Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner

1 - 4 of 4 Posts

·
Registered
2006 chevy trailblazer_lt
Joined
·
4 Posts
Discussion Starter #1
okay to start I have a 06 Trailblazer with the 5.3. I had a DOD lifter fail on me so I did the DOD delete.

New PCMofNC Rob style cam
LS7 lifters
LS7 valley pan replacement
new valve springs
PCV delete
PCMofNC mail order tune

everything else is stock. I'm getting some valve train noise after everything so I have ordered a pushrod length checker and waiting for it to some in so i can check my lifter pre-load. (re-used the stock push rods)

the questions I have is about the oil pump. I'm reading mixed things from different places online.

Do I need to change my oil pump to a non-DOD pump off an LS2?
do I NEED to plug the oil pressure relief vale in the oil pan?
I'm sitting at 55psi at idle with 5w30 (on a cold start then drops back down to about 45) I'm also in Chicago with the cold weather.

this is a daily driver that may see the track here and there.

I did not plug the DOD oil holes under the valley pan..

if I can just get the valve train to shut up after the new pushrods I will be happy..

I don't really want to drop the oil pan as it is a 4WD truck

until I get the pre-load checked I'm not spinning the motor over 3,000 rpm


TL;DR: Do I need to change the oil pump and block off the oil pressure relief vale in the oil pan?
 

·
Vendor
2007 chevy
Joined
·
486 Posts
Hey, saw you had some of our parts (thank you!) You are using an aftermarket valve spring, correct? That cam isn't meant to work on stock springs (even if new).

It is possible the pushrod length is off, that will definitely give you added racket. LS valvetrains are noisy by nature, so adding a larger cam with more lift/duration will sometimes make them sound louder than stock, even if PR length is correct.
 

·
Registered
2006 chevy trailblazer_lt
Joined
·
4 Posts
Discussion Starter #3
Hey, saw you had some of our parts (thank you!) You are using an aftermarket valve spring, correct? That cam isn't meant to work on stock springs (even if new).

It is possible the pushrod length is off, that will definitely give you added racket. LS valvetrains are noisy by nature, so adding a larger cam with more lift/duration will sometimes make them sound louder than stock, even if PR length is correct.
Hey Kelly... it's Me Mike.... the guy that COMP messed up the cam on..... i just picked up push rods off you the Brian Tooley 7.425 ... fixed up my problem :) Idle's better, started easier, and the exhaust tone sounds so much better!

just installed them on Sunday. sounds a lot better... but i think my tune from your guys may be a little rich... getting about 9mpg in the city and some rotten egg smell after reving it up to 6K

i just got a fresh tank of gas and want to use it all up before i start to look deeper into it. (maybe a bad cat)

i will use my OBDII logger too to check the cat temp... (could be a bad cat)

when i pulled the plugs they where like brand new so i'm not sure yet... i will post you posted :)
 

·
Registered
2006 chevy trailblazer_lt
Joined
·
4 Posts
Discussion Starter #4
also the 7.425 push rods give me a 0.075 preload on the lifter. just under the 0.080 i was shooting for.
 
1 - 4 of 4 Posts
Top