Loss of Power - not the cats

[03EXp]

I have a 2003 ford expedition 4.6 2wd with 167K miles. A spark plug blew out of the head so had my mechanic repair - installed a helicoil and replaced all the plugs and the one ignition coil that was on plug that blew. I told them it seemed like the truck had less power than usual when I pulled my camp trailer (pop-up trailer) and asked if they could test it for any issues. They said I had about 10lbs of back pressure when testing the drivers side and that I needed new cats. When trying to drive it home the 2 rubber hoses on the driver side that connect to the exhaust and EGR popped off. I had it hauled back to the mechanic, they replaced the DPFE and hoses and I then hauled it to the exhaust shop. They cut the cats off and said they are not bad but my muffler was dented so they replaced that. The hoses still blew off - after about an 80 mile drive. Next they took the intake manifold off and found 1 exhaust port completely blocked and another partially blocked. They cleaned them out, put it all back together again and after a short test drive (about 2 miles) so far the hoses haven't popped off but it still lacks power, seems even more than I initially complained of. It feels like when you start off you are in second or third gear and have to really give it gas to get it moving, there is no "get up and go". Oh and they tested the fuel filter and pressure, they said that all checked out also. Any ideas? The mechanics seem stumped and I am running out of money with the attempts to fix. Please help?? Thank you!

 

[toms89]

I would say there is something wrong with the cylinder(s) where the exhaust ports were blocked?! I don't see how that is possible if the cylinders were firing normally. A few misfires should not block the exhaust manifold. Cats maybe if they overheat from raw fuel.

I.M.O... Cleaning out a blocked exhaust port is fixing the symptom. Not the cause.

 

[toms89]

My guess if an exhaust port truly got completely blocked would be valve train issue on that cylinder that impeded exhaust flow or burning high quantities of oil.

I would do a compression test as well as a leak down test to check the condition of each cylinder.

 

[03EXp]

Loss of Power Continued - Please HELP

I forgot to say on top of everything else, the mechanic said the inside of the exhaust manifolds are white and should be black. Any ideas on that. I will take any ideas to them to consider. Thank you for any help and/or ideas.

 

[FordandPolaris]

Does it feel like a miss? If you have a dead cylinder it would not run at all smooth. If it feels smooth but just slow then there has to be something that is plugging it up or not reading correctly. If the inside of the exhaust mani is white, it seems that the fuel mixture is off in my opinion. That could be a lot of things but MAF would be a good start.


Sent from the Pocket Computer