Well folks, I admit my failure in what I thought was the low oil pressure signature coming from Mike Holhuts 1996 “Phantom Menace”.
On Saturday Mike and I with our photographer Gary Smith tore into his V8 SHO motor, now this was his Front intake cam and the same cam that drives the water pump. At first when we removed the valve cover we tried to move the sprocket to no avail, so of course I started to grin figuring once again “ HA “ but I said ah what the hell lets really look over this camshaft good maybe its not the Exhaust cam like our “trustworthy” discounted Ford shop thought it was. So we began to look at this setup pretty closely and if it was not a bad sprocket – Well quite frankly I did not want to be the one who throws the Engine so far out of whack. I had noticed the there is a cam slave chain tensioner that is held on by two bolts, by removing this you wont throw the engine out of time; and that’s exactly what we did. Now were seeing some movement front to back and wiggling it from left to right and it’s the front intake cam.
Well Mike said it has to be fixed anyways so we removed it, Mike cleaned it up pretty well and cleaned what we thought was all of the oil out from the splines. Now the sprocket can wiggle ¼” down the shaft, and 1/8th side to side. Not a very good site to see! Like I stated last night the most disturbing part is that we all think the teeth are being removed from the sprocket. That is entirely false, the only reason we thought that so far is because all the cams that we have seen have been spun and Mike s has not. The problem here is that the sprocket IS harder that the shaft and the teeth are removing metal from the shaft slowly working back and fourth until there is no more material left on the shaft so it breaks free and digs up the shaft as we have seen with the other camshafts.
Procedure for testing your sprockets:
1. remove vanity cover
2. unbolt IMRC and slide it out of the way
3. remove 8 – 10mm bolts and unplug your coils
4. remove the coils
5. remove valve cover
6. visual inspection might be all you need here, if visible
7. find the inner chain, there will be a tentioner between the Intake and exhaust cams, remove the 2-10mm bolts holding it down to the block, squeeze it together (spring loaded) and remove.
8. wiggle the sprocket if you can
Rear bank :
1. remove surge tank as like you were doing your plugs
2. follow steps 3 through 8
Other side notes:
The cam bearing surfaces on the cam and holders were marked up pretty badly.
The cam lobes shown discoloration
The valve shims were worn more in the center of the cam than the outsides.
The first bearing cap (Sprocket side) would not sit flush; it would rock back and fourth. About .30-.40 thousandths
The amount of oil still in the upper end was amazing, after flushing out the splines oil continued to come out.
I am sending the pics directly to Tim so it doesn’t bog down people with a slow connection.
The cam I had in my possession for a while confirmed, and I reported some weeks ago, that the teeth were not breaking off, or wearing much on bad cams. On the one I had, you could slide the sprocket onto a good part of the shaft, and it would have almost zero clearance. This would indicate SOME wear on the teeth of the inner portion of the sprocket, but not much. This cam had spun the shaft so bad that there was maybe 1/8" material gone from the outer portion of the surface where the shaft had spun.
And, the bearing surfaces on the cam shaft are smaller than the shaft itself, as reported earlier, since they have to machine the surfaces on the shaft surface, it can't be any other way the way the thing is put together.
Good detective work, it confirms what we knew was happening by prior inspections/information.