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Old 05-31-2018, 11:28 PM   #1
Metzenw
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Question EJ255 Engine Vibration

Hello,

I'm currently working on my 2005 WRX. I bought it with a bad engine and have swapped in an EJ255 from an 2005 Outback XT.

Did the usual, swap intake cams, Cam Position Sensor mount, blah blah

All went well, fired the engine up, it started with no hiccups.
Took the car for a test drive, and i get this Horrible vibration from the engine.
But the vibration goes away during wide open throttle above 3500rpm and comes back as soon as you lift the throttle.

At first I'm thinking, Ok it's doing this because I haven't gotten the engine tuned yet. No big deal. But if I'm at 5500 RPM coasting down hill and shut the engine off, the vibration is there.

I checked the timing and found that the Left Exhaust Cam was off one tooth and thought HA, that's the problem. After 14 (Yes 14) attempts to get the timing belt set correctly. I finally got it. Retest drove the car, Hey little more power and the vibration didn't change at all.

I swapped harmonic balancers, No change.

I pulled the engine again yesterday to inspect the Clutch and Flywheel as that is the only thing left externally that could cause this problem.

I put a dial indicator on the face of the flywheel near the outter surface where the clutch rides. I measure .004" TIR.

Is .004" TIR too much? I've read that most people agree you don't want more then .002" TIR.

Also checked the crank, nothing more then .001" TIR

Rotated the Flywheel 180 degrees, Exact same readings in the exact same spots.

I do a more through inspect of the clutch, it's used but not bad, easily has more then half it's life left.

So, My plan is to buy a new Flywheel and an Exedy Stage 1 Clutch.

If the vibration still remains it has to be an internal problem.

Anyone have any advice? I'm just about at my budget breaking point for this project. The last grand is for a Cobb AP, clutch and Flywheel.
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Old 06-01-2018, 09:17 AM   #2
Zmanwrx23
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what about motor mounts/pitch stop? could be thrashed and in need of replacment
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Old 06-01-2018, 10:37 AM   #3
Charlie-III
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OK, so downhill at 5500RPM and you shut the engine off, we assume you either push in the clutch or go to neutral?
If so, then it's drivetrain related vibration. Could be trans mount, driveshaft, driveshaft center carrier, etc. Engine off, clutch pedal down or trans in neutral you take the clutch pressure plate and flywheel look out of spinning mass.
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Old 06-01-2018, 01:21 PM   #4
Metzenw
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Quote:
Originally Posted by Zmanwrx23 View Post
what about motor mounts/pitch stop? could be thrashed and in need of replacment
I will check those today after work. That is a good suggestion.

Quote:
Originally Posted by Charlie-III View Post
OK, so downhill at 5500RPM and you shut the engine off, we assume you either push in the clutch or go to neutral
I leave the engine in gear with the clutch released so that the engine is spinning without fuel or spark. Probably my mind playing tricks on me, but It feels as if the vibration is worse with the ignition off.

Quote:
Originally Posted by Charlie-III View Post
If so, then it's drivetrain related vibration. Could be trans mount, driveshaft, driveshaft center carrier, etc. Engine off, clutch pedal down or trans in neutral you take the clutch pressure plate and flywheel look out of spinning mass.
With the clutch pushed in, and/or in neutral I have zero vibration. This for sure is engine related. But I will double check all my Engine/Transmission mounts.

The Flywheel looks to be made in several pieces, there isn't some sort of vibration dampener in it is there?
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Old 06-01-2018, 04:16 PM   #5
Charlie-III
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If you are coasting engine off, in gear, clutch engaged, then yes, look at trans and engine mounts.

Sounds like a loose or bad mount. Loaded in acceleration it shakes, loaded in decel it doesn't shake.
Sounds like mounts.
Flywheel or clutch should be the same if the engine is spinning, regardless.
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Old 06-01-2018, 09:28 PM   #6
Metzenw
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It does not vibrate under full throttle. But vibrates during all other driving conditions regardless of the ignigtion on or off. The clutch in or out, in gear
or out of gear. If the engine is spinning, it's vibrating. They're no shakes/clungs like that of a bad motor mount, I have experienced that before. It feels like an engine that lost a balancing shaft. Could failing bearings cause this vibration? Someone out there has had to have experienced this.
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Old 06-26-2018, 08:29 PM   #7
Metzenw
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The Problem has been solved. Turns out it was exhaust restriction. I got new exhaust from the downpipe back, and the Vibration is gone.

My advice is if you get something weird, check your exhaust before you go replacing your Motor Mounts, Pitch Stop, and Clutch and Flywheel. Could save yourself a $1000.
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Old 06-26-2018, 11:04 PM   #8
Charlie-III
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Hey, glad you got it fixed.
Also really glad you closed this out as it may help others out down the road.
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