Checking the Alignment of Timing Marks

A "How-to" Guide by Stephen C. Kempf

NOTE:  Instructions given are for a 1993 Stealth ES with a manual transmission. Methods should be similar for other Stealth and 3000GT DOHC models, but may require the removal of additional items, particularly on turbocharged models.  If you have an automatic transmission car, you will have to move the timing marks into position by turning the engine at the crankshaft with a wrench on the bolt/nut head at the end of the crankshaft.

10 mm wrench (a 1/4" drive socket wrench with a 6" extender and 10mm socket works best).

Flashlight.

PROCEDURE:

( Important NOTE:  Before you begin, move your car to a flat (level) region of pavement where you will be able to push/pull the car forward a few feet. )

1.  Remove the two 10 mm bolts that secure the front cylinder bank timing belt cover.

2.  Lift the timing cover off the engine.  When you lift the front bank timing belt cover, be careful not to lose the metal sleeves that are present in the bolt holes of the plastic cover.  If the plastic has cracked anywhere around the metal sleeve, they may fall out.  Also, take care not to lose the dust seal on the bottom rim of the cover where it contacts the valve covers.  This seal may stick to the valve covers and break as you remove the timing belt cover.  If it does break, it should be replaced.

3.  Disconnect the spark plug ignition wires from the coils!!!!!!!

      (I repeat...)

Disconnect the spark plug ignition wires from the coils!!!!!!!

4.  Check and see if you can see the timing marks on the backs (side nearest the valve covers) of the cam gears on the front bank of cylinders.  If you can, make sure they are the right marks for the two pointers on the valve cover (see the figure below).  If they are, proceed to step 5.  If not, have someone get in the car and briefly engage the starter by turning the ignition key.  This will have to be done repeatedly until the correct marks can be seen on the backs of the cam gears.

5.  Turn off the ignition key, put your car in 4th or 5th gear, and release the emergency brake.  Pull/push the car forward until the exhaust cam gear timing mark on the front bank of cylinders is aligned with the "triangular" pointer as shown in the figure above.  If your cam gear mark is close to alignment when you start, this won't take much forward movement of the car.  Do NOT push the car backward to do this, because rotating the engine opposite the direction it normally turns can compress the timing belt tensioner and throw off the crankshaft timing mark alignment.

We're getting close now...!

6.  Next remove the three 10 mm bolts that secure the rear bank timing belt cover.  When you lift the rear bank timing belt cover be careful not to lose the metal sleeves that are present in the bolt holes of the plastic cover.  If the plastic has cracked anywhere around the metal sleeve, they may fall out.  Also, take care not to loose the dust seal on the bottom rim of the cover where it contacts the valve covers.  This seal may stick to the valve covers and brake as you remove the timing belt cover.  If it does, it should be replaced.

You will not be able to actually completely remove this timing belt cover because of other cables that are in the way;  however, you can lift it up and slightly cock it to one side so you can see the backs of the cam gears on the rear cylinder bank.

7.  If everything is correct, the cam gear timing marks on both the front and rear banks of cylinders will be exactly aligned with their pointers as shown in the figure above and the crankshaft timing mark on the crankshaft pulley will be exactly aligned with the letter "T" (for top dead center) on the timing advance plate next to the crankshaft pulley.  The timing marks for the cam gears on the rear cylinder bank are easier to see if you use a flashlight.  I suspect that the timing marks can get a little "off the mark" with time due to stretching of an old timing belt, but they should be very close to exact alignment.  If alignment is a tooth or more off on the cam gears, things are not right.

8.  If things are off, count the number of gear teeth on the cam gears that the mark deviates from correct alignment.  Note whether it's intake or exhaust, front bank or rear bank, and whether the deviation is a rotation toward the front or back of the car when you look at the backs of the cam gears.  On the crankshaft, estimate how many degrees off from TDC it is and the direction of rotation.  If you're going to complain to the dealer that they didn't do things right when they installed the belt, take pictures of the timing mark deviations, if possible, or get a mechanic from another local shop to verify your findings.

9.  Reassemble everything once the deviations have been documented.  Take care to get the timing belt cover dust seals properly in place if they are still intact.  If they aren't intact, they should be replaced.

10.  Reconnect the spark plug wires to the coils.

Hey, that wasn't too bad, was it?