Noise on startup - ZR-1 Net Registry Forums

Dime · 03-10-2012

I haven't started the car for 5-6 weeks. Start it this morning and heard a knock for a few seconds until oil pressure built up. Went for a drive with my dad and it never did it again on start up. This is the only time the cars ever done it, and it's the longest the cars sat with out being started since I've owned it.

Any ideas what it was, and should I worry, or is it normal?
Lack of oil until pressure is built?

Z51JEFF · 03-10-2012

Cam chains,the oil has drained from the filter and it takes a few seconds to pump up.The Bosch filter has a better check valve than the others on the market and it holds oil a little better.

ScottZ95ZR1 · 03-11-2012

Quote:

Originally Posted by Z51JEFF

Cam chains,the oil has drained from the filter and it takes a few seconds to pump up.The Bosch filter has a better check valve than the others on the market and it holds oil a little better.

Marc's latest oil filter recommendation states he has found that some recently produced Bosch filters have leaking anti-drain back valve.
Read it here:http://www.zr1specialist.com/HAT%20W...ate%202011.pdf

mike100 · 03-11-2012

I bought mine at 27k miles and it didn't do it, but 5k miles later and some different oil filters, it finally started up with the noise. Really nothing has to be done about it, but you might be able to find a new cam tensioner to fix it,

GOLDCYLON · 03-11-2012

Quote:

Originally Posted by mike100

I bought mine at 27k miles and it didn't do it, but 5k miles later and some different oil filters, it finally started up with the noise. Really nothing has to be done about it, but you might be able to find a new cam tensioner to fix it,

Only if its the ugraded RH Cam Tensioner which allows the oil to pool a little

VetteMed · 03-11-2012

It's more an annoyance than a real problem. The chain guide is tapping against the cylinder head. The chain is not subject to any additional wear.

Dime · 03-11-2012

That's what I thought (or hoped) it was. I never heard it do it before. It was a lot more racket than I expedited chain rattle to be. I was wondering why other owners complained about chain rattle. Now I know. I'm just glad it has only done it this that one time so far. Hopefully I'm lucky enough that it will only do it after sitting for a long period of time.

RHanselman · 03-11-2012

I've never heard the chain make a knocking sound it's always been a rattle... You know it could have been the DMF. It can knock until the engine smoothes out...

Jagdpanzer · 03-11-2012

Here are a couple of excellent tech articles Marc Haibeck wrote on the subject of the LT5 cam drive.

As our engines gracefully mature we need to be especially mindful about the condition of the upper cam chain guide strips as Marc points out in his article. Failure to maintain the upper guide strips will lead to the breakage of cam chains which otherwise would have served reliably for many more thousands of miles to come. I know of two recent cam chain breakages on higher mileage LT5s due to this issue. An expensive headache that one should avoid.

zrwhat · 03-11-2012

I know its not a end all, cure all but when mine sits for extended periods of time, I spin off the oil filter, dump some oil down the center cavity of the filter housing, spin the filter back on and start up, without doing this, I would get momentary chain rattle, by adding this small amount of oil, chain rattle is not heard or detected on a start up after extended inactivity.

My guess is this oil going to the pick up tube fills quickly and fills the oil filter much faster.

Has anyone ever done a oil filter relocation on a LT-5 where the filter sits in a right side up position and is always full and can't drain back , this in itself should slow down or stop the "Dry Filter Syndrom" and either slow down or stop this momentary rattle of the TC's......

Gibby

03-10-2012	#1
Dime Join Date: Feb 2011 Location: Vicksburg, MS Posts: 135	Noise on startup I haven't started the car for 5-6 weeks. Start it this morning and heard a knock for a few seconds until oil pressure built up. Went for a drive with my dad and it never did it again on start up. This is the only time the cars ever done it, and it's the longest the cars sat with out being started since I've owned it. Any ideas what it was, and should I worry, or is it normal? Lack of oil until pressure is built? __________________ [B][U]1991 No. 519[/U][/B] Last edited by Dime; 03-11-2012 at 12:29 AM.

03-10-2012	#2
Z51JEFF Join Date: Dec 2007 Location: Fremont,Ca Posts: 3,058	Re: Noise on startup Cam chains,the oil has drained from the filter and it takes a few seconds to pump up.The Bosch filter has a better check valve than the others on the market and it holds oil a little better.

03-11-2012	#4
mike100 Join Date: Feb 2011 Location: San Marcos CA Posts: 1,802	Re: Noise on startup I bought mine at 27k miles and it didn't do it, but 5k miles later and some different oil filters, it finally started up with the noise. Really nothing has to be done about it, but you might be able to find a new cam tensioner to fix it,

03-11-2012	#6
VetteMed Join Date: Mar 2009 Location: Orlando, FL Posts: 1,828	Re: Noise on startup It's more an annoyance than a real problem. The chain guide is tapping against the cylinder head. The chain is not subject to any additional wear. __________________ 2004 Z06/Z16 LeMans Commemorative Edition 1991 ZR-1 #302 White/Gray (sold) 1991 ZR-1 #1147 Red/Saddle (sold)

03-11-2012	#7
Dime Join Date: Feb 2011 Location: Vicksburg, MS Posts: 135	Re: Noise on startup That's what I thought (or hoped) it was. I never heard it do it before. It was a lot more racket than I expedited chain rattle to be. I was wondering why other owners complained about chain rattle. Now I know. I'm just glad it has only done it this that one time so far. Hopefully I'm lucky enough that it will only do it after sitting for a long period of time. __________________ [B][U]1991 No. 519[/U][/B]

03-11-2012	#8
RHanselman Join Date: Jul 2005 Location: Cresson, TX Posts: 970	Re: Noise on startup I've never heard the chain make a knocking sound it's always been a rattle... You know it could have been the DMF. It can knock until the engine smoothes out... Last edited by RHanselman; 03-11-2012 at 07:11 PM.

03-11-2012	#9
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,655	Re: Noise on startup Here are a couple of excellent tech articles Marc Haibeck wrote on the subject of the LT5 cam drive. http://www.zr1specialist.com/HAT%20W...20Failures.pdf http://www.zr1specialist.com/HAT%20W...e%20Rattle.pdf As our engines gracefully mature we need to be especially mindful about the condition of the upper cam chain guide strips as Marc points out in his article. Failure to maintain the upper guide strips will lead to the breakage of cam chains which otherwise would have served reliably for many more thousands of miles to come. I know of two recent cam chain breakages on higher mileage LT5s due to this issue. An expensive headache that one should avoid. __________________ Phil Wasinger 1994 Torch Red ZR-1 WAZOO Member George Braml Intake Last edited by Jagdpanzer; 03-11-2012 at 10:00 PM.

03-11-2012	#10
zrwhat Join Date: Sep 2008 Location: Maryland Posts: 119	Re: Noise on startup I know its not a end all, cure all but when mine sits for extended periods of time, I spin off the oil filter, dump some oil down the center cavity of the filter housing, spin the filter back on and start up, without doing this, I would get momentary chain rattle, by adding this small amount of oil, chain rattle is not heard or detected on a start up after extended inactivity. My guess is this oil going to the pick up tube fills quickly and fills the oil filter much faster. Has anyone ever done a oil filter relocation on a LT-5 where the filter sits in a right side up position and is always full and can't drain back , this in itself should slow down or stop the "Dry Filter Syndrom" and either slow down or stop this momentary rattle of the TC's...... Gibby Last edited by zrwhat; 03-12-2012 at 09:15 AM.