How to shim cam sensor?

[Tim Cucci]

Can some give me details on shimming the cam sensor such as where to shim? I know the remove and install procedure I just don't know exactly where to shim.
I have a rattle type noise that goes up and down with rpm. It actualy sounds like lifters but when I take a long screwdriver and use it like a stethascope I get a direct knocking noise from the top of the cam sensor.
This is a rebuilt engine with less than 1500 miles with the stock crank,rods,and pistons reconditioned. Stock cam,lifters,and pushrods reused. Freshened Up.

Thanks
Tim

 

[S10xGN]

Tim,

A dial indicator is nice, but feeler gauges will work too. You'll need either of the above, plus a distributor shim kit for a small-block Chevy (commonly sold through Summit or Jegs for ~ $6.00) and a NEW hardened roll-pin for the gear.

Use the indicator or feelers to measure the "slack" in the shaft (up and down movement). Drive the roll-pin out of the gear end and pull the gear off. Now add shims until your new clearance is around 0.015" or so. I add them between the stock wave washer and the gear. Recheck your clearance after driving in the NEW roll-pin. I stress NEW because I've seen them come out in pieces! Remember - if the pin fails you'll have "0" oil pressure!

HTH,

 

[bsdlinux]

Hey Tim,

I am having the same problem with my newly rebuilt engine. I also can get a knock from the oil pump area as well. I am figuring that the whole problem is shimmimg. At first I thought it was an exhaust leak, lifter , etc. But it is definitely coming from the cam sensor and the oil pump area.

S10 - Thanks for the info. Sounds pretty simple.

 

[turboaddict2]

Yup I'm having that same problem too. Sounds just like lifters tapping but it ain't. And this not on a rebuilt motor. Still stock motor and probably original cam sensor. I'm actually afraid to touch the cam sensor since I never fiddled with it.

 

[Tim Cucci]

Thanks guys, I hope this solves my problem. I can't stand this thought of having to go back into the engine. I am really concerned with the noise. I also have thought of it being exhaust leak,loose rockers,lifters, piston pin, piston slap,accesories, etc. I have been all over and under that engine with a screwdriver to my ear and the only odd noise is the cam sensor knocking. At boost it sounds like a rattle. Is that the same as you guys?
Tim

 

[bsdlinux]

How did it come out Tim? I haven't got to mine, yet. Just wondering if the shimming or a new cam sensor assembly fix you up.

 

[Tim Cucci]

Removed sensor and checked endplay with dial ind. End play was .030". I have an old distributor so I used the big washer from it to shim with which was a perfect .015". So now the total end play is .015". Reinstalled and it was loud on initial startup but as the engine got hot it quieted down some and the rattle at high rpm also quieted. But I can still here it and if I use a screwdriver to listen with it is loud as he!!. If you listen with a screwdriver at initial cold start it is terrible. Now I have reshimmed it again using one thrust washer and two of the wave springs which gives about .022" end play. The noise is still there.

Can you shim these things down to say maybe .005" with no ill effects?

I don't think a new one will be any quieter. I keep thinking it could be something else but everywhere else is smooth and quiet, stick it on the sensor and it blows your ear away. I hate to spend a $100 bucks on a new one and get the same results.
Don't know?

Tim

 

[bsdlinux]

Tim

My cam sensor also doesn't seem to be out of spec on clearance. My engine is a freash rebuild as well with about 4k on it. I have all new parts, high volume front cover, etc. I was wondering maybe if the oil pressure relief spring could cause a noise similiar to what I have. The only difference is my noise will get worse when the engine is warmed up.

Can you feel the knocking around the oil pump area as well? Maybe a cam button issue?? I know it is not the cam and lifters beacuse that noise I have finally gotten used to.

These engines are just noisy as hell. If my old small block chevy made noise anything close to this engine I would know for a fact that something was amiss.

Anyone out there at all had a similiar problem with a fix??

Later

Gary

 

[bsdlinux]

Tim Any updates??

I am still tracking down my problem. Could it be the thrust surface in the oil pump?? Only knocks below 50 PSI....when hot.