Subaru: 04 WRX pinging

Could be piston slap - well known but this is about the newest engine
I've heard of this occuring in. Good news is it won't affect the
lifespan of the motor. On the forums at www.usmb.net there are folks
with over 250K that had it the whole time.

However, I'd be concerned you have a bad knock sensor. It tells the
engine how far to move the timing before detonation is detected. Try to
buy gas at the same location every time you fill up and disconnect the
negative terminal of the battery, wait 15 minutes, hit the brake pedal a
couple of times(or wait for an hour) to clear the ECU. Then it should
learn the same octane gas and maybe not be confused.

Carl
1 Lucky Texan


Mike M. Miskulin wrote: 


--
to reply, change ( .not) to ( .net)

PISTION SLAP... if it is not noisy... Normal engine "slap" If under warranty
have dealer check it for free. Could be timing chain tensioner (replaced free
under power train warranty)
Want to head mine.. www.butkus.org look for subaru piston slap. Save file to
HD then run the file.


In article <com>, com says... 

It won't help. Actually I had 4 new pistons to get rid of the "slap" and they
changed to "stardard" plugs after replacing pistions via SOA requirements.
I was charged $30 labor in install spark plugs when the engine was
already disassembled ? ? ? They also changed the timing belt tensioner first
to remove the start-up noise (mine was bad). Got them to replace the three
belts (timing and 2 drive belts) for just the $86.



In article <google.com>,
net says... 
news:<not>... 
news:<69.154.202>... 

Piston slap is a big problem in the auto industry. Check out "piston slap" and
you'll find GM has a big problem and the customers are really upset.


In article <69.154.201>, net
says... 

Never thought of the "piston slap" affecting the "knock sensor"... humm that
could affect the sensor and retard your spark. Worse gas mileage.
Pulling the fuse would be better than the battery. All your radio stations
would go too if you pull the battery.


In article <not>, not says... 

With all the comments about piston slap, tensioners, knock sensors..

wouldn't these kind of problems be reflected all the time the car is
running, not just going from cold to warm?

mike

Mike M. Miskulin wrote: 

Mild valve tap while cold is common, if not universal in
these boxer engines. As the engine warms up, the metal
expands and tightens up clearances and the tap goes away.

I have no idea how the other problems would go away at
temperature.

While pondering the Universe, com (Jim Stewart) wrote
<bq5h3n$airnews.net>:
 


So it sounds like I really shouldn't be too concerned unless I start
hearing it when the engine is warm too.

mike