piston slap sound

Ever since I changed my oil about a month ago I am hearing a piston slap type of sound. The thing is that the sound is only present at lower rpm's like making a turn or driving through a parking lot when rpm's are just above idle. At higher rpm's the car sounds fine. I've researched and i'm aware that piston slap isn't automatically bad in Subaru's. Just wondering if anyone has insight into this and if it is something I should be worried about.

Piston slap just sounds bad, is that just before you spin a bearing?

 

Are you burning.g a lot of oil?

The car doesn't burn any oil. Ill also mention that the sound isn't really loud like an engine knock its pretty faint but definitely noticeable. Could certain brands of oil make an engine more noisy than others?

Does it sound like this, and it happens mostly when cold?

 

[ame=http://www.youtube.com/watch?v=PBCYP-Bi0IA]Subaru ej22 rod knock or piston slap? - YouTube[/ame]

Mine isn't as constant and sounds more clanky, but is a similar sounding. As far as it happening when its cold, I still hear it long after the car has warmed up.

A knock in the motor has a pretty definitive sound, if the piston slap is what is coming from your car it should go away after operating temp is reached.

 

A heavier oil will drown the sound out a little, but if its too heavy you will feel and hear it during start up even more than usual.

Yes once the pistons get warm and expand they won't make noise anymore. It should only last around 10-20 seconds.

No worries, piston slap comes standard with Subaru ...same thing w/ all the other mysterious noises

 

Bout time Subaru stepped up their game w/ the radio to drown it out

what oil did you put in? and what oil was in prior... as you weren't having an issue before the change? different weights in oil are more likely to cause a change in engine sound vs different brands, better brands and synthetics will do a better job of lubricating and leaving a coating that quiets the slap but does eliminate it.

 

Also Subaru Injectors are pretty noisy.. I thought my engine was going to blow up for a bit before I found out what all the taptaptaptap was at idle.. if yours is not consistent maybe one is slightly sticky? just a thought I Have a ej205 but I remember hearing them on my last legacy aswell.

I'm hearing the same sound like the one in the video posted above. I've put in the Lucas oil stabilizer in my last oil change (2 weeks ago) and I still hear it. Doesn't matter if it's cold or warm, it's always there. Spun bearing? Rod knock? Either way, it sounds like $$$ to fix or replace.

May be lifter tick if its phase 2.

 

Rod knock sounds like a ball pein hammer hitting the engine block and spun bearings sound like there is sand in the crank journals (gravely sound).

boy oh boy, piston slap gets blamed for everything.

 

i had a 97 obw with piston slap. i bought it w/ 98k miles and a known ''bad wrist pin''. i had an engine and i was planning on swapping it out. but after i started driving it and reading up on piston slap i realized it did not need an engine. so i drove it. i drove it for 40k miles and sold it for $2300, $100 more than i paid.

 

it made noise at start up, and the noise lessened as it warmed up, but it never went away. it sounded a little like a diesel and want-a-be mechanics were always tell me i had a stuck valve.

 

but not all engine noise is piston slap. ESPECIALLY if it is always there and always the same. and it is not always rod knock or a bad rod bearing. but it could be.

 

if it is rod / bearing related the noise should go away if you pull the plug wire for the noise maker.

real piston slap is loud a cold start and lessens or goes away as the engine warms.

 

valve noise is different.

 

get a mechanics stethoscope and isolate the noise. in the middle of the block, or farther out to one side in the head? or up front behind the timing cover?

Johnegg, thanks for the clarification. I'll stop by Harbor Frieght and pick up a stethoscope.

Subaru is very specific bout their fluids. The OEM oil that you buy at subaru is always the best choice since it has the correct fluid properties for the engine. They use very specific alloys in their engines and certain chemicals react differently with these metals. Also with the cooling system. Do you ever notice how some engines turn a brownish color inside and some remain the silver color. Its all chemical reaction, and this can effect the seals, bearings etc... As far as the knock sound its prob the rod bearings. They were a poor design and don't supply the right amount of lubrication. Subaru has an updated bearing but eventually the same issue can occur, but there are aftermarket companies that make high quality bearings that will provide proper lubrication. Anyways, that's my experience with the issue.