How do I know when it's time to replace a timing belt on my 2003 Sorento? A local mechanic said it idles rough because the teeth are breaking off on the belt. How would he know that by just replacing spark plugs?

hi carlos.
not sure if this link will help you out but have a look.
How to replace the timing belt on 2003 kia sorento Google Search

replaced crank and cam sensor [Archive] - Sorento Nation - KIA ...

www.sorentonation.com/forum/archive/index.php/t-913.html

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replaced crank and cam sensors put back together cranked up very rough idle some tapping any ... 12-17-2012, 12:24 AM ... It's a 2006 3.5 Kia Sorrento. ... I found theproblem the SUV has a aftermarket alarm and remote start system I tripped ...

Kia Rio Crankshaft Position Sensor Replacement - YouTube

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https://www.youtube.com/watch?v=hihQxMWuSFY
Mar 21, 2014 - Uploaded by Jason Roush
While looking for how to replace a Kia Rio crankshaft positionsensor, ... is on and i have a P0340 code, think this is theproblem? kia rio 2002.

Kia Sorrento/Sedona: 3.5 Litre Engine/Timing Belt/Crank ...

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https://www.youtube.com/watch?v=CjaD_zYPrUA
Mar 29, 2014 - Uploaded by JamieJones TheCarMan
Repair and/or Replacement tips for timing belt, crank sensor,cam sensor, water pump and drivebelt ...

Crankshaft position sensor - 2003 Kia Sorento - RepairPal

repairpal.com > Questions > Kia > Sorento > 2003 Kia Sorento

I want you to go to this url, it's the official KIA forum dealing with older Sorentos.https://www.kia-forums.com/2003-2010-sorento-forum/53820-sorento-crank-bolt.html It's free to create a login.
It details the need to replace the crank pulley bolt with a new one supplied by KIA. This bolt, if reused, can break causing a catastrophic engine failure. Do not buy any other bolt., it's not worth trying to save a few pennies.I have a 2005 Sorento and had my local KIA dealer do this job and other work as long as the front cover is off, replace the water pump, the timing belt idlers and tensioner assembly. It's cheaper to d all that at one time than to go back and have to redo the cover removal. Hope this helps.

Take it back. Sounds like the timing belt is off by 1-2 teeth

The timing belt's going to have to come back off. These are somewhat difficult to install because of the space. The technique that your mechanic may need to apply is to counter spin. As he installs the belt over the pulleys and sprockets, the last sprocket (should be a cam sprocket) should be rotated 2 teeth in the OPPOSITE direction of the movement of belt when tension is applied. This will cause the timing marks to fall right into place, but it takes a few tries and some patience. Good luck.

when i was working at an AUDI dealer, they way MYSELF did it was to use whiteout and make dots on the teeth of the belt and the gears before you pull the old one off. then transfer the marks by counting the teeth to know which marks go where and install new belt. if nothing has moved you should be fine. I dont think the sorento has an "interference" head, meaning if you mess up the marks by a tooth or so, you wont do any real engine damage. for future reference i suggest my whiteout technique!!

Here is a diagram for your belts the power steering belt is the one that broke the tensioner will need to be loosened to install a new belt. depending on your mechanical ability you should be able to handle this job. hope this helps

take the head off bent valves thats for sure

timing belt may have jumped a couple of teeth.bring #1 cyl. to tdc and check timing marks on crank and camshaft gears.perform a cylinder leak down test with the radiator cap off to see if the head gasket is blown into a water passage.

sounds like the timming belt is one or two teeth out, check it again.. more than two or three teeth out and you will bend valves