Engine Noise Video

lovemysan · October 28, 2008

Recently noticed this noise from the engine on my suburban. Its not noticeable from inside the cabin or when leaving the garage etc. You can hear when close to the wheel wells or coming out of the grill so its not loud or pronounced. When you pop the hood it first sounds like an exhaust leak or loose plug wire. It seems to be coming from the injectors but it did not make this noise when I bought it 5k miles ago. Mixed in the sound there is one audible tap that sounds like a lifter. I took it to a GM tech and he recommended I try heavy oil. Its currently running amsoil 20w50. No change in sound.

2000DV4.8 · October 28, 2008

Can't see the video at school, but check the exhaust mainfold bolts. Sometimes the bolt-heads pop off, and the leaking manifold makes a knocking/ticking sound.

pennzoil29 · October 28, 2008

Welcome to the forum . It almost sounds like an exhaust leak, but might be a lifter. If you would have rev'd the engine a bit, I could've had a better idea.

lovemysan · October 28, 2008

It sounds like an exhaust leak in the video but the noise dies out when revved.

Zembonez · October 29, 2008

You are not using the right oil.

+1

20w50 isn't the right weight for a 5.3. I'd switch to a correct oil first.

You might have lifter noise? The video sounds like an exhaust leak but if it was that bad, it wouldn't go away when revved.

lovemysan · October 29, 2008

You are not using the right oil.

+1

20w50 isn't the right weight for a 5.3. I'd switch to a correct oil first.

You might have lifter noise? The video sounds like an exhaust leak but if it was that bad, it wouldn't go away when revved.

I know its the not the correct oil. The GM tech suggested I try heavy oil. He thought that it was valvetrain noise caused by poor maintenance or being run hard. At this point I'm not sure. The heavy oil made no difference in sound. I discussed the 20w50 with my amsoil guy before trying it. He said that I could run any weight amsoil with no ill affects(I'm running 0w20 in my saturn SL). He's been selling/using the stuff since the late 70s. The video was taken after 500 mile drive so its hot. I may try the 0w30 signature next oil change. I guess will just have to see if it gets worse before it can be diagnosed. I did save some oil to do a UOA. Maybe that will turn something up.

lovemysan · October 29, 2008

Some other symptoms. This occurs only after the engine is warmed up. It goes away when revved or under load. It sounds like a mixture of injector, lifter, chain noise with dabble of exhaust leak mixed in. The Tech that listened to it had never heard anything like it. The oil pressure gauge has always acted normal and reads 35lbs at idle. Oil weight doesn't affect it. The engine was flushed before changing to the current oil. I running a amsoil Ea oil filter.

Zembonez · October 29, 2008

Some other symptoms. This occurs only after the engine is warmed up. It goes away when revved or under load. It sounds like a mixture of injector, lifter, chain noise with dabble of exhaust leak mixed in. The Tech that listened to it had never heard anything like it. The oil pressure gauge has always acted normal and reads 35lbs at idle. Oil weight doesn't affect it. The engine was flushed before changing to the current oil. I running a amsoil Ea oil filter.

I have to agree with the tech. The AMSOIL probably won't hurt a thing. We were just commenting that it wasn't the prescribed weight (which you know) I've heard 200K 5.3s and none of them really made any noise. Nothing like that anyway. The 4.8 / 5.3 engines do all have a bit of a clatter to them, even when fresh. It's just a characteristic of the engine.

Before changing your oil, you should try some Lucas additive... just to see if it changes the sound.

pennzoil29 · October 29, 2008

Some other symptoms. This occurs only after the engine is warmed up. It goes away when revved or under load. It sounds like a mixture of injector, lifter, chain noise with dabble of exhaust leak mixed in. The Tech that listened to it had never heard anything like it. The oil pressure gauge has always acted normal and reads 35lbs at idle. Oil weight doesn't affect it. The engine was flushed before changing to the current oil. I running a amsoil Ea oil filter.

This is just a thought, but if you flushed the engine, you may have dislodged some crap, and now you might have more clearance. If that makes any sense to you. I'm not a firm believer in engine flushing. It can sometimes cause more harm than good. jmo

lovemysan · October 29, 2008

Some other symptoms. This occurs only after the engine is warmed up. It goes away when revved or under load. It sounds like a mixture of injector, lifter, chain noise with dabble of exhaust leak mixed in. The Tech that listened to it had never heard anything like it. The oil pressure gauge has always acted normal and reads 35lbs at idle. Oil weight doesn't affect it. The engine was flushed before changing to the current oil. I running a amsoil Ea oil filter.

This is just a thought, but if you flushed the engine, you may have dislodged some crap, and now you might have more clearance. If that makes any sense to you. I'm not a firm believer in engine flushing. It can sometimes cause more harm than good. jmo

I flushed it after I noticed the noise. I'm not a fan of flushes either. I've since driven 1300 miles with the new oil. No change in sound. I'm going to check the exhaust manifold gaskets soon. It sounds like an air leak of sometype. Maybe it will throw a code and give me a clue.

My brother has a 2000 silverado 5.3 with 144k and its very quite at idle it also has a lot more power than the burb. Wonder why it has more power? What are the differences between the 2.

97SierraGMC · October 29, 2008

could be a vacuum leak.. but sounds like its chattering..

my idler pulley was doing this on my 97, not as loud but same type of noise when idling..

lovemysan · October 30, 2008

could be a vacuum leak.. but sounds like its chattering..

my idler pulley was doing this on my 97, not as loud but same type of noise when idling..

It does have a alternator idler thats getting noisy but its not noticable in the video.

wdavrac · December 13, 2008

Hey all got the same issue with my 05 5.3 sierra, any answers on what your issue is yet? Gm told me it was a cracked flywheel the sound is nowhere near the flywheel pinpointed around no 2 cylinder. Also not any pully driven item (though thats what it sounded like kinda like a squeiling belt) anyways pulled the belts started, noise still there???? Added oil additive no change, been acting weird since I started using synthetic?????

lovemysan · April 17, 2009

I thought I'd update this. I've switched to amsoil 0w30. With no noticable change in sound. So far the sound really hasn't changed. 4 months ago I chased a burglar who broke into one of my tenants. I followed the car for 10 minutes and spent a lot of time at WOT. We followed him into a rough part of town and turned back. We were able to catch and contain the other one who ran on foot. He was arrested. And his friend in the car was caught 2 weeks later.

Anyway the suburban didn't seem to care, the noise didn't change either. It came away with nice little battle scar on the front bumper too. I was shooting for a cave in but the "abuse mode" prevented me.

Deichler · April 17, 2009

Are you talking the kind of screaming noise? Thats the alternator, my 08 sounds like it has a Turbo! As for the engine itself, yea, it sounds a bit different. I can't put my finger on it but I may do a vaccum test once. Especially since you are losing power. How is the fuel millage? That may also tell a vacuum leak also.