Hi everybody. I'm new here. I just bought a 99 4runner v6 with 107k miles on it. The day I bought it I had the timing belt and water pump changed at the dealership in the town I bought it in, 2 hours away. The next day the belts began to scream so I took it in to a little shop in town and they said the belts were extremely loose from the timing belt installation. They also found bolts that were completely loose and about to fall out.

The same day, a few hours later, my car began to throw a multiple misfiring code and an oxygen sensor code. The more I research this the more I begin to think this could be because of a mistake during the timing belt installation. I talked to the previous owner and he claimed he hadn't had any problems like this.

Would an incorrectly installed timing belt cause misfiring? It runs fine at speed. Maybe some lack of power. When it idles it drops to 400-500 at times. Sputters and sounds like it may stall.

Could the fact that he left some bolts loose and the tensioner loose cause the belt to jump some teeth knocking the timing off?

Any input would be hugely appreciated. I'm trying to decide what my next move should be.

Thank you!

 

I'd get a letter from the shop in your town itemizing what they found and take it straight back to the dealership.
Might have been better to have had it towed back to the dealer right off.

 

Dang--that's unforgivable. How much did the stealer charge you for that butcher TB/WP job?

Which o2 code? Those would be hard to tie to a timing belt problem but it would be nice to know the exact code number.

On the misfires, my big concern would be a loose crank pulley bolt. The little magnets in the crank sprocket held on by that bolt determine when the ignition fires and a loose one can generate misfires all over the place as it slides forward and loses proximity to the Crank Position Sensor. I can also see why it would be worse at idle than at speed. That crank bolt needs to be torqued to a whopping 218 ft-lbs. and if they effed up the belts and little bolts I'd be super worried about the big critical one. If that bolt gets too loose, it can eff your crank shaft (meaning new engine time), the harmonic balancer and conceivably the radiator, fan and other stuff in the vicinity. Get this checked NOW and rule it out before you have a disaster. (You also have the concern that it WAS loose, your shop fixed it, but the key was buggered and so now ignition timing is off. I'd ask if your shop checked if crank bolt torque was to 218 ft-lbs. and what they found.)

Otherwise, if valve timing is off enough to bugger compression, that could cause misfires, too. The TB controls valve timing, not ignition timing.

Keep us posted and good luck. Makes me glad I could do my own TB.

 

The guy I bought it from works at a dealership and had the work done for me off the clock. I've talked to the mechanic who performed the work a few times and he confirmed that he correctly torqued the crank bolt. Perhaps he didn't correctly line up the timing belt. Tomorrow morning I will be making the 2 hour drive back to the dealership for them to fix their mistake. Hopefully this time it will have a better ending. Wish me luck and I'll keep yall posted.

Any suggestions that I should make him do/check?