2015 S4 b8.5 74k Miles

[Ajwhite]

So about 1000 ish miles ago, just checked the oil. At the max level according to the MMi

Just checked today and it's below half way on the MMI.
Can't see a leak or oil on the undertrays.

Is this normal or some kind of common issue?

Sent from my VOG-L09 using Tapatalk

 

[Dippy]

Audi engines can burn oil but it should not be considered normal. Have you checked for any signs of oil in the coolant? Any signs of exhaust smoke? Also how easy is it to remove the oil filler cap? If the PCV is malfunctioning then as well as the oil level dropping it can create a vacuum beneath the cap.

Since the MMI did show maximum then it's probably OK but sensor faults have been known. It is possible to get a dipstick for this engine (or rather one which fits this engine).

 

[ninjag]

So about 1000 ish miles ago, just checked the oil. At the max level according to the MMi

Just checked today and it's below half way on the MMI.
Can't see a leak or oil on the undertrays.

Is this normal or some kind of common issue?

Sent from my VOG-L09 using Tapatalk

Same car, same mileage and mine can do this sometimes. It's irregular, so can't really pin point why and have no codes showing either. Fuel trims are perfect etc.

I did notice it happened pretty quickly after doing an oil change with Mobil and in the past with Miller. Seems better with Castrol though, so I'm not sure if oil brand could be the reason? They are all VW504.

I keep a litre of oil stored with the spare wheel just in case and bought a manual dipstick as well, but keep that with the oil and not permanently in the dipstick tube.

 

[NHN]

Reminds me of the piston ring issues in the 2.0 tfsi b8, 8.5.

 

[Ajwhite]

I have had it before with my old 2.0 tfsi engine. But that was consistent. Every 1000 or so miles it would need topping up.

No smoke, codes etc. Coolant hasn't changed. No obvious leaks.

It's being serviced soon so I'll mention it, but I really hope it's not piston rings

Sent from my VOG-L09 using Tapatalk

 

[NHN]

Do an oil service & get the stuff from audi, that way it's as guaranteed as possible to be authentic as there's a huge amount of fake oil on the market tbh, not to say it's this but it is always possible & tbh S4 isn't known to be that bad afaik.

 

[Dippy]

FYI mine's also a 2015 with CREC engine and the car has done almost 26K miles. It uses negligible oil - between annual services the MMI might drop 1 or 2 bars at most.

 

[Ajwhite]

FYI mine's also a 2015 with CREC engine and the car has done almost 26K miles. It uses negligible oil - between annual services the MMI might drop 1 or 2 bars at most.

So they do use a little, this is just under halfway on the MMI. I am hoping it's a PCV issue and nothing more annoying. Drives perfect, idle can be a bit lumpy but put that down to carbon build up?

I'll get it looked at in the next week and report back. Needs a major service due around now anyway, so at least it has good timing....

Sent from my VOG-L09 using Tapatalk

 

[ninjag]

So they do use a little, this is just under halfway on the MMI. I am hoping it's a PCV issue and nothing more annoying. Drives perfect, idle can be a bit lumpy but put that down to carbon build up?

I'll get it looked at in the next week and report back. Needs a major service due around now anyway, so at least it has good timing....

Sent from my VOG-L09 using Tapatalk

Well isn't it just typical that last night I had to top up my oil! lol Only about 1/3 litre though.

The CREC engine introduced a Manifold Port Injection system to integrate with the Direct Injection system and I believe this should help significantly reduce carbon build up.

If you've not already seen the case study, here's some extracts from it about the dual injection system if it's of any interest:

 

[Ajwhite]

Well isn't it just typical that last night I had to top up my oil! lol Only about 1/3 litre though.

The CREC engine introduced a Manifold Port Injection system to integrate with the Direct Injection system and I believe this should help significantly reduce carbon build up.

If you've not already seen the case study, here's some extracts from it about the dual injection system if it's of any interest:

View attachment 268408
View attachment 268409
View attachment 268410

View attachment 268411

This is mega useful and I wasn't aware so this is great to know!

Sent from my VOG-L09 using Tapatalk

 

[Ajwhite]

Audi engines can burn oil but it should not be considered normal. Have you checked for any signs of oil in the coolant? Any signs of exhaust smoke? Also how easy is it to remove the oil filler cap? If the PCV is malfunctioning then as well as the oil level dropping it can create a vacuum beneath the cap.

Since the MMI did show maximum then it's probably OK but sensor faults have been known. It is possible to get a dipstick for this engine (or rather one which fits this engine).

1 point to you @Dippy oil filler cap is sucking like a trooper!

Could explain the bumpy idle? Idle went bad when it went on my 2.0 tfsi, that only how i knew it wasn't right.

Is PCV a 'relatively' inexpensive thing?

Sent from my VOG-L09 using Tapatalk

 

[Dippy]

As @ninjag noted, in theory the port injection on the CREx series engine should prevent significant build-up of carbon at the valves. Based on the few photos I have seen of CREx valves compared to the many of the previous engine it appears that this is proving to be the case.

PCV failure was a semi-common problem with the previous engine. There were design changes to the PCV arrangement on the CREx but maybe it wasn't enough. Repair/replacement involves removing the supercharger to gain access, so it should take a few hours. If the car has done 74K miles it might be worth servicing the waterpump at the same time.

Has the car had the fuel line recall work done?

 

[ninjag]

Would it be worth having a quick look at the fuel trims as well?

 

[Ajwhite]

As @ninjag noted, in theory the port injection on the CREx series engine should prevent significant build-up of carbon at the valves. Based on the few photos I have seen of CREx valves compared to the many of the previous engine it appears that this is proving to be the case.

PCV failure was a semi-common problem with the previous engine. There were design changes to the PCV arrangement on the CREx but maybe it wasn't enough. Repair/replacement involves removing the supercharger to gain access, so it should take a few hours. If the car has done 74K miles it might be worth servicing the waterpump at the same time.

Has the car had the fuel line recall work done?

Hey @Dippy

PCV was replaced, how do i find out about the fuel line recall work?

I'll check the docs tonight but don't remember seeing anything & noting on the recall checker via the Gov MOT site.

Sent from my VOG-L09 using Tapatalk

 

[Ajwhite]

As @ninjag noted, in theory the port injection on the CREx series engine should prevent significant build-up of carbon at the valves. Based on the few photos I have seen of CREx valves compared to the many of the previous engine it appears that this is proving to be the case.

PCV failure was a semi-common problem with the previous engine. There were design changes to the PCV arrangement on the CREx but maybe it wasn't enough. Repair/replacement involves removing the supercharger to gain access, so it should take a few hours. If the car has done 74K miles it might be worth servicing the waterpump at the same time.

Has the car had the fuel line recall work done?

Hey @Dippy

PCV was replaced, how do i find out about the fuel line recall work?

I'll check the docs tonight but don't remember seeing anything & noting on the recall checker via the Gov MOT site.

Sent from my VOG-L09 using Tapatalk

 

[ninjag]

It should be noted in the service history. Mine was.

 

[Ajwhite]

Yeah just found it, was carried out in 2019

Sent from my VOG-L09 using Tapatalk