I got a chance to start tearing into it today. I found the marks on the cam sprockets and was able to line them up with two notches on the inner lip of the plastic timing cam cover that bolts to the top of the engine. They basically line straight up (in relation to the engine's slight rearward tip). Assuming this is correct, I rotated the engine several times watching the cam marks. I used a screwdriver to determine piston #1 TDC. Every time the cam marks came to the top the screwdriver indicated the piston to be near bottom. My next question is where are the crank pulley marks and what are they supposed to line up with on the engine. My 850 manual isn't much help here so thanks for all the help!

I ordered the OEM belt kit from IPD which includes the manual tensioner & idler pulley for my engine. I also paid for the three day shipping which meant it should have arrived today despite the holiday yesterday. Guess what, it didn't! :(

JR

With having the belt already off, or slipped, I think the procedure might have to be modified a bit. Klaus has way more experience than I do, so I'll toss out some concerns and perhaps Klaus can help out or tell me I'm off base!

If the belt is on, but slipped to the point you got an engine code, but the engine still ran, then this is the best situation, and we know there was no engine damage.

If the belt came off entirely, then I believe you'll have to attach it to get the cams and crank back into alignment. DO NOT START THE CAR. This will all need to be done by hand since it is an interference engine. At this point you will need to ask yourself a very difficult question: Did damage occur to the engine when the belt slipped? If there was damage, then replacing the belt won't help. I do not know enough to help you determine if the engine was damaged. Perhaps Klaus can?

1) Rotate the crank clockwise until the exhaust timing mark is in alignment, then rotate 90 degrees further, then come back to get the exhaust cam into alignment. Since the exhaust cam has the VVT I would think this is the more important of the settings and should be done 1st.

2) If the intake cam is not aligned when the exhaust is after step 1, disconnect the belt at this point and move the intake cam by hand to get the intake aligned. It does not have VVT and is less sensitive. Generally I recommend counting the number of teeth in the belt between alignment marks on the cams, so you set the new one back the same. However, since there was slippage, the initial amount of teeth between may not be correct now, but if the belt feels firm between the cams, then this might be a good number.

3) Obviously the crank will also need to be aligned by hand at this point. Its alignment mark is VERY DIFFICULT TO SEE, and you might need to pull the number 1 spark plug and watch the piston to find TDC. On a different engine, I put a small rod through the plug hole and attached a dial indictor to it to find the exact TDC. However, if you can get it close, you’ll at least be able to concentrate on finding the mark on the crank gear to get perfect alignment. Once you do find alignment, I recommend using a grease pencil or similar to mark the gear to verify it does not move during belt installation.

Hopefully now all is set to put on the new belt and as Klaus mentioned the NEW tensioner. Check the idler pulley for wear, and replace if needed. I think the common wisdom on this is to do it every other belt replacement.

Hope this helps,
Jerry
01 V70 T5a