1996 Chevy Tahoe changing engines

Tiny
JUNIORRICHARDSON
  • 1996 CHEVROLET TAHOE

Engine Mechanical problem
1996 Chevy Tahoe V8 Four Wheel Drive Automatic 190000 miles

I have a 1996 chevy tahoe (5.7) vortec engine. I WOULD LIKE to know if I could use a engine out of a 1995 chevy pick-up truck(1500) which has a(5.7) liter engine(not a vortec) the only diffrences I see are my alternator and ac areon oppisite sides, but if I use the brackets off my vortec engine will the bracket holes line up on the other engine so I could use my original alternator on ac compressor, also would I have to change the intake manifold

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Monday, July 28th, 2008 AT 6:51 PM

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Tiny
JUNIORRICHARDSON
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The reason I felt I needed to change the engine is because. When I start the truck it has a knocking sound that strart about (30sec)after the engine strarts running if I press on the gas pedal and raise the r.P.M, s the noise kind of dies down, also if I put the truck in drive the noise is not as loud as it is in park. I. Ve checkedthe oil, not water is in it, l. Ve changed th oil too. Also i, ve checked the spark plugs. The look fine. The check engine, service engine lwarning lights are not on, it has around (40psi) oil pressure. So I really cant find anything wrong.

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Thursday, July 31st, 2008 AT 11:27 AM
Tiny
BLACKOP555
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Ok, well ill give you a few things that can cause a knocking sound like you described and are relatively easy to check, and probably save you the trouble of the new engine.

I would eliminate the valves clicking because sounds like you got sufficent oil.

A torque convertor that is loose on the flex plate or a cracked flex plate will cause a knockiing sound like that, usually mistaken for a main bearing going. Its normally most noticable in idle when speed is low and no engine load.

Next thign to do is ground out one cylinder at a time and see if the noise stops. Do this by putting a piece of vaccum hose in the spark plug wire and on the spark plug then grounding it out with a grounded test light, if noise stops when one cylinder is disabled it could be a piston pin that knocks, it also usually gives off a double knock sound.

I would eliminate timing chain noise as if the vehicles chain is worn that badly your vehicle will be running poorly. With main and rod bearing noise it depends on speed and engien load the noise it will make so I dont think that would be the problem.

If you have a heat riser remove the vaccum line from it and remove the drive belt, does noise stop when this is done?

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Thursday, July 31st, 2008 AT 4:37 PM
Tiny
JUNIORRICHARDSON
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So, when I ground the spark plug and wire with a test light and the engine noise stops what is causing the problem? And if it, s a piston pin who will I know? Also I put a wrench on the belt tensioner(which is so weak I could have held it down by hand) and let slack in the belt and the noise is still the. Does this mean any thing. PS I ONLY GET PAID ONCE A MONTH(1st-3rd) I, LL BE SURE TO SEND YOU A DONATION YOU HAVE BEEN A REAL HELP IN TIME OF NEED AND I WANT TO SAY THANK YOU!

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Thursday, July 31st, 2008 AT 7:51 PM
Tiny
BLACKOP555
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Are you saying the noise stops when you ground out a cylinder? Which one?

Take the drivebelt completely off and see if the noise still continues, a defective belt can cause a knocking type noise and is often mistaken as something much more serious.

And I would like to thank you ahead of time for the donation, it is very helpful!

Get back to me.

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Friday, August 1st, 2008 AT 8:51 AM
Tiny
BLACKOP555
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If it stops on a particuallar cylinder you can suspect a worn rod bearing on that cylinder or piston slap on that cylinder.

If it dont stop on any cylinders yoiu can suspect everything else I listed.

Id like to ask some more questions bout the sound

is it a clicking noise like clicking a pen?
A clanking noise such as tapping on metal?
Clunking like shutting a door
clatter, like marbles rolling around
knock, such as knockign on a door
or rattle type noise.

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Friday, August 1st, 2008 AT 9:00 AM
Tiny
JUNIORRICHARDSON
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I, am sorry! My question was (if) the noise did stop what was causing the problem? Also if it didn, t stop what was causeing the problem? The noise I hear is that of a metal clanking sound. Just a regular clank, clank, clank as in it something metal with a hammer

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Friday, August 1st, 2008 AT 7:27 PM
Tiny
BLACKOP555
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As I said above if the knocking stops then either you have a case of piston slap or rod bearing on that cylinder, even a hole in the piston!

