KNocking sound! Clip Included!

[jene]

Ok.. so that knocking is still annoying me. So I finally made a clip for ya to hear. Turn the volume up and watch the whole clip!!   You can clearly hear it and whne i pop the hood it is louder and when i zoom inot the valve cover.. it kinda looks like it it going with the rockers... but i am no expert and i sounds like poop!!  It use to go away after about 5 minsute of driving.. but now it seems to stay longer, but after the first 5 mins it get quieter?? Im not totally sure about that though... i need to pay attention..

what i do know is when i used regualy 5 30 oil..it didnt seem to do this.. but over the last year tires plus has been doing an oil change and using semi synthetic and it seems to be doing this more... not sure if that has anything to do with it or now..

any ideas.. should i just not worry? is it the regular 60 degree knock i am hearing??

I should add it has been doing this for almost a year now...not anything new

Engine Knock

[SuzukiGhostRider]

It sounds like a noisy valve train,but then again there also appears to be a heavier knocking that sounds like it's coming from the bottom end. This is one of those things that's really hard to diagnose w/o being physically present with the car...... Sorry I can't be more helpful than that Jene.

[jene]

To mee it seems to get louder when i uncap the valve cover.. but like i said.. im not expert.

I have been driving like this for  a year.. racing like this for a year...  I just want to be well prepaired if the engine is going to go so i can have another 3400 and swap time lined up so i dont miss any racing...

Plus scott says it is the normal 60 degrees knock.. i just want to be sure of this...


Scott looked like a freak and put a screw driver from his ear  to the engine and said it sounds like rockers??? IS HE OFF HIS ROCKER??? hahaha

[Rodville]

No putting a screwdriver to your ear is a way many mechanics look for where the sound is coming from. The ticking sounds like what mine sounds like when I try to drive it.

And I had to comment on the vid sorry. That first guy to comment was a a-hole.  

[MichaelW]

my 3100 sounds like that too.  Im in search of what it is too, but for the mean time I just blast my sub to cover the sound ( but the sound is not very loud anyways, but i like an excuse to blast the sub anyways  )

[jene]

(Rodville @ Apr. 06 2008,18:20)QUOTENo putting a screwdriver to your ear is a way many mechanics look for where the sound is coming from. The ticking sounds like what mine sounds like when I try to drive it.

And I had to comment on the vid sorry. That first guy to comment was a a-hole.  

Lol.. scott is funny.. he seen the screwdrive thing on tool time and figured he would try it..lol

he also listend from the bottom end and its not coming from there..  Maybe it is the normal knock... it kinda goes with the lifters and rockers..

no biggIe.. he is a D anyways  

[pimpz26]

I use a wood broom handle to listen to engines.  Found many problems just by listening.  Try it, it works.

[jene]

These are all tools i like to beat scott over the head with sometimes!! it will be easy to remember next time  i need to listen to something!

[jene]

What to you think about me replacing the  rockers and push rods?? think that might fix it?? or a stupid move?? the lifters we got from 3400 modified and i trust that they were good lifters.. so i am highly doubting it is those...

What are the torque specs for the rockers when we put them back on...

we are throwing on 3400 exhaust manis (with flange and 2.5 down pip thingy) in a month or so anyways.. might be a good idea to do this all at once??

OH AND I KEEP ASKING... I HAVE THE 3100 EXHAUST MANIS ON... HOW MUCH WILL IT HELP TO PUT THE CORRECT 3400 ONES ON.. HP AND TIMES ESTIMATE...

Thanks you guys!!! I love you!!

[Barry]

I have the same EXACT noise, but much quieter. However, Im in the process of swapping topends, including rockers. Ill see if the noise goes away. Its not something that im worrying about though...

[Mr. Beefy]

My corsi sounds like that for the first 2-3 minutes at cold startup. Then it doesnt make noise. My sister-in-law's boyfriend's 3100 GP sounds like that all the time with 170K on the clock.

[JeffD]

That noise is very common on the 60* engines, it's piston slap. it happens on all the higher mileage engines. GM officially considers it normal. it's caused by an excessive gap between the piston and cylinder wall, and when the piston fires is slaps the piston against the wall. it'll go away cause the pistons expand when the get hot.
My friends 96 3100 does it too, I wouldn't worry about it unless boring out the engine and buying new pistons is in the budget. lol  

[jene]

Anything is in the budget... but this engine only has about 35,000 miles on it..

[6r8ph1X]

i have to agree with scberetta3800  THATS PISTON SLAP!!!!!!!!!!!!!!!!! WooHoo!!!!!!!!! welcome to the piston slap club!!!!!         I got it too Jene don't worry, nothing to bad. Although i replaced my lifters and it helped alittle.  

[2tone88]

Ok I'm prolly gonna get beat for sugguesting this......
 I know theres no such thing as a mechanic ina bottle but would an oil treatment like lucas or stp help quiet the noise any?