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Mysterious vibration after changing engine mount could it be the repaired spark plug harness wire? (bad engine mount)

847 Views 0 Replies 1 Participant Last post by  Digitalwheel
I changed the left (facing front) engine mount. This may have broken from a minor accident I had that I repaired the body about a year ago. The car ran ok but had a vibration before I fixed it. Now it has a different vibration almost seems like something is loose, (the mount was torqued) Using a screwdriver I did not feel any vibration from the unchanged right mount, HOWEVER, cutting the hard-to-reach bolt to remove the airbox resonator (it was on too tight to be normally removed by a small ratchet that just fits at rear of engine) I clipped the furthermost-left spark plug wire harness wire that has a plug on the end for the coil on top of the spark plug. Taking the wire a bit apart I repaired it with a bridge and soldered the repair and put tape separating the 3 wires.

Could this repair make the 3rd (its either the 1st cylinder or 3rd the most left one) run incorrectly? I do not get an engine light or 'check engine' light. I don't get a misfire error. Test driving it does not sound like it is running on 2 cylinders and has power. The vibration has some resonance to it like it could be coming from the exhaust. The engine shakes a tiny bit but now nearly as much on the left side as it did before I put the new mount in. It is a generic mount bought from eBay. (I have a right mount too not installed yet and maybe not necessary to install) Anyone know what this vibration is? (I should mention too with the new hard-to-reach bolt on the airbox resonator it now comes off easy with removable nut and bolt it makes it easier to change the air filter since once the bolt is out the airbox resonator at the air box moves more to remove the rubber connectors)

If the repaired wiring harness to the spark plug coil is causing the vibration by misfire/timing (can't imagine how except the resistance might be changed in the wire with solder) I might want to look for another harness. I believe though this is unlikely. A current mystery. The center mount was changed recently.

Update (same day as I posted this) I read somewhere to try to put some pressure underneath the engine with a jack just enough to perhaps raise 1/4" and then see what vibrates. Well I did that and the vibration went away. I'm guessing this may be the right engine mount whose side I put a bit of pressure.

Update 11 8 20: Next day - That's what it was. The right engine mount came out in 2 pieces. Replaced with an eBay new generic mount I had laying around. No more vibration

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