1.5 tsi, any progress?

[Tester01]

Found an exploded image of the 1.5tsi mechatronic thermostat/pump assembly:

View attachment 47513

Was reading my service manual yesterday unsure how easy the coolant sensors and thermostat for a wannabe mechanic like myself

But defo think there’s something weird with coolant that might be worth chasing. Will mention it when I take it to be serviced whether Seat will actually look into it not sure.
Guess have to try look further into it myself if they don’t.

What do you think of that coolant temp jumping to nearly 30c in less than minute of engine being on after being left overnight in the snow when it was 2c.
Is that to be expected?

But that mechanic I spoke to said based on that and things he’s encountered in the past could be causing issues.

As he said for him he’s seen similar issues on Leon’s and said things around coolant and thermostat play a part. He just wasn’t sure what sensor could be problematic as there’s several I believe

 

[SuperV8]

Will track it later today.
When you say engine temp do you mean coolant temperatures or another sensor readings should be looking at

From memory when driving when I’ve last looked at coolant temps using obd I’ve seen it in the 90s go up to 110.

Just the radiator outlet temp always looks way out of wack in comparison and maybe why I’ve not heard the fans in a long time.

Funnily enough I had a mechanic out in January one of those mobile ones to see if they could shed any light on why fuels so poor.

It was a snowy day so outside temp was 2c. He plugged his diagnostic tool in and started the engine and within less than minute, coolant temps was showing at around 29c.

Which he said was suspicious and thought based on that one of the sensors could be giving false readings.

View attachment 47514

Would you agree with that being odd? I’d imagine the coolant temp would’ve been same as outside temp initially?

I would expect these two to be similar:
actual measured value and the specified value would probably be the 'target' value.

How long was your engine running at this point? as 88 seems low if you have been driving for a while.

number 9 is your rad outlet temp sensor. 06A919501A
number 6 is your engine coolant temp sensor 03F919501B
Coolant pump/regulator 05E121111AB

 

[SuperV8]

Both coolant temp sensors look like the have the same resistance/temp curves:
You could check their resistance with a DVM - and a thermometer to ensure its similar to below:

Temperature T(ºC)	Resistance R(Ω)
-20	13 - 15 k
-10	8.6 - 10.1 k
0	5.5 - 6.5 k
10	3 - 5 k
20	2 - 3 k
30	1.4 - 1.9 k
40	900 - 1300.0
50	750 - 900
60	500 - 700
70	380 - 460
80	280 - 355
90	200 - 270

 

[Tester01]

I would expect these two to be similar:
actual measured value and the specified value would probably be the 'target' value.
View attachment 47515

View attachment 47517
How long was your engine running at this point? as 88 seems low if you have been driving for a while.

number 9 is your rad outlet temp sensor. 06A919501A
number 6 is your engine coolant temp sensor 03F919501B
Coolant pump/regulator 05E121111AB
View attachment 47516

Not sure how long had my engine running it was an old screenshot I found from when I was monitoring coolant.

But I’ll go on a drive later down the motorway or something see if I gather some data.

really appreciate your help btw

To access the radiator and engine coolant sensor would I need to remove the front grill or radiator?

Just want to get to bottom of once and for all especially as it’s under the extended warranty until later this year.

 

[DEAN0]

Is that the same as the 1.4? So much plastic.

The EA888 2.0 engine also has a full plastic housing and it is very prone to cracking / leaking.

At around £700 a time ( fitted at an independant ) - or £1200 a time at a stealers - it is costly out of warranty.
You can get the parts for around £300 if you are capable with the spanners.

But VAG say it is not an issue and refuse to do anything about re-designing it.

 

[Tester01]

I would expect these two to be similar:
actual measured value and the specified value would probably be the 'target' value.
View attachment 47515

View attachment 47517
How long was your engine running at this point? as 88 seems low if you have been driving for a while.

number 9 is your rad outlet temp sensor. 06A919501A
number 6 is your engine coolant temp sensor 03F919501B
Coolant pump/regulator 05E121111AB
View attachment 47516

Set obd11 to record and chart a bunch of data across a 20 mile drive down mostly down the M60.

Which it was then when I went to save it...I pressed the wrong thing and cleared the chart.

Had it tracking coolant temp and oil temperature

But here's what I managed to screenshot from live data a minute or two after I parked up.

Coolant when I checked live data initially was at around 103c.

Sadly don't know how much it fluctuated during the drive and how quickly it got to that temperature sadly.

Will try do another run after work tomorrow from cold start and this time chart some data.

