5.7L truck engine help

[Johnny Drama 5,000+ posts]

I would go get a second look. Your timing could be off. Even though its electronic its still timeable. You have to unplug the computer timing wire under the glovebox. time it then plug it back in. 20-25 psi is ok.

Did you change any of the sparkplugs or wires recently?

 

[supa_c 5,000+ posts]

nope. i dont think its the timing. it was running fine before. just this past 2 weeks its gone down the drain. the check gauges light comes on because the oil pressure is in the red and the truck starts to shake. is your premium $2.60 a gallon. how would plugs make a knock?. it isnt a quiet knock either. it is loud enough to be heard a 1/2 block away.

im gonna try the preimum since the tank is low on fuel. prob wont help but worth a try.

 

[helotaxi 5,000+ posts]

If is sounds like a diesel, it is probably dieseling. Possible causes are predetonation from too low an octane fuel or a fouled plug not firing until the cylinder is basically vapour lock and then firing. If the latter is the case, you need to fix it ASAP or you will do damage. The former will cause damage over time.

 

[supa_c 5,000+ posts]

it goes away when the revs are up at 1k.

ill try to get the plug out but its in there. stupid headers!

87 octane has been fine since i had it, but you never know? my dada wants to know since he's gonna be dishin out the $$. the lower $$ the better. it some times shifts at 3500 and makes this bone jarring rattling that is like a whirring rattle (like a rev up and down). other times it shifts at 2K woth no rattle. ill be back in a while gonna check the plug(s). any more ideas would be appreciated.

 

[supa_c 5,000+ posts]

well i took out the plugs and managed to break one. had to drive on 7 cyls to get another. $6.99 for 1 freakn plug. i got the cheap o ones!. im gonna see if i can get my engine rebuilt, it will prob be cheaper. need to take to a mechanic with a stethoscope to see what cyl it is.

 

[Johnny Drama 5,000+ posts]

One last thing. Have someone check your oilpump.

 

[supa_c 5,000+ posts]

yeah i think its broken, or kinda broken.

 

[Johnny Drama 5,000+ posts]

get the pump fixed and you can get a rebuild kit for like $300. Do it yourself have your dad help. Worst you can do is ruin the motor and it sounds like that is gonna happen anyway.

 

[Johnny Drama 5,000+ posts]

You never know the oil pump may solve your whole problem,

 

[supa_c 5,000+ posts]

well if it can get rid of a loud Knock. i told my p[arents we might need a new one but they blew it off. now its come back to bite them!

gtg to go to smr school, be back at about 1 if you have any more advice please post

 

[94gmsierra 10+ year member]

You can still adjust the timing by twisting the distributor cap, but first under the dash close to the computer there is a brown wire that needs to be unplugged. This is your electronic control, if its not unplugged don't bother like you said cause it will wonder all over and look way off. unplug it and see if your timing is @ 0 this is where it should be , ifits advance some how maybe thats your knock, Also when you changed the oil did you get the right filter sometimes those cross-referenced ones are exact size but don't have the flow back valve in it. Unless thats only for 4x4's where the filter is sidways? check into this to. Most likely if its still running, you don't need a new engine, likely just a rebuild maybe even just a top end . If your real lucky maybe just a stuck lifter.

 

[supa_c 5,000+ posts]

i got the best fram filter i could find $11. so i dont think its the filter. i highly doubt its the timing because the truck runs fine at cold start up. i think im gonna get a rebuild if the internals arent shot to bits.

P.S

i really appreciate all this feedback. thanks guys!

 

[InhumanAcura 5,000+ posts]

get the pump fixed and you can get a rebuild kit for like $300. Do it yourself have your dad help. Worst you can do is ruin the motor and it sounds like that is gonna happen anyway.

Does it come w/ a hottank, a kit for magnifluxing, and something to bore and deck the block, and mill the heads. Can I have a link please..? //content.invisioncic.com/y282845/emoticons/waycrazy.gif.f4a380c3f94043939fd369defd9e6be2.gif

 

[Johnny Drama 5,000+ posts]

Nope it doesnt but I was told his dad was a mechanic and he would have connections to get the block and heads done cheap. Thus my statement for the rebuild kit.

 

[Sleeklsc 5,000+ posts]

timing chain?