Timing Belt off?

[buder]

My timing belt is off by about half a tooth I think, car idles fine and cruises, but I am having a problem with knock at WOT. From what I have read some people actually retard the exhaust cam by 1 tooth on purpose and this does not cause any issues, does it look like my exhaust cam is retarded? Or is something else going on here and I need to redo my timing belt? Here are some pictures, with the bottom mark aligned, cams off, and with the cams aligned, and bottom mark off. Thanks for any help.

 

[TheBoz]

I would redo the timing belt if it was my car. Also when I do my timing belt, I always spin the motor through a few cycles to make sur that the timing marks all line up again before I put all the covers and belts back on.

 

[brian9397gsx]

your timing on your cams looks fine, dont know about on your crank seeing as though you need to remove the crank pully to check that. your can not be half a tooth off seeing as though your gears do not have half teeth.

 

[->PrOjEcTGS<-]

Well... There are a number of possible scenarios here...

The best thing for you to do is to pull off the crank pulley and timing belt cover and verify that the crank is actually at TDC by using the actual timing marks on block and the trigger plate.

This is because the crank pulley (Harmonic Balancer) could be separating and have rotated causing the pulley to read TDC at a different point than what is acually TDC.

Also, the timing belt cover is plastic and could possibly not be as accurate as we would like them to be thus when you are actually at TDC you may or may not be actually lined up to TDC on the cover.

Then again you could just be off a tooth at the crank.

Do this, take a ruler with your cam gear marks lined up and place it across the marks on both sides of each cam gear. If your cams are off by any number of teeth you will either be high or low in the center of the ruler because the gears are lining up at a different point. If all 4 cam marks line up perfect with a ruler then your cams are lined up to each other and your problem either lies with an inaccurate crank pulley or your timing belt is a tooth off at the crank.

You can not be half a tooth off seeing as though your gears do not have half teeth.

While this is true... Think about it this way. The crank gear has 1/2 as many teeth on it than the cam gears do that means for every 2 revolutions of the crank shaft your cams turn 1 time.

That's why if the crank is off 1 tooth it would only look like 1/2 tooth at the cams.

 

[brian9397gsx]

that is very true but like i said hard to say with out removing the crank pulley and checking. going off the plastic cover and stock crank pulley is not the way to go.

 

[Rob10_99]

I would rotate the crank until it lines up again, with full tension on the belt check where things line up again.

 

[jrohner]

It looks good to me. Use a straight edge across the gears though, don't just eyeball that the 2 are lined up together.

 

[ArticNemesis]

It looks good to me. Use a straight edge across the gears though, don't just eyeball that the 2 are lined up together.

He was showing that when the cam gears are lined up, the mark on the crank pulley looks to be one tooth off from TDC.

Pull the crank pulley to verify on the crank sprocket/trigger plate.

 

[DSM1G90]

When I did my belt, I began with the off-set notch setup on the cam sprockets when completed, but found out that my adjuster was out and redid the adjuster. That got everything up to line.

I did my alignment with the pulley not installed on the crank and using the spots on all of the three sprockets themselves to their respective marks on the block.

 

[Awdboost]

It's hard to tell on camera. It looks off a tooth on the crank.. Make sure the marks line up.. NOT the teeth on the cam gear. Turn the motor over a few times and line up the marks. See if they line up again.

 

[buder]

Well i removed my crank pulley today and everything is lining up correctly, so i guess my pulley and/or cover are just off a little from where they should be. Thanks for all the input.