introduced to piston slap ...or worse?

[tricked919]

I'm so frustrated. I picked up a 97 OBW last month that had new HG's, seals, radiator, T-belt, tensioner, and AC condenser. It had a bad BPT solenoid that was bypassed and it ran fine (no CEL). My wife has been driving the car and said she's been noticing the cold start immediate piston slap but the car drives like a dream.

 

I ordered a new BPT for it just to make it right. I put it on tonight and a 10 minute drive later, the CEL came on (go figure). We also noticed a sound at revs over 2500rpm that sound like lifter tapping. The engine was totally warmed up. Cruising at 2500rpm and lower, it drives and sounds like a brand new car. We got home, I popped the hood and I let it idle (still with CEL on). At idle, it sounds pretty good. As soon as I rev it up manually from the throttle body, the slap/knock sound becomes VERY noticeable. I've heard bad bottom ends and its not quite "knocky" It sound like a lawnmower. At 3000rpm+ it gets louder. Drop it back to idle and it's barely noticeable.

 

I put the old BPT back in (bypassed) and its still doing it - clearly coincidence. Should I be worried? I'm freking out because everyhting I know about slap doesn't jive with a motor that is warmed up. Aside from the new gaskets, belts and seals - its still an EJ25 with 149K. This SUCKS!!

 

Suggestions please ...Thanks guys

Edited May 6, 2010 by tricked919

[tricked919]

this morning I did a true cold start and the piston slap happened the instant the motor cranked and was gone is less than a second. That sound is nothing like the high rpm noise I'm hearing. It idles like a sewing machine for as long as I let it idle. When I reved it up, as soon as it appproached the 2500-3000rpm range, the obnoxious noise came back. I was afraid to take it up to 4-5K. I let it return to idle and smooth again.

 

Somebody please tell me this is a timing problem or loud valve chatter that's developed from the heads not being put back together properly from the HG replacement (FYI, that was about 800 miles ago).

 

Oh, and I disco'd the battery last night, left the old (bad) BPT in and no CEL came on during this. I could care less about the BPT issue now if that's not relevant.

Edited May 6, 2010 by tricked919

[davebugs]

97 should have valve shims to adjust the valves.

 

But if it got hot before the HG's were done it could easily be rod bearings.

 

Perhaps others here will have more positive suggestions than rob knock/rod bearings.

 

 

I usually listen to the area behind cyl#3 - closest the firewall on the pass side while standing at the front of the car.

 

I pay particular attention to the noise when coming down from reving the engine.

 

Good luck.

 

Please give WNC a little more meaning - like a city/state. Someone here may be able to listen to it for you as a second opinion.

[tricked919]

97 should have valve shims to adjust the valves.

 

Please give WNC a little more meaning - like a city/state. Someone here may be able to listen to it for you as a second opinion.

 

Yes, it does have valve shims. The guy who put it back together and sold it to me showed me his shim chart. All of them spec'd within acceptable limits.

 

I don't notice any wrapping as its coming down off the revs. Its just while the motor is at higher rpms. As soon as it dips below 2K, it shuts up significantly

 

Sorry, WNC is western north carolina. I'm a little west of Asheville.

Edited May 6, 2010 by tricked919

[hankosolder2]

I trust your oil level is OK?

[bheinen74]

maybe change brands of oil. What are you using now for oil?

[tricked919]

yes - oil level is perfect. Not an ounce burned in the past 800+ miles. Still clean. Not sure what's in it. Its still on the first round of oil from the HG replacement and tune up.

 

I'm just torn over whether this is worth fixing or dumping while its still running somewhat decent. Regardless, if the sound is harmless or catastrophic, its not going to be an easy fix - its internal - I know it.

The car is in AWESOME condition. Body and interior is as good as it gets and everything works perfect - and despite the chatter, you can eat off the motor. Everything we were warned about on the 97's was addressed too. Short of needing a new rack soon, I don't see any potential problems. We have $3000 in the car. If another $2000 for a motor will get me a ride that I can trust road tripping across the country, I might do it. But the last thing I want is to buy a used short block or assembled motor that comes with drama and be buried in a piece of crap that just looks nice.

