Sydwayz

iTrader: (1)

It's a magnet, $.36 (cents) of copper, maybe $1 worth of plastic and a rubber boot. I bet they cost $6; & Mercury pays $8 for them.
Then the Mercury & Dealer markups kick in.

MANY thanks John. I got your PM. Both of my Camshaft Position Sensors popped right out. I cleaned them, and re-installed. I'll be doing the resistance test on them this evening.

BUP

iTrader: (9)

Crank PS has different values (MOHMs testing) than the cam PS.

Crank PS is A to B 23.2 mohms then B to C 23.21 mohms

also engine wiring harness SPLICE 100 is sensor ground for these
and Splice 101 is sensor POWER the 5 volt reference as some of the info in the pm.

Already gave you the cam sensor testing mohms

BUP

iTrader: (9)

I will post the latest and not so great info for anyone who has a bad cam position sensor in the older 496's. The new Cam PS is the only one available and it will not work for the older 496's unless you change to the newer timing gears and chain and new timing cover and new grommet and more. Just over a stupid sensor in which the manu cost would 20 bucks at the complete max. This even holds true for the GM truck and RV side for the 8.1. How stupid and parts selling greedy is that. Talk about really jackin up and throwing a monkey wrench in the 496 for the older models.

Sydwayz

iTrader: (1)

Thanks for all of your diligent research John. I am hoping I don't have a Cam Sensor issue in the future.

Knot 4 Me

Nobody has the old ones in stock? What is considered the older model years? My 496 was manufactured 9/03. Thanks.

BUP

iTrader: (9)

Currently I am not the one who found out about this beforehand - or least would not think so. With that said in the past 2 months. A tech along with who is a marine instructor in Wisconsin and me looked into this before installing just the new cam sensor. Anyways I will know more and hopefully have a fix that is just as easy as installing another cam sensor - I say hopefully. I will be talking face to face with some engineers, ex GM and now contracted to a certain OEM marine engine manu about how and why this happened along with other solutions.

I will not be able to talk to them until this Sept when I run into these people. I will have a solution either from them or on my own.. Just saying and believe it or not I am heavily involved deeper in the marine end than a lot of people think or would ever think, as I am 90 % I will come up with a solution in due time. Heck I own a 496 as well plus still work on about 30 to 40 a year from Volvo and Merc..

Brian thanks for the thanks and really just bringing forth the info in which I still can not believe that GM has made a sensor NLA on a 8/9 to 15 year old engine. I will post all the important info tonite about it. Do not forget a bad cam PS can cause your boat not to start among running condition problems if it does start and run.

BUP

iTrader: (9)

03 you as of current are chit out of luck for just replacing the new senor (cam). It goes by engine serial # along with GM block codes I have all the info as I have looked into this very hard and detailed. I will post it tonight. I had GM large dealership look for back dated sensors and aftermarket so far nothing comes up on their end nor mine. Checked with wells and walker no dice.

BUP

iTrader: (9)

All Marine engines go off of engine serial # for motor side and if its transom or outdrive stuff then they go off of that serial # for repairs, service manuals, and parts that are installed.

The 496 cam sensor has been changed completely and not to go into a long story about that alone so here is the jist.

496 MAG engine serial # 0M025000 thru 0M672040 the new cam sensor is not a plug and play. Engine serial # 0M672041 and UP it will work.

496 HO engine serial # 0M025000 thru 0M667237 the new cam sensor is not a plug and play. Engine serial # 0M667238 and UP it will work.

496 ENGINE BLOCK CODES GM and of course these are where Merc and the rest of the marine engine manufacturers bought from so again the new cam sensor will NOT just plug and play. The GM block codes are 1XA, 1XW, 2XA, 2XW, 3XA, and 3XW the cam sensor will NOT just plug and play.

ALL GM BLOCK CODES 4XA and 4XW and anything that could be possible up from these block codes will have a plug and play with the new cam sensor.

The old cam sensor is not available anymore and I have not found an aftermarket one either. Yes aftermarket has the cam sensor but its the new style.

If you have engine serial # listed and or GM block codes listed that will not work for the new cam sensor here is the deal to make it work. You have to change the pigtail harness to the new cam sensor for correct connection. You have to change the cam timing gear that has the newer reluctor so that cam sensor has the correct tolerances to read properly, you have to change to the new timing cover, and a new timing cover gasket, you have to use a new timing cover crankshaft oil seal, Of course you have to take the whole front off on the 496 to get to this stuff. Also many boat apps the motor might have to pulled out because of very poor access to get to anything. What a huge expense just for a freaking cam sensor.

IMO it might be wise if you have to do the cam sensor change and parts install, that you might want to buy the complete timing gear set and chain.. It is a double roller set but IMO again if your boat is older and you are in there you have to change the cam timing gear anyways so for another 150 maybe change the chain and crank gear out. Cost in parts if you bought retail thru merc depending on which way you go can cost 500 to 850 without labor and if the engine has to come out then we all know what a PITA and expense that will be.

More info later.

BUP

iTrader: (9)

If anyone has an old cam sensor NLA either new sitting around for years or used or bad from their 496 could you please send it to me if you want to.

Brain can you post pics of your cam sensors I know you told me you bought a new one in 2012 and new one just lately. Thank you.

Sydwayz

iTrader: (1)

The one I bought in 2012 and the one I bought last month are both the new style, tan in color.
Mercury Part Number: 892615002 Mercury Dealer Price: $115-ish
RockAuto.com Part Number: 12568983 RockAuto.com Price: $31.79
They both look like this:






This is one of the original ones out of my 2003 MY 496HOs.
Mercury Part Number: 12575182 NO LONGER AVAILABLE
[ATTACH=CONFIG]526885[/ATTACH]

Compare the insert size of the old (black) one, and the new style (tan) one. Notice that the tan one is bigger, and will interfere UNLESS you change out a BUNCH of parts that John/BUP mentioned above.

I believe I have found a NOS source for the original black ones (12575182). I will confirm this week.