Engine help/ swap help

[Brandon15zzz]

Alright I have an 02' silverado ext 4x4 with the 4.8L V8 I've been having some engine problems lately. I had a miss when I first bought the truck not noticeable normally only on the scanner computer thing. Changed the plugs and plug wires, on the scanner no more misses. Thought my problem was fixed. Then every once in a while I would start my truck start to drive off and it would be kind of hesitant. So I figured it was nothing so I would push down on the gas a little harder and my rpm's would spike almost as if something was clogged. Then it wouldn't happen for a little while. Now it happens a lot more almost every other time I start my truck. So I just pull over turn my truck off. Restart it and it runs fine, untill I start my truck the next time. I've noticed lately it's started spitting like black stuff out of the tailpipe. It's not full blown liquid or oil it seems more like a suet. My stepdad said its a valve or something and that the stuff out of my tailpipe is cause my pistons rigs are leaking. Anybody have any ideas on what it is? Any help would be appreciated. I'm going to my gf's house this weekend cause her dad is pretty much a mechanic. He has a computer and all that stuff.

My next thing is that if this motor is pretty much gone I wouldn't mine replacing it with something bigger like the 5.3L if anyone knows how difficult it would be to swap the engines as in just swapping engines and flashing the computer compared to changing trany, computer, etc... Or where a decent place is to get motors for a good price. Or what I'm looking at for a swap or rebuild of my motor.

Thanks for any help.

[Dangrebel]

Everything is the same on those motors man. It should just drop in and flash you computer.

[Brandon15zzz]

Good to know. Might just try to find one and swap it then rebuild the 4.8 for a spare.

[Dangrebel]

The 4.8 is a good motor. I would just rebuild it and not swap. Save the money and spend on new heads or something ya know?

[Brandon15zzz]

Yea. I wouldnt buy performance parts with the extra money I would save. Just more audioz.

[b-dubs89]

does it consume oil ? what is your gas milage like , does it consume coolant ?

[Brandon15zzz]

My truck takes 6 quarts I'm normally down to about 3 or so by the time I change my oil again normally around the 3,000 miles. Gas mileage isn't all that great probably anywhere from 11-15 average. No it doesn't consume coolant. My temp gauge stays around 210 or whatever it's suppose to even on long drives.

[b-dubs89]

i think you go through more oil than you should , my experience is about 1 quart by the time due for an oil change in an engine that don't otherwise consume oil . sounds to me like you may be due for a re-ring or complete overhaul . could re-ring only but for the work to get that far you would be wise do a complete overhaul being that far in .

in the mean time you could probably slow you oil consumption alot with lucas oil stabilizer , i have owned many high mile gm vehicles and it always slows or stops oil consumption for me .

[Brandon15zzz]

Some people told me it might be a clogged injector so I bought gum out. You put it in your gas tank and it runs through the engine. I haven't put it in yet but I will today. Not that it will necessarily do anything but maybe. If I pull and rebuild the motor should I go ahead and do the transmission as well?

[b-dubs89]

bad or cloged injectors definetly could cause some of your problems , if your injectors are working that bad 1 course of fuel injector cleaner probably won't cut it , i would do 2-4 courses of sea foam in the gas tank to try and clean these injectors