Engine Had Developed a Chirp Today

Tech tips and how to's

Moderators: notoptoy, garth, S Allen

User avatar
Copterpilot
Site Supporter
Posts: 552
Joined: Tue Jun 05, 2012 1:50 pm
Location: Woodville, OH

Engine Had Developed a Chirp Today

Post by Copterpilot »

Today I heard a very noticeable chirp from the engine, most distinct when applying power. Anyone have an idea of what might cause a chirping? I’ve never heard it before that I can remember. Since my last drive, with no chirping, I tuned the carbs (SU) as it wasn’t running very well. Now it runs great but has this noise. Any thoughts would be appreciated.
White 1968 2000 Roadster
Gray 2003 VW Jetta TDI
Red 2005 Pontiac Vibe
2112 Toyota Highlander
Platinum White F150 Platinum Powerstroke
AS365 Dauphine
A109E Power

User avatar
bakerjf
Site Supporter
Posts: 1321
Joined: Wed Sep 07, 2011 5:48 pm

Re: Engine Had Developed a Chirp Today

Post by bakerjf »

Air leak around the intake manifold
J. Baker
Cupertino, CA
'69 2000 (Solex)

User avatar
theunz
Roadster Nut-Site Supporter
Posts: 1640
Joined: Sat May 02, 2009 1:54 pm
Location: Catoosa Ok.
Model: 2000
Year: High Windshield-68-70

Re: Engine Had Developed a Chirp Today

Post by theunz »

Agree witMr Baker. You can spray some WD40 around suspected areas while the car is running and if rpms increase you’ve found your leak.
Mike M
1969 2000 solex mine since 1972, under resurrection. (Finally resurrected as of spring 2019!) 1969 Porsche 911s -worth more, but not as valuable! (Soon to be resurrected)

User avatar
cole455
Roadsteraholic
Posts: 553
Joined: Tue Oct 23, 2007 12:03 pm
Location: Lewisville, NC

Re: Engine Had Developed a Chirp Today

Post by cole455 »

Is it super pronounced? If so, probably a vacuum leak. If it’s noticeable when cranking the engine, pull the coil wire and see if chirps with the throttle wide open. If so, look at the insulators and intake gasket as a leaking source.
SPL 311-01617
SRL 311-00042
SPL 311-28701

User avatar
Linda
Roadster Enthusiast
Posts: 7584
Joined: Sat Nov 05, 2005 11:37 pm
Location: Los Angeles
Model: 1500/1600
Year: High Windshield-68-70

Re: Engine Had Developed a Chirp Today

Post by Linda »

Are you missing, or have a loose, a smog insert plug? Part 2208 datsunparts.com
Linda
Last edited by Linda on Tue Jun 02, 2020 8:19 am, edited 1 time in total.
68 1600 Los Angeles, CA
New owners must read: the ultimate road trip, by Scott- roadsterroadtrip.com-http://www.roadsterroadtrip.com/index.php/readfromstart

User avatar
jrusso07
Roadsteraholic
Posts: 1421
Joined: Sat Aug 02, 2008 9:02 am
Location: Penn Yan, NY
Model: 2000
Year: High Windshield-68-70

Re: Engine Had Developed a Chirp Today

Post by jrusso07 »

Agree with others on intake leak. I had a chirp/short screech when accelerating...it was from the alternator belt, it was just a tad too loose.
Joe

1969 SRL311 - Solex
1970 SPL311 - U20 mod
1970 SRL311

User avatar
Copterpilot
Site Supporter
Posts: 552
Joined: Tue Jun 05, 2012 1:50 pm
Location: Woodville, OH

Re: Engine Had Developed a Chirp Today

Post by Copterpilot »

I was afraid of that! The bottom nuts are virtually impossible to get a wrench or socket on to get them tight. It hasn't shown up till after I've driven for a whole season of driving. Any tricks to get to them? Special tool? anyone had any luck with putting sealant on the outside edges?
White 1968 2000 Roadster
Gray 2003 VW Jetta TDI
Red 2005 Pontiac Vibe
2112 Toyota Highlander
Platinum White F150 Platinum Powerstroke
AS365 Dauphine
A109E Power

bajaroadster
Roadster Fanatic
Posts: 112
Joined: Fri Jun 28, 2019 1:29 pm
Location: Loreto B.C.S. Mexico
Model: 1500/1600
Year: Low Windshield-64-67.5

Re: Engine Had Developed a Chirp Today

Post by bajaroadster »

Simplest solution would be to check fan belt adjustment as Jrusso suggested if not already checked. Not the likely culprit but sometimes we get lucky.
Ive seen normal. It aint pretty.