Could also do a recording tomorrow on the way to work but mostly town driving

Can see the coolant at radiator is still low in comparison to coolant and specified

 

[SuperV8]

Something is wrong.
After a 20 minute drive, rad outlet actual temp and rad outlet specified temp (target) should be quite close.
I would say, either the rad outlet sensor (or its wiring/connector) is 'miss behaving/faulty' or the thermostat/regulator is over cooling/faulty.

The rad outlet temp sensor should be an easy one to test.
Unplug the connector - put a DVM on the two pins and read the resistance - and measure the actual temp of the sensor/radiator outlet with a thermometer and check against the expected values I posted previously. Be good to do this at two or three temperatures.
If the resistance is in accordance with the expected resistance values - then you need to do some further electrical tests to check the wiring.

If the thermostat/regulator is working properly I would expect to see your engine temp quickly get upto temperature and stay there and not fluctuate too much.
If you see the coolant temp get upto 90-100, but then drop if you go on a fast road/motorway I would say your thermostat/regulator is faulty.

And - 88 seems a little low for oil temp after a 20 min drive - don't know what to expect on the 1.5tsi? quite often oil and coolant temps are similar as there are usually heat exchanges between oil and coolant systems.

 

[Tester01]

Something is wrong.
After a 20 minute drive, rad outlet actual temp and rad outlet specified temp (target) should be quite close.
I would say, either the rad outlet sensor (or its wiring/connector) is 'miss behaving/faulty' or the thermostat/regulator is over cooling/faulty.

The rad outlet temp sensor should be an easy one to test.
Unplug the connector - put a DVM on the two pins and read the resistance - and measure the actual temp of the sensor/radiator outlet with a thermometer and check against the expected values I posted previously. Be good to do this at two or three temperatures.
If the resistance is in accordance with the expected resistance values - then you need to do some further electrical tests to check the wiring.

If the thermostat/regulator is working properly I would expect to see your engine temp quickly get upto temperature and stay there and not fluctuate too much.
If you see the coolant temp get upto 90-100, but then drop if you go on a fast road/motorway I would say your thermostat/regulator is faulty.

And - 88 seems a little low for oil temp after a 20 min drive - don't know what to expect on the 1.5tsi? quite often oil and coolant temps are similar as there are usually heat exchanges between oil and coolant systems.

See if Ive got a voltmeter somewhere.
Will relook at the service manual for location of sensors

Wonder if it’s worth me also in the meantime seeing if there’s any air in the coolant system and trying to bleed any if there is.

I was thinking that about the oil seemed little on low side. Not sure what the typical time and temp it should be

Going to try get some data this weekend on a drive.

Didn’t end up taking car in yesterday as whoever booked it didn’t sort out a loan car to use whilst it was in annoyingly. Just hassle getting to and from Seat dealer so much rather have one.

Now going in next month but guess gives me more time to hopefully compile some data to present to them and get to bottom of issue.

Thinking to hopefully get the following data on a drive:
Coolant sensor 1 & 2
Coolant at radiator outlet actual and specified value
Oil temp
Ambient temp
Intake air temp
Speed - to check if I’m going faster and coolant temp drops like you said.
Coolant radiator fan % - 10.15% seems to be equal to no fan activity

 

[Tester01]

Actually forgot I captured this on way back home from office on Tuesday evening.
Mostly city with a bit of spirited driving through during rush hour about 25 minutes of driving.
Roughly a 5mile journey from home to my office when im in.

Chart looks a bit messy admittedly - probably best to keep it simple and not try and track so much data.
Have hidden Time, intake air and outside air from it.

View chart and the logs here - Can see things in more detail and hide/show specific fields.

Log #930678

log.tunezilla.com

Looking at this snapshot can see the coolant fans did kick in briefly? Seems early though considering when coolant was at 100c+ it didnt come on but did when the coolant was reported 93 (Coolant sensor 1) and 96 (Coolant Sensor 2).
Coolant at radiator still doesn't get near the specified value, max it reached was about 40c.

 

[Tester01]

Also is “Engine Control Module temperature” mean much in the grand scheme of things?

 

[Mr Pig]

The EA888 2.0 engine also has a full plastic housing and it is very prone to cracking / leaking.

Yeah, it's pathetic. I've been looking at Mk3 Audi TTs and it's not a case of if this housing is going to fail, just when. And VW have done nothing to address this issue. The new parts supplied today are the same as the ones that fail. What do they expect people to do? Other than not buy their cars.

 

[RUM4MO]

I might just be imagining this, but is there not an aftermarket supplier of a more robust assembly that has less plastic in it - probably a performance orientated aftermarket specialist for this EA888 engine?

