Knocking sound at idle, but goes away under load?? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

SRx7 · 02-28-2006, 02:01 PM

I am getting an SR from a friend who said that the motor he pulled out of his car had a slight knock to it, but it only occured at idle and went away when there was load applied to the car. I am thinking of replacing the rodbearings and putting a new oil pump in it just to be safe, Does anyone have any ideas off the top of there head before I tear it apart??
Thanks

gp1300r · 02-20-2010, 12:42 AM

i need to know as well. i'm having the same problem. after 2000 rpms the knocking is gone.

Chrischeezer · 02-20-2010, 01:27 AM

get an oil pressure gauge.
rule number one of all car repairs, find the problem before you start fixing it.
get someone with a trained ear who can locate where the sound is coming from.

gp1300r · 02-20-2010, 01:30 AM

sorry to jack the thread. the sound is coming from the front of the valve cover.

Chrischeezer · 02-20-2010, 01:45 AM

i really don't mean to sound like an assh*le, but your sense of where the sound coming from "might be" untrained and lacking experience.
most people who can hear parts of a motor wouldn't ask for assistance /what to fix.

step 1 - get a mechanics stethoscope (great $5 tool), you can use a screw driver but get the stethoscope its better. probe for sound around the motor, to be accurate this skill really comes from experience.

If you think the sound is coming from the chain, remove chain tensioner, check for proper operation.
if OK then remove the valve cover, check ALL 3 chain guides for abnormal wear..

Mister.E · 02-20-2010, 02:07 AM

is it an S14 SR? does it sound like this?

if so replace VTC sprocket or get rid of VTC altogether

gp1300r · 02-20-2010, 07:19 PM

Quote:

Originally Posted by Chrischeezer

i really don't mean to sound like an assh*le, but your sense of where the sound coming from "might be" untrained and lacking experience.
most people who can hear parts of a motor wouldn't ask for assistance /what to fix.

step 1 - get a mechanics stethoscope (great $5 tool), you can use a screw driver but get the stethoscope its better. probe for sound around the motor, to be accurate this skill really comes from experience.

If you think the sound is coming from the chain, remove chain tensioner, check for proper operation.
if OK then remove the valve cover, check ALL 3 chain guides for abnormal wear..

a good friend of mine who specializes in 240s also said it was coming from the front valve cover. he thinks it's the 2 chain guards or the trnsioner.

gp1300r · 02-20-2010, 07:35 PM

Quote:

Originally Posted by E Double

is it an S14 SR? does it sound like this?

if so replace VTC sprocket or get rid of VTC altogether

that's it!. i looked up more videos on youtube and it sounds exactly like that. thanks

Mister.E · 02-21-2010, 02:41 AM

Quote:

Originally Posted by gp1300r

that's it!. i looked up more videos on youtube and it sounds exactly like that. thanks

good shit man

gp1300r · 02-21-2010, 12:19 PM

is this something that needs to be fixed right away? or is it possible to drive on it? i know it needs to be fixed but the vct sprocket is expensive

Jakob · 02-21-2010, 12:36 PM

well if its not annoying to you then you dont need to rush it. as far as i know there havent been any failures with the vtc sprocket.

gp1300r · 02-21-2010, 07:08 PM

Quote:

Originally Posted by Jakob

well if its not annoying to you then you dont need to rush it. as far as i know there havent been any failures with the vtc sprocket.

thanks. that's the answer i was hoping for. sorry SRx7 for jacking the thread. hopefully we had the same problem and your questions were answered.

02-28-2006, 02:01 PM	#1
SRx7 Join Date: Feb 2006 Location: Kennewick, WA Posts: 9 Trader Rating: (0) Feedback Score: 0 reviews	Knocking sound at idle, but goes away under load?? I am getting an SR from a friend who said that the motor he pulled out of his car had a slight knock to it, but it only occured at idle and went away when there was load applied to the car. I am thinking of replacing the rodbearings and putting a new oil pump in it just to be safe, Does anyone have any ideas off the top of there head before I tear it apart?? Thanks

02-20-2010, 01:27 AM	#3
Chrischeezer Zilvia FREAK! Join Date: Jul 2005 Location: earth Age: 41 Posts: 1,406 Trader Rating: (2) Feedback Score: 2 reviews	get an oil pressure gauge. rule number one of all car repairs, find the problem before you start fixing it. get someone with a trained ear who can locate where the sound is coming from. __________________

02-20-2010, 01:45 AM	#5
Chrischeezer Zilvia FREAK! Join Date: Jul 2005 Location: earth Age: 41 Posts: 1,406 Trader Rating: (2) Feedback Score: 2 reviews	i really don't mean to sound like an assh*le, but your sense of where the sound coming from "might be" untrained and lacking experience. most people who can hear parts of a motor wouldn't ask for assistance /what to fix. step 1 - get a mechanics stethoscope (great $5 tool), you can use a screw driver but get the stethoscope its better. probe for sound around the motor, to be accurate this skill really comes from experience. If you think the sound is coming from the chain, remove chain tensioner, check for proper operation. if OK then remove the valve cover, check ALL 3 chain guides for abnormal wear.. __________________

02-20-2010, 12:42 AM	#2
gp1300r Join Date: Jan 2010 Location: destin, fl Posts: 29 Trader Rating: (1) Feedback Score: 1 reviews	i need to know as well. i'm having the same problem. after 2000 rpms the knocking is gone.

02-20-2010, 01:30 AM	#4
gp1300r Join Date: Jan 2010 Location: destin, fl Posts: 29 Trader Rating: (1) Feedback Score: 1 reviews	sorry to jack the thread. the sound is coming from the front of the valve cover.

02-20-2010, 02:07 AM	#6
Mister.E Post Whore! Join Date: Oct 2007 Location: Las Vegas Age: 40 Posts: 4,590 Trader Rating: (53) Feedback Score: 53 reviews	is it an S14 SR? does it sound like this? if so replace VTC sprocket or get rid of VTC altogether

02-21-2010, 12:19 PM	#10
gp1300r Join Date: Jan 2010 Location: destin, fl Posts: 29 Trader Rating: (1) Feedback Score: 1 reviews	is this something that needs to be fixed right away? or is it possible to drive on it? i know it needs to be fixed but the vct sprocket is expensive

02-21-2010, 12:36 PM	#11
Jakob Zilvia Junkie Join Date: May 2006 Location: deutschland Age: 36 Posts: 483 Trader Rating: (1) Feedback Score: 1 reviews	well if its not annoying to you then you dont need to rush it. as far as i know there havent been any failures with the vtc sprocket.