I had the truck taken into the shop after messing with the timing and that didn't work. The mechanic said that something terrible had happened, probably spun a cam bearing or something. He was talking like I'd have to replace the cam, timing chain, bearings, and a lot of the valve train. Still waiting on more info, but this might get expensive. I posted the symptoms a while back in "400 carb problem/backfiring" post, but all those problems led to this, and it could be expensive. THe mechanic said some valves were stuck open, and that the engine was dead on three cylinders, and had flooded gas into the oil pan. So now I'm hoping to get my taxes back soon and save up some money to get her back on her feet. What's really strange is, I didn't think something like this could happen to an engine that's only 15,000 miles old. Looks like I'll be riding on the LPC's for a while.

 

How does spinning a cam bearing cause backfiring?

My advice: find a new mechanic. This guy wants to take you for a ride.

The backfiring issue you cited is likely nothing more than carbon buildup on the intake valves. You reported that the spark plugs were sooty. Both are a sign of running too rich.

Get your truck away from that guy before you give him any of your money.

 

AMEN to that:
Most any mechanic can make up a line of BS to where you'd think that just driving the truck another 50' would turn you into a midget and make all your future children turn out in a horrible shade of orange.
There are honest mechanics out there but I don't know many, sorry if you're the one who is honest. My great-aunt is an example, I was talking to her one day and she had a big repair bill for an annual tuneup of a car that gets driven 5000 miles a year, lots of new pieces including parts and labor for points and condensor - on an electronic ignition car! How about the brilliant guy at one of Denver's oldest and most respected dealerships (L___) who wanted to charge $200 more than the advertised price to do a front end alignment on my Suburban because he "had to take out some tabs with an air chisel" when it was obvious to anyone who cared too look that the work had already been done and the adjustment kits installed some miles ago. ?They even tried to charge me for looking at my truck! I could go on and on with horror stories.
How the guy can decide that something deep down inside your engine had malfunctioned in a very short time makes me immediately suspicious. Go somewhere else.
R.

 

besides what the last poster said I have never seen a "spun cam bearing" if you have a such a lack of oil as to cause this on a 400 you would have spun the rod bearings long ago, and the flooded gas into the oil pan is an easy check- is your oil over full, if not then this guy is a liar, and if he has a problem with that he could call me and I will tell him to his face. also there is absolutly NO way he could diagnose a spun cam bearing without tearing the motor down stuck valves will not fill the crankcase up with fuel, I didn't read your other posts but having valves stuck open would caused alot of valve train noise you know like loose rockers. I could go on but no need get your truck away from this guy as fast as you can, and if he charges you for this turn him into the BBB, call the local prosucuting attorney on him for fraud, and call you local state attorney general, and get his licsence revoked, this is the type of mech we need to get out of the business they give them all a bad name. Oh one other thing if this clown starts to make comments about shade tree mechanics, I am a ASE certified master auto tech, I attended WTI in Laramie and recieved the second highest score in the 25yr (at that time which was 13 yrs ago) history of the school and was the first student asked to be a instructor before I even graduated, which is something considering that they require atleast 7yrs experience before you can be hired as a instructor

 

Just do a compression and vacuum test, that will tell the truth and is much cheaper than a mechanic.

 

He called to ask to tear into the motor after he took off the valve covers and saw some rocker arms weren't working or something. Then he said that a bunch of the valve train might need to be replaced. I haven't heard from him since last thursday. Thanks for the advice. I'm going to go down there and see what's going on today. I've never had to deal with a mechanic before, thanks to my trusty Ford, but now I'm a little worried.