Newbie with Motor Questions

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Davecal
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Newbie with Motor Questions

Post by Davecal »

Hi Folks,
New to the Forum and new to Subaru as well. Just recently purchased a 2003 Baja with 114K and looking for advice on what is considered “normal” motor noise.
I love this little truck, always wanted one and finally bought this as a second vehicle. I hear a cold knocking noise, gets much better when warm, kind of sounds very solid like a lifter and appears to be coming from the right side rear cylinder area.
I’ve read a lot of posts on this topic and it seems that these motors are noisy but I’m not sure where the line is between normal and not.
Some history...the former owner had the head gaskets and timing belt done but unfortunately the subpar mechanic chose not to replace the spark plug tube gaskets so the plug wires were taking a oil bath.
I replaced the tube seals, cover grommets, and valve cover gaskets. Also adjusted valves while it was open hoping that might quiet it down.
Changed the oil with 5W-30 Synthetic, noise not much better.
I’m sorry for the mouthful just thought some history would help.
On a positive note, I put all new brakes, rotors, belts, and changed all fluids and this truck runs and drives great. Very impressive ride and handling and feels like a much bigger car on the road.
Any input will be much appreciated.
Thanks, Dave


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Guacamole
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Re: Newbie with Motor Questions

Post by Guacamole »

Hey there, first off congrats on the purchase & welcome to the forums!
So this knocking noise: does its speed increase & decrease with the RPM, and does it completely or nearly go away once the engine is warm? If yes to both, it's piston slap. As long as it goes away once the engine is warm it's nothing to worry about, just natural wear on the engine block. My 06 Sport (190,600 on the odometer as of this post) has a real nasty slap when it's cold- sounds like a ticking clock, but almost completely goes away once the engine is warmed up.
Piston Slap noise (2000 Legacy, same engine as Baja): https://www.youtube.com/watch?v=DIWFkQYDvpg

I'm no engine expert (lol, far from it) but from the info you've provided it sounds like that's what it is. Nothing really to worry about, only consequence is a small dip in engine performance.
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Davecal
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Re: Newbie with Motor Questions

Post by Davecal »

Hi, yes to both, increases with RPM and much better when warm but still slightly noticeable. Worse under a load when cold as you’re first taking off on a cold morning.


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BajaTim
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Re: Newbie with Motor Questions

Post by BajaTim »

Davecal wrote:Hi, yes to both, increases with RPM and much better when warm but still slightly noticeable. Worse under a load when cold as you’re first taking off on a cold morning.


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As a Baja owner since July of this year (having owned a 2000 RS, and two WRXS, 2002 (sedan) & 2004 (wagon), these Subarus (turbo more than NA) are time bomb booby traps waiting to take off an arm & a leg ($$$)...unless your Suby is under a bumper-to-bumper warranty get ready to spend on the endless maintenance/failure issues:)...if u have a turbo start with the banjo bolt:) I’ve got 3 of my mechanics lined up to buy mine at $5k more than I paid...I’m checking out Ridgelines and Explorer Sport TracsImageImageImage


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kamesama980
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Re: Newbie with Motor Questions

Post by kamesama980 »

BajaTim wrote: Sun Dec 10, 2017 10:08 pm
Davecal wrote:Hi, yes to both, increases with RPM and much better when warm but still slightly noticeable. Worse under a load when cold as you’re first taking off on a cold morning.


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As a Baja owner since July of this year (having owned a 2000 RS, and two WRXS, 2002 (sedan) & 2004 (wagon), these Subarus (turbo more than NA) are time bomb booby traps waiting to take off an arm & a leg ($$$)...unless your Suby is under a bumper-to-bumper warranty get ready to spend on the endless maintenance/failure issues:)...if u have a turbo start with the banjo bolt:) I’ve got 3 of my mechanics lined up to buy mine at $5k more than I paid...I’m checking out Ridgelines and Explorer Sport TracsImageImageImage


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any car's a ticking time bomb at 15+ years old and all cars need to be maintained. Take care of it and it'll take care of you.
-Russell
"You don't get to judge me for how I fix what you break"
03 sport 5mt
05 turbo 5mt vf39 and other STI bits, 3" turbo-back
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anarchy1024
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Re: Newbie with Motor Questions

Post by anarchy1024 »

One other possibility is the timing belt tensioner.

I had a noise that sounded exactly like piston slap; even the mechanic who built my engine said it's definitely piston slap. It was loud when the engine was cold, and gradually faded over a few minutes. I didn't think it was piston slap because the sound (when the engine was cold) got significantly worse about a week or two after doing the timing belt, as opposed to gradually louder over time (as expected with engine wear). After taking the timing belt cover off, I saw the tensioner was "flapping" slightly, and using a wrench to add some extra force made the noise go away. And this was a new tensioner, replaced at the same time as the belt.

Exchanged the defective tensioner and it no longer made that noise during cold starts.
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Davecal
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Re: Newbie with Motor Questions

Post by Davecal »

Thanks for all the input, just one more question.
Has anyone had success with different types of oil?
When I bought the car I changed the oil in the first 100 Miles as I had no idea what they had in there. I used the recommended 5W-30 but I feel like the piston slap is louder now than with the previous oil. Curious if anyone tried different oil types or grades to quiet the piston slap down. Thanks


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kamesama980
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Re: Newbie with Motor Questions

Post by kamesama980 »

Davecal wrote: Thu Dec 14, 2017 4:18 pm Thanks for all the input, just one more question.
Has anyone had success with different types of oil?
When I bought the car I changed the oil in the first 100 Miles as I had no idea what they had in there. I used the recommended 5W-30 but I feel like the piston slap is louder now than with the previous oil. Curious if anyone tried different oil types or grades to quiet the piston slap down. Thanks


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the previous owner probably had it full of gear lube and lucas syrup for the sale. Mine was the same, he'd added the lucas so recently the oil filler tube was still goopy from it. Running different oil won't fix it. thicker oil and lucas may dull it some but won't make it any better and won't do the rest of the engine any favors. I run M1 5w30 and drive gently until it quiets down.
-Russell
"You don't get to judge me for how I fix what you break"
03 sport 5mt
05 turbo 5mt vf39 and other STI bits, 3" turbo-back
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