Warrior193

Hello, are you sure of your engine specs - has the engine been modified in this car?

Check at the front of the engine, on the side opposite the battery - see if there is any fuel dripping near there. Been there, done that! although in my case, the engine would fire - then immediately shut down.

Yes filler cap. Loosening the cap, particularly when hot, releases the normal pressure build up in the coolant system - which can cause the coolant to rise, giving a misleading level.

@goatboy Were you getting misfiring with the faulty coil, if so, was it particularly noticeable?

I think that would be a good assumption to explain the fault. The slightly high resistance in the circuit will probably remain and may possibly cause spurious alerts in future. If access is easy, I'd suggest checking/cleaning the lamp contacts.

One issue with that is if the electronic service history is important to you - your BSG is unlikely to have access to upload service history updates.

The cooling fan should definitely run if coolant temperature has risen above normal, particularly when vehicle is stationary. Coolant fan not normally required at normal engine load and with vehicle moving at speed.

I'd recommend using a proper engine or brake cleaner rather than brake fluid to clean off leaked fluid. Brake fluid will leave its own residue behind.

Check reason for coolant fan not running when engine overheating. If 'Mit Silicat' bag is still in expansion tank, remove it or replace EV for one without it ASAP.

A tip if you are attempting to verify age of battery - there is usually a date stamp on the top of the negative terminal, format is WW,YY.

Not familiar with the Mk2 - but does your car have separate fluid cylinders for brake and clutch? The mk3 shares the fluid for both systems. Probably not necessary to change the clutch fluid if it is a separate cylinder though. Have you had the brake fluid tested to see if it is actually necessary to change - or are you simply following recommendation?

If that is while the temperature gauge is indicating high temperature, it will be the cause of overheating while stationary, particularly while undergoing a DPF regen. You previously said that the fan does run when you switch off engine during regen, so I'd suggest checking the coolant fan thermo-switch.

Suggest check for DTCs referring to any under boost issues.

Hoping that you didn't really mean 'jump' on the bonnet - that would certainly be an abomination unto Nuggan. 😁

But does the cooling fan run DURING the regen while the engine is indicating overtemperature?

@chelon Is your coolant level relatively steady now that you are not filling above max. line? NB. there will be some changes in level, depending on whether checked hot or cold, but should remain in vicinity of markers if no losses from system. NB. don't remove EV cap when checking coolant level.

Is the car level when you check? if so, that oil level is far too high, probably by at least 1/2 litre. I assume the car was in for an oil service, what does the manager of the garage say?

Is the radiator fan running during the regen?

Regardless of fuel type, consistent short runs of only a mile or so as you propose are pretty much the worst thing you can do - the engine will always be running cold.

Hello, welcome to the forum. Has the temperature gauge done this since your parents bought the vehicle, or has this just started? I'd suspect a faulty thermostat. Coolant temperature should read approx. 90 degrees on the gauge after 1 or 2 miles. If your parents car has the maxidot display (small square screen between rev-counter and speedo) you can read the oil temperature on that - what does that read?

I rather fear that you will have to resign yourself to early DPF issues. As far as I'm aware, there is no snake oil additive that will help.

My MY16 Octavia was originally fitted with an AGM - replaced, along with alternator under warranty, within a year. EFB was fitted as replacement. If I knew then what I know now, I would have insisted on another AGM, but the Moll replacement is still good at 8 years.

If oil level is around bottom of dip stick, probably about 1 litre - only put 1/4 litre in first, wait 2 mins, then wipe stick, recheck and repeat. Fill to upper level line. Do not overfill.

Looked up for 2012-2021 2.0 TDI - same VW spec, either 0W-30 or 5W-30. Did you check oil level before start of this trip - or after the last service?

Good morning, oil to VW spec 504/507, 5W-30 for TSI.