Truck surges on startup from cold, fine after running a few minutes

I have been running 5w30 Amsoil diesel oil now for nearly 2 years in all weather. I can't imaging it's the oil.

I'm down to 2 things.

1) it's a sensor that is not working correctly when the truck is warming in the morning during glow plugs running
2) due to glow plugs running, there isn't a correct voltage detected by the VR on the alternator (one I am not monitoring) and the truck thinks it needs to charge / not / charge / not / etc.

Next step, going to run a tap to the wire on the alternator directly to battery voltage and bypass the computer to see if there is something there BEFORE I go off and start replacing sensors.
 
Bumping for any update. My brother is having almost the same problem but right after the change oil, surging at cold start for a couple of weeks now. He's thinking it's the alternator. We will take a look at it right after the smittybilt bumper and new tires installation on our current Jeep project. Any chance your new alternator is acting up?
 
These engines are known to surge when cold starting. This is due to the oil, 15W 40 is what the factory puts in. I changed to 5W 40 and the surging went away. I have never heard of the alternator causing surging.
 

Members online

No members online now.

Forum statistics

Threads
30,613
Messages
266,350
Members
14,749
Latest member
Leeken
Back
Top