2009 vibe misfire code tip
Posted: Sat Jul 13, 2013 6:54 am
I had frequent misfire codes (check engine light on). Mechanic originally changed two coil packs and Autolite spark plugs. Engine light soon came back. Took the car to the toyota dealer for a real factory trained troubleshooting. Mechanic said I had a strange problem and suggested replacing the Autolite plugs with OEM Denso ones. To save a few bucks I changed the plugs out myself. Started the car and the battery warning light came on along with the check engine light. Engine was running fine with no misfire. I put a voltage meter on the battery terminals to discover the alternator wasn't charging as my meter only displayed battery voltage.
Now I'm thinking my original misfires were caused by sporadic low voltage!?
Here's why.
My 1.8 liter has a disengagement or clutch pulley on the alternator. Mine completely stopped functioning the pulley was essentially free wheeling and not turning the alternator.
I'm thinking this pulley failed sporatically, maybe not all at once.
Hence my theory of low voltage tripping the check engine light. However note I only saw the battery warning light once.
But seems coincidental to me to have two problems (coil packs gone bad) and non charging alternator.
Either way be advised your alternator has a disengagement pulley. To troubleshoot spin the pulley by hand while looking inside the alternator. You can see and feel the internal parts moving inside the alternator. Fortunately for me my local auto parts store wasn't able to check my alternator because it had a "clutch pulley". This got me thinking about it freewheeling. I bought a $50 disengagement pulley on amazon and this has so far (day 1) fixed my problems.
Hope this helps others out. Thought I'd repay the favor as while troubleshooting I read many blogs of this forum!
Now I'm thinking my original misfires were caused by sporadic low voltage!?
Here's why.
My 1.8 liter has a disengagement or clutch pulley on the alternator. Mine completely stopped functioning the pulley was essentially free wheeling and not turning the alternator.
I'm thinking this pulley failed sporatically, maybe not all at once.
Hence my theory of low voltage tripping the check engine light. However note I only saw the battery warning light once.
But seems coincidental to me to have two problems (coil packs gone bad) and non charging alternator.
Either way be advised your alternator has a disengagement pulley. To troubleshoot spin the pulley by hand while looking inside the alternator. You can see and feel the internal parts moving inside the alternator. Fortunately for me my local auto parts store wasn't able to check my alternator because it had a "clutch pulley". This got me thinking about it freewheeling. I bought a $50 disengagement pulley on amazon and this has so far (day 1) fixed my problems.
Hope this helps others out. Thought I'd repay the favor as while troubleshooting I read many blogs of this forum!