500 Exhaust Manifold Bolts

[JerryRJ]

I have a 2011 1.2 Fiat 500. I took it to a local garage (that I trust and use regularly) to look at the exhaust because the rear box is rusty. However on inspection the garage think that 2 of the manifold bolts are either missing or sheared off. Is this a regular problem with Fiat 500s and do you need specialist Fiat parts or tools to fix? Many thanks

 

[John202020]

There's a bracket that goes from the exhaust to the gearbox at the front, it often rusts away completely this can then stress anything "up front" did they say whether the bolts are underneath or on top of the manifold, can you take a picture it maybe covered with the heat shield though

 

[JerryRJ]

There's a bracket that goes from the exhaust to the gearbox at the front, it often rusts away completely this can then stress anything "up front" did they say whether the bolts are underneath or on top of the manifold, can you take a picture it maybe covered with the heat shield though

Hi John thanks for coming back to me. I attach 3 pictures taken by the garage from above the manifold beside the heat shield. The middle one seems to suggest bolts are missing. They didn't mention the bracket by the gearbox so I will look at that when I can.

 

[John202020]

I would agree with the garage, wow, this could be a hard fix, this is my "fix" for the missing clamp/steady

 

[z rider]

You don't really need specialist parts but sometimes it's easier to get the studs that sheared off from the dealership.
Will need exhaust manifold gasket, the studs and new thermal nuts to screw manifold back. If the strut John202020 described is missing you will need this too plus fixing material. The tricky part is to get the rest of the studs out of the head after manifold is taken away. Don't know if you are used to repairs like this, it takes a lot of patience do drill out sheared bolts in aluminum (if there is no other way to get them out), so if not give it to a trusted mechanic.

 

[Pugglt Auld Jock]

Hi John thanks for coming back to me. I attach 3 pictures taken by the garage from above the manifold beside the heat shield. The middle one seems to suggest bolts are missing. They didn't mention the bracket by the gearbox so I will look at that when I can.

Looks to me like the studs, which are screwed into the head and then have nuts screwed onto them to hold the manifold in place, have sheared. There are various ways to deal with this but it's not the sort of thing you're going to do if you're inexperienced with only limited poor quality tools. Garage workshops deal with this sort of stuff on a regular basis but some prefer to strip the part off and send it to an engineering workshop - which can get expensive. Definitely get an estimate in writing before you agree to let anyone loose on it. If you ignore it the gasket will blow - if it hasn't already - which then introduces the risk of exhaust gasses being drawn in through the heater system - not a biggy on very short trips, but not so good on longer journeys or in winter when you may be stuck in a traffic jam for a while with the heater on and windows wound up.

 

[JerryRJ]

I would agree with the garage, wow, this could be a hard fix, this is my "fix" for the missing clamp/steady

Thanks very much for your help John.

 

[JerryRJ]

You don't really need specialist parts but sometimes it's easier to get the studs that sheared off from the dealership.
Will need exhaust manifold gasket, the studs and new thermal nuts to screw manifold back. If the strut John202020 described is missing you will need this too plus fixing material. The tricky part is to get the rest of the studs out of the head after manifold is taken away. Don't know if you are used to repairs like this, it takes a lot of patience do drill out sheared bolts in aluminum (if there is no other way to get them out), so if not give it to a trusted mechanic.

Thank you Z Rider for your thoughts. I am definitely not experienced enough to drill out any sheared bolts nor do I have the tools. My dilemma is do I give the work to the local garage I trust or go to an exhaust centre or Fiat dealer. My local Fiat dealer has told me I have to pay £175 for them just to look at it and won't give advice over the phone. I'm going to try an exhaust centre later this week for their thoughts. Many thanks again

 

[JerryRJ]

Looks to me like the studs, which are screwed into the head and then have nuts screwed onto them to hold the manifold in place, have sheared. There are various ways to deal with this but it's not the sort of thing you're going to do if you're inexperienced with only limited poor quality tools. Garage workshops deal with this sort of stuff on a regular basis but some prefer to strip the part off and send it to an engineering workshop - which can get expensive. Definitely get an estimate in writing before you agree to let anyone loose on it. If you ignore it the gasket will blow - if it hasn't already - which then introduces the risk of exhaust gasses being drawn in through the heater system - not a biggy on very short trips, but not so good on longer journeys or in winter when you may be stuck in a traffic jam for a while with the heater on and windows wound up.

