6G Celicas Forums

driving home from work, im 4 blocks from house when i get to a stop sign. when i go again my motor stops and when i try to start it up only the starter is heard which brings me to conclusion that when i open the hood the timing belt snapped. i read that the 5a-fe are non- interference motors and after the belt snaps it kills the motor to prevent damage to the internals. is this true and of course i will check the inside... im just looking for relevance and good hopes!!

This post has been edited by pnoywitmustrdsauce: Jul 5, 2012 - 12:58 PM

they are not interference motors. What brand of belt did you use?

The 5SFE is NON-Interference. Meaning yes, when the timing belt snaps the engine is disabled to prevent damage.

My timing belt snapped on me while driving down the highway - all of a sudden the engine stopped and I coasted to a safe place.

The timing belt on the car was the original - I had just bought the car at the time and the KM's were at 224, 000, on the ORIGINAL timing belt. So yeah they should last you awhile if they're done right and the car is maintained.

Yeah the 5SFE is a Non-Interference meaning that the pistons and valves cannot hit each other and damage the engine.
A new timing belt is maybe $40, and it is something you can change yourself. The Passenger side engine mount must be removed(you will need a jack under the engine for this), the serpentine belts must be removed, the upper timing belt cover and finally the crankshaft pulley and lower timing belt cover. It will take 1-6 hours depending on your skill.

thanks for the reply, needed the positive news

toyota... cost $56

What else did you change with the belt?

Just becareful if you are replacing it your self, a timing belt is sensitive to tightness, it is not like the other belts, if you have a service manual pay close attention to the belt tightening or torque. over tightening one of these will cause it to snap in a very short time.

Both of the USDM engines have an automatic tensioner. Really just a spring that tensions the pulley till you torque the bolt down

Ya it's automatic, it's perfect everytime don't worry, what could go wrong?

Well for me I've had the timing belt off my 5sfe so many times that Im sure I could change it in under an hour. So yes I have little fear as once again its a non-interference motor. I just had to change the timing belt (the leaking water pump was behind it) on my friend's V6 mazda and that took a whole friday evening and saturday. Plus if it breaks that KLZE engine will be ruined so yes on something like that I would worry about whether the automatic tensioner was torqued right or someone would be buying a new engine. But the OP has absolutely no need to worry if he screws something up and the new belt snaps. The belt will be under warranty, he has sourced the proper/improper tools before and no engine/vehicle damage occured in the process. Need I elaborate more on why pnoywitmustrdsau... should be able to do this by themself.

This post has been edited by Special_Edy: Jul 6, 2012 - 6:59 PM

Oh and definately think about changing the crankshaft seal, waterpump, motor mount and serpentine belts while you have the timing belt off. If you change the belt yourself or get a buddy to do it then you probably dont need to worry about anything other than just purchasing a new timing belt.
If however you are paying someone to do the labor on this repair you need to invest in a waterpump and crankshaft seal for sure. They are cheap and easy to install once the timing belt has been removed and you may save yourself having to pay someone later on to remove the timing belt AGAIN just to change a leaky water pump.

I concur Doctor!
Of course while your in there you could always replace the under hood assembly just to be sure!

update: brand new timing belt installed...nothing damage thank god!!! but now my acceleration feels sluggish around 4000 rpm and i get a little back fire shifting from gear to gear out coming out of gear!?? any thoughts...imma time it soon to see if its off, aside from that she feels good driving her again...

This post has been edited by pnoywitmustrdsauce: Jul 7, 2012 - 6:20 PM

Sounds like one of the cams might be off by a tooth.

everything else pretty much has been changed... the oldest was the timing belt which was just a little under two years... motor mounts less than 2 months ago and the waterpump less than 6 months ago... thans for the heads up!!




how i made sure the crank was tdc and the cams were 0 degrees!!!???

Spin the crank around again and recheck that they are still at 0.
Lining them up once is not enough. There can be slack in the belt that will cause them to look ok when first installed but be totally off after a few revolutions. I had to redo the belt on my 3sgte at least 4 times before I got everything lined up correctly. Your 5s will be easier but you should still check it again.

thanks lagos... will check again is it ok to run like it is right now tho? i'll have time tomorrow to recheck it again!

Remove the upper timing cover and keep the lower one in place.
Use a mirror (they have them for $2 at AutoZone) and look into the hole in the side of Cam Sprocket. It should be lined up with a small mark on the cam bearing behind it. The notch is directly at the top of the bearing surface but because the engine is raked its maybe 25 degrees off vertical.
Now look at the crankshaft pulley, it should be at 0 degrees TDC.

doublecheck if your belt snapped or jumped but you can also check if your timing belt snapped by the dizzy rotor not moving