[Jason22045]

Hey guys so i ran in a issue where my cam gear rotates but the plate infront doesn't after i manually spin the crank. I torqued down the cam bolts down to 15 foot pounds and also did the 180° turn and the cam plate on exhuast side is not following the cam gear. Any clue what I could have done wrong?

[Jason22045]

Here is a link to a video I took of it. The car is a 2007 bmw 328i n52 engine
Thank you for your time and help
https://youtube.com/shorts/i345W163h...LdxPYfLdPvK1qX

[BRG_N54]

It looks like it is getting hung up on the position sensor. Are you sure that is the correct sensor in there? Secondly, proper engine timing is critical! There is a jig that has to be installed to get everything lined up correctly, prior to tightening those cam bolts.



Thirdly, those bolts are torque to yield and should be replaced if they are loosened, for fear of breaking them off in the cam when you torque properly. If that timing wheel can move freely like that, they are definitely not torqued correctly.

[Jason22045]

Hey thank you for your reply!
I belive it does has the right sensor is in there and that plate in the front doesn't move at all even if I were to try and move it my hand. It stops moving after a while of rotating the engine by hand. Ans then moves again. Do you think the cam gear could be faulty?

[BRG_N54]

I do not know what may be wrong, however, that front plate should not move freely, it should always turn with the gear.

My primary concern is that the bolt is not fastened like you think it is. The bolt goes through the timing plate and then through the gear and then threads into the cam. When tightened properly, the clamping force is what holds those items together and keeps them all in sync. For that plate to move, as in the video, it means the clamping force is not sufficient to hold it to the rest of the camshaft assembly.

You failed to mention if you replaced those bolts with new ones. I could imagine a scenario where the old bolt was re-used and has snapped in two inside the camshaft, which would release the clamping force, even though it may appear to be assembled correctly.

It would also help to verify that the timing wheel is not actually contacting the position sensor, it may be installed incorrectly and causing interference with the timing wheel. The two should get close, but not touch on either side. The more information you can provide, the better we can assist in diagnosing your issue.

[Jason22045]

I did buy new bolts and I used them once but i had to take them out a second time. Do you believe that could cause an issue?

[BRG_N54]

Originally Posted by Jason22045

I did buy new bolts and I used them once but i had to take them out a second time. Do you believe that could cause an issue?

Again, I would verify the clearance between the timing wheel and the position sensor first. Even if torqued down properly, physical blockage might cause the timing wheel to get out of alignment and move independent of the gear.

If that checks out ok, I might suggest getting some new bolts on hand and removing, at least the exhaust side, to verify all is well there. I distinctly remember fearing the worst when I did that 180 degree final torque on mine.

I would also re-time everything, just to be certain on first start up that you will not hear any metallic clanging noises. I believe these are interference engines and could cause malice in the combustion palace.

[Jason22045]

Okay I'll try this out. Thank you but let's say the sensor does clear, timed correctly, and the new bolt is in and torqued and also the one 180 degree but it's still doing it. What do you think it could be then?

[BRG_N54]

Originally Posted by Jason22045

What do you think it could be then?

Hard to say without being present, however..... I just watched the video a few more times and I am not so alarmed any longer. If you watch when the timing wheel stops, the bolt also stops and the cam looks like it stops. This means that they are all in sync and clamped together properly. What you may be witnessing is the actuation of the VANOS timing changes, in the gear itself. I should have paid closer attention to the bolt and the cam in the video.

In other words, it may be completely normal to see this without oil pressure in the system. I am not an expert, and again, it's hard to tell from a 10 second video.