to ?

Unsure if linked but I’ve noticed an issue with radiator fan and engine temp. Doesn’t seem to kick in even though engine coolant temp reaches 90 and above 100c.

Only seems to kick in if I turn heater up with AC on, but when the coolant temperature is showing as 108c for example. It’s not turning on for some reason…Don’t think that’s normal?

how do I also check if coolants flowing correctly, someone mentioned the top radiator pipe but unsure where’s his located or looks like on my 1.5 TSI engine

Still no closer to figuring out mpg issue very stumped and frustrated.
 

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Tester01

Active Member
Oct 24, 2022
91
10
Yes from cold, my thoughts were to do a drive which is optimal for getting a decent mpg - just to see if the car is able to get a reasonable mpg - to be honest that 47mpg for a 3 mile journey is good - and shows that the car is 'capable' of decent mpg.

The 150 Leon real world mpg figures are between 34 & 52.
Anecdotally I find these honest john real world figures quite accurate for the various cars I have used.
View attachment 39319

Yes, your low pressure pump is your in tank pump of fuel module.
I think I would try and log your engine temperatures (coolant & oil) - as the 47mpg when hot on a short run is good. Could be its taking too long to get upto temperature?
Did a run down the motorway - at speed limit generally there was a few minutes of standstill traffic due to an accident but generally smooth sailing.

And this is the best I got this afternoon from cold on a 23 mile trip. 🙃

IMG_4295.jpeg

Stopped off at a relatives then when restarting car I manually reset since start data, as it doesn’t anutomatically do
It until a few hours off. And even on trip back didn’t get much better.

Not sure what to as definitely not normal.
Oil temp seems fine see it hits 100c
Coolant temp from obd11 live data, reached 90 and into the 100s so seems to be heating up okay? Unless it’s false readings.

Just don’t get why it’s so poor.

gonna make my own thread also at some point this week as I know I’ve hijacked this thread unintentionally.

but any further suggestions from anyone would be helpful
 

SuperV8

Active Member
May 30, 2019
1,354
600
Did a run down the motorway - at speed limit generally there was a few minutes of standstill traffic due to an accident but generally smooth sailing.

And this is the best I got this afternoon from cold on a 23 mile trip. 🙃

View attachment 39849
Stopped off at a relatives then when restarting car I manually reset since start data, as it doesn’t anutomatically do
It until a few hours off. And even on trip back didn’t get much better.

Not sure what to as definitely not normal.
Oil temp seems fine see it hits 100c
Coolant temp from obd11 live data, reached 90 and into the 100s so seems to be heating up okay? Unless it’s false readings.

Just don’t get why it’s so poor.

gonna make my own thread also at some point this week as I know I’ve hijacked this thread unintentionally.

but any further suggestions from anyone would be helpful
I sat in my father inlaw's 1.5 150tsi VW T-Roc (DADA engine) a couple of days ago and noted their MPG - after a long drive to London (motorway speeds) MPG was 48, long term ave was 41 and since re-fuel was 38 (more local driving).

The much more slippery Leon should be bettering the TRoc for efficiency!

Did ACT activate much?

The first post from here is basically my opinion on this:
Personally I would be looking at a remap from a reputable company.
 

Tester01

Active Member
Oct 24, 2022
91
10
I sat in my father inlaw's 1.5 150tsi VW T-Roc (DADA engine) a couple of days ago and noted their MPG - after a long drive to London (motorway speeds) MPG was 48, long term ave was 41 and since re-fuel was 38 (more local driving).

The much more slippery Leon should be bettering the TRoc for efficiency!

Did ACT activate much?

The first post from here is basically my opinion on this:
Personally I would be looking at a remap from a reputable company.
ACT seems to okay driving around town.
Don’t really notice it much on a motorway driving even with cruise control on though

You’re right about Leon should be much better.
Cars like Troc and Leon ST using same 1.5 engine, getting consistently better MPG and I’m struggling to get 40 even on long run.

Not expecting to be getting amazing mpg on every drive of course.
But averaging low to mid 30s even a long run when engines warm?

Yet Seat in the past have told me my mpg is normal, especially as no fault codes. Which to me is a cop out I don’t believe it’s normal.

Funnily enough was looking at stage 1 maps
last night, as I know in some cases they can improve mpg. And if not at least it would be a bit more fun to drive.

Quoted £349 by DDG Tuning
150bhp > 180bhp
250nm > 335 nm

Part of me wonders if previous owner might have a poor map out on it.
Although whilst I’ve never driven a mapped car, nothing about driving my car screams it’s been mapped.

