You can try one treatment and see how that works for you. The stuff isn't cheap, but it's highly regarded in the automotive community. Sludge around the oil cap doesn't say very much, there's a baffle on the head too so you can't see down to your valvetrain to actually tell if you have sludge. That having been said, at 170k, it would be worthwhile to give autoRX a run.

http://www.auto-rx.com/pages/applications2.htm

^ give it a try for one application. If you're not satisfied, do 2... I would do 1 though. Audi engines, if proper OCIs are observed, don't show a whole lot in the way of sludge.

 

Is there a downside to more than 1 application besides price?

 

depends on what you call sludge and the colour the oil cap will collect residue if car isn't driven for long distance because there is condensation in the system and that's normal

 

Is there any easy way to tell the severity of my sludge issue? I recently had my oil pan off and i didn't notice any deposits in it or the oil screen. I'm going off the oil cap sludge alone. Seafoam or Auto Rx?

 

An update. The sh*t on my oil cap is gritty like a very fine sand. It may make more sense to call this carbon deposits? What is this stuff and should I worry about it?

 

Up.

 

duburban, don't worry about the gritty carbon, it's normal.

 

Great, thanks. I looked for Auto RX but only found seafoam and risoline. I put in the risoline first and i've lost the slight chugging around 75% throttle. Seafoam in the tank and crank after i change the oil again.