Marbles in my engine - '78 Spider

The forum for all of your technical questions on your classic FIAT autos
User avatar
MrBlimp
Posts: 32
Joined: Sat Jun 17, 2017 10:23 pm
Last Name: Blimp
First Name: Myster

Marbles in my engine - '78 Spider

Post by MrBlimp » Tue Nov 13, 2018 9:48 pm

I've recently noticed a sound like marbles in the front (or maybe top) of the engine on my '78 Spider.

If it was an American car I would think it is the start of a water pump failure.

Anyone have any ideas on what I should be checking?
Last edited by MrBlimp on Sun Apr 14, 2019 4:36 pm, edited 1 time in total.
1969 Triumph Spitfire
1970 MGB
1978 FIAT 124 Spider
1992 Mustang LX
2000 Jeep Wrangler Sport
2000 Ford Rangler XLT
User avatar
vandor
quattromila club
Posts: 4514
Joined: Sun Jan 24, 2016 10:03 pm
Last Name:

Re: Marbles in my engine - '78 Spider

Post by vandor » Tue Nov 13, 2018 11:49 pm

Could be a water pump. Maybe use a stethoscope to isolate the sound?
Csaba
Parts: http://www.autoricambi.us
Cars: http://italiancarclub.com/csaba/Fiat.html
'71 124 Spider, much modified
'72 124 Coupe, new project, ex-Pete, ex-Eli, ex-Jack car (all Mira members)
'73 124 Wagon, no floors
User avatar
mikehynes
Posts: 611
Joined: Sun Jan 24, 2016 7:55 pm
Last Name:

Re: Marbles in my engine - '78 Spider

Post by mikehynes » Wed Nov 14, 2018 9:09 am

Timing belt tensioner bearing?
Two '80 124 Spiders
Lots of X1/9s
Mike Hynes
User avatar
rridge
tremila club
Posts: 3686
Joined: Sun Jan 24, 2016 9:18 pm
Last Name: ridge
First Name: richard

Re: Marbles in my engine - '78 Spider

Post by rridge » Wed Nov 14, 2018 9:30 am

If you loosen the tension in the accessory belt and the sound goes away you know that the problem is a bearing in either the water pump or the alternator. if the sound does not go away, the bearing in the timing belt tensioner is going. A bad tensioner will soon allow the belt to jump teeth. Don't wait to track the problem down.
Richard
'81 Turbo Spider
Rockville, MD
81-SPIDERMATT
Posts: 35
Joined: Thu Mar 16, 2017 9:02 pm
Last Name: Lingg
First Name: Matt

Re: Marbles in my engine - '78 Spider

Post by 81-SPIDERMATT » Wed Nov 14, 2018 9:41 am

Is it a constant noise? Only under load while driving? Here is why I ask . (not my fiat) recently went to a pertronix unit and it changed my timing drastically and engine started pinging ... it could easily be described as marbles or similar noise. Just another thought ....Matt

a stethoscope is a great tool to have in your box for sure
It's not an oil leak...that's power sweat

Matt in Fort Collins, Co
User avatar
bartigue
seimila club
Posts: 6446
Joined: Sat Jan 23, 2016 11:49 pm
Last Name: Artigue
First Name: Bradley
Contact:

Re: Marbles in my engine - '78 Spider

Post by bartigue » Wed Nov 14, 2018 12:39 pm

Take off the accessory belt and run the car. If the noise persists then it isn't the water pump or alternator.

Also check the tightness of the water pump bolts and crankshaft nut.
-----------------------------------------------------------
Brad Artigue
1969, 1969, 1970, 1979, 1980, 1981, 1982, and 1982 124 Spiders
1969, 1970 850 Spiders
77 X1/9
http://fiat.artigue.com
fp55scca
duemila club
Posts: 2634
Joined: Sun Jan 24, 2016 11:34 am
Last Name:

Re: Marbles in my engine - '78 Spider

Post by fp55scca » Wed Nov 14, 2018 3:35 pm

--As Matt suggested, gross mis-timing can cause such a sound. If you have a timing light, check timing. If not, then at idle, loosen the distributor and turn is slowly (and slightly) counter-clockwise first, and then clockwise if the problem persists.

