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2004 engine noise (clattering)

9

9fingers

Full Member
Joined
Sep 23, 2004
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104
Bought this new, but it's starting to make some engine noise on startup. Let it idle a bit. (Maybe 2-3 minutes) And it's just fine. But start it, throw it in gear, and it sounds like a diesel.. it has a clatter. I'm assuming it's just taking a while for the oil to get to where its suppose to be.. is this something to worry about. Or just let the oil get where it's going and not worry. Is there something I should do ?
It's the 5.3 engine if that makes a difference.
Thanks !
 
Check your engine oil level?

How many quarts come out after an oil change? How long since last oil change?
 
I've had an Avalanche since 2002. The 8.1L engine has always made a clattering noise for the first minute after startup. It now has 235k on the engine. It doesn't burn any oil, no smoke and the clattering goes away. It's just the way the engine has always been. Perhaps your 5.3 is the same way.
 
Piston slap it is called, On the 8.1 the piston skirts are short to get the stroke and the size of the piston is reduced so that on startup the skirt does not gull on the cylinder when its cold. Your pistons may have the skirt wearing to the point that now it needs to be warmed up. Could be that the lifters are needing longer to pump up also. How many miles?
 
Just changed the oil, but didnt really notice how much came out... it has 110k on it. I'm thinking it may be the lifters not pumping up.. hard to know. But want to make sure I dont screw it up any more than it might be.
I use standard oil, this time was high milage oil
Thanks for the help !
 
What is the oil pressure reading when it happens.
 
When I start it. The guage immediately shoots up to 40. Add a little gas and up to 45.
 
That's a strange one, what state are you in and how cold is it.
 
40 is way low for a cold engine. My 2004 5.3 with 160K is 60+psi with 5W30, but your gauge could be off. Better get pressure tested as could have some bigger issues. What about pressure at (30 minutes or longer) hot idle in drive? Does the problem occur before putting in drive or reverse?
 
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It seems like has always read that.. since new. I did have to change out the gauge board though.
 
I was thinking that's low also, mine starts at 60-80 then drops to 40 when it warms up.
But the AV stays in Michigan
 
9fingers said:
Bought this new, but it's starting to make some engine noise on startup. Let it idle a bit. (Maybe 2-3 minutes) And it's just fine. But start it, throw it in gear, and it sounds like a diesel.. it has a clatter. I'm assuming it's just taking a while for the oil to get to where its suppose to be.. is this something to worry about. Or just let the oil get where it's going and not worry. Is there something I should do ?
It's the 5.3 engine if that makes a difference.
Thanks !
Click to expand...
Hmm. mileage? I have a 5.3 with 270K. Sounds identical, mine is lifters. I'll be getting engine rebuild.
 
My 2003 1500 Z-66 with the 5.3 has 250K miles on it.

Cold oil pressure at idle is 40-45.

Hot oil pressure at idle is 30-35.

Hot oil pressure at cruise RPM is 45-50.

I don't doubt that a new oil pick up tube o-ring would help, but the pressures are sufficient, at the moment.

The engine has lifter noises when it is first started from dead cold, but within a minute, the engine goes silent and stays that way for the rest of the day.

This engine runs very smooth and quiet, for it's age and mileage.

My 2004 EXT with 236K miles on it and the 6.0 engine has a different set of problems.

The engine developed some lifter noise that was later determined to be caused by a crack in the driver's side head that was allowing coolant to seep down into the crankcase when under pressure and mix with the engine oil.

This coolant contaminated oil could not allow the lifters to stay pumped up after sitting for a while and the lifters would clatter until the oil/coolant mixture was able to pump them back up.

When the engine was running, the lifters were quiet as expected.

After a fresh oil change, the engine started and ran quietly.

It was only after a couple of hundred miles did the start up lifter clatter return.

Since the engine had been run for more than a year with these symptoms before I determined the actual cause, I have no doubt possible damage to not only the lifters, but also to bearings, cam and other wear surfaces inside the engine may have occurred.

The EXT has sat unused in the garage since February, 2020 while it waits for a reman engine to be installed.

Since I have the Avalanche to drive as my daily, I am waiting to see how this virus thing shakes out before dropping that dime.

The money for this repower is ready and waiting, but I want to sit on that dough until we see what is in store.
 
I had a very similar issue. Thinking it was a lifter tick. Dropped some seafoam into the crankcase before doing an oil change and it helped a bit but the ticking was still there....To make a long store short I discovered that I had a couple bolts that broke off the exhaust manifold. Replaced the gasket and bolts and ticking was gone.
So what was happening was when the engine was cold it would tick for a bit but when warmed up the metal expands closing the gap.
If you want to see if this is what is causing your issue attach a shop vac to the tailpipe and have it blow in. Then get some soapy water and spray around.
Hope this helps and best part it doesn't cost a cent.
 
My EXT did have a couple of broken exhaust bolts.

I had them all replaced.

No joy for me.
 
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