 

[Mr Pig]

I might just be imagining this, but is there not an aftermarket supplier of a more robust assembly that has less plastic in it - probably a performance orientated aftermarket specialist for this EA888 engine?

I thought that but I've asked a performance specialist and he said no, it's just the plastic one. As well as the plastic cracking, it seems that the rubber seal fails too so it can feck up your life in multiple ways! And there is no rhyme or reason to it. You could have a car for years without issue or it could fail at 10k. Have to say it puts you off buying that engine, which is a shame as it seems very good otherwise.

 

[Tester01]

@SuperV8

So did a 71 mile round trip of mostly motorway on this sunny Saturday.
Managed to squeeze just over 40mpg - Cant say im impressed considering the type of journey...

Start of trip:

Coolant temp	Oil Temp	Actual Coolant temp at radiator	Specified Coolant Temp at radiator
13c	13.5c	13.8c`	105c

End of trip:

Coolant temp	Oil Temp	Actual Coolant temp at radiator	Specified Coolant Temp at radiator
101c	96.5c	41.7c	102.7c

Logs from this journey:

Log #934498

log.tunezilla.com

Radiator temp peaked at 51c

Fan operation vs coolant temp

 

[Mr Pig]

So did a 71 mile round trip of mostly motorway on this sunny Saturday.
Managed to squeeze just over 40mpg - Cant say im impressed considering the type of journey...

No, that's terrible. My last three tanks were 43.9, 43.7 and 47.5 and that is not motorway driving. That's over the whole tank with little motorway driving. On a run I'll get high forties, maybe 50. The last 20-plus tanks only one has been just under 40 with the rest being mid to high 40s and two 50.

Although I will say that how you drive matters. My wife get's not much more than me out of her diesel but when I drive her car I get better mpg out of it. It's not that she drives fast but she accelerates harder than I do, anticipates less and is just generally less sympathetic.

 

[Tester01]

No, that's terrible. My last three tanks were 43.9, 43.7 and 47.5 and that is not motorway driving. That's over the whole tank with little motorway driving. On a run I'll get high forties, maybe 50. The last 20-plus tanks only one has been just under 40 with the rest being mid to high 40s and two 50.

Although I will say that how you drive matters. My wife get's not much more than me out of her diesel but when I drive her car I get better mpg out of it. It's not that she drives fast but she accelerates harder than I do, anticipates less and is just generally less sympathetic.

I agree 71 miles majority on the motorway and 42 mpg is pathetic.

Not impressed was understatement but didn’t surprise me.

Driving wise it was mostly sensible odd bit of spirited acceleration when needed. As overall I was conscious of seeing what I could pull.

I just want to get to the bottom of the cause, just don’t get it at all…And to be told I’m the past my mpg is “normal”….Is what frustrates me the most.

Surely somethings up yes there’s no fault codes but somethings triggering crap fuel economy.

 

[Mr Pig]

I just want to get to the bottom of the cause, just don’t get it at all…And to be told I’m the past my mpg is “normal”….Is what frustrates me the most.

You can't trust anything dealers say. They'll never admit there is a problem unless confronted with evidence they can't ignore. I'd just trade the car. Annoying I know but if you've got bad vibes about a car I think it's the best thing you can do. That's my experience anyway. Once I take a dislike to a car it's time to go.

The flip side is how much is the poorer economy actually costing you? Have you worked it out? If it's the only issue with the car, might be worth just forgetting about it and enjoying the car.

 

[Tester01]

You can't trust anything dealers say. They'll never admit there is a problem unless confronted with evidence they can't ignore. I'd just trade the car. Annoying I know but if you've got bad vibes about a car I think it's the best thing you can do. That's my experience anyway. Once I take a dislike to a car it's time to go.

The flip side is how much is the poorer economy actually costing you? Have you worked it out? If it's the only issue with the car, might be worth just forgetting about it and enjoying the car.

Don’t even know what I’d get next.

But if not I guess best thing to do would be to get rid and ideally id do that before my Seat all in one plan with the extended warranty ends which is later this year.

Part of me just wants to get to the bottom of it after having it since late 2022 so if anyone else has any suggestion of things to check feel free to throw them at me

 

[Mr Pig]

Don’t even know what I’d get next.

Struggling with that myself. Looking at Audi TTs just now.

 

[Jason2023]

I agree, the 1.4 is sweet. I'd rather stick with it but finding the right car is tricky. A 2018 car is already six years old and ideally I'd rather get something younger with low millage.

What about using the money to recon you engine and bearings etc… I only say because I had to fit a replacement lower engine from an Audio last year it’s like new car.. my car is on 125000 on the clock but I’m keeping as long as possible as I agree with all your comments. Whats out there to replace with