496 mag running issues
02-29-2012, 10:40 PM
#31
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I would agree with thirdchildhood, had the same issue with my port engine a year ago or so. Scans showed no codes but the temp was about 10 deg higher on the guage, I back flushed the raw water side from the heat exchanger inlet & the problem went away. The p/s & oil coolers can get partially plugged you wont notice at idle on muffs but under load it would show up immediately. I run on the missouri river so i can pick up junk all the time. Hope that helps, Randy
02-29-2012, 11:07 PM
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I don't think it's the IAC. As mentioned I think that affects idle. Do the other stuff. A steady alarm is supposed to be over revving (not your problem), low oil pressure or high engine temperature. The knock sensor wire thing is interesting too. I'd back flush the heat exchanger when you do the raw water pump. You will like the Hardin SS pump.
03-01-2012, 07:31 AM
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I would agree with thirdchildhood, had the same issue with my port engine a year ago or so. Scans showed no codes but the temp was about 10 deg higher on the guage, I back flushed the raw water side from the heat exchanger inlet & the problem went away. The p/s & oil coolers can get partially plugged you wont notice at idle on muffs but under load it would show up immediately. I run on the missouri river so i can pick up junk all the time. Hope that helps, Randy
03-09-2012, 07:36 AM
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I got my Hardin pump in last night it def sucks more water than my old pump. I'm taking it out tomorrow for a test run hopefully I won't hear the alarm. I just wanna thank everyone one here that posted all the good advice.
03-10-2012, 08:45 PM
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Well I went testing today alarm was still their. Took it an got it scanned and was the water pump psi sensor. Replaced the sensor and now it's back firing really bad at 3k and above. Should I start with the spark plugs and do a compression check while they are out? What is the correct compression psi these motors should be at? Thanks
03-10-2012, 09:26 PM
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Spark plugs is a good idea. Bad plug or two will do this and not show up on scanner. Also make sure plug wires from coils are on correct plugs especially if they have been unplugged or removed for any reason. Compression test is good idea also. Should be about 155-160 psi all cylinders with throttle open. Disconnect main injector plug near ecm to do test as you do not want all that fuel pumping into cylinders when cranking. Open throttle wide open also.
You might also have some bad plug wires. You can check that with engine running , hatch open in the dark at night no lights on or to much background light and look for arcing around the plug wires where they run by manifolds,etc.
Hope you find your gremlin easily.
Best Regards,
Ray @ Raylar
You might also have some bad plug wires. You can check that with engine running , hatch open in the dark at night no lights on or to much background light and look for arcing around the plug wires where they run by manifolds,etc.
Hope you find your gremlin easily.
Best Regards,
Ray @ Raylar
03-10-2012, 11:16 PM
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Spark plugs is a good idea. Bad plug or two will do this and not show up on scanner. Also make sure plug wires from coils are on correct plugs especially if they have been unplugged or removed for any reason. Compression test is good idea also. Should be about 155-160 psi all cylinders with throttle open. Disconnect main injector plug near ecm to do test as you do not want all that fuel pumping into cylinders when cranking. Open throttle wide open also.
You might also have some bad plug wires. You can check that with engine running , hatch open in the dark at night no lights on or to much background light and look for arcing around the plug wires where they run by manifolds,etc.
Hope you find your gremlin easily.
Best Regards,
Ray @ Raylar
You might also have some bad plug wires. You can check that with engine running , hatch open in the dark at night no lights on or to much background light and look for arcing around the plug wires where they run by manifolds,etc.
Hope you find your gremlin easily.
Best Regards,
Ray @ Raylar
