motor clatter??

[texasfunk]

well, just recently the motor has started a clatter, doesnt at idel, but it gets louder with acceleration, i took the valve covers off (revealing whoeverbuilt the motor put some good money into it, has guides, hardened welded pushrods, and roller rockers) and it seemed the push rods and rockers were all in good working order, then i noticed, the header on driver side(cant notice it on passenger side at all)is missing the back 3 bolts, could this be it? i know its the source of the small tick i have been hearing, but could it be the cause of the clatter?

[bhunt31]

Originally Posted by texasfunk

well, just recently the motor has started a clatter, doesnt at idel, but it gets louder with acceleration, i took the valve covers off (revealing whoeverbuilt the motor put some good money into it, has guides, hardened welded pushrods, and roller rockers) and it seemed the push rods and rockers were all in good working order, then i noticed, the header on driver side(cant notice it on passenger side at all)is missing the back 3 bolts, could this be it? i know its the source of the small tick i have been hearing, but could it be the cause of the clatter?

What does this clatter sound like? Does it sound like a loud tick or something metal clanging around? At any rate, it's a good idea to get those bolts back in there.

[texasfunk]

Originally Posted by bhunt31

What does this clatter sound like? Does it sound like a loud tick or something metal clanging around? At any rate, it's a good idea to get those bolts back in there.

more of a loud tick, kind of like valve chatter? or when ur low on oil, i dont think it can be a spun bearing(at least i hope) cause i had tht in my elky, and it was extremly loud, and yea, tomorro i will get the bolts in,

[bhunt31]

Originally Posted by texasfunk

more of a loud tick, kind of like valve chatter? or when ur low on oil, i dont think it can be a spun bearing(at least i hope) cause i had tht in my elky, and it was extremly loud, and yea, tomorro i will get the bolts in,

You should know a spun rod bearing, it will be resonating from lower in the block than around the heads. You mentioned it had roller rockers...you wanna keep an eye on those. I had an issue running the nylon locking rocker nuts they suggest with the magnum tipped roller rockers coming loose which eventually led to the destruction of my 292H comp cam. Sounds to me like your problem is going to either be found in that exhaust leak or with an improper timing/fuel grade issue possibly causing some spark knock.

[bhunt31]

The pulse waves of the exhaust system actually suck air back to the engine for a split second, and with an exhaust leak you can get cold air back up around the valves causing it to burn a valve if not taken care of in a timely manner.

[texasfunk]

hmmm, i noticed the roller rockers were crower, how are these? and the exhause will get done tomorro, i was under the truck today, and the entire exhaust is held up by, HANGER WIRE!!! i guess he pulled the exhaust off something else and just ghetto rigged it, cause none of the mounts on the exhaust lined up, tomorro i'll run the engine without the valve covers and see what i find, luckily i got an extra set of roller's and pushrods lying around just in case,

[bhunt31]

Originally Posted by texasfunk

hmmm, i noticed the roller rockers were crower, how are these? and the exhause will get done tomorro, i was under the truck today, and the entire exhaust is held up by, HANGER WIRE!!! i guess he pulled the exhaust off something else and just ghetto rigged it, cause none of the mounts on the exhaust lined up, tomorro i'll run the engine without the valve covers and see what i find, luckily i got an extra set of roller's and pushrods lying around just in case,

Are they anodized aluminum bodied rockers? If so, they're high dollar awesome as long as they're locked down tight and set right. Just remember that Aluminum will shatter like glass when struck sharply, so you wanna be extra careful about lash being too loose. When you run it, start it cold, then wiggle each rocker as it's running, there shouldn't me much, if any, play in any of them, if there is play, it's too loose, but you should be able to hear it plain as day if there's one that's too loose.

[bhunt31]

Just struck me too, if the exhaust isn't mounted correctly, you could have a pipe getting into something and knocking around under acceleration. Might be another thing to look at.

[texasfunk]

Originally Posted by bhunt31

Are they anodized aluminum bodied rockers? If so, they're high dollar awesome as long as they're locked down tight and set right. Just remember that Aluminum will shatter like glass when struck sharply, so you wanna be extra careful about lash being too loose. When you run it, start it cold, then wiggle each rocker as it's running, there shouldn't me much, if any, play in any of them, if there is play, it's too loose, but you should be able to hear it plain as day if there's one that's too loose.

they arent square, they look kind of like regular rockers, but with a roller tip, and they say crower on them, the motor has abt 6000 miles on it, if it is a fuel/timing prob, and i have never heard the clatter before, what could have caused it?

[texasfunk]

Originally Posted by bhunt31

Just struck me too, if the exhaust isn't mounted correctly, you could have a pipe getting into something and knocking around under acceleration. Might be another thing to look at.

thought abt tht after one of them came loose, but its very noticable under the engine compartment, its not as loud when i rev it in park, but seems louder in drive under acceleration

[bhunt31]

Originally Posted by texasfunk

they arent square, they look kind of like regular rockers, but with a roller tip, and they say crower on them, the motor has abt 6000 miles on it, if it is a fuel/timing prob, and i have never heard the clatter before, what could have caused it?

Oh, then they're roller tipped rockers. They're still good, Crower is an excellent manufacturer. I never had any problems out of my Comp Magnum Roller tips, just the nylon nuts.

