Hi all


Posting this on behalf of a friend who has a 2008 F-450 with a 6.4L diesel engine. The engine starts and idles nicely, but has almost no power. In fact, my friend tells me that the truck barely has enough power to pull itself up the driveway.

He did some checking and was told that a frequent failure that could cause this is an exhaust sensor. Knowing little about diesel engines, what's an exhaust sensor? That seems like a pretty generic term to me. Do diesel engines have oxygen sensors? Any ideas what the term "exhaust sensor" would refer to?

 

Ask and see if there is a strange noise when the truck revs up..Could be a hole in one of the CAC boots. Specifically the one under the left front tow hook. If he hears air sucking in , that is the problem. If it has a hole in it, and you can't right off hand find a 6.4 boot, the 6.0 boot will fit. IT is just about 5/8" shorter but plenty of room to work with. I've had to do this before. This did not throw a code either.
If he has the wrench displayed on the dash, then he has a sensor problem somewhere. However, usually the EGT sensor will shut the truck down and prevent it from starting.

 

Thanks for the post. The EGT sensor, it that exhaust gas temperature? Are there any other sensors in the exhaust system? Also, what's a CAC boot? What's it do? These are all terms that are new to me in my gaspot world...lol.

 

No check engine light?

 

Will check on the light. Can't remember if he said yes or no.

 

So many things this could be. Need to get it on a computer.

 

The CAC is the charge air cooler. Lay down under the front bumper, looking in the area behind the left front tow hook. You should see a large pipe about 3 inches round. Where it attaches near the radiator area, you will see a blue, black or orange rubber "boot" that joins the two pipes together. It is there to enable the pipes to move when the torque is applied to the engine. This boot is always moving and gets full of water and oil that eat the boot up. Common failures on these trucks as they age. They will idle fine, but can't develop boost due to a hole in the pipe. The truck will sound a little differently, throw no codes and barely move at all.

If there is a code, then more than likely the engine has been put into 'limp' mode caused by a sensor failure. However, usually if it is the EGT sensor, the truck is shutdown completely as a safety to keep something from burning up.

 

I just spoke with my buddy....he says there is a CEL light, and a wrench symbol that appears on the digital readout on the dash.

My Buddy is back in town next week, so we'll have a look at the CAC pipes then. Probobly will need to get the truck on a computer, buy we're hoping to elmiminate a few things or try a few things before putting the truck on a hook to the dealer.

 

Yep, get it on a puter and let us know what you find ok??