Tracking down a ticking at idle

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grrrdot
Posts: 224
Joined: Mon Jan 02, 2012 11:14 pm
Your car is a: 1967 124

Tracking down a ticking at idle

Postby grrrdot » Sun Feb 04, 2018 9:38 pm

Hi,
I've been trying to track down this ticking sound at idle, it drives me crazy!
i checked the tappet clearance a few times and it appears to be in spec. I have an Allison tubular header on that I pulled and trued up the gasket face, it was way out! I've taken a stethoscope and moved it around the engine but nothing stood out to me.

I made a little video of the car idling so you can hear the sound ( not much to see it was too dark for the camera )

Any ideas?
https://youtu.be/s5fhp7t1wZI

-G

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nelsonj
Posts: 394
Joined: Thu Oct 14, 2010 5:37 pm
Your car is a: 1972 Spider 124

Re: Tracking down a ticking at idle

Postby nelsonj » Sun Feb 04, 2018 10:10 pm

What condition is your timing belt in? Are the teeth nice and square? How about your cam gears? Are the teeth square and clean or do they have dips/saddles in the middle? It there grease and grime in the cam teeth?

My car started ticking and it was because the timing belt slipped a tooth or two and the best I can figure the ticking was light contact between the valves and the pistons. The car ran ok, it just "ticked". The belt then slipped further while driving and I lost all power and the engine would not run. It turns out I bent all 8 valves, had zero compression, and needed to rebuild the head.

I'm not saying this is your problem but: Check to make sure you static timing is correct, and if you see any problems with the condition of the belt and/or the cam gears, I STRONGLY suggest not even running the motor until you replace the belt and/or gears.

Good luck.

Peace.
Out.
Image
Simi Valley, California
Spider 1800
Romans 10:9

grrrdot
Posts: 224
Joined: Mon Jan 02, 2012 11:14 pm
Your car is a: 1967 124

Re: Tracking down a ticking at idle

Postby grrrdot » Mon Feb 05, 2018 1:42 pm

OK,
I've actually had that happen to me before! Totally forgot. I did put on a new aux and crank timing belt pulley and timing belt within the last 100 miles or so, maybe I screwed something up. I'll double check that when I'm in the garage next.

Keep the ideas coming!

-G

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FiatMac
Posts: 290
Joined: Sat Aug 01, 2009 1:14 pm
Your car is a: 1982 2000 Spider
Location: Salisbury, North Carolina

Re: Tracking down a ticking at idle

Postby FiatMac » Mon Feb 05, 2018 2:18 pm

grrrdot wrote:OK,
I've actually had that happen to me before! Totally forgot. I did put on a new aux and crank timing belt pulley and timing belt within the last 100 miles or so, maybe I screwed something up. I'll double check that when I'm in the garage next.

Keep the ideas coming!

-G

If any of the cam pulleys or the aux pulley are the phenolic design with the metal hub insert, the bond between the phenolic and metal can break down and become loose. This will create a clicking sound that is audible at idle. If so, need to replace before complete failure.
Stan McConnell
Retired Mechanical Engineer
Salisbury, North Carolina
82 2000 Spider (driving)
78 124 Spider on the rotisserie
76 124 Spider parts car or possible Lemons racer
83 parts car

grrrdot
Posts: 224
Joined: Mon Jan 02, 2012 11:14 pm
Your car is a: 1967 124

Re: Tracking down a ticking at idle

Postby grrrdot » Mon Feb 05, 2018 7:38 pm

Ah that's a good one too.
Thankfully all the wheels are metal!
-G

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nelsonj
Posts: 394
Joined: Thu Oct 14, 2010 5:37 pm
Your car is a: 1972 Spider 124

Re: Tracking down a ticking at idle

Postby nelsonj » Mon Feb 05, 2018 10:59 pm

Make sure you set the Aux gear properly. With both cam gears at their marks, the aux gear has two dots that should be pointing at about 1'o clock. (at he bolt that the spring for the tensioner pulley rests on.)
Image
Simi Valley, California
Spider 1800
Romans 10:9

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RRoller123
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Your car is a: 1980 FI SPIDER 2000
Location: SAGAMORE BEACH, MA USA

Re: Tracking down a ticking at idle

Postby RRoller123 » Tue Feb 06, 2018 6:00 am

One more possibility: I had an odd tick noise as well, and discovered that the PO had not reinstalled the spacer on the bottom mount for the plastic timing belt cover, and the crank pulley was just very slightly touching it. Not too easy to check, but try to see if you have any wear down at the bottom of the cover on the inside.
'80 FI Spider 2000
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