Could a main dealer in theory check or flash the ECU and adaptions etc back to faxtkry

Last month changed:
Wideband o2 sensor
Map Sensor

Easy to access and change but been no difference, so waste of money.
However at least can rule those out.

Are the following worth looking at?
Throttle Body - Although cars only on 38k, so shouldn’t be gummed up?

Spark Plug & Air Filter - should have been changed last year with the air filter when I got a major service at Seat.

Injectors - See AwesomeGTi offer service for injectors to check spray pattern and clean them using ultraonic
Or is that a waste of time and money?

Trying to do as much self servicing and investigation on my side, to save repeated expensive trips to dealer and co, to be told “everything’s fine”

So annoying just wish I had just rejected it when I initially had the kangarooing issue
 
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SuperV8

Active Member
May 30, 2019
1,354
600
ACT seems to okay driving around town.
Don’t really notice it much on a motorway driving even with cruise control on though

You’re right about Leon should be much better.
Cars like Troc and Leon ST using same 1.5 engine, getting consistently better MPG and I’m struggling to get 40 even on long run.

Not expecting to be getting amazing mpg on every drive of course.
But averaging low to mid 30s even a long run when engines warm?

Yet Seat in the past have told me my mpg is normal, especially as no fault codes. Which to me is a cop out I don’t believe it’s normal.

Funnily enough was looking at stage 1 maps
last night, as I know in some cases they can improve mpg. And if not at least it would be a bit more fun to drive.

Quoted £349 by DDG Tuning
150bhp > 180bhp
250nm > 335 nm

Part of me wonders if previous owner might have a poor map out on it.
Although whilst I’ve never driven a mapped car, nothing about driving my car screams it’s been mapped.

Could a main dealer in theory check or flash the ECU and adaptions etc back to faxtkry

Last month changed:
Wideband o2 sensor
Map Sensor

Easy to access and change but been no difference, so waste of money.
However at least can rule those out.

Are the following worth looking at?
Throttle Body - Although cars only on 38k, so shouldn’t be gummed up?

Spark Plug & Air Filter - should have been changed last year with the air filter when I got a major service at Seat.

Injectors - See AwesomeGTi offer service for injectors to check spray pattern and clean them using ultraonic
Or is that a waste of time and money?

Trying to do as much self servicing and investigation on my side, to save repeated expensive trips to dealer and co, to be told “everything’s fine”

So annoying just wish I had just rejected it when I initially had the kangarooing issue
Air filter is an easy/free to check - just unclip the lid and check - but should have been done at the major service I would think.

Could take some of the intake pipes off to check inside for oil/contamination?

With all the discussion of the kangarooing on that engine - personally I would stay clear of a VW map (if your car's out of warranty?) and look at a quality remap - as mentioned in the post I shared I think their hands are tied.
There are many cases where the VAG revised map's on TDI's from the 'emissions sandal' make the engines worse on fuel.
 

Tester01

Active Member
Oct 24, 2022
91
10
Air filter is an easy/free to check - just unclip the lid and check - but should have been done at the major service I would think.

Could take some of the intake pipes off to check inside for oil/contamination?

With all the discussion of the kangarooing on that engine - personally I would stay clear of a VW map (if your car's out of warranty?) and look at a quality remap - as mentioned in the post I shared I think their hands are tied.
There are many cases where the VAG revised map's on TDI's from the 'emissions sandal' make the engines worse on fuel.
Engine Air Filter and Intake
Will check this hopefully later, had lost the screw driver I needed but think ive found it.
So hopefully try and check tonight or sometime this week.

Will see if I can figure out the intake pipes removal and check - I find the workshop manual bit confusing but sure I'll figure it out.

Kangaroo issue
I had that latest ECU update for DADA in 11/22 , which seemed to have calmed it down.
Experienced similar behaviors' every now and then but not consistently like before.
I've read in the past on that Skoda forum that people reporting the their fuel economy reduced a bit after the ECU update to "fix" the issue.

Cannot comment on mine prior, as the kangaroo issue was my main focus - which took 2 trips to Seat for them to replicate and confirm the issue.
Do recall though when it was delivered to me it had done a 200mile trip and i distinctively remember the MPG being 44mpg, delivered by an older guy, which isnt that impressive...Maybe I should have clocked on from there.

Warranty
As of last month cars now under the All in One Plan warranty.
Which I mainly bought to cover my back if the DSQ200 wets the bed.

