UnZFeat'd

iTrader: (1)

Hey guys, so I just bought a 2004 Silverado 2500 with a 6.0 LQ4 in it. Paid 2k for the truck and I drive it maybe 10 minutes after buying it and the thing sputters and overheats. Going to scan for codes once I get back to my house, but anyone have any ideas?

Bought the thing so I could evebtually put the engine and tranny into my camaro. I was just hoping I would.be able to drive this truck around until I'm done painting the camaro.

UnZFeat'd

iTrader: (1)

Also... I could have sworn there was a coolant cap on this but it's gone now. Could have been on loose and shaken off, or could have popped off. Guessing that could be the reason for the overheating, but any idea about the sputtering?

UnZFeat'd

iTrader: (1)

Soooo theres no gas cap either haha. Good golly!

RB04Av

Fix all the OBVIOUS things you can find, like, pieces right out in the open that aren't there; scan for codes; come back with some useful actionable informative information. With what you've posted so far, there's basically no way anybody out here can do any more than just bald-faced GUESS AT what your new-to-you truck's problem is. Sounds on the whole though, like maybe Billy Bob and Uncle Cletus have been "improving" on it a little bit; and you might have to do some archeology to get at what all they did.

UnZFeat'd

iTrader: (1)

It was a commercial vehicle with a single owner and nothing looks like it's been messed with, but the guy did say he replaced the spark plug wires and plugs... I'm guessing one of them isnt in all the way or something.

RB04Av

Sure, definitely check that. Maybe even just bust out the parts cannon and do a pre-emptive first-strike on the plugs since they're notorious for "looking" "good" and still not working right even when "new" especially if some problem occurred at some point in the past (bad gas for example) and damaged one.

Any codes?

UnZFeat'd

iTrader: (1)

So I got the gas cap and coolant cap on there, new coolant, and oil change. Did all the spark plugs and wires and it is throwing a p0300 code. Before I did anything it was throwing these...p0300, p0332, p1258, p0300, and another p0332. Done for the day. Any ideas on what to do tomorrow? In my experience the coils rarely go out, do I really dont know what it could be. Most likely going to try compression test tomorrow. Thoughts?

UnZFeat'd

iTrader: (1)

Just did a compression check.

Here are how the cylinders tested...
1 - 150
2 - 140
3 - 150
4 - 160
5 - 160
6 - 170
7 - 180
8 - 180

Now, this is with a 50 dollar tester that i just bought, but there is definitely a difference in how the front vs back cylinders tested. Looking at this, i am going to plan on replacing the intake manifold gaskets. Does anyone have any other input?

UnZFeat'd

iTrader: (1)

Anyone have any suggestions? First LQ4, but I've had LS motors.

RB04Av

Intake manifold gaskets won't affect compression.

Not that I am NOT saying "the gaskets are good"; "don't change your gaskets"; NOT NOT NOT NOT. Only, they won't affect compression.

Were all spark plugs out, the throttle blocked open, and a good hot battery used during testing with a charger on it between cylinders to keep it topped up?

UnZFeat'd

iTrader: (1)

Just realized that the engine wasnt warmed up. I should probably do the test again. When I see people with compression issues, there seems to be a bad cylinder with under 100 psi. None of mine were under 100, but there is a slight variation more than what would be ok. There is a hesitation when I blip the throttle, too. Do you think this could be more of a fueling issue? The motor is super dirty and the block is covered in like a half inch of nasty blackness.

trilkb

iTrader: (4)

Fuel pressure regulator may be a good start. How’s it start when hot?

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iTrader: (1)

It actually starts right up every time. Today i drove it around for about 15 minutes and when I parked it, there was a little smoke coming out of the back of the drivers side head. Looks like that is where my PCV is, since it isnt attached to the brake booster. I was going to seafoam it to see if I could clean it out, because it looked like there was a lot of oil covering it. Does anyone have any experience on where to remove that piece so I can get some seafoam inside?

lawrenq

iTrader: (2)

Just finished fixing some similar issues on a donor truck that I just bought. In my case I had multiple cylinder misfire codes and to fix it I just removed the intake and cleaned out alot of the oil that was built up on the inside of the intake and intake ports. I also ran some seafood through the fuel system. Like others have said check for cracked vacuum lines and things of that sort.