RS4 B7 – Oil Burning issue resolved.
I had an oil burning issue on my car which I have resolved. I was having to put over a litre of oil in per 1000 miles, and gradually more often. Car is a daily and at around 120k miles.
The symptoms were occasional puffs of smoke at cold start, as well as a smoking exhaust during driving. Also at high revs when pushing on a spirited drive there might be some smoke.
On rare occasions in heavy traffic I also got a big dump of smoke after being sat idle for a while.
Also there was a suspected issue of a spark plug gasket leaking as I did witness wet oily plugs on a couple of occasions.
The overall symptoms seemed to imply an issue with the valve stem seals, spark plugs gaskets and fouled\stuck piston rings. Worst case scenario was that it was also worn valve guides. A lot of information online etc suggested it could be the latter which is a big expensive job to fix.
I trialled and tested a series of things to rectify the issue and I am detailing my journey to success in resolving this in order to help anyone else out there with similar issues.
The first thing was changing the oil from 5w30 to 5w40. Most specialists and tuners in the UK recommend 5w40 despite the Audi suggestion of 5w30. This had a noticeable impact to oil consumption. Simply put 40 is thicker at operating temperature than 30 and this has an effect on how much oil gets past pistons to burn.
The second thing was to deal with the issue of the valve stem seals and or other rubber gaskets which harden over time in the engine. After reading a lot of information and success stories I used the Forte Seal Conditioner treatment which is added to the oil at an oil change. This additive works on the rubber that is contact with the oil condition it again and thus revive it. It completely stopped the random smoke pluming issue I experienced in traffic or idle.
https://www.forteuk.co.uk/product/seal-conditioner/
2 bottles are required for our 9.3L oil capacity. The Forte Seal conditioner takes some time and miles to get working. The longer in the oil the better. I used it twice over 2 oil changes over the year, and I do a lot of miles.
At this point I thought I’d resolved the issues but after some considerable miles and many months later it was still burning oil again but now just in general driving. No plumes or big dumps of smoke, just a smokey exhaust regular need for oil top ups.
With a camera I inspected by pistons and they were covered in an oily film.
I had seen you tube videos of people doing “Piston Soak cleaning” using a product called Berrymans B12. I did this process right after an engine flush with BG EPR. My smoking has gone, and the oil consumption has dropped significantly to a more acceptable level. The car drives nicer too.
This was the process I followed:
First,
Engine Flush with BG EPR. This product is not like the cheap engine flushes. BG’s technical information states that for our cars (which have at least 9 litres of oil in them) require 2 x 325ml cans.
1. Bring the car up to warm temperature, then add the BG EPR cans to the oil. Then idle the car at 1200 rpm for 20 minutes. I actually did it for 30 minutes at 1300rpm.
2. Drain the oil immediately and fully. I even added 500ml of fresh oil to get the last bit out of the sump.
3. Now do the piston soak and clean. (Do not add new oil at this stage. Leave sump open).
Now onto the piston soak and clean.
Get 3 x 444ml cans of Berrymans B12 Chemtool Fuel Injector Cleaner.
Remove the spark plugs and ensure sockets are free of debris with a vacuum.
Using a measuring cup, and funnel with a tube attached, pour around 83ml of the B12 directly into each chamber. (This amount will give you 2 fills for each chamber when using the 3 cans.)
Rotate the crank. I had the car on the ground with one front wheel off the ground. With the car in 5th gear you can rotate the wheel to rotate the crank. Easy.
Leave to soak overnight, but try to gently rotate the crank every few hours to create agitation. Cover the spark plugs holes so nothing falls in and reduce evaporation.
Next day you will find most of the B12 has dissipated.
I bought this piston cleaning brush from online.
By attaching to a drill on slow speed you can gently agitate the surface of the pistons.
Now go around and evenly add the remaining B12 into all the chambers. Rotating the crank as normal and using the brush to agitate the fluid on the piston surface.
Here is a piston prior to vacuuming out the slurry: Much better already.
Now you have to vacuum and extract the slurry mix. I got some flexible tubing and taped it to the wet\dry vacuum and sucked it out. By rotating the crank and moving the tube around you can get most of it out.
I added a litre of oil to the engine to help drain out any B12 that was left in the sump.
With my pistons and rings cleaned out I refilled the car with fresh 5w40 and rotated the crank a few times. The put the car back together and started it up. It took a few goes to get the oil pressure up but it started fine.
Over the next miles it burnt off any residues, and over the next few weeks I did some spirited driving to help clear it out. I then changed the spark plugs as when I checked they were caked up. Probably from the resecured being burnt off.
I did this process at the end of November and its now March and I’ve done thousands of miles. Car has been smoke free and faultless since.
I believe the piston soak and flush clears out the piston rings.