The Official Vortec 454 Info thread

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RichardSwinger

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I've been playing around with this OBDII scanner and trying to learn what all this stuff means. My REAL question is: which is more accurate/reliable? The $15 scanner from china or the 23 year old dash gauges? I'm finding that the scanner is showing RPM consistently 300 lower than what the tach is showing. Same for the Voltmeter: scanner shows 14.0v while the gauge is showing two ticks above 14v. What's even weirder is that with the oversized tires that came with it (285/75R16 where as the Vin says stock size is 245/75R16) my MPH per the gauge is consistently 5 MPH higher than actual when I've checked it against GPS. But with the scanner (and GPS turned off) the ECU/scanner seems to know what the actual speed is even when the gauge is reading low! Supreme weirdness...
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smokymtn65

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I've been playing around with this OBDII scanner and trying to learn what all this stuff means. My REAL question is: which is more accurate/reliable? The $15 scanner from china or the 23 year old dash gauges? I'm finding that the scanner is showing RPM consistently 300 lower than what the tach is showing. Same for the Voltmeter: scanner shows 14.0v while the gauge is showing two ticks above 14v. What's even weirder is that with the oversized tires that came with it (285/75R16 where as the Vin says stock size is 245/75R16) my MPH per the gauge is consistently 5 MPH higher than actual when I've checked it against GPS. But with the scanner (and GPS turned off) the ECU/scanner seems to know what the actual speed is even when the gauge is reading low! Supreme weirdness...
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I would suspect your alternator may have wrong pulley, seems like the diesel pulley is about 300 rpm different. Measure it at verify
 

RichLo

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I'm thinking about picking up a good OBD2 scanner, what do you guys recommend?
 

Mangonesailor

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Use a OBDlink mx, and torque pro or Dash command... reputable apps that have a good history and good support.

the ECU/scanner seems to know what the actual speed is even when the gauge is reading low! Supreme weirdness...
I don't know either but I'd like to find out
Because the speedo is able to be calibrated separately.

Voltage at the OBD 2 port and at the ECU are two separate readings... and the gauge needle can be moved a smidge here and there.

Your 20yr+ gauges are not going to extremely accurate... and your tach doesn't run off of the alternator... it's picked up by the crank pos. sensor measuring the frequency of pulses.
 

RichardSwinger

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Ok, I'll keep posting questions and observations on my L29 truck until y'all tell me to stop cluttering up the thread [emoji16].

When I got the truck the engine was rebuilt with 160K on the odometer. It was rebuilt with stock spec stuff and the PO had receipts out the wazoo. I have full faith and confidence in the work that was done and she runs great (after the Bosch injector and FPR replacement). If anything, she's TOO quiet for a big block. I keep going back and forth on getting long tube headers and a Dyno tune at my local speed shop (a surprisingly GOOD speed shop called "Muffler shop of Columbia") but the fact that it's a daily driver and more of a cruise/Putt-Putt truck than a hotrod has kept me from jumping into that end of the pool. That, and I'm super nervous about having the truck on a Dyno, in the event that something went wrong I'd be extremely sad [emoji28].

I did the first oil change with around 200 miles on the rebuild. Second oil change at about 1000. Super overkill but I'm trying to do things as well as I can to make it last. Oil wasn't too dirty and I dug around the drain bucket with a magnet and nothing stuck to it. Using Rotella T-4 10W-30 and a bottle of TB Zinc plus with every oil change (the zinc is probably overkill but shouldn't hurt it).

I'm trying to push the third oil change to about 4K miles. I checked the level today at 2K miles and noticed I was about a quart low. There's no visible leaks and the only noise she ever makes is a slight tick on cold startup that lasts maybe 3 seconds (which makes logical sense to me, that's how hydraulic lifters work, right?) I'm trying to develop a maintenance routine and it seems like 2K miles is a reasonable spot to check oil and expect to add a quart on a rebuilt but still 23 year old big block.

Other than her being super thirsty (which is annoying when the southeast is in a micro-gas crisis) this truck has been really good to me so far and I'm really enjoying learning about it from all you guys!
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smokymtn65

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ha sounds like we both got in this game about the same time, but PO rebuilt the motor and bent some push rods bought it like that, and just tinkering with it as I have time. 1200 on rebuild 109k on truck
 
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