Injector #4 mechanical malfunction

Dang. Would have been cheaper to get a generator & portable A/C if all that is related to idling.

 

How many miles between oil changes?

I had 930k when I had a valve issue. #5 injector would show fault. They removed valve cover and intake valve spring had metal shaving on the spring. The head ended up being trash. So had a remanufactured head put on. Almost 100k later still going strong.

 

check compression on piston #4 its going to be low if it's not a bad camshaft has to be a head no other reason or you have a bad injector but not very likely.

 

Mine did the samething it was really loud at start up but would quite down once warmed. Like Nasriza said do a compression test and verify low compression.

 

I bet that thing is packed with soot if it still has the emissions. Have you done an EGR Tuneup? Not that it will solve your problem, but your motor will thank you. What kind of mileage were you getting before the injector issue? I would also do the oil changes sooner than 20,000 miles, may be a good idea to install an oil bypass filter too. If you still have the emissions.