5.7 vortec engine sound. is this normal?

[hi54lofi]

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Sounds like this and worse when first starting cold. then gets quiet like this after 30 seconds. ive heard it may be piston slap but I dont know much about how an engine should sound. any thoughts? thanks in advance. 97 k1500 burb 225,000

 

[movietvet]

To me, yes, it sounds like piston slap and typically goes away after a few seconds after a cold start. There is also a chance of lifter bleed down after higher mileage engine sitting overnight and has to pump up after a cold start. That noise would be a higher pitch and typically goes away quicker. What oil do you use and what weight? What filter do you use? Oil change intervals?

 

[hi54lofi]

i usually use mobile 1 5w 30 synthetic. I use a fram 10k interval filter. intervals are about every 2.5k. I just worry because it never fully goes away. hopefully it doesnt get worse. i dont have a trained ear but to me it sounds more knocky or lower pitched. I never noticed the noise until recent winter months where temps got down to 30f

 

[movietvet]

Just for giggles, try a 10w-30 Mobil 1 next time. I doubt that the filter is causing any worries but I have always used WIX XP filters. I am i the same camp for oil change intervals too. I go between 2500 to 3000 miles. At 225,000 miles, I would not worry too much. What is the oil pressure at cold start and after complete warm up, both readings at idle?

 

[95burban]

Thicker oil for sure. I use 15-40 rotela, haters gonna hate but I’ve never had issue with it. It was recommended to me by my machine shop/engine builder that builds nitro funny car engines.

 

[someotherguy]

When I switched from whatever the previous owner was using in my rode-hard '93 454, to Mobil1 5W30, it sped up the leak that I believe is the rear main seal. Truck went from just having visible signs on the engine of a leak, to staining the driveway. Hopefully just rear main seal and can deal with it when the NV4500 is out for upcoming rebuild.

Not sure I'd go to 15w40 where it gets cold. OP is in Washington state.

Richard

 

[movietvet]

When I switched from whatever the previous owner was using in my rode-hard '93 454, to Mobil1 5W30, it sped up the leak that I believe is the rear main seal. Truck went from just having visible signs on the engine of a leak, to staining the driveway. Hopefully just rear main seal and can deal with it when the NV4500 is out for upcoming rebuild.

Not sure I'd go to 15w40 where it gets cold. OP is in Washington state.

Richard

Really depends on where he is in Wa. state. They get a lot of rain, like we do in Oregon. I ran shops here in Eugene area since 1996 and have advised this oil weight change before with positive results. Some took it further to 10w-40 and they were happy too.

 

[hi54lofi]

oil pressure at cold idle is around 40-45, warm idle is around 20. cruising warm is around 40-45. assuming my oil pressure gauge is accurate.

 

[pilly]

Sounds like a Rod Bearing to me, My 96 did same thing, Ended up w Reground Cranks and Bearing set.

 

[tinfoil_hat]

Slap at #5. This seems to be common.