I have just read a bunch about pinging and will be trying some of the solutions to carbon build-up. Are there any autoparts stores in the US that carry seafoam? I think the spark plugs were changed at 65k miles. I am at 120K miles now. Some new plugs sounds like a good idea. The spark plug wires look like they are in good condition. I will leave those alone. How do I check the knock sensor? The cheapest troubleshooter will be to run 91 octain. Gonna try that tomorrow on empty tank.

 

NAPA carries Seafoam but if you are going to try it change your plugs right after.

 

No need. I've been doing SeaFoam treatments on my car for the past 2 years, (and my cars before that). I do it every other oil change, no fouls, no need to replace the plugs.

Advance Auto also carries sea foam. Id run a bit thru the fuel tank and see if it clears up the knocking

Running through the fuel tank only helps out the fuel system mostly, but it won't stick to the carbon buildup on the valves and pistons. To do a proper "top end treatment", you need to introduce half a bottle of SeaFoam into the intake system so the engine sucks it in evenly. I SLOWLY pour in half the bottle into one of the intake lines (one of the vent lines that comes from the heads into the intake). This allows the turbo to suck in the fluid, mix it up and it sticks to the pistons and valves. Once you pour half the bottle in, turn off the car for 10 minutes. When you start it back up, rev it constantly until the white smoke goes away (you will see a HUGE amount of smoke, DO NOT DO THIS IN YOUR GARAGE, do it out on the street where the fumes won't fill up your garage or house. It'll take you 5-10 minutes of revving (I rev to about 4,000 RPM, then every once and a while, a redline blip of the throttle). The ticking seems to subside massively after a SeaFoam treatment, and the engine becomes a LOT more responsive as well. I notice this difference each time I do it, and I do it every other oil change. These engines get a lot of carbon build up in them, and top-end treatments is what eliminates that.

SeaFoam is highly recommend from me (if you couldn't already tell).

ALSO: Make sure your oil is TOPPED out (like right above the full line). Running even a quart low (which can happen after only 3 weeks of hot desert driving) it'll tick very loudly I noticed. And being that you are in the desert, during the hot summer months, try to run a higher viscosity oil. A 10w-40 or higher if you can. My engine gets VERY ticky during the hot months with the A/C on if I run 5w-30 for some reason. And being that living in the desert is considered "severe duty" by Subaru's manual.......they recommend at 10w-40 up to 20w-50 (which I'm changing to this week).

Hope this helps,

Josh.

 

Advance Auto also carries sea foam. Id run a bit thru the fuel tank and see if it clears up the knocking

 

Update: replaced plugs and wires. She runs like a champ now with no pinging sound. I bought seafoam but have not used it yet. I am gonna use it in the gas but am still hesitant about the top end cleaning. Thanks for all the advice!

 

Seafoam works

I'm an extreme Subie newb, having just signed up last week. But regarding Seafoam, my personal experience (not theory or 2nd hand info) for many years of owning several full-size Jeep Waggy 360s, is that its one of those rare additives that actually works as advertised: Clears out stuck hydraulic lifters when added to oil and keeps carbs clean when added to gas. I don't know if I have any FI issues at this point on my new (to me) '99 Legacy Outback, but I poured a bottle in the gas tank on my first fill-up without hesitation. Tip: The bottle does not have a narrow neck that permits easy intro to the fuel filler The little spring-loaded flappy thing will block a fast flow from the bottle and it will back up and overflow all over your shoes if you try to just dump it in. So you need to either dribble it in with patience or use a funnel to get past the flap.

 

Any advice on the engine tick? I did a little research already and I've read to check valve clearance. That will be my next project, but in the meantime any advice? Thanks!

Best indicator that an engine tick is really an exhaust leak is that you do not hear it (or hear it loudly) at idle but definitely louder on acceleration, as you indicated. That's when the exhaust burst from each cylinder is the highest pressure and therefore the leak will sound louder. And of course, it will only get worse as the leak slowly opens up over time, and the "tick" will slowly turn into a "rap".