Where is TDC on Exhaust Cam- cam gear has been removed

hauler66 · Post by **hauler66** » 05 May 2012, 16:35

I just put a new exhaust cam seal (and a new VVT exhaust cam gear) on my 2001 V40 1.9t. I don't have the special tool that locks the cams in place at the rear of the cams, but I've been able to fabricate a tab to fit in the notch and hold it while I tightened the gear to the required specification.
My concern is that the cam rotated while the cam gear was off and I rotated it back in place, where the notch in the rear of the cam is horizontal and inline with the engine, but I might have rotated it 180 degrees off. There is another small notch on the rear of the cam that lines up the cam position sensor correctly- it is angled and branches off the main notch that is used to lock the cam.

Is this small notch supposed to be above the large adjustment notch or below it when the large adjustment notch is horizontal?
This assumes that the timing marks line up on the crank pulley as well as on the intake cam gear pulley.

I have it all back together but don't feel comfortable starting the car since I don't know if the exhaust cam is at TDC or 180 degrees out. I have turned the engine over by hand forward and backward a couple times and it seems ok, but something feels unnatural when I bump the starter.

I didn't take a picture but here is a drawing that may help.

I would be very grateful if anyone familiar with this can help me out so I can get to work Monday.

hauler66 · Post by **hauler66** » 07 May 2012, 20:15

I was able to determine which way was TDC by looking at the back of the exhaust cam. The small notch was down, not up. More accurately the large notch, which is not centered along the back of the cam, sits on the low side of center not the high side. This is where you want your exhaust cam situated when all of your timing marks line up on the crank and intake cam.

Very glad I confirmed this before turning the car over. I was able to rotate the engine by hand more than 3 turns with the exhaust cam upside down but when I bumped the starter it didn't feel normal.

This issue is only relevant if you remove the VVT exhaust gear without locking the exhaust cam in place with the volvo tool.
Hope this helps someone!