1.5 tsi reliability
- Thread starter Efraim christos
- Start date
Well, you could check how the car slows out when on a section of level road when not in gear, also "carefully" touch the wheels near their centre after driving it in an area where regular braking is was not needed.
If the brakes were strongly seized you would know about it - you'd feel a strong brake drag/pull and burning smell.
The brake can drag lightly though and it can be difficult to tell from the 'drivers seat'
Jack up each corner so the tyre is just off the ground.
Stand on the brake pedal and release.
The wheel should rotate freely. Best to get both front tyres off the ground at the same time if you can so your not also spinning the diff. One wheel will spin backwards with both tyres of the floor.
Thanks will see if I can get some equipment and try this weekend.
I just don’t know why the fuel economy is so bad the car would be fine if it wasn’t for tha
I guess I know what to make sure to check extensively whenever I get a next car, is if fuels bad run immediately and don’t just think it’ll improve.
Did another scan on OBD11 no fault codes
Frustrating I guess I bought a lemon
Has your car ever had any 'kangaroo fix' software update from Seat? Just wondering if this can negatively effect MPG? I know the 'diesel gate' software update does - though not related.
Does your car ever activat ACT - 2 cylinder mode when you're cruising?
Yeah I had the kangaroo fix
It had the update first which didn’t resolve but then they did a basic reset of the gearbox and not had issues since.
Although my MPG was pretty poor before that, so wouldn’t say it was negatively impacted by this at least not noticeably anyway.
And yeah the ACT eco mode pops up when cruising and light on throttle. Quite often actually only time I see my MPG rapidly increasing but still not to a satisfactory figure though.
Didn’t manage to get anything to jack it up but got ahold of a laser temp rear thing.
Each brake pad seemed similar temp there was no one that was abnormally hot in comparison to the other.
So looks like it’s not a brake issue.
But going in for MOT so guess if there is a brake issue they’ll spot it.
Given up at this point completely lost at what could be it. And due to no fault codes seat aren’t much use in potentially locating the issue.
Threw in some cataclean for a last ditch attempt at helping clean any residue in the fuel system.
Put me off the car and Seat.
Seems like it’s idling rough too at times
Definitely not coolant temperature, it’s specifically the “Fuel temperature” as per OBD11.
I can see the coolant temperature data in addition to fuel temperature, ambient temperature etc
Coolant looks fine as far as I can see in terms of number wise, seems to fluctuate 90-100 generally, when warmed up.
More specifically concerned about the fuel temperature which seems to be overheating
Can try get some screenshots later to show.
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Fuel temperature sensor is near your fuel filter and high pressure pump in the engine bay.
part number 04L919824 superseded to 04L919824C after 03.04.2018
90c seems high for fuel temperature - but I have no experience on what the fuel temp range could be?
Does it start at ambient temp after a cold morning start? and slowly increase?
Thanks for the part number!
I’m trying to read the mk3 workshop manual, believe “3” is where it’s located? The sensor seems to be located basically under the washer Resovoir?
Am I reading it correctly?
As for if it’s normal, from what I can see from searching the net…which is hard enough as fuel temperature sensor is also bringing up coolant sensor results.
My understanding is no it’s not supposed to get that hot and when it gets that hot it starts to boil and evaporate - which cant be good for the car and fuel economy in general.
If it is indeed actually reaching that temperature and the sensor is accurately reading.
Why it’s getting that hot I guess that’s what I need to figure out.
At cold morning start it does seem to be close to ambient.
See quick screenshot I took at start on Thursday.
Can’t remember the values when I reached work sadly, but I’m gonna guess around 65ish on that 15 minute journey.
Usually higher if I drive longer but I chill check tomorrow before and after I reach work
Be interesting if anyone has an OBD and can capture live data, to see what their fuel temperature is after a drive to compare and see if there’s gets that hot?
