Here is a real head scratcher. Before I take my head off I am setting TDC. I find the mark on the Crank Shaft and the cams line up with someone elses marks. See photos.





I cant even see the timing mark on this cam sprocket.







Heres the rub. If I put a shaft down the spark plug hole and physically turn the engine to TDC I get a different result. I checked and double checked....its TDC!.



Notice the crank notch is off to the right.



Its off one tooth for the Crank notch and the cams. How could this be?????

 

Because the marks are not at TDC they are mainly marks to set timing.

Is there a mark somewhere else on the intake cam like someone put the pulley on wrong?
It looks like the pulley has been off once already.

If you feel safer make your own marks and take the belt off and go to town.

 

looks like someone made some marks, and took the belt off and put a new one on and didnt worry about the timing marks because they made their own...

and you might not be able to line up the real marks because you need to retate it once more, or the timing was advanced.

 

Something like this happened to me. When we got the 850, it has a blown head gasket and every cooling hose leaked. So i replaced all of it and prior to, set the cams up and slid on the new belt ( when i do belts, i line up the marks thats on cams, then make my own so its easier to see) The car had been down for a while so the lifters had bled down. Go to start the car and no compression. I had the head checked and was all good so what could have it been. Was trippin real hard. Looked again and saw two other marks,about 180* out.I started sweatin real bad cause all i could think about was bent valves. Took off and re-alighned the cams. car started right up and was all good. I had checked the history as this was a customers car that he sold me, and another tech had did the belt like a year prior. He doesnt line up the marks and just marks it were he took it off, but doesnt clean off marks made. He diddnt work with us anymore so i couldnt give him s**t.

 

I had to call in the expert for the same situation, other freaking marks and crank was all off...I am struggling with no ignition coil spark, but that's another story...this guy had special order books that told him where and how the crank and cams should be at etc etc...

Maybe they changed out the intake camshaft or something like that

we ended up taking out the belt
align the cam marks
rotating the crank shaft twice using a 33mm socket with tire off
installing ipd's cam tool so they would not move
(I had to remove completely, the tension er.
put everything back together


I might have bad compression on one cylinder so I too will be doing a valve job or replacing the heads all together...

have fun...

 

Since the engine ran great how they are set now, I plan to set up the timing belt in the same way. Better safe than sorry.

 

Yes, you can make your own marks, I would highly recommend using the cam tool...if you use the tool, make your marks first, them slip in the tool. I had to fight a little to find the right spot on the cam gears.

 

I would just use the cam marks you already have and swap the belts. You know the car is running well the way it is now so just make sure everything lines up when you put the new belt on.