hi people, looking for some assistance. i have a 2005 express 3500 w/6.0
its been running fine up till last week. it had a bad o2 sensor for a while but was still running good. we dont drive this van very much. my wifes daughter ran it empty on gas. after that is when i noticed the problem. i filled it up and went to tow my wifes horse trailer with it and it started acting like it is now. it starts and warms up fine but seems low on power and sluggish. when its warm it doesnt want to accelerate. it will but not like it wants to. when the rpms are around 3500-5000 when you mash the throttle it sort of accelerates but with a slight misfire and knock(seems like its leaning out). also there is a swoosh/whistle coming from the top of the intake area right of idle and when you goose the throttle. i dont recall it being so noticeable or that noisy before. is this normal? any ideas? thanks

 

driving with a bad 02 sensor can screw your cats. You may need to check your emission system. I would go for a shop tune up. They can check your tailpipe emissions and your codes. Also change your fuel filter. You may have sucked up some crap when running out of gas. Never run below 1/4 tank on a regular basis. The fuel in the tank cools the fuel pump, and running low all the time will shorten the fuel pump life.

 

Your fuel filter might be clogged. Whens the last time you checked it? What speed does the bogging happen at?

 

Well update on the 2005 express. Check all the coils. Fuel pressure is around 55-60. Found something interesting. Did a compression check and 1, 2, 7, and 8 had a funny reading. When cranking over only about 100-130psi with a few turns. Then if you stopped and then gave a few more turns or let it run it would jump up to 155psi. Any thoughts. I've heard of a broken valve spring or carbon build up causing the valves to stick. Does this sound like something like that? Anybody had this happen to them?? Thanks.

 

I have heard about the sticking valve issue. Pulling the heads and redoing the valves is the only real cure. I was in no way gonna spring for that so I started trying every brand of fuel system cleaner out there. You might want to give them a try.....