--If not timing, follow the advice from others for accessory/bearing checks.

--If nothing else, check to see if you have the plastic cam wheels installed. When worn badly, these can rattle.
Jim Scurria
Norfolk, VA

1972 Fiat 124 Spider
1971 Spider - SCCA FP-24
1974 CSA Abarth Replica
1981 Fiat Spider Ratrod
User avatar
MrBlimp
Posts: 32
Joined: Sat Jun 17, 2017 10:23 pm
Last Name: Blimp
First Name: Myster

Re: Marbles in my engine - '78 Spider

Post by MrBlimp » Sun Apr 14, 2019 4:30 pm

OK,I used a stethoscope - it isn't the water pump.

It is on the drivers side top end. Very noticeable at the camshaft-sprocket/timing gear end (front of engine), but I can hear it resonating at the back of the engine.

I can see that the PO changed the timing wheel/gear on that side, but not on the other. The PO gave me the other wheel/gear with the parts pile that came with the car. And they are the plastic cam wheels/gears.

So now I have to make a decision of what's next. -

I'm thinking that with the other (points losing their gap) timing issue I've had that I have a timing belt related issue.

How do I determine if it is the bearing in the timing belt tensioner or if it is the wheel/gear itself?

Or should I just change both camshaft-sprocket/timing gears, the timing belt tensioner bearing, and the timing belt itself, all at the same time?
1969 Triumph Spitfire
1970 MGB
1978 FIAT 124 Spider
1992 Mustang LX
2000 Jeep Wrangler Sport
2000 Ford Rangler XLT
User avatar
davedecker4
Posts: 795
Joined: Sun Jan 24, 2016 11:05 am
Last Name: Decker
First Name: Dave

Re: Marbles in my engine - '78 Spider

Post by davedecker4 » Mon Apr 15, 2019 1:13 pm

Yes,
that would be most prudent and possibly easiest or at least quickest.
So is the replaced gear also plastic or just the one removed to replace?
If you have the type of stethoscope with the metal rod at the end, you can put it on or around the tensioner bearing and listen for difference, or louder noise. Then compare to cam gear.
If you have to replace, metal will last longer than plastic and give better piece of mind. Replace both sides if you're doing this.
If you don't know when tensioner bearing was done, it may be a good idea. Its best to change with timing belt, but if your doing timing belt frequently and it sounds good, looks good and uncorroded and you know history, it can be okay to leave bearing to every other belt or so.
You may want to check water pump and be sure its good if you're doing this. Its a lot easier to replace with the belt off than later on.
If your engine sounds like a blender full of marbles, I would try not to run it until you fix. If its a slight noise or rattle, try to only run it at idle for diagnosing and check all those bearings. Or if its sounds more like pinging, could be one of those gears. Also check the auxiliary to make sure its timed right, especially when reinstalling. Turn the engine by hand at least two full revolutions and check for any binding or evidence of hitting.
Good luck. Welcome to Fiat maintenance and enjoy the ride after you're done.
Dave Decker
a 'couple' Fiats and Lancia's
User avatar
bartigue
seimila club
Posts: 6446
Joined: Sat Jan 23, 2016 11:49 pm
Last Name: Artigue
First Name: Bradley
Contact:

Re: Marbles in my engine - '78 Spider

Post by bartigue » Mon Apr 15, 2019 2:42 pm

A normal timing belt procedure is to change the belt, water pump, and tensioner bearing. In your case, change the timing gear as well. Personally I'd set that motor at an intermediate position (all pistons 1/2 way up) and put a socket and drill on that intake cam and spin it, listening for noises. If none then reassemble (use the new gear anyway).
-----------------------------------------------------------
Brad Artigue
1969, 1969, 1970, 1979, 1980, 1981, 1982, and 1982 124 Spiders
1969, 1970 850 Spiders
77 X1/9
http://fiat.artigue.com
Post Reply

Who is online

Users browsing this forum: No registered users and 61 guests