Well, so much for not working today. Got a call from the service that the '08 F450 ambulance that I drive on shift was having difficulties. I called the crew and they stated that it started running rough after a call and the wrench light came on. Luckily, they were near the dealership in town and I sent them there and called ahead to the tech. He called me back a little while ago and said the news wasn't good. The engine has lost compression in #3 and #4 with a bad miss. So, the truck is now being taken back to the manufacturer(ambulance body) so the box can be slid back and the cab taken off to sort it all out. The manufacturer is an Authorized Ford Service center. I asked about possible rocker arm failure to which the tech said it's possible. No coolant in oil and vice versa. So, now the waiting game. Will probably be down a few weeks. The truck has 91k on the clock and has had a leaking turbo, shut down due to EGT sensor, PCM failure(5,000 miles) and has ahd all the reflashes that have been out. Last week it started out with a little smoke on acceleration and going into regen every 70-100 miles or so. But these trucks idle a lot, so who knows. No codes were initially shown prior to the compression loss. Will let you guys know at a later date what the verdict is.

 

Verdict in today. Broken rocker arm as suspected. The tech says nothing wrong with DFP and is not smoking now. We pick it up tomorrow and should be back in service by the weekend.

 

How often are the oil changes on this motor? I suspect some of the previously reported rocker arm failures were from wear.

Primarily cause was excessive wear due to fuel dillution and extended oil change intervals combined.

 

These units are service at every 5k interval. Oil at 5, fuel filters at 10. Since day one. I got them to do this after reading the manual when the truck was new. The only thing they haven't done is an oil sample. These trucks are idled a lot while on scene, but I believe the biggest culprit is shutting it down while in regen. A lot of times we don't have the luxury of not shutting them down, especially when crews are delivering patients to the ER. At our normal emergency rooms, we have really ticked off security because of them demanding us to shut down the units. For the last year and a half , we have not done that. We remove the patient from the unit then move it so it can stay running. Like I said though, sometimes we have to shut it down in while in regen. Only one time have I been able to pull the dipstick and actually smell fuel. It was serviced that day. The tech said that this was not the first '08 EMS unit to be brought in with rocker arms failure. He didn't elaborate. But I will ask.

 

Interesting. So idleing it in park not allow it to complete.

At least it won't for our personal trucks.

 

When the truck was brand new, it would complete in park and on high idle. After a re-flash a several months after we got it-it stopped. It will only complete now while being driven. Funny thing, one of the hospitals used to use plastic cones as a back-up guide for units to use while backing up the hill. One day we all smelled something burning and found a cone right near our exhaust pipe in a puddle of melted plastic. Yep, you guessed it-it was in regen! We still all laugh about that because the hospital still puts them out every once in a while. But to further answer you question Senix, the regen now stops when the truck is put into park.

 

UPDATE: Truck was picked up from dealer today. All of the rocker arm assemblies on the passenger side were replaced due to "all of the tips being worn flat". Both heads taken off, cleaned, pressure tested and new head gaskets installed. The turbo gasket(where they join) replaced for the second time. EGR cooler gaskets replaced and system pressure tested. Tech says the rocker arms on the driver's side are fine. Really makes me wonder why the passenger side ones are so bad. Anyway, truck due to be put back in service on Thursday. Mileage on truck at time of service was 90965.

 

You have these guys out there trying to save lives, meanwhile their truck is in the shop for a month because of an emissions related failure. The EPA is saving the environment at the cost of the people who live in it, gotta love it.

 

I agree! That's why our service and a lot more around here are going with Freightliner's or buying 350s and 450s with gas engines and putting electric fans on them to keep them cool in the summer time. It's very hard to justify a truck being down for a month, especially when this is the second time. First time it was out of service for 6 1/2 weeks due to a turbo issue. A lot dealers will not even mess with a 6.0 or 6.4 due to the cab having to come off and having to disconnect all of the electrical and air components that come on ambulances. Even the running boards have to come off when the cab goes up due to the style of boards that are put on them. One of the nearby services have 2 '11s. I'm very interested to see how those work out.

 

Yep, lots of companies with large fleets around here have switched to gas on their 2011 trucks. Ambulances are still mostly 6.0s or Chevy 4500 diesels though. If this stuff keeps up diesel sales are going to go way down. Maybe that's what the govt wants...