mlite

Your opinion please!

I have a MY97 Impreza Turbo, would like to change the Timing Belt, but somehow I'm having a disagreement with a local shop.

I'm basing the timing belt change procedure with the Haynes Manual for 1990-1998 Subaru Legacy.

It says that when all timing marks are aligned, either Piston1 or Piston2 can be at TDC, and you need a compression tester to determine which of the piston is at TDC.

1. Does this apply to the Impreza 2.0 Turbo engine?

2. What would happen if Piston2 is at TDC?

(the shop owner just put off the manual, and said it's for a legacy, and all engines at timing marks would be at piston1 TDC. i was disapointed with his response, but i have to say i don't have much choice in shops. Yes, if ever, my car would be it's first impreza to work on.)

Thanks

ustolemyname??stevieturbo

iTrader: (1)

There are markings already on all pulleys, for a belt change. You do not change the belt at TDC, although there are arrows to indicate TDC on the pulleys.
You change the belt when all the pistons are level, and there are small notches on the pulleys that will align when in this position, with the arrow on the crank pulley being at 90deg to this.
If you buy a gates belt, it will show the markings on the box, for changing the belt.

Andy.F

Agree with Stevie re the 90 degrees from TDC. This is also the 'safe' area to turn cams without hitting pistons with valves
The belts also have lines drawn on them to coincide with the timing marks on the 5 wheels to make it easy for you

PS Being a 'boxer' engine No1 & No2 pistons are at TDC at the same time (not 1 & 4 as I found marked on a flywheel on an engine I recently timed in )

Andy

mlite

So if i understand correctly, as long as the 'timing marks' on the pulleys and cams align with that on the engine, everything will be set, it is not necessary to use a compression gauge to determine if piston1 is at TDC...

Quoting Haynes Manual, page 2A-4, section 3(Top Dead Center(TDC) for number one piston-locating)
"Note: Because either cylinders 1 or 2 could be at the TDC position when the timing marks are aligned, it is important not to mistake the wrong cylinder at the TDC position; make sure compression is apparent at the number one cylinder as the crankshat is rotated and the notch on the pulley is nearing the timing scale."

ustolemyname??stevieturbo

iTrader: (1)

If all the timing marks are aligned, then it is correct.

Andy.F

What are they on about ? The cams positions dictate which piston is on the compression stroke. If the cam timing marks are aligned then you will automatically be on No1 compression stroke, no need to check this.

Yes you will feel compression on No1 before removing the old belt....but the notch (in the front pulley) will be well away from the timing scale on the plastic cover.

If in doubt, mark all your pulleys with marker pen and ensure they are in exactly the same position when refitting. The left hand pulleys usually spin round as you remove the belt, it's handy to have someone hold them in the correct position whilst fiting the new belt.

Andy