Bad tank of gas could cause spark knock, not all gasolines are the same, you might get a tank of really good fresh gas, the next might not be so fresh. The vacuum advance could also be acting up retarding the timing too much under load. Spark knock is most prevelant when the engine is under a load.

[bhunt31]

Originally Posted by texasfunk

thought abt tht after one of them came loose, but its very noticable under the engine compartment, its not as loud when i rev it in park, but seems louder in drive under acceleration

I'm gonna say that you're probably going to find your problem in that exhaust leak. If you have a little spare cash to throw toward it, get a set of copper or embossed header gaskets and throw on it if it doesn't already have them. If it's got the regular header gaskets on it, they're already burnt out where the 3 bolts are missing, then when you put the bolts back in, put some red loctite on the bolts to keep them from coming loose again.

[texasfunk]

Originally Posted by bhunt31

Oh, then they're roller tipped rockers. They're still good, Crower is an excellent manufacturer. I never had any problems out of my Comp Magnum Roller tips, just the nylon nuts.

Bad tank of gas could cause spark knock, not all gasolines are the same, you might get a tank of really good fresh gas, the next might not be so fresh. The vacuum advance could also be acting up retarding the timing too much under load. Spark knock is most prevelant when the engine is under a load.

Originally Posted by bhunt31

I'm gonna say that you're probably going to find your problem in that exhaust leak. If you have a little spare cash to throw toward it, get a set of copper or embossed header gaskets and throw on it if it doesn't already have them. If it's got the regular header gaskets on it, they're already burnt out where the 3 bolts are missing, then when you put the bolts back in, put some red loctite on the bolts to keep them from coming loose again.

it doesnt have a vacuum advance, the original owner converted the truck to carb because he cammed it, has a 750 double pumper holley, but has the original dist with all the connections and the coil, would this mean anything?

and def hoping the exhaust fixes it, it worries me a bit, but the truck is running great, just loud chatter!

[bhunt31]

What year is this engine?

[texasfunk]

Originally Posted by bhunt31

What year is this engine?

original TBI truck, so thats why it has a TBI distributor and all, supposedly the engine is out of a 96 burb,but it has for a mech fuel pump? which leads me to beleive it is not a vortec, but, another thing is the dipstick is on passenger side, never saw a 350 with it on this side, but it has a 350 balancer, i was told the newer 5.7's had it on passenger, but i never knew this, heads are def vortec, has a crower cam as well, and is bored .30 over,

[bhunt31]

and it still has the computer? The dizzys on those were computer controlled timing. There should be a tan wire going from the Dizzy to the computer that controls the timing advance.

[texasfunk]

Originally Posted by bhunt31

and it still has the computer? The dizzys on those were computer controlled timing. There should be a tan wire going from the Dizzy to the computer that controls the timing advance.

yea, the comp is still intact, has all the wiring intact, wiring forthe throttle body is just laid to the side, could the be a newer 350? i have only seen 305's with the dipstick on the passenger side

[bhunt31]

Ok, had me wondering there for a second about that timing issue. In mid 96 they changed from the tan/black stripe wire to not being able to control timing at all, it was all done in the computer and GM called the hard timing(turning the dizzy) the Cam Retard Offset and could only be set with a computer scanner.

If it is a 96 Suburban engine it has to be a 350, they didn't come with a 305. Only the 350, 454(in 3/4 ton models) and the 6.5L TD.

[texasfunk]

would a 96 350 have the dipstick on passenger side? this is what throws me off

[bhunt31]

yeah, the newer engines don't play by the same rules as the old engines do.

[bhunt31]

Here's a pic of a Vortec 350 engine compartment, see the yellow dipstick handle on the passenger side? Our 1996 3/4 ton 4x4 Silverado with the Vortec 350 was the same.

[texasfunk]

sweet, then i guess it is a true vortec and 96 engine as said, i swore it was a 305, then noticed the 350 balancer, this had me going NUTS! never fdealt with a newer engine besides the one in my 1990 454SS, well, tomorro trucks coming apart, and hopefully i'll fix the prob! and finally get the a/c working, found out the entire time, the compressor was leaking, not the lines! > so new comp going on, new powersteering pump, and painting the engine bahy, also rebuilding the entire steering! its gunna be a day, so night! and thanx for the help, appreciate it tons! hopefully i'll fix it.

[bhunt31]

Not a problem, let me know what you find out.

[68 TT]

The tick you described earlier sounds like when the lifters need to be adjusted but you won't know for sure until you replace the missing exhaust bolts. Three missing is half the mounting bolts. Some if not all the noise could be coming from that. Hopefully the mount bolts are not sheared off in the head. That is a real pain to repair in the truck.

In my experience roller rockers have always needed to be adjusted more frequently than stock rockers. By the mickey mouse exhaust system I wouldn't bet he adjusted the valves correctly when he installed the roller rockers.

It is possible you have a bad lifter causing the tick as well. If it is a 96 Vortec engine then it has a roller cam too so at least you don't have as much chance of it being a worn out cam lobe causing the tick.

[metalgod]

tex take a pic of this engine and post it.........i just got done reading all this and im smashing my head into my keyboard so had im going to have to get the space bar sergicaly removed from my head..........ok so you have a tbi truck? with a 96 vortec engine? with a carb? and an electric computer controlled distributor?........im missing somthing...........so is the engine have the mech. fuel pump or electric?...............i can help you out here just got to understand what your working with!!