Go Back  Offshoreonly.com > Technical > General Q & A
496HO Crank Position Sensor Problems??? > 496HO Crank Position Sensor Problems???
Like Tree0Likes

496HO Crank Position Sensor Problems???

Reply

Old 03-25-2002, 01:55 PM
  #1
Rough Seas Lie Ahead
Gold Member
Thread Starter
 
Reckless32's Avatar
 
Join Date: Feb 2002
Location: Virginia Beach, VA
Posts: 2,465
Default 496HO Crank Position Sensor Problems???

Two friends with new boats (under 20 hours) with twin 496HO's have both had a crank posisiton sensor switch ( located on the aft port side of engine) fail. Symptoms are; up on plane then around 35-4000 rpm the engine dies. Initially it won''t start back up. After allowing it to cool/sit for 15 minutes or so, it fires up. One boat couldn't get onplane without it happening again. The most recent can plane, run for a minute or two then crank out.

I too have a 496HO and so far no problems during some hard running last summer. Funny thing is, back to back new boats has each had this item fail. I'm wandering if maybe Mercruiser made a bad batch of these things or if maybe there's others having the same problem and another recall is on the horizon?

Any of you guys had this or know of another who has had it???

Rick
Reckless32 is offline  
Reply With Quote
Old 03-26-2002, 12:27 AM
  #2
Rough Seas Lie Ahead
Gold Member
Thread Starter
 
Reckless32's Avatar
 
Join Date: Feb 2002
Location: Virginia Beach, VA
Posts: 2,465
Default

BTT
Reckless32 is offline  
Reply With Quote
Old 03-26-2002, 07:45 AM
  #3
Registered
 
Pure Energy's Avatar
 
Join Date: Oct 2000
Location: N. NJ, Eastern LI
My Boat: 2001 Superboat Y2K
Posts: 3,027
Default

I had this problem on my F-350 PSD. Would start and idle but as soon as I touched the pedal it would stall. It was the cam position sensor.
Pure Energy is offline  
Reply With Quote
Old 03-26-2002, 08:17 AM
  #4
Rough Seas Lie Ahead
Gold Member
Thread Starter
 
Reckless32's Avatar
 
Join Date: Feb 2002
Location: Virginia Beach, VA
Posts: 2,465
Default

Do you know if a recall was in the works or just something we should expect to happen at some point in time? I'm assuming that was a 496 right?

Rick
Reckless32 is offline  
Reply With Quote
Old 03-26-2002, 09:52 AM
  #5
mlitefan
Guest
 
Posts: n/a
Default

Rick...I think the guys I purchased my Vindicator from had that same problem on a new Vindicater they picked up for personal use. 2001 with the 496HO.
 
Reply With Quote
Old 03-26-2002, 10:26 AM
  #6
Registered
 
kr1276's Avatar
 
Join Date: May 2001
Location: Tampa,Fl
My Boat: Baja 442
Posts: 574
Default

I too am having problems with 496HO's. it started as if it was surging and prgressively got worse until I couldn't keep it running.
Then went to take it to the shop by water and it ran perfect. Only one engine is acting up. Sounds like i might have the same problem.
kr1276 is offline  
Reply With Quote
Old 03-26-2002, 11:03 AM
  #7
Registered
 
Cattitude's Avatar
 
Join Date: Jun 2001
Location: Tulsa, OK, Grand, Beaver, LOTO
My Boat: '97 Scarb Thunder, '06 Formula 330ss for sale
Posts: 1,213
Default field fix??

How difficult is it to change these on the water? That sensor likely has a GM part number- it may be worth carrying some sensors and the proper tools- beats getting towed or having an unplanned "Gilligans" Island...

Then again if you had Maryann and Ginger
Cattitude is offline  
Reply With Quote
Old 03-26-2002, 11:12 AM
  #8
pimpthis.com
Charter Member
 
Mrgoodwrench's Avatar
 
Join Date: Oct 2000
Location: LBC, So Cal. Where else?
My Boat: 1998 American Offshore 2600
Posts: 284
Default

We are seeing an unusual amount of the crank sensors failing on the 496 truck motors. The sensor is very diffacult to replace on the trucks. Engine removal is almost necessary.
Mrgoodwrench is offline  
Reply With Quote
Old 03-26-2002, 11:39 AM
  #9
Registered
 
Join Date: Dec 2000
Location: Solomons Island, Md
Posts: 916
Default

The Merc part# is 881667. They run about $90.00 each. Don't yet know how easy they are to fix on the water but I will be investigating.
29 OUTLAW is offline  
Reply With Quote
Old 03-26-2002, 11:42 AM
  #10
Rough Seas Lie Ahead
Gold Member
Thread Starter
 
Reckless32's Avatar
 
Join Date: Feb 2002
Location: Virginia Beach, VA
Posts: 2,465
Default

They're simple to get to. They're located on the port rear top of the motor. The first guy I know discovered the sensor problem after the mech troubleshot and was baffeled. Low and behold it was found out the factory changed a sensor once (or alledgedly) so the mech swapped out the one on the good engine and duplicated the problem therefore isolating the problem. Now a month later, another new boat with twins is encountering the same problem. It's got me wandering if I'm to expect it to happen to me sometime this summer....

Rick
Reckless32 is offline  
Reply With Quote

OSO Sponsor
OSO Advertiser
OSO Advertiser
OSO Advertiser