Seat Leon Cupra 150hp PD ARL - smoking and misfiring under load

Hello,

I have a SEAT Leon with a 150hp ARL engine that is experiencing misfires under load and producing smoke.
The performance is far too low.
Loader pressure is okay.
currently trying to etch the PD elements without success.
Measurements 13, 18, and 23 are okay.
The car is shaking very strongly under load and feels like it's running on only 3 or 3.5 cylinders.
'At idle, everything is okay. Measured values show a difference of -0.26 to .51, with a maximum variation of 1.51.'
Does anyone have an idea? There's a problem somewhere.

best regards, Marco

If everything is okay, then it's okay.

What I mean to say is:
Please provide us with logs, not incomplete sentences like "Block 13 is ok."

Perhaps you've overlooked something or misinterpreted it. However, we can verify this using specific data (i.e., log files).

Sorry, that's the only way we can help you.
Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

If everything is okay, then it's okay.

What I mean to say is:
Please provide us with logs, not incomplete sentences like 'Block 13 is ok.'

Perhaps you've overlooked something or misinterpreted it. However, we can verify this using specific data (i.e., log files).

Sorry, that's the only way we can help you.
m;

Okay, I will run the logs in idle mode and under load tomorrow morning.
What do you want to see?

best regards, Marco

I think a Screenshot of the engine running at idle, followed by an acceleration log (from 1500-4000 rpm with full throttle), focusing on blocks 003, 008, and 011, would be a good starting point for investigation.

It's important that it really goes full throttle. Remember that in the third gear, you'll be going approximately 50-110 km/h, so DO NOT try this in rush hour traffic or in the city center.

If you take your foot off the gas pedal even for a moment, it's pointless.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

Hello!

I have seen something similar in multiple patient records. There is nothing to note regarding the diagnosis.
No errors in the error memory.
But the engine isn't running smoothly.

The wiring harness for the power distribution unit (PD) was replaced, and at the same time, the seals on the PDs were also replaced.

It completely fixed the problem in 3 out of 4 cases.

The wires are submerged in oil, and the insulation material becomes brittle. As a result, something may no longer function at 100%.

'In a Bora, the ESP (Electronic Stability Program) would sometimes activate for no apparent reason. There were no error codes visible in the engine control unit.'
The above has been updated, and everything is okay! Apparently, the ESP (Electronic Stability Program) in some cars is much more sensitive than the engine control unit (ECU). It detects even slight irregularities in the engine's operation and then makes you think that something needs to be done.

So, just my tip .

I just replaced the wiring harness, but it didn't work.

Here are the logs.

I hope someone has another idea.

I now have...

New pump attached to the head.
4 other nozzles with new seals.
harness
The pump in the tank is okay.

marco tdi wrote:

I now New pump attached to the head. 4 other nozzles with new seals. harness The pump in the tank is okay

.
Okay, the previous logs weren't exactly what we were looking for, but now we know that the power distribution units (PDUs) are likely electrically okay.

Are the PDE and NW settings configured correctly (please refer to the documentation)?

Okay, next, let's combine data from sensors MWB 4 and 10, with a full-throttle acceleration in 3rd or 4th gear, from approximately 1300 to 4300 RPM.
If it starts sputtering again, try to estimate the RPM at which it happens. If not, continue running the engine (with partial load, deceleration and acceleration, etc.) until it sputters again, or try to provoke it.

Okay, I have some time for the car today and will immediately do a log of runs 3 and 4.

best regards, marco

I think I've found it.
I measured the compression, and it's okay. However, when I let the car run without the hose connected to the intake manifold, you can hear a slight whistling sound.
I just lost weight in a different area and I can't hear it.
The combustion pressure is often several times higher than the compression pressure.
I will remove the head today or tomorrow and report back.

Thank you everyone for the help.

"A whistling sound is quite common in many TDI engines and doesn't necessarily indicate a problem. So, I wouldn't bet that it's the cause."

Hi,

I had the exact same car as you, and I actually experienced the same behavior at that time of year, when it was below 6°C in the mornings. The problem didn't occur during the summer.

Anyway, the problem was fixed after deactivating the EGR valve, and the car ran normally even in winter.

After extensive research on forums, I found out that this specific pattern often has these kinds of problems. Apparently, there's a special metal plate with a reduced bore size available from the contract pharmacy specifically for this issue, which can be inserted into the AGR (Abgasrückführung) system. Simply adapting to the lowest possible AGR rate isn't sufficient to solve the problem.

Temporarily disable the EGR system (by disconnecting the hose and inserting a screw) and only start the car in cold mode in the morning. (The error light is not a major concern).

If your car exhibits similar issues when it's warm or in warm weather, then this wasn't the problem! (But it will only take you 30 seconds of your life and no money to check for this error.)
(to encircle)

If you try to be friendly with a mechanic, he will likely charge you an exorbitant amount for any work done on your car.

Good luck!

Hello,

Today I disassembled the cylinder head.
'An intake valve is only opening 2mm, and a piston is damaged.'
You can see that the valve has been stamped on.
The problem has likely been there for a long time because the customer bought the car like that and said it was normal, as well as how it was running.
The intake valve seals tightly but only opens 2mm because it's bent, although not on the bottom side.
The problem wasn't as noticeable at idle or during gentle driving, but when accelerating to full throttle, one cylinder was almost not getting any air.

Greetings and thank you for your consideration!

'So, the camshaft is also defective.'
The cam lobe that operates the intake valve is worn because it probably experienced too much resistance due to the bent valve.

best regards, marco