Technical A part fell off while driving... where does it go?

[GeigerUncounter]

Took the 124 for a short drive last night and after <1 mile I heard that dreaded sound of ringing metal as something fell off the car and rattled along the road. Fortunately, I had the top down and I was the only car out so I was able to hear it clearly (I didn't see the part in my rear view mirror though). I stopped the car as soon as I could to inspect it and I didn't find anything obviously wrong, so I finished the drive (~3 miles).

Today, I returned to the spot in daylight and I found the part in the picture below. I'm virtually certain this came from my car. Any ideas what it is or where it goes?

I'll add that recently the car has been acting strange. It's hard to describe, but power & acceleration feel very weak for all gears - despite the fact that the engine is revving very loudly. Not sure whether that is related to this part falling off, but there's definitely something wrong.

Any thoughts/advice are much appreciated, thanks!

 

[Greasytrucker]

Looks like a manifold to exhaust clamp to me, the white deposits are sealing paste. Definitely exhaust related. If it was leaking gas before the car would most probably be down on power as older engines often rely on some back pressure to work at there best

 

[rmjbn1]

+1 on exhaust clamp, those things used to fall off my 2CV all the time!

 

[The Panda Nut]

Holds the exhaust onto the engine, but if its yours , you might well have had the exhaust fallen off. It could be off someone elses car and you just ran over it. Get the exhaust system checked over. Its a $5 part.

 

[124BC1]

I thought that all the 124's used a flange with 4 studs and nuts to attach the front ex. pipe to the manifold and slip joints (one pipe fits inside the other) and 'U' or 'D' clamps elsewhere on the ex. system. But looking at U.S parts suppliers they also show the clamp pictured by the OP as having been fitted to the 124 between '75 and '80, (OP previously said his car is a '77) so very possible it did fall off his car (if original, the bolt heads may have FIAT stamped on them).
The front section of the exhaust is held by a bracket and clamp at the rear of the gearbox (transmission) so it can't fall onto the road - unless, of course, this mounting bracket is also broken (which it often is or has been left off in the past ).

If OP can't get a replacement exhaust clamp easily/quickly, he could probably re-use the one he retrieved by straightening the bent bolt and just replacing the lost nut - it's a standard (regular) 8 x 1.25mm pitch metric nut, -the same as used all over the Fiat 124, just clean up the ex. pipe to manifold sealing faces, apply a little ex. sealing paste as insurance against a leak and refit the clamp alternately tightening each side a little, until secure.

 

[GeigerUncounter]

If it was leaking gas before the car would most probably be down on power as older engines often rely on some back pressure to work at there best

Thanks for that! I'm wondering why you said "If it was leaking gas before...". What made you think there was a gas leak?

 

[GeigerUncounter]

Thanks everyone! You're all right! The missing part clearly connects two exhaust pipes (pictured below).

Since you all got me looking closely at the exhaust I also notice that there is nothing holding the exhaust pipe to the engine. The pipe is only loosely pressed against the engine, and it's easy to move aside with bare hands. Surely there should be a clamp there, right!? See photo below.

And finally, the exhaust connection to the engine has a hole in it that blows exhaust with force while the engine is running. I'll guess that there shouldn't be a hole here, right? Immediately before I bought the car a bunch of emissions compliance gear was (hastily) removed by the former owner. I wonder whether this hole was left this way by mistake?

 

[Slotman]

Thanks for that! I'm wondering why you said "If it was leaking gas before...". What made you think there was a gas leak?

I believe he meant exaust gas that normally would be going out the exaust pipe...with out that back pressure from a large leak it changes how the motor runs...

 

[Greasytrucker]

I believe he meant exaust gas that normally would be going out the exaust pipe...with out that back pressure from a large leak it changes how the motor runs...

Correct

 

[Pugglt Auld Jock]

Thanks everyone! You're all right! The missing part clearly connects two exhaust pipes (pictured below).

View attachment 457267

Since you all got me looking closely at the exhaust I also notice that there is nothing holding the exhaust pipe to the engine. The pipe is only loosely pressed against the engine, and it's easy to move aside with bare hands. Surely there should be a clamp there, right!? See photo below.

View attachment 457269

And finally, the exhaust connection to the engine has a hole in it that blows exhaust with force while the engine is running. I'll guess that there shouldn't be a hole here, right? Immediately before I bought the car a bunch of emissions compliance gear was (hastily) removed by the former owner. I wonder whether this hole was left this way by mistake?

I'm just a little puzzled by this post. With the downpipe actually detached from the manifold, like this picture shows, the noise must have been deafening? Have you been driving it around like this? If so I'm surprised you've not been pulled over by the police!

 

[GeigerUncounter]

I'm just a little puzzled by this post. With the downpipe actually detached from the manifold, like this picture shows, the noise must have been deafening? Have you been driving it around like this? If so I'm surprised you've not been pulled over by the police!

No, I haven't been driving the car because I was aware that something was wrong with it. You're right that it was very loud! The short trip where the clamp fell off was for diagnostic purposes as I was trying to better understand the symptoms.

Thanks very much for the help everyone! I'll clamp those exhaust pipes & somehow plug that hole in the exhaust manifold.

 

[s130]

No, I haven't been driving the car because I was aware that something was wrong with it. You're right that it was very loud! The short trip where the clamp fell off was for diagnostic purposes as I was trying to better understand the symptoms.

Thanks very much for the help everyone! I'll clamp those exhaust pipes & somehow plug that hole in the exhaust manifold.

Until you get a proper solution to the blanking of the top exhaust outlet port then just be careful. I'm not saying you stuffed a rag in it but that manifold port will have lovely combustion flames present and any material not capable of securing them could catch fire and give you additional problems.

