5.3 Tick/Knock?

[rockola1971]

yeah would probably need a right hand drill no chance I fit a normal one in there.

But also I’m starting to think it’s a lifter not an exhaust leak. The tick almost sounds like it’s coming from farther up on that bank not from that exhaust bolt missing.

Drop a quart of transmission fluid in your oil and let idle. See if tick goes away. (Do all this immediately BEFORE you do an oil change). DO NOT drive around with a quart of tranny fluid in your oil. Tranny fluid will free up stuck lifters.

 

[JPVortex]

use a stethoscope

good idea, ill have to pick one up. I had one but have no clue what I did with it

 

[JPVortex]

Drop a quart of transmission fluid in your oil and let idle. See if tick goes away. (Do all this immediately BEFORE you do an oil change). DO NOT drive around with a quart of tranny fluid in your oil. Tranny fluid will free up stuck lifters.

Yeah I’ve read about this will definitely try this when the time comes(still have like 1k miles until the next change). How long would you recommend idling it in the driveway before dropping the oil?

 

[Doubeleive]

Yeah I’ve read about this will definitely try this when the time comes(still have like 1k miles until the next change). How long would you recommend idling it in the driveway before dropping the oil?

I have added a qt before and driven it like 10 miles, didn't hurt anything and in my case didn't help either but can be worth a try as well

 

[viven44]

How likely is it for a loose rocker arm ? If/when valve covers are off, be good to check all the rockers, ensure the engine is at the appropriate TDC positions before checking each rocker.

I don't know much about these LS engines... but assume these are like any old pushrod with non-adjustable valves. I would certainly like a link to any factory manual procedure to check rocker bolt torque for my reference.

Thread below seems like a good reference

5.3 Valve Lash

Hello, I am new here but i have a 2001 5.3 vortec tahoe. It is having some valve knock or lifter rattle on startup and i want to lash my valves. does anyone have a guide on this or the exact torque specs and lash chart? thanks.

www.tahoeyukonforum.com

 

[Fless]

According to Haynes, the torque setting for the rocker arm bolts is 22 ft-lbs. And here's the short part of the installation instructions:

 

[viven44]

According to Haynes, the torque setting for the rocker arm bolts is 22 ft-lbs. And here's the short part of the installation instructions:

View attachment 439856

View attachment 439857

Thanks much. Simple enough. If the OP is trying this, I must insist using an accurate torque wrench. A 3/8 inch torque wrench but I prefer an adapter like this.

https://www.harborfreight.com/38-in-drive-59-59-ft-lb-digital-torque-adapter-58705.html?utm_source=google&utm_medium=cpc&utm_campaign=12192884362&campaignid=12192884362&utm_content=163981024442&adsetid=163981024442&product=58705&store=&gad_source=1&gclid=Cj0KCQjw6oi4BhD1ARIsAL6pox3L1rx2qI4Fu2UHqpFip90xCj0vm4jES5ltymTa3_rdthBnnHrNQtcaAhOVEALw_wcB

 

[JPVortex]

How likely is it for a loose rocker arm ? If/when valve covers are off, be good to check all the rockers, ensure the engine is at the appropriate TDC positions before checking each rocker.

I don't know much about these LS engines... but assume these are like any old pushrod with non-adjustable valves. I would certainly like a link to any factory manual procedure to check rocker bolt torque for my reference.

Thread below seems like a good reference

5.3 Valve Lash

Hello, I am new here but i have a 2001 5.3 vortec tahoe. It is having some valve knock or lifter rattle on startup and i want to lash my valves. does anyone have a guide on this or the exact torque specs and lash chart? thanks.

www.tahoeyukonforum.com

Yeah definitely will retighten each of the rocker arm bolts(at least on passenger side) when I do that valve cover gasket job.

Based on the manual that @Fless sent over, seems you don't have to set TDC for each cylinder. Seems like you set cyl. 1 to TDC and tighten half the cylinders bolts down to 22ft lbs. Then you rotate the engine 360 degrees and torque the other side.

Doesn't that mean the whole time you're setting the torque that you'll have cyl. 1 at TDC?

 

[JPVortex]

Thanks much. Simple enough. If the OP is trying this, I must insist using an accurate torque wrench. A 3/8 inch torque wrench but I prefer an adapter like this.

https://www.harborfreight.com/38-in-drive-59-59-ft-lb-digital-torque-adapter-58705.html?utm_source=google&utm_medium=cpc&utm_campaign=12192884362&campaignid=12192884362&utm_content=163981024442&adsetid=163981024442&product=58705&store=&gad_source=1&gclid=Cj0KCQjw6oi4BhD1ARIsAL6pox3L1rx2qI4Fu2UHqpFip90xCj0vm4jES5ltymTa3_rdthBnnHrNQtcaAhOVEALw_wcB

Seems like a cool tool! need to pick myself up one of these!