Don’t know any other Seat owners local to see sadly
Sorry - scratch that - that is a DIESEL fuel temp sensor!
Hmm - I tried searching in Leon parts catalogue for fuel temp sensor - and that is the only one which comes up - listed against diesel engines.
Can't see anything listed for a petrol!
Weird hmm.
in that screenshot from the workshop manual do you think number 3 is the sensor?
So one thing I noticed today, was fuel temp seems to rise when idle e.g. in slow moving tra? Would that be the expected behaviour.
SuperV8 do you have an ODB device? Curious to see what your fuel temp reads as after a journey - if you have time to check
Tbh I’m just fed up of trying to figure out why car has such poor fuel economy. Over a year trying to get to bottom of it
There’s no codes and seat won’t investigate further because of this and fob me off as normal. So just £99 every time I’ve been for diagnostics to be told, can’t find anything so…Fuel system cleaners I’ve lost count.
Major serviced.
I don’t think average 30-34mpg on a long journey at speed limit on a clear motorway, is normal imo.
I’ve seen people with Seat Leon ST with the same engine get 45mpg+ with ease and that doesn’t make sense to me as it’s pulling a much heavier car…
Just don’t get it or know where to turn next.
Countless hours scanning the net for answers.
Will try anything at this point lol
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I do have a scan tool but I have a TDI i'm afraid.
Agreed probably the best way to check your fuel temps are sensible if to log a similar engine/car.
Number 3 in the diagram would be most likely I think, but something seems strange - I can't find any mention of a fuel temperature sensor in the parts catalogue. I'm thinking maybe the fuel temp is done by another sensor - maybe the rail pressure sensor - or by the intank fuel pump/module?
I would agree 30-34mpg on a run is crap. Mother in laws 1.5 150 Troc does high 40's on a run.
Driving from Gloucestershire to Sheffield via a short run on country roads & then M5, M42, A42, M1, which is 159 miles in just under 3 hours, gives 50-52mpg in my 2018 1.4TSi(150) FR. Would expect a 1.5TSi to be close to the same.
Looking in wiring diagram for your engine
I can't see any fuel temperature sensor, in fact I can't see any fuel temperature sensor for petrol engines, ONLY Diesels.
this is your fuel delivery module wiring - GX1; G6 your fuel pump, and G your fuel level sender - so no fuel temperature.
And G247 is your fuel pressure sender - only three wires, so no temperature.
From your post - "pull off electrical connector -1- on fuel temperature sender - J623"; well J623 is your main ECU connector. Could be a typo.
I think either your diagnostics is incorrectly labeling that value as fuel temperature - or the ECU calculates the approximate fuel temp from other sensors.
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.
Interesting will take a look.
Coolant temperature looks okay seems to fluctuate been 90-105.
But then I’m unsure about the radiator fan, when I’ve seen coolant values at 105, the fan doesn’t seem to be kicking in.
Just remains about 10.5%, I can get it to kick in by turning the AC on full blast.
So I don’t know that’s normal?
How do I check if coolant is flowing into the radiator properly also?
what would be a normal fuel pressure? I’ve been looking into but unsure what would be classed as good or bad.
I’ll give the motorway test a try pretty sure I’ve done something similar in the past but will give it a wiz maybe Saturday.
Also noticed sometimes the car seems to vibrate on idle, rpm at like 6-700 but car feels like it’s shaking a bit - but I don’t know if that’s me just hunting for an issue that’s not there
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Honestly if I did that same journey I’ve probably get like 35mpg if I’m lucky.
I’ve never seen 45 nevermind 50mpg in this car regardless of journey
Even had a Quick Look to see if any of the wheels are abnormally hot compared to the others but nope. So looks like there’s not a stuck brake calliper
just stumped.
Feel like just booking in at Seat and dumping it with them for a week and telling one of the service guys to drive it to and from work. And see what the mpg they can average.
But need a car for work so unless they can give me a courtesy bit difficult
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?
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