Engine Hours

[Dockoelboto]

I'm looking at an 09 Malibu response LXI. Overall in great condition but there is a dash hours vs computer hours discrepancy. The dash says about 900 hrs, if you plug it in the computer says about 1200ish hours. The seller is upfront about this, my question is this normal? is it a idle vs run time issue or just the inaccuracy of the dash hours clock? Has anyone seen anything like this?

 

Thanks!

[BraceMaker]

Computer is run hours.

 

Hour meters have different tactics and sometimes get replaced.

 

09 Malibu may tick gauge based on charging voltage over 14, so it may not tick at idle or when bilge running. Gotta investigate

[Dockoelboto]

not sure how common this is, seems strange. I guess on the digital gauges you can find the computer hours deep in the system - the owner says that is where he gets the 1200ish hours from. the basic hobbs meter has 900 or so on it.

[vtjc]

Is a marine dealer accessible that could scan and read hours from the drive train? Does it have Perfect Pass that could also list hours? Either way the boats condition and maintenance records is likely more predictive of future wear.

[BraceMaker]

PP just asks for hours when you reboot it - doesn't really know the hours, mine currently reads 30 because I installed v9.12 and didn't care to enter hours.

 

Tach/Hour meters function in 1 of 3 ways - either power from ignition to on position causes it to tick (common through the 80's and early 90's. Or since a charged battery reads ~12-13 volts and an alternator outputs 14+ volts some particularly digital ones tick when the key is in on and the voltage goes up (meaning if you turn the key to on and put it on a battery charger it will count) Or the more modern is that the ECU reads the hours and the gauge displays those hours.

 

All can be defeated, but if the engine computer says 1200 then at the minimum that computer is 1200 hours old. Could be a replaced computer at any point in a 900 hour boat but way more likely that the gauge would be replaced and or the gauge just wasn't functioning properly for about 1/4 of the boats life.

Old mechanical gauges often would tick if you left the switch in accessory position - which would tick till the battery died which could be quite a few hours.

.

[Dockoelboto]

@ vtjc and @BraceMaker thanks for the info - that may explain it, the boat has ZO but he replaced a GPS puck and did some other stuff when he bought the boat with 350ish hours. he says the 899 hrs represent the hours he put on the boat, there may be a way on the digital display to have something like a trip meter - hours you can reset but the owner says deeper in the settings you get to the original hours. He has been upfront on the hours, I just didn't think you could reset the hours or have something like a trip meter.

[Zman]

@Dockoelboto Hours noted by the ECM cannot be changed. And, those are the hours that display in the Malibu view screen in the middle of the dash.

I have had to replace an ECM a couple times. If the replacement is a remanufactured or used ECM, it will reflect whatever hours it has been in use. Could be higher or lower than actual hours on the boat it is installed in.

Is the seller the only previous owner? If so, ask if the ECM has ever been changed.

Not sure what you mean when you say, "if you plug it in the computer says about 1200ish hours".

When you say, "the dash", are you talking about the Malibu view screen in the middle of the dash? Pictures?