Hi Scotty, My wife has a 2015 Golf Sportwagen TDI (auto transmission) with approximately 120K miles. Just days after her last oil change, she received a "Reduce Oil Level" warning on the vehicle diagnostics screen. Our mechanic believes that it's not likely to be the oil level sensor, but rather a problem with the DPF regeneration system. I'm reluctant to bring to our VW dealer as we've had bad experiences before (long story). Not really sure how the DPF system even works, so hoping you can explain how to diagnose and possibly fix. I've seen DPF cleaning products but do they actually work? Thanks for your help!!
Cool little car. The VW diesel scandal left a bad taste in a lot of peoples' mouth, but that particular model has a lot of appeal, IMO.
Don't know about DPF cleaners, but rule of thumb is that most products in that space are useless.
You might look on the VW forums or Golf/Rabbit enthusiast clubs to see if there are any common, known issues. (Get it? "Golf clubs"?)
Most DPF issues are not DIY-ready. I can appreciate your desire to avoid the local VW dealer. You'll probably be better off with an independent Euro-diesel mechanic, if you can find one (I know one in Nor-Cal, just in case you're out that way.) Otherwise, you might inquire with the Mercedes dealers in your area, especially if they sell a lot of Sprinter vans; possible they could have a diesel guy who is willing to work on a veedub. Probably an expensive option, but the sofas in the waiting area would be pretty cush.
Welcome new member!
Took your advice and contacted my local Mercedes dealer for a local diesel mechanic referral. The mechanic also advised against using any of the "garbage" (his words) DPF cleaning agents since they actually cause the filter to get gunked up faster in the future. We checked the oil level which significantly higher than when changed, and his assessment was that since my wife tends to make several short A>B trips, the car has been attempting too many DPF regeneration cycles, but never completing them. When attempting regeneration, the system injects small amounts of diesel into the engine oil to increase exhaust temperature, which is needed to clean the filter. Since the process has been staring and failing to complete so many times, the engine oil has become diluted with diesel fuel and thus causing the oil level to rise above spec. He recommended we take the car for a relatively long drive (100+ miles non-stop) to allow the regeneration process to initiate and fully complete. We actually did better and took a drive 300+ miles to visit her parents allowing the regeneration to complete two consecutive cycles and wouldn't you know it, the reduce oil warning went away. Most of the excess diesel which had diluted the engine oil had burned off, the DPF was cleaned. Decided to change with fresh oil when we arrived at my in-laws and hope this never happens again. It is a great car so maybe we'll take it out on the weekends to stretch its legs a bit moving forward. Appreciate your help!
Awesome. Glad it’s doing better!
Have you checked the engine oil level?
I agree with @yaser, check th oil level.
DPF is mounted within the exhaust system and has physically nothing to do with the engine oil. On the other hand, if you use bad quality oil with sulphur, it can destroy DPF.
More about DPF and engine oil
https://www.valvoline.com/en-au/dpf-and-engine-oil-explained/
Nice summary on the Valvoline link.
wife tends to make several short A>B trips
took a drive 300+ miles
Diesels aren’t made for low running. They are made to munch miles. You may be better off getting her a petrol vehicle which doesn’t mind sparse usage. Just my $0.02 from owning a sparsely used diesel sedan.
