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chevy 350


MILO

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my dad's suburban ('98 i think) sounds pretty rough when it is first started up, and for about the first 10 minutes or so of driving, then it quiets down and sounds normal. it almost sounds like the rockers/rods are gonna come through the valve covers on both sides of the motor, not just one tapping. oil pressure is pretty high at first, then usually levels off to normal later also. all the normal tune up things haven't helped a bit. it almost sounds like the oil pump isn't working too hot till things get warmed up or something. any other ideas or experience? :confused:

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If its a rapping noise its probably rod bearings, If its more of a hollow sound its prolly main bearings, oil pumps don't make any noise other than a wine sometimes.

Lifters make a ticking sound but and can sometimes "pump up" after the engine has run for a while and smoothen out, but if thats the case then the lifters are toast and need to be replaced. If you ask me (and I build these things for a living) it sounds like bottom end noise and any further driving will do more harm than good. I think your dad is lookin at a rebuild.

Be thankful its a 350 chev and not some $1,000,000 dollar nissan twin cam vvt, dfi sst fu2 v6 rebuild!....in otherwords there pretty cheap to rebuild :D

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what motor? 5.3, 6.0 or 8.1 (5.3 is the only all aluminum of the 3)

if it happens on cold startup, i will have too say it is piston slap (which is normal in the all aluminum LS based motors).

it is very common!

some motors have it worse then others tho.

if you have some sort of warranty, try and get GM too install a crate motor (they have done it for others because of the piston slap)

my guess is that when the weather warms up in the spring and summer, it wont be as noticeable but will still be there

Edited by Mullet Man
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if i'm not mistaken tho, GM made the switch away from the SBC's of old in '98 for the trucks (which if his has a 350 it would be the Vortec 5.7) and into the new LS based motors in '98 for trucks (i could be wrong tho, thats why i asked) and with that switch, the trucks never got a 5.7L 347cid LS1 that only went into F and Y body's, they got either an aluminum block 5.3, iron block 6.0, iron block 8.1 or deisel

 

find out which it has for sure, once you open the hood it should be in plain site either on the engine cover or stickers on the radiator support

Edited by Mullet Man
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1998 suburban should have a 350 in it.

What kind of oil filter are you using in it?

THe old 350's take a PF35 in the ac delco brand.

The late ones, I think 1988 on up take a PF1218.

The 1218 has a check valve and keeps oil on top of the engine for start ups.

The wrong oil filter will cause a lot of noise due to inadiquate lubricaton on the top of the motor during startup . This may be what's happening to you. I used to work in auto parts and I've seen this shit happen a lot. :lol:

Not sayin it's ur situation but something to look at. :shrugani:

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if i'm not mistaken tho, GM made the switch away from the SBC's of old in '98 for the trucks (which if his has a 350 it would be the Vortec 5.7) and into the new LS based motors in '98 for trucks (i could be wrong tho, thats why i asked) and with that switch, the trucks never got a 5.7L 347cid LS1 that only went into F and Y body's, they got either an aluminum block 5.3, iron block 6.0, iron block 8.1 or deisel

 

find out which it has for sure, once you open the hood it should be in plain site either on the engine cover or stickers on the radiator support

466913[/snapback]

 

the 4.8 was also an option ;)

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my mistake, it is a '97 - 5.7 vortec.

after discussing it with my dad again, he said that it only started making noises shortly after the first oil change that he did just a few months ago. he then drained out some oil, and put in some stp and it seemed to clear up until a week or so ago again. so we changed the oil again a few days ago and added stp again, but it still sounded the same. he wasn't sure of the # of the filter before the 1st change but the PF52 is what the parts store listed, and he used 5w30 on the first change, and 10w40 this time.

his manual states to use PF1218, but has a note that for a 4wd, which it is, to use a PF52. so we're gonna dig a little deeper into this filter ordeal, since it's obviously the easiest and cheapest solution. :P but if that doesn't pan out, we'll be looking at other things.

thanks guys. :cheers:

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Oh shit. I forgot to mention if it was a 4x4. The late Z71's with the 5.7 (350)

took the pf52. If im not mistaken it has the check valve in it. You may could try a different brand of filter, maybe as a cheap start. Try a WIX brand if you can find one at an autoparts store. I know they have the checkvalves in em. I think most NAPA's have wix filters. 7 or 8 bucks.......cheaper than a set of lifters and a camshaft, if that is ur problem :lol:

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