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Friday, August 1st, 2008 AT 8:00 PM
Tiny
JUNIORRICHARDSON
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When grounding out the cylinder where shoul I ground the clip end of the test light on. And what do I touch with the probe end of the test light the spark plug wire or the spark plug itself

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Friday, August 1st, 2008 AT 10:00 PM
Tiny
BLACKOP555
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Hook the groudn on a good engine ground on the block, touch the probe on the vaccum line you put on the spark plug tip and into the spark plug wire.

To ground it out simply touch th eprobe part of the test light on the vaccum line.

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Saturday, August 2nd, 2008 AT 11:56 AM
Tiny
BLACKOP555
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And since you said its a clacking noise, then the most common causes of that are, a worn pison pin, a broken piston even valve clearence that is out of specs will cause that noise due to the slack.

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Saturday, August 2nd, 2008 AT 11:59 AM
Tiny
JUNIORRICHARDSON
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After I put the radiator back in, the hoses and all electric connecters that I hade disconnected (i was going to change the engine) the exact way they came off, because I labeled each piece. Now I got in the truck and turned the key and to my suprise it wont crank. The dash lights come on and they stay on while I turn the key but the starter dont engage the engine wont turn over. Do you have an idea of what, s going on. Also I took a good hot battery out of my car and put it in the truck, but it still will not turn over

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Tuesday, August 5th, 2008 AT 1:27 PM
Tiny
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Does it attempt to crank? Crank slowly fastly? Or does it crank normally jsut not start?

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Tuesday, August 5th, 2008 AT 8:22 PM
Tiny
JUNIORRICHARDSON
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It dont even etempt to start. It dont make a sound when I turn the key the only thing that happens is the dash lights and radio lights up also the interior lights

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Wednesday, August 6th, 2008 AT 6:43 AM
Tiny
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When key is turned to start do the dash lights go out like normal or stay on? Turn on the headlights and attempt to crank it, anything?

I would double check all connections and grounds might have knocked one loose, make sure you hooked up wires properly also.

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Wednesday, August 6th, 2008 AT 9:08 AM
Tiny
JUNIORRICHARDSON
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The dash lights stay on when the key is turned

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Wednesday, August 6th, 2008 AT 9:11 AM
Tiny
BLACKOP555
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Sounds like a bad ignition switch to me.

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Wednesday, August 6th, 2008 AT 12:56 PM
Tiny
JUNIORRICHARDSON
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Would the ignition switch go out just like that, I nver had any problems out fo it before, also I took the starter back off and the little bolt that the (purple) wire goes on which would be the stud for the starter (s) has broken in half do to rust. But it, s not enough left to put a nut back on it with the terminal on the purple wire. So I wrapped the wire around what little bit of stud is left sticking out. And put the starter back on and when I turned the ignition switch this time it clicked so I turned the switch off, then I tryed it agian and it clicked again as in the battery post was loose or something! So I checked the post they both are tight and the starter wires are tight. Got in the truck and tryed again and nothing, s happing now no click or anything so I know I need a new starter because the terminal is broken do I need to purchase a ignition switch as well

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Wednesday, August 6th, 2008 AT 3:10 PM
Tiny
BLACKOP555
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Hmmm, sounds like the ignition switch is good since it clicked like that. Still could be a error with it but I wouldnt buy one till hte starter is replaced, also have the solenoid looked at also whle your there.

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Wednesday, August 6th, 2008 AT 7:00 PM
Tiny
JUNIORRICHARDSON
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I, grounded the cylinders out like you told me to./The noise is still there.I performed this test with the serpintine belt on the engine, did I do this correct. Also I took the belt off and started the truck and the noise is still there also, but I didnt perform the grounding cylinder test with the belt off, was I suppose to? I let the truck run for about5-10 minutes and the noise sounds like it, s at the top of the engine alsoit kinda sounds like a lifter clicking orvalve noise I really dont know, i, am nota mechanic so can you to me what I should do next

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Saturday, August 9th, 2008 AT 5:04 PM
Tiny
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After 5 or 10 mins it starts making that noise not when cold?

If you shut it off and then restart it right away does it take 5-10 mins to reapear or does it start right away?

Are you planning on switching the engines out or no?

Maybe you can take the valve covers off see if theres any wear on the pushrods or lifters. Indicating a lack of oil to them or too little oil.

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Sunday, August 10th, 2008 AT 8:56 AM

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