1998 ej25 sounds like diesel

[Garrison]

Care to guess what this could be?

1998 EJ25D 149,700 miles
Started the car for the first time in a few days and during the warm up period, the engine sounded a dead-ringer for a diesel engine.
EDIT: Could hear the sound definitely coming from the driver's side (#2 & #4 pistons AND/OR Heads)

After driving for a period of 10 minutes I pulled over to listen again and the sound was completely gone.

Ideas?

[Huffer]

Heat shield w/ exhaust leak.

[Garrison]

I removed the heat shield when I was working on the shift mechanism, but thank you for the guess.

I've done some more research, it looks like it's one of these three:

Piston slap (common on older subarus, fixed with replaced pistons)
Valve ticking (don't think so, but easy enough fix, adjust valves)
Timing-belt tensioner (sealed hydraulic unit, knocks like crazy when worn out/leaking; replacement is a swap of unit)

What say you sir?

[Huffer]

I have piston slap on my 1998 EJ25, with 112k, goes away when the engine is warm. I figured you knew what PS was...

The fix for piston slap is to actually sleeve the cylinder, as the piston itself doesn't expand fast enough when the engine is started.

[Garrison]

So if I'm planning to do a block swap later on, to an EJ222, now would be the time?


EDIT: Also, why sleeve the cylinders instead of sizing up the piston .06", or .10"? I would think piston swapping (as per SOA's traditional method of repair) would be the easier, more OEM friendly solution.

*Added information to original post*

[anothernord]

Video of noise? Could be the traditional cold start piston slap. Even my old EJ25 that was new at the time did it on real cold mornings.

[Garrison]

Well I've been waiting to get a good video, but the sound simply hasn't occurred since I first posted this thread. Am I being a bad owner by not worrying about it?

[jjay03]

Mine is pretty noisy I think most of it though is from the header even though it is wrapped. I am going to check my valve clearances while I have my engine apart. You cant just adjust them you have to buy a shim of the correct size.

[Garrison]

I think it's the wrist pin. I took a video of it when it showed up again and let a mechanic listen to it. He asked the symptoms and circumstances when it shows up; and wrist pin was his guess. He said to just drive it and not worry, and if I was going to replace the block, now's the time.

[Garrison]

Here's the video I took. Finally got around to uploading it.

This is right after ignition.
http://static.photobucket.com/player.sw ... EO0008.mp4 (http://static.photobucket.com/player.swf?file=http://vid1003.photobucket.com/albums/af158/Garrisonbowers/VIDEO0008.mp4)

[Navi271]

Almost sounds like a little rod knock. Make sure you're full on oil!