 

[Pugglt Auld Jock]

Until you get a proper solution to the blanking of the top exhaust outlet port then just be careful. I'm not saying you stuffed a rag in it but that manifold port will have lovely combustion flames present and any material not capable of securing them could catch fire and give you additional problems.

Yup, it will need to be a metal blanking plate of some sort. I'm very puzzled by that port. The manifold looks unusual in this respect. Where the downpipe fits, I mean the joint where the clamp fell off and let the exhaust pipe fall away from the manifold, looks as you would expect but the port/hole/whatever you want to call it, in the top of the manifold is very strange. I'm wondering if it's an early attempt at exhaust gas recirculation due to American regulations - which we wouldn't have seen over this side of the pond? It would be interesting to examine the inlet manifold to see if there is any kind of corresponding porting in it.

 

[GeigerUncounter]

I got the clamp reinstalled! While working my wife came to check on me & I complained about missing the plug for the exhaust port. I showed her a photo, she looked in the engine bay & nonchalantly declared "here it is" and pulled it out of that dark cavity in the photo below the exhaust pipe!!! It must have unscrewed itself, fallen, & gotten stuck? Very strange. I'm extremely lucky it remained in the engine bay, & doubly lucky that she noticed it!!

The car runs nice & quiet now and all of the missing power is back! What a relief!! Thanks again everyone for the help, your advice is invaluable!!

I'm very puzzled by that port. The manifold looks unusual in this respect. Where the downpipe fits, I mean the joint where the clamp fell off and let the exhaust pipe fall away from the manifold, looks as you would expect but the port/hole/whatever you want to call it, in the top of the manifold is very strange. I'm wondering if it's an early attempt at exhaust gas recirculation due to American regulations - which we wouldn't have seen over this side of the pond? It would be interesting to examine the inlet manifold to see if there is any kind of corresponding porting in it.

Yes, it's definitely something to pass emissions in America. The emissions compliance gear was installed in the '90s & the prior owner hastily removed it before selling me the car this summer. They gave me all of the gear in a box (photo below). The part I'm holding in the upper-right of the photo I believe mates to the hole in the exhaust manifold. I think that the pump in the box is a smog pump like this one.

 

[124BC1]

Thanks everyone! You're all right! The missing part clearly connects two exhaust pipes (pictured below).

The exhaust pipe clamp (arrowed in green) is usually fitted where the exhaust pipe connects to the exhaust manifold. The usual exhaust pipe clamps elsewhere on the exhaust system are usually 'D' shaped clamps with one bolt and nut or aftermarket 'U' shaped clamps (U bolt plus a saddle and 2 nuts).

The usual way (on classic Fiats) of connecting the various pipes, mufflers etc. in the exhaust system is by slip connections, where each pipe fits inside a belled-out (expanded)section on the next pipe and is then secured by a D or U shaped clamp. Of course it's always possible that someone may have altered things from the norm.

The bracket (arrowed in red) is the support bracket connecting the exhaust pipe to the rear of the transmission - it reduces the stress on the exhaust pipe to manifold connection and also will prevent the front exhaust pipe from dropping to the ground should the exhaust manifold clamp become detached (as happened to your car).

 

[124BC1]

If you haven't already done so, might I suggest you tie/clip that cable? (arrowed in red below) away from the exhaust manifold

 

[Pugglt Auld Jock]

I got the clamp reinstalled! While working my wife came to check on me & I complained about missing the plug for the exhaust port. I showed her a photo, she looked in the engine bay & nonchalantly declared "here it is" and pulled it out of that dark cavity in the photo below the exhaust pipe!!! It must have unscrewed itself, fallen, & gotten stuck? Very strange. I'm extremely lucky it remained in the engine bay, & doubly lucky that she noticed it!!

The car runs nice & quiet now and all of the missing power is back! What a relief!! Thanks again everyone for the help, your advice is invaluable!!

View attachment 457315




Yes, it's definitely something to pass emissions in America. The emissions compliance gear was installed in the '90s & the prior owner hastily removed it before selling me the car this summer. They gave me all of the gear in a box (photo below). The part I'm holding in the upper-right of the photo I believe mates to the hole in the exhaust manifold. I think that the pump in the box is a smog pump like this one.

View attachment 457316

Ah yes, Smog pumps. Something they thankfully never got round to over here - Exhaust gas recirculation is quite bad enough thank you!

 

[GeigerUncounter]

View attachment 457326

The exhaust pipe clamp (arrowed in green) is usually fitted where the exhaust pipe connects to the exhaust manifold. The usual exhaust pipe clamps elsewhere on the exhaust system are usually 'D' shaped clamps with one bolt and nut or aftermarket 'U' shaped clamps (U bolt plus a saddle and 2 nuts).

The usual way (on classic Fiats) of connecting the various pipes, mufflers etc. in the exhaust system is by slip connections, where each pipe fits inside a belled-out (expanded)section on the next pipe and is then secured by a D or U shaped clamp. Of course it's always possible that someone may have altered things from the norm.

The bracket (arrowed in red) is the support bracket connecting the exhaust pipe to the rear of the transmission - it reduces the stress on the exhaust pipe to manifold connection and also will prevent the front exhaust pipe from dropping to the ground should the exhaust manifold clamp become detached (as happened to your car).

Thanks for pointing this out. You're right that I had this wrong (as evidenced in the photo). I've got the clamp moved to the exhaust manifold-exhaust pipe connection under the hood. That leaves the pipe connection unsecured, so I'll find myself a D or U shaped clamp for that connection. Thanks!