Alright guys I need some help... I have a 2008 Ford F350 V10 that is only firing on 5 cylinders. The whole right side bank is not firing! I have injector pulse, and I have spark. All the plugs on the bank that is not firing are soaked, and there is gas in the oil. I have good oil pressure, My head gasket isn't leaking, and I have compression in each of the cylinders that are not firing.... I am completely stumped and lost as to what to look for next. Any help would be much appreciated!

 

Fuel
Air
Spark
Timing

You need all 4 for combustion. You've verified fuel and spark. Now, air.....vacuum leak on that bank?

 

How do you know there is spark? So if you do indeed have spark how did this all start?

cam timing? normal compression? The spark has to occur when the piston is almost to the top of its stroke and both valves need to be closed at that time. If it doesn't no fire! I forget how the spark is controlled..

So exhaust blocked on that side! cam broken or cam parts came unglued.

 

I will have to check for vacuum leaks in the morning. Also, I was going to check if the cat is plugged, and then last but not least I'll have to tear into the cam... I'm really hoping it's not somthing with the cam because I know that's a lot of work...

I bought this truck Sunday and was told it was blown up... I have another V10 that would fit it but the symptoms were not adding up for me so I started digging. That's how this all came about. When I first picked the truck up I heard a slapping noise that appeared to be coming from under the valve cover but that has not gone away... I wonder if the timing chain broke?

 

If you pull the valve cover then crank the engine, you'll see easily if the camshaft is spinning....but I doubt that is the issue. You'd think at least one valve would be left open, and you'd be getting an intake or exhaust backfire.

But, I could be wrong. Have been before, probably will again. Just ask my wife.

 

It does sound like you need to check the cam on that side. Something doesn't add up though. You said that you had fuel, spark, and compression on all cylinders and that the plugs were "soaked". If the valves are closed due to broken cam chain, compression would be low on the closed cylinders due to no air coming in, and if the valves are open the compression would be even lower due to the open valves. The plugs would not be "soaked" on the cylinders with the closed valves because fuel couldn't enter those cylinders either. I think that you should re-verify your symptoms to get a better direction for locating the problem. Also, pull the valve cover and see what is really going on.

 

Like mentioned above, it can only be air, spark, or fuel.



Some quick shade tree mechanic tests that you can do to check for any gross anomalies:


Hook up a fuel pressure gauge and check the fuel pressure to make certain its in the correct range.

Swap the coil packs from the working side and place them on the non working side to see if those cylinders start firing.

Pull the plugs and turn the motor over so you can listen and tell if the piston is creating any suction or pumping force. That will give you an idea of whether or not there are any grossly mis-timed valve openings or whether or not they are opening at all.


Since you have the plugs out, change them.