What is Making this Grinding Noise?

[Pete112]

Hi,

So I did decide to pick up the '76 from a friend of mine (if you read my last post). Now I'm going through it to make it safer and 100% road worthy. It hasn't been driven much in the last few years.

I have 2 questions - one is about brakes so I'll post that under a different topic. The other is about what seems to be a bearing noise coming from the front of the engine. Mind you, this is the first FIAT engine I ever heard running. But it doesn't seem normal nonetheless. The engine runs very well if that helps.

Onto the task of trying to describe a noise in writing... The noise seems to come from the very front of the engine. I can't hear a difference on either side so maybe it's coming from the middle or both sides of the front? It's just as loud at idle as it is at higher RPM's. It doesn't sound like a tap and when I open the oil cap, it doesn't get any louder. So I don't think its valve adjustment. To me, it really sounds like the bearings in something that is turning constantly is lacking lubrication.

I know it's difficult to diagnose without hearing it. But has anyone had a similar experience? Is there something I can do to troubleshoot it? E.g. spray some lithium grease somewhere to see if it quiets it a bit? I know that would only be temporary but I'm really just trying to figure out what to replace!

[mbouse]

my first and second guess don't count, right? i mean, since i cannot hear the noise, you gotta give me more than three chances to get it correct.

you said - front of the engine
you said - no change in volume when you listen inside the oil cap (doesn't that splash oil on your ear?)
you said - no tapping
you said - sounds like a bearing

guess # 1
water pump
guess # 2
tensioner bearing for the timing belt

what did i win?

[Pete112]

mbouse, you described my problem better than I did

Is the tensioner bearing and water pump the same on the 1800 as the 2000? Just curious because I have an extra 2000 around and it would be an easy test.

Are there any bearings in cams? That's where it sounds like its coming from but sounds are hard to pinpoint - especially with an ear full of oil!

[mbouse]

Hi,

So I did decide to pick up the '76 from a friend of mine (if you read my last post). Now I'm going through it to make it safer and 100% road worthy. It hasn't been driven much in the last few years.

honestly? it sounds like it is time for a timing belt change anyway, by your description above.

i advise replacing the water pump at the exact same time, especially if you think you have the original pump in place. and since the tensioner pulley is suspect, order all three at the same time and throw them in together.

the pump for the 1800 and two litre should be an even up swap, as should the bearing be.

[baltobernie]

Got room for another guess?

Alternator bearing?

Did the 1976 model have an air pump? Might this be the source? (OK, two guesses. But Mike got two )

[So Cal Mark]

first remove the fan belt so that the accessories don't turn. If the noise is still there it's probably the tensioner bearing. No bearings on the camshafts.

[Pete112]

Those are all great ideas! For some reason I didn't even think of removing the accessory belt for just a quick run.

Yes, I just ordered the timing belt. One of the reasons I was asking was to combine the timing belt replacement with troubleshooting this noise. The bearing was $50 so I didn't want to just assume and replace it.

No airpump and it sounds too high to be the alternator. But I guess it's possible.

[Pete112]

Just wanted to give an update. Your reccomendations definetely helped - it was the water pump! Took the belt off and a big My engine didn't sound like a garbage disposal anymore! Even when I spun the water pump by hand it made a slight grinding sound. That should be pretty easy to replace as I'm doing the timing belt and radiator anyway.

Well, thanks for the help!

[So Cal Mark]

just make sure you bleed the air from the cooling system once it's reassembled

[mbouse]

DANG !! I'm so HOT i s-s-sizzle

[ga.spyder]

Would someone pleeeeeeease get Mike some water?

[Pete112]

I have some Water Wetter. That will help Mike even more!

[mbouse]

if you ask the right people, there is little that can be done to help me.

BTW - what did i win for the correct analysis of the grinding noise without hearing the noise, on the first guess?