Knocking / tapping noise

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aevansgatech
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Your car is a: 1982 Spider 2000

Knocking / tapping noise

Postby aevansgatech » Mon May 08, 2017 2:33 pm

I know this topic has been touched some, but I am hearing a pretty loud knocking/tapping noise coming from the top of the engine. I have seen that a couple possibilities are low oil pressure/level and something internal like a crank bearing. Below is the information I've gathered so far:

Oil Level/pressure
I did do an oil change this spring and put Rotella 15W-40. I have goot oil pressure (55lb running, a bit less once warmed up) and checked the level. I'm wondering if the heavier weight isn't making it to the top end and reaching the cams.

Internals

This is a possibility, but I didn't do any major work on it over the winter and did not have the pronounced knocking beforehand.
If a crank bearing or rod is knocking it would be new
-Note: I have about 97k miles on the engine but it has had timing belt serviced along with other maintenance roughly 5k miles ago.

Other / Environment
It has been a bit chilly this spring, so I haven't had a nice warm/hot day to see if the issue goes away. I'm wondering if the thicker oil and cool temperatures is causing a lubrication issue.

Any other ideas would be appreciated!
1979 Spider 2000 (gone)
1984 Pininfarina Azzurra (for sale)
1982 Spider 2000 (here to stay)

samakijoe
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Your car is a: 1975 Fiat 124
Location: Original Washington (1776) NC

Re: Knocking / tapping noise

Postby samakijoe » Mon May 08, 2017 3:36 pm

This is a gadget that will pinpoint the problem. Great for locating bad bearings, tappets, etc .
https://www.amazon.com/Lisle-52500-Mechanics-Stethoscope/dp/B0002SQYSM
It will be the best $10.00 you ever spent... :lol:
Lots of other places to get one.
SAMAKIJOE
AKA GRANDPA GRUMPYPANTS

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aevansgatech
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Your car is a: 1982 Spider 2000

Re: Knocking / tapping noise

Postby aevansgatech » Tue May 09, 2017 9:48 am

I did notice on the drive home that the noise is greatly diminished (almost gone) once the temps got up to 65 outside and engine warmed up.

So there was a big difference between cold start 35 degrees outside and warm operation 65 outside. I'm pretty sure it's not getting the oil up to the cams quick enough. Weak oil pump? Try going back to a 10W oil?
1979 Spider 2000 (gone)
1984 Pininfarina Azzurra (for sale)
1982 Spider 2000 (here to stay)

djape1977
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Location: Belgrade, Serbia, eastern Europe

Re: Knocking / tapping noise

Postby djape1977 » Thu May 11, 2017 6:32 pm

check if your camshaft pulleys are plastic. if yes, change them immediately

76was124
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Re: Knocking / tapping noise

Postby 76was124 » Thu May 11, 2017 7:14 pm

Hi Andrew,

Some things to check could include: valve clearances, engine knock, exhaust leak, cam pulley bearings, distributor rotor,

The stethoscope:samakijoe recommended works well to isolate where exactly the noise is coming from. You just move it along and touch the various parts until the sound is loudest. A wooden dowel, or large screwdriver held to your ear work too, just avoid moving parts and also avoid the distributor and spark plugs/wires with anything metal.

You can also get a stethoscope for $5 at the local 1 and Done tool store (HF)
Current 81 Spider 2000
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sptcoupe
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Re: Knocking / tapping noise

Postby sptcoupe » Thu May 11, 2017 7:31 pm

You should also consider pulling the cam box covers off (very easy) and check to see that you don't have a worn cam lobe. This is a common problem because of the lack of zinc in modern engine oil.

spider2081
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Re: Knocking / tapping noise

Postby spider2081 » Fri May 12, 2017 8:02 am

check if your camshaft pulleys are plastic. if yes, change them immediately


Just witnessed this on a Spider with less than 100,000 miles on it. The noise occurred most when idling and was kind of intermittent.

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aevansgatech
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Re: Knocking / tapping noise

Postby aevansgatech » Fri May 12, 2017 1:27 pm

spider2081 wrote:
check if your camshaft pulleys are plastic. if yes, change them immediately


Just witnessed this on a Spider with less than 100,000 miles on it. The noise occurred most when idling and was kind of intermittent.


Do you mean literally check if the two pulleys are made of plastic? The engine is all original and I expect them to be metal. Maybe I'm missing a reference to something here..
1979 Spider 2000 (gone)
1984 Pininfarina Azzurra (for sale)
1982 Spider 2000 (here to stay)

djape1977
Posts: 985
Joined: Sat Apr 21, 2012 6:08 pm
Your car is a: 1970 fiat 124bc
Location: Belgrade, Serbia, eastern Europe

Re: Knocking / tapping noise

Postby djape1977 » Sat May 13, 2017 3:44 am

some twincam fiats had plastic pulleys from factory. this was done for only couple years total. check if your car has plastic pulleys. if it does, loosen the cam belt and you will find one or all pulleys to have play in the center. change for all metal pulleys asap.


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