Corolla Cam and Crank Shaft Timing Marks

[SlyckTom]

Good morning everyone. I am new to this forum after lurking for a few months. Finally registered and hope to participate in the vast knowledge contained here!

I'm a DIY mechanic, as I have virtually no trust for shop mechanics (other than a good machine shop near me) and feel I can do a better job on my own.

That said, a few weeks back I decided to change the timing belt on my 1993 Corotlla DX, 203,000 miles, 4 speed auto. I've changed timing belts before, so this wasn't such a big deal. When I was finished, the engine vibrated extensively which had me very concerned. However I had foolishly powerwashed the engine prior to starting it, and I suspect moisture had caused this. After a few days the vibration dissipated, and is very slight now. I have not owned the car very long, so I simply can't remember whether there was a slight vibration prior to the job. From what I read here, this is normal so I've learned to live with it.

Never-the-less, my impetuous nature got the better of me, and I decided to pull the valve cover off to see if the cam timing marks lined up properly when the crank was at 0 (zero) degrees. I took two pictures for better illustration:

From the side:




From the top:



As you can tell from the side picture, the cam mark is virtually dead on. However, it appears a bit left of center. It is not so obvious from the top view


If I move the crank shaft so the cam timing mark is more center (which is a literally a millimeter of movement towards the right), the crank advances a few degrees from zero.

In any case, my big concern and question is whether the pics fall within the realm of acceptability? Could I be undermining the integrity of the engine? I was sure that it was lined up when I did the job...but at tight angles its kinda tough to see straight on. Any thoughts on this issue are welcome!

[Flashmn]

Looks ok to me.

[SlyckTom]

Thank you for getting back to me. I also suspect its ok. Any other thoughts from the group?

[tashirosgt]

If you feel vibration when the engine idles but no loss of power in the engine when driving then bad motor mounts are one suspect on a car with that many miles. The rear mount seems to go bad first.

Did you do timing after changing the belt?

[SlyckTom]

Yep...I'm very particular when it comes to my ignition timing - its set exactly to 10 degrees BTDC. I've also pried and tugged on every engine mounts and they all appear ok. From what I've read from people with similar vibrations, changine the mounts solves nothing...so I'll save that expense.

I'm not really concerned with the engine vibration; I've accepted that it's normal...I was more concerned whether a slight timing deviation from dead center was a problem.