Oil
Would oil have a major impact too? One thing I noticed when looking at the service sheet.
I see on the job sheet the 504 oil is mentioned as used and not the 508 oil, which was is recommended in the manual.
From googling 508 00 has lower viscosity
I believe the 508 oil can be used but is optional.
972195316_Screenshot2019-07-21at16_37_00.png.8d4d9f7044d54aed70e7ca9a6b87deb7.thumb.png.7a8f51523788b984deae4eabf059bc54.png


Taken from - https://www.briskoda.net/forums/topic/481795-what-oil-for-15-tsi/

Was something that I noticed recently when looking at the docs, have my next oil change due in March,
So maybe I should specify they use the VW 508 00.

I guess if all else fails then may be pushed to get a remap as last resort, and If that doesnt improve things then I'm fully stumped.
Just wish there was an easy way to tell on my side if the car is defo running the stock vw map, just weird hope theres Trocs or even identical Leon FRs with the same engine that can easily achieve better MPG.

Definitely not my heavy foot as im now more conscious then ever about it.
 
Last edited:

SuperV8

Active Member
May 30, 2019
1,354
600
Engine Air Filter and Intake
Will check this hopefully later, had lost the screw driver I needed but think ive found it.
So hopefully try and check tonight or sometime this week.

Will see if I can figure out the intake pipes removal and check - I find the workshop manual bit confusing but sure I'll figure it out.

Kangaroo issue
I had that latest ECU update for DADA in 11/22 , which seemed to have calmed it down.
Experienced similar behaviors' every now and then but not consistently like before.
I've read in the past on that Skoda forum that people reporting the their fuel economy reduced a bit after the ECU update to "fix" the issue.

Cannot comment on mine prior, as the kangaroo issue was my main focus - which took 2 trips to Seat for them to replicate and confirm the issue.
Do recall though when it was delivered to me it had done a 200mile trip and i distinctively remember the MPG being 44mpg, delivered by an older guy, which isnt that impressive...Maybe I should have clocked on from there.

Warranty
As of last month cars now under the All in One Plan warranty.
Which I mainly bought to cover my back if the DSQ200 wets the bed.

Oil
Would oil have a major impact too? One thing I noticed when looking at the service sheet.
I see on the job sheet the 504 oil is mentioned as used and not the 508 oil, which was is recommended in the manual.
From googling 508 00 has lower viscosity
I believe the 508 oil can be used but is optional.
972195316_Screenshot2019-07-21at16_37_00.png.8d4d9f7044d54aed70e7ca9a6b87deb7.thumb.png.7a8f51523788b984deae4eabf059bc54.png


Taken from - https://www.briskoda.net/forums/topic/481795-what-oil-for-15-tsi/

Was something that I noticed recently when looking at the docs, have my next oil change due in March,
So maybe I should specify they use the VW 508 00.

I guess if all else fails then may be pushed to get a remap as last resort, and If that doesnt improve things then I'm fully stumped.
Just wish there was an easy way to tell on my side if the car is defo running the stock vw map, just weird hope theres Trocs or even identical Leon FRs with the same engine that can easily achieve better MPG.

Definitely not my heavy foot as im now more conscious then ever about it.
508 spec is 0w20
504 spec is 5w30

I don't think this will cause a measurable difference in mpg for you. like less than 1%.
 
Feb 7, 2024
18
1
hi, i want to fully disable the ACT using remap, no stage1 or other changes, did anyone of you done this?
someone from VAG Speed done it.
any advices?
thanks.
 
Feb 7, 2024
18
1
the kangaroo still exist but it is only in the first minute of the engine startup (there is a 20% gap in the gas pedal response), after the idle is dropping back to 700-800rpm the engine is working better.

1.5tsi-dpca, 110kw, mq281-uet, ECU sw update (in 2023) from 0863 to 1910, Kangaroo 50% fixed.

i'm 99% sure that the kangaroo is from bad ECU maps engineering.
 

Tester01

Active Member
Oct 24, 2022
91
10
So had a mechanic look at my car who actually had a look rather then just scan for fault codes and call it a day if not.

He noted that to him the piston rings are worn, and oils leaking into the spark plugs and intercooler pipe.

Cars booked at seat about fuel and performance issue, prior to finding this out. So sent photos over of the plugs that mechanic sent me via email in the meantime.

Apparently the oil on the plugs which were changed last year is normal? And the oil in intercooler isn’t anything abnormal.

anyone chime in if that is normal?
Just trying to finally get to the bottom of this ongoing issue fed up, I think if Seat don’t agree or find any issues in their opinion jsut going to have to sell and cut my losses. Definitely something oddd going on with the car

xJQGA8X.jpeg

ysXb3yz.jpeg

0h8xnFL.jpeg
 

SuperV8

Active Member
May 30, 2019
1,354
600
I would agree with your mechanic - those plugs look rather oily.
And the inlet looks oily - though that will never be perfectly clean with a turbo engine - difficult to tell from a photo how bad, but it its pooling - or runs out I would say its bad.

