2008 LR3 110k miles

Ran the truck yesterday with no issues. Went to start up this morning and get a check engine light on. I actually notice a rough idle before I noticed the light was on. Put the code reader on and getting P0300, P0303, P0305 and P0316. So a misfire on cylinders 3 and 5 at startup. Truck seems to turn over just fine and notice of any issues when driving. My hope is a spark plugs are going and not the coils. I’m not sure if the plugs have ever been serviced.

Anyone have any input on it? Any need to not drive the truck till I can get it figured out?

 

110k for plugs is about when they are due, but unless there was some abuse to the engine they should actually be okay at that milage - meaning not worn enough to cause flat-out misfires. Probably factory plugs still in there too as they hold up very well. You may consider getting new plugs and when pulling the old ones you can get an idea if there is an issue for specific cylinders by how the plugs look. Even for coils that is not really in the milage for them to fail yet. If I put a bet, I would say its something else. A vacuum leak is very possible. You may also want to inspect the connection for the ECU, behind the battery. If the battery is not vented properly is can gas out and cause corrosion on the connectors.

 

Thanks. I was planning on ordering the plugs from Atlantic British tonight and going from there. I did clear the codes to see if would pop back up and since clearing I have started and drive. The truck 4-5 different times without a misfire or codes popping back up.