Wanted to share...

So my mom has a VW Tiguan, basically a 4x4 GTI, with 70,000 gentle highway miles on it. Yesterday her CEL came on, then started flashing. She called me to help her figure out what to do.

So I hook up the scanner and get p300, p301, p303 ...misfires all over the place. Start investigating online. Turns out there are common issues with coilpacks going out around this age. Keep reading, turns there is also a common problem with direct injected engines where everything before the intake valves gets horribly carboned up from the PCV recirc because there is no fuel washing things down. Carbon also takes out the intake flappers.

Solutions: replace coils, decarb, hope you don't need to take stuff apart. Now where have I heard this before....

 

A red line a day keeps the carbon away!

 

Exactly!

 

I'll let my mom know

 

Actually redlining wouldn't help the VW issue. The Ford EcoBoost GTDI engines all solved the problem by changing valve timing at certain times to allow charge reversion to carry fuel out into the intake and get pulled back into the engine in order to clean the valves. The pics i've seen of those after driving a lot have all shown no more carbon buildup than a normal port injected engine.