79-2000- constant clicking

[minimike]

Hi all. New to the 79. I just bought it a month ago, finally got it started with a new dizzy module. PO said there was an engine noise, hence the sale. Initially I thought it was a rod bearing, but now it appears to be top side. Constant knocking during running. Any ideas? Dropped valve? collapsed lifter? (no lifters on this car???) broken valve spring? Jumped time?
Where should I start dissassemby?

I'm a car guy with about 10 other vehicles and had an 1800 more than 20 years ago. Wondering if this might sound familiar
to you current fiat guys.
thanks in advance
mike on LI, NY

[mbouse]

make sure it is not an exhaust leak

[Fiat88]

Sorry ,can't give you any advice but welcome fellow New Yorker!

[minimike]

OK, I think I'm gonna pop off the cam covers and have a look inside. Check the valve clearance, and go from there.
Any other ideas are welcome.

[narfire]

damb...second attempt, submit at same time as fiat88 and mine did'nt go through.
Anyway take a long handled screwdriver and use it like a stethascope to localize the sound/noise. This might narrow it down a bit more, enabling a better guess.

[manoa matt]

Is it clicking or knocking?

As Mike said, an exhaust manifold leak will sound like clicking. Some ultra high temp copper RTV on each side of the gasket will stop it.

The distributor clicks as it distributes sparks

Valves out of adjustment will sometimes click.

A constant knocking sound could be the auxillary shaft hitting the #3 connecting rod. Make sure the cam gears, crank, and aux shaft are properly timed.

If it's not one of the above, then plan on engine work.

[minimike]

what is the aux shaft connected to? or what is it's purpose? It doesn't sound automotive dude.
This is an engine noise, not an exhaust noise. I'll pull plug wires tomorrow in daylight and see if I can ID the cylinder. Also will use a stethoscope to narrow down the location.

[So Cal Mark]

on a 79 I'd second the suggestion of the aux shaft knocking. If the t-belt was replaced, there is a good chance the aux shaft is mis-timed. Set up the timing marks and check the aux shaft pulley. The dot on the pulley should line up with the pivot bolt for the tensioner. The aux shaft drives the oil pump and the mechanical fuel pump, so it is necessary

[SLOSpider]

I had a clicking noise once from the exhaust cam pulley, it was plastic and beginning to separate from the steel insert. I replace all my plastic pulleys with metal since then. Also may just be a shim out of spec.

[minimike]

Is there a timing mark on the aux shaft? I know where to look for the valve cams and crank pulley.

[mbouse]

"Is there a timing mark on the aux shaft? " yup.

still think before you go thru all that work, the simplest yet JUST AS POSSIBLE source should be ruled out. quite easy to rule out an exhaust leak.... which causes constant clicking, varying directly with rpm. no stethascopes involved, no cam cover removal and feeler gauges needed. no pulleys to replace, no timing belt covers to yank.

exhaust noises ARE engine noises. aux shaft IS automotive, dude.

have fun with your project.

[wachuko]

Is there a timing mark on the aux shaft? I know where to look for the valve cams and crank pulley.

Here are a few photos:

Look at the marks of the holes aligned with the pointers.



Look at the auxiliary shaft alignment. You will see a mark in the pulley... an indent. That needs to be aligned with the tensioner bolt as in the photo. If not, the knocking will turn into a new engine - here, take a look - Can engine block be fixed

[minimike]

I'll have a look this afternoon after work. I take it there is a groove on the aux pulley. Is there anything on the back of the pulley or just an idler wheel to put the belt where it needs to be? I'll also check for exhaust leak, but this doesn't sound like the phfit, phfit, phfit, you get from an open header. It's more like tak, tak, tak.
Thanks guys. You are all very helpful, and the pix say 1,000's of words to me.

[mbouse]

the aux pulley has a hole in it... just like the cam pulleys. set it to one o'clock when the engine is a TDC.

and.... the exhaust leak at the manifold to down pipe sounds like tick-tick-tick, not phish-phish as you suggest. you have nearly described the sound quite well.

[minimike]

Update: I pulled plug leads one at a time and started engine. No difference in noise.
I removed the cam covers, everything was clean. put cam covers back in place.
removed rad/fan,hoses, timing belt cover. Marked cam wheels, aux wheel, and crank pulley along with corresponding
alignment marks. With a 1 1/2" socket I was able to turn engine almost to align all pulleys, but could go no further. I got out the 3' pipe and put it on the 2' breaker bar. So I had almost 4' of leverage. the engine would not budge. I went the other way. when I got to TDC or damn close, again, I was unable to move the engine. I'm afraid it is time to yank this lump. I'm thinking something is hanging up in the crank, like a broken rod!

Can I access the rods if I jack up the car and pull the oil pan? It might be worth a look to see what's going on in there.
today when I started the engine and rev'd it up, the sound was like a baseball card in the spokes on a bicycle, but metal ish. not cardboard sound at all?

I do have a donor car that I just got and have put some MM oil in the cylinders. I will be yanking that rad and trying to turn that lump next. This one is condition unknown, but I'm sure it was parked due to the rotted body. It's horrible looking and only the mechanicals are worth taking. All the tires are shreded. I think the only panel worth saving is the hood. All glass, calipers, and trans. Coil is already gone as it the dizzy. Gauges look OK and some wood bits on the dash. Where do I list spares for sale on this forum?

Mike