User avatar
theunz
Roadster Nut-Site Supporter
Posts: 1640
Joined: Sat May 02, 2009 1:54 pm
Location: Catoosa Ok.
Model: 2000
Year: High Windshield-68-70

Re: Engine Had Developed a Chirp Today

Post by theunz »

I don’t remember with the SU’s, but with my Solex’s I can use a 1/4” drive socket and a very long extension to get to them. Might have to use several to get the right length to get to the outside of the carbs. 1/4” sockets and extensions have saved my bacon many times :D
I had an intake chirp when I rebuilt my engine that like to drove me crazy trying to locate. Had the carbs off several times with no success and finally in desperation I put a small piece of duct tape over the leak and it went away!
Mike M
1969 2000 solex mine since 1972, under resurrection. (Finally resurrected as of spring 2019!) 1969 Porsche 911s -worth more, but not as valuable! (Soon to be resurrected)

User avatar
bakerjf
Site Supporter
Posts: 1321
Joined: Wed Sep 07, 2011 5:48 pm

Re: Engine Had Developed a Chirp Today

Post by bakerjf »

theunz wrote:
Tue Jun 02, 2020 6:02 pm
I don’t remember with the SU’s, but with my Solex’s I can use a 1/4” drive socket and a very long extension to get to them. Might have to use several to get the right length to get to the outside of the carbs. 1/4” sockets and extensions have saved my bacon many times :D
I had an intake chirp when I rebuilt my engine that like to drove me crazy trying to locate. Had the carbs off several times with no success and finally in desperation I put a small piece of duct tape over the leak and it went away!
I’m in the same boat. I do know it’s easier to get to some of those nuts from under the car believe it or not. I also learned there is a specific order when removing the front and rear carburetor (mounting points) from the manifold, and conversely installing them. A couple of times ago I wrote the order down as a note to myself and stored it in my phone. Nice not to have to reinvent the wheel every time you have to do that job.
J. Baker
Cupertino, CA
'69 2000 (Solex)

User avatar
Copterpilot
Site Supporter
Posts: 552
Joined: Tue Jun 05, 2012 1:50 pm
Location: Woodville, OH

Re: Engine Had Developed a Chirp Today

Post by Copterpilot »

There is just no easy way to get at that nut and put any torque on it 😤
You do not have the required permissions to view the files attached to this post.
White 1968 2000 Roadster
Gray 2003 VW Jetta TDI
Red 2005 Pontiac Vibe
2112 Toyota Highlander
Platinum White F150 Platinum Powerstroke
AS365 Dauphine
A109E Power

User avatar
Copterpilot
Site Supporter
Posts: 552
Joined: Tue Jun 05, 2012 1:50 pm
Location: Woodville, OH

Re: Engine Had Developed a Chirp Today

Post by Copterpilot »

Spent all day trying to tighten the nuts, even took the starter off, a job in itself. Got a quarter turn on the problem nut. Chirp seems to be a little worse now, UGH!

This is extremely frustrating as it was running so quietly up to yesterday.

Bakerjf, would you be will to post the order of removing and reinstalling the carb to manifold nuts?
White 1968 2000 Roadster
Gray 2003 VW Jetta TDI
Red 2005 Pontiac Vibe
2112 Toyota Highlander
Platinum White F150 Platinum Powerstroke
AS365 Dauphine
A109E Power

User avatar
keith0alan
Roadsteraholic
Posts: 802
Joined: Wed Sep 22, 2004 10:07 am

Re: Engine Had Developed a Chirp Today

Post by keith0alan »

The easiest way to get to the manifold nuts is to remove the carbs and heat shield. Seems counter-intuitive but it really is.

User avatar
Linda
Roadster Enthusiast
Posts: 7584
Joined: Sat Nov 05, 2005 11:37 pm
Location: Los Angeles
Model: 1500/1600
Year: High Windshield-68-70

Re: Engine Had Developed a Chirp Today

Post by Linda »

Can you get a box end wrench on it? The torque for the nuts is not that high, I believe.
Also the stubby ratcheting wrenches are handy for many tight areas, though they are not thin walled.
Linda
Last edited by Linda on Wed Jun 03, 2020 2:05 pm, edited 1 time in total.
68 1600 Los Angeles, CA
New owners must read: the ultimate road trip, by Scott- roadsterroadtrip.com-http://www.roadsterroadtrip.com/index.php/readfromstart

User avatar
Gregs672000
Roadster Fanatic-Site Supporter
Posts: 7059
Joined: Fri Aug 07, 2009 11:47 pm
Location: Tacoma, WA

Re: Engine Had Developed a Chirp Today

Post by Gregs672000 »

Like Linda, I use a very thin walled box end of a 13mm wrench. I no longer run a carb heat shield as the header shield stuff I'm using is amazing. Carbs are probably off too when I do them (Dellorto). You could try to source a 12mm nut with the correct pitch... I've had some before. Might make it easier to get a wrench on it.
Greg Burrows
'67 2000 #588
Tacoma, WA