How does he know the rings are worn? did he do a leak down test? or just an assumption from the oil? Does it use any oil? How many miles has it done?

From here -
earlier engine but would think your plugs should look more like these: and not all oily.
1708503709195.png
 

Tester01

Active Member
Oct 24, 2022
91
10
I would agree with your mechanic - those plugs look rather oily.
And the inlet looks oily - though that will never be perfectly clean with a turbo engine - difficult to tell from a photo how bad, but it its pooling - or runs out I would say its bad.

How does he know the rings are worn? did he do a leak down test? or just an assumption from the oil? Does it use any oil? How many miles has it done?

From here -
earlier engine but would think your plugs should look more like these: and not all oily.
View attachment 40780
Unsure how he came to conclusion about Piston but will check with him.
He just mentioned that and said oils leaking into the turbo?

Will check Oil Level today, not checked it in a while tbh.

40K miles on the clock.

Will see what Seat say when it goes in next month.
Oil is due to be changed same time also as part of service schedule.

I just want to get to bottom of this fuel and performance issue.
Never been so frustrated with a car.
Feels like im just constantly going in circles, just want the car to perform as intended.
All this hassle from a relatively dull car.
 

SuperV8

Active Member
May 30, 2019
1,354
600
Unsure how he came to conclusion about Piston but will check with him.
He just mentioned that and said oils leaking into the turbo?

Will check Oil Level today, not checked it in a while tbh.

40K miles on the clock.

Will see what Seat say when it goes in next month.
Oil is due to be changed same time also as part of service schedule.

I just want to get to bottom of this fuel and performance issue.
Never been so frustrated with a car.
Feels like im just constantly going in circles, just want the car to perform as intended.
All this hassle from a relatively dull car.
The top/porcelain of the plug should be clean/dry - maybe this contamination is effecting the ignition/spark - which will effect your cylinder burn?

topside of the cylinder-head cover - where your plugs go through:
1708512627080.png


underside
1708512708200.png


There is a seal between this cylinder head cover (cam carrier) and the cylinder head, which I think is the only way the plugs could get oily on the top? unless there is a leak on top - where the coil packs go which I think is unlikely?

1708512868777.png


The tip end of your plugs didn't look so bad - so maybe it's not burning much oil?:
1708513130017.png
 
Feb 7, 2024
18
1
Engine Air Filter and Intake
Will check this hopefully later, had lost the screw driver I needed but think ive found it.
So hopefully try and check tonight or sometime this week.

Will see if I can figure out the intake pipes removal and check - I find the workshop manual bit confusing but sure I'll figure it out.

Kangaroo issue
I had that latest ECU update for DADA in 11/22 , which seemed to have calmed it down.
Experienced similar behaviors' every now and then but not consistently like before.
I've read in the past on that Skoda forum that people reporting the their fuel economy reduced a bit after the ECU update to "fix" the issue.

Cannot comment on mine prior, as the kangaroo issue was my main focus - which took 2 trips to Seat for them to replicate and confirm the issue.
Do recall though when it was delivered to me it had done a 200mile trip and i distinctively remember the MPG being 44mpg, delivered by an older guy, which isnt that impressive...Maybe I should have clocked on from there.

Warranty
As of last month cars now under the All in One Plan warranty.
Which I mainly bought to cover my back if the DSQ200 wets the bed.

Oil
Would oil have a major impact too? One thing I noticed when looking at the service sheet.
I see on the job sheet the 504 oil is mentioned as used and not the 508 oil, which was is recommended in the manual.
From googling 508 00 has lower viscosity
I believe the 508 oil can be used but is optional.
972195316_Screenshot2019-07-21at16_37_00.png.8d4d9f7044d54aed70e7ca9a6b87deb7.thumb.png.7a8f51523788b984deae4eabf059bc54.png


Taken from - https://www.briskoda.net/forums/topic/481795-what-oil-for-15-tsi/

Was something that I noticed recently when looking at the docs, have my next oil change due in March,
So maybe I should specify they use the VW 508 00.

I guess if all else fails then may be pushed to get a remap as last resort, and If that doesnt improve things then I'm fully stumped.
Just wish there was an easy way to tell on my side if the car is defo running the stock vw map, just weird hope theres Trocs or even identical Leon FRs with the same engine that can easily achieve better MPG.

Definitely not my heavy foot as im now more conscious then ever about it.
Oil:

you can use 0w20LL4 or 0w30LL3 in DADA or DPCA

(probably your fuel economy will have a little drop but the long term lifetime of the engine will be better)

it is official and approved by VW, see the picture :)
 

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