Edited May 6, 2010 by tricked919

[tricked919]

I've been crushing the searches and I'm learning about flexplates. What I'm finding seems really similar. I just can't think of what other things would have the motor sounding good at idle then getting ugly at higher rpms. Dumb question . there's no way to check a flexplate w/o pulling the motor is there?

[idosubaru]

Are you positive it's from inside the motor?

 

Other loud noises that can be RPM dependent:

 

Timing belt tensioner. RAP, RAP, RAP, RAP at higher rpm's as the tensioner gives way to heavier loads. I believe you can see it moving too if you remove the drivers side timing belt cover which isn't too hard and only takes a few minutes. The "newer" style tensioner installed on late 90's EJ engines is not as reliable as the older ones so this is fairly common.

 

Doesn't sound like it, but exhaust shields wouldn't be it right?

 

If the backing plate screws on the oil pump get loose enough I wonder if that would cause any noises? I feel like someone mentioned a symptom of loose screws before, though I've never seen symptoms even though nearly every EJ pump has at least one or more screw loose.

 

There's an access hole to the flexplate under the throttle body. It's tight and hard to get to so I'm not sure how much visibility you have but it's used to remove the torque converter to flex plate bolts. by rotating it 360 degrees you might find crack? Some vehicles also have minimal access from underneath too.

[tricked919]

Are you positive it's from inside the motor?

 

Other loud noises that can be RPM dependent:

 

Timing belt tensioner. RAP, RAP, RAP, RAP at higher rpm's as the tensioner gives way to heavier loads. I believe you can see it moving too if you remove the drivers side timing belt cover which isn't too hard and only takes a few minutes. The "newer" style tensioner installed on late 90's EJ engines is not as reliable as the older ones so this is fairly common.

 

Doesn't sound like it, but exhaust shields wouldn't be it right?

 

If the backing plate screws on the oil pump get loose enough I wonder if that would cause any noises? I feel like someone mentioned a symptom of loose screws before, though I've never seen symptoms even though nearly every EJ pump has at least one or more screw loose.

 

There's an access hole to the flexplate under the throttle body. It's tight and hard to get to so I'm not sure how much visibility you have but it's used to remove the torque converter to flex plate bolts. by rotating it 360 degrees you might find crack? Some vehicles also have minimal access from underneath too.

 

yeah, its easy being more familiar with inline motors to forget how short this motor really is. The sound seams to definitely be favoring the back of the case. Considering that the flexplate on this car is where the #2 cylinder is on inline RWD cars, its very feasible (and I'm praying) that it's the culprit.

 

I just went home at lunch to check it out. The car has been sitting all day. It fired up and sounded awesome at idle. I even ran it up to 3500rpm and other than being loud, there was no knocking. It's about 90 degrees here today. I still can't help but think (as much as it sounds like it) that a serious internal issue would a.) be heard at any rpm - and b.) be MORE noticeable when its cold.

[idosubaru]

doesn't sound like rod knock based on your description and familiarity. good luck, hope you can track it down. i've seen other cracked flexplate threads, not sure if it was this forum or another though. be nice to compare symptoms to someone else that has had it, sounds like you did?

[ShawnW]

maybe change brands of oil. What are you using now for oil?

 

What does the brand of oil have to do with a piston slap or knocking noise again?!?

 

Weight might but certainly not brand!

[ShawnW]

A rod knock will get worse as it warms up. It will not knock for a second cold and then go away.

 

I think you have a timing belt tensioner that somebody compressed in a vice too fast and blew the seal out on.

[tricked919]

A rod knock will get worse as it warms up. It will not knock for a second cold and then go away.

 

I think you have a timing belt tensioner that somebody compressed in a vice too fast and blew the seal out on.

 

If you were right I'd be thrilled. How do I diagnose the tensioner? There's not a drop of anything leaking. That's just the 1st thing I thought of when you said "blew the seal out"

 

As for the rod knock - if I had to say, it does get more noticeable once the motor is warm. However, even when its warm it only "knocks" above 2500rpm but then is super smooth at idle.

[johnceggleston]

i came across this, i don't know anything about the quality of the work, but R & R a subaru engine for 350$ is a pretty good deal. includes new oil, filter and coolant.

 

http://asheville.craigslist.org/cto/1728929525.html

 

 

 

i would think a mechanic's stethoscope would help track down where the noise is coming from.