 

[JPVortex]

Yeah definitely will retighten each of the rocker arm bolts(at least on passenger side) when I do that valve cover gasket job.

Based on the manual that @Fless sent over, seems you don't have to set TDC for each cylinder. Seems like you set cyl. 1 to TDC and tighten half the cylinders bolts down to 22ft lbs. Then you rotate the engine 360 degrees and torque the other side.

Doesn't that mean the whole time you're setting the torque that you'll have cyl. 1 at TDC?

I'm very stupid, obviously it takes 2 rotations to get cyl. 1 to TDC. 360 degrees after TDC would be 180 out from TDC.

 

[viven44]

Yeah definitely will retighten each of the rocker arm bolts(at least on passenger side) when I do that valve cover gasket job.

Based on the manual that @Fless sent over, seems you don't have to set TDC for each cylinder. Seems like you set cyl. 1 to TDC and tighten half the cylinders bolts down to 22ft lbs. Then you rotate the engine 360 degrees and torque the other side.

Doesn't that mean the whole time you're setting the torque that you'll have cyl. 1 at TDC?

Yes that is correct. Your are rotating the crank, so the camshaft will be rotating at 1/2 the speed. You will rotate the crank 360 degrees 2 times for a complete cycle. The first time you are at TDC you will check 1/2 the valve train, the second time you are at TDC you will adjust the other 1/2.

PS: On the old trucks its really intuitive as you will also have the distributor cap off so you can monitor where the rotor is in relation to cylinder 1. You will see clearly that the first time you are at TDC, you are ready to fire cylinder 1 and the second time you are 180 degrees out on the rotor.....

 

[viven44]

I'm very stupid, obviously it takes 2 rotations to get cyl. 1 to TDC. 360 degrees after TDC would be 180 out from TDC.

No you are good!

Watch the valve train. At true firing TDC cylinder 1 (or any cylinder for that matter), the intake and exhaust valves are equal and closed.

 

[JPVortex]

No you are good!

Watch the valve train. At true firing TDC cylinder 1 (or any cylinder for that matter), the intake and exhaust valves are equal and closed.

Yeah I’ll also throw a long zip tie or a wooden skewer or something down the spark plug hole and wait till it doesn’t come up anymore.

 

[viven44]

Yeah I’ll also throw a long zip tie or a wooden skewer or something down the spark plug hole and wait till it doesn’t come up anymore.

Don't insert anything brittle like a wooden skewer. (DAMHIK )

But honestly thats not necessary and oftentimes kind of pain to watch and figure out TDC, if you have the valve cover off, you WILL notice the valve positions and know you are at TDC. If you want to get real accurate, use a leak down testing kit and fill up the cylinder with compressed air, it will put things at TDC even if you are just a hair bit off ( the valves will close with air pressure) !!

 

[JPVortex]

Don't insert anything brittle like a wooden skewer. (DAMHIK )

Maybe something that won’t break easily then

 

[viven44]

Maybe something that won’t break easily then

Sure, but I'd any day prefer a leakdown tester to put valves dead center. Based on what @Fless sent you want cylinder 1 at compression TDC for the first set of adjustments (checks) and cylinder 6 at compression TDC for the second set of adjustments (checks).

The idea is to get least amount of air leak past the valves as you are spinning the crank... when you are at exact TDC, you will hold air pressure inside the cylinder.

Oh, and do not forget to remove the wrench off the crank before starting the vehicle! I've had a lot of luck in this department after forgetting to! Haha

 

[rockola1971]

Yeah I’ve read about this will definitely try this when the time comes(still have like 1k miles until the next change). How long would you recommend idling it in the driveway before dropping the oil?

You can let it sit all day at idle if you want but if you have a stuck lifter, the tranny fluid will circulate and free it up within 10-15mins. You can give the engine some revs but me personally I do not load the engine down out on the street with anything but oil in it. Ive even heard of some old timers (much older than my old a^^) use diesel fuel, kerosene, etc to free up stuck lifters.

 

[JPVortex]

Thank you guys for all the tips!

another tip I found on finding TDC is by actually using an engine vacuum gauge attached to the hose for a compression tester. Never seen that done before but seems interesting.

 

[frank1]

Just about everyone I have owned, were noisy on cold start,but usually quite down when warm.

 

[JPVortex]

Update time, paid closer attention to the noise.

It does seem to be a bit louder when cold, quiets down a little bit when it’s warm.


I got my coworkers opinion(a former mechanic) he ran the throttle and to him he said it sounded like a lifter.

However then I put a stethoscope on it. I can hear the ticking no matter the position of the scope on the head BUTTT when I put the stethoscope right on the top of the exhaust manifold where the broken stud is, the sound got MUCH louder, almost enough to hurt my ears.

Number 1 suspect is exhaust leak now. I don’t think a lifter would be that loud right where the broken exhaust manifold bolt, especially since the lifter is facing the inside of the head towards the intake.