Timing Issue Topic is solved

jmana · Post by **jmana** » 17 Mar 2017, 20:54

I am having a heck of a time with my timing belt and exhaust VVT replacement. I thought I did everything right, had the cams locked, everything was lined up perfect, started it and it ran bad. Had very little power and the engine was sputtering. Shut it off, checked the codes and the exhaust cam position sensor was flagged. Ok, took everything apart again and the intake cam was off a tooth or 2. Lined it all back up again, wouldn't start. Checked codes and both intake and exhaust cam positions flagged. Looked at the crankshaft and it's too far forward by about 2 teeth. Belt off, lined up perfect, rotate engine and still the crankshaft is off. What the heck am I doing wrong??

Post by **cuhfs** » 18 Mar 2017, 11:07

It can be tricky to spring load the VVT gear while doing the timing belt. When I did that job on my C70 I needed a helper for an extra set of hands. Probably need a helper to hold gear while it is spring-loaded clockwise. Could that be the issue? Just a thought. The C70 only had 1 VVT (exhaust side) but if your has an intake VVT to that may have been spring loaded too (unsure)

Also, Assuming everything was marked when you removed the gear and put back together properly, sounds like you need to realign the crank again, attach the tool on back of cams to properly position and reinstall belt.

As you know... be sure to rotate the engine by hand at least 2 full revolutions past the marks to be 100% sure engine is "in time" so as to not damage.

jmana · Post by **jmana** » 18 Mar 2017, 15:09

I figured it out. My VVT's don't seem to be spring loaded, or if they are the springs aren't working very well! But that wasn't the issue, what was going on is that there will always be some slack in the belt between the intake cam and the crank shaft. No matter how tight I thought it was, when I would rotate the engine the crank would always be ahead by a couple teeth. To solve this I got the cams positioned properly with the belt on, then took 2 clamps and clamped the belt to the pulleys so they wouldn't move. Then I removed the belt off the water pump, which put the slack in the belt as the belt comes off the crank enough to slip. Then I moved the crank backwards a couple teeth, so when I put the belt back on the water pump and took up the slack by rotating the engine, the crank would line up with the cams. Worked perfect and it runs smooth as silk now

Post by **cuhfs** » 18 Mar 2017, 15:34

Nice job! Thanks for the update. I have heard that some vvt are spring loaded and some not.
Glad it worked out for you.