Hi Pugglt thanks for your advice. I will take it to an exhaust centre this week to view and then probably go back to my local dealer to sort out. They also advised about the exhaust fumes too which was reassuring. Thanks again

 

[mtimm]

When I got my wife's 500, 3 of the exhaust manifold studs were sheared off. due to other work been done the front was off the car so I had good access to the head. (Full disclosure my background is engineering maintenance) literally 10 min per stud, pilot drill the stud, drill to tapping size, 6.8mm for m8 and clear out with a tap.( you could try drill the stud and use stud removers but I've had limited success with these in the past)

This should NOT be done by someone with out the necessary experience, if the hole is not properly centered the drill bit will drift badly into the aluminium of the head, away from the steel stud and possibly destroy the head.

 

[vexorg]

If it's had the sump replaced then the manifold needs to come off, and at that age ther eis a good chance it will have been done (at least once!). More than likely someone broke the studs then.

 

[Pugglt Auld Jock]

Thank you Z Rider for your thoughts. I am definitely not experienced enough to drill out any sheared bolts nor do I have the tools. My dilemma is do I give the work to the local garage I trust or go to an exhaust centre or Fiat dealer. My local Fiat dealer has told me I have to pay £175 for them just to look at it and won't give advice over the phone. I'm going to try an exhaust centre later this week for their thoughts. Many thanks again

If the local garage is competent and you trust them I'd go with them all day long. A "Fast Fit" type exhaust centre? wouldn't go within a city block of one for this sort of job!!! Main Dealer? Would do a "Rolls Royce" repair, or you would hope they would? but at "Rolls Royce" prices. Having struggled for years with this sort of job (and broken my fair share of drills and eezi outs in the stud, which then makes a difficult job much more difficult) These days, in most situations, I would reach for my welding torch, and weld a new nut to what was left of the stud - leaving the drills and eezi outs in the drawer - The heat passed into the broken bit of stud loosens it, especially where it's a stud in an alloy casting, and the welded on nut lets you unwind it. It's a technique that needs you to be quite good with your welder and practice a few times on scrap, but once you've mastered it, it works well most times but can be difficult on studs that have broken off well below the surface.

 

[Ralf S.]

You might be lucky and the studs may just have vibrated loose. When the manifold is removed (for the sump, amongst other tasks that might require it) you can find that the nut is so rusted to the stud that the whole stud unscrews rather than the nut only... so the stud/nut combo act like a regular bolt.

They're supposed to be Loctited in place but it's 99% likely that whoever did that job probably just screwed in the stud/nut and that was that.

Stick a small screwdriver into the hole to see whether there is any stud still in the hole, or whether the hole is empty (you might be able to feel the screwdriver running over the threads).

Buy new manifold studs and new nuts. Buy a new bottom clamp.



Ralf S.

 

[Pugglt Auld Jock]

When I got my wife's 500, 3 of the exhaust manifold studs were sheared off. due to other work been done the front was off the car so I had good access to the head. (Full disclosure my background is engineering maintenance) literally 10 min per stud, pilot drill the stud, drill to tapping size, 6.8mm for m8 and clear out with a tap.( you could try drill the stud and use stud removers but I've had limited success with these in the past)

This should NOT be done by someone with out the necessary experience, if the hole is not properly centered the drill bit will drift badly into the aluminium of the head, away from the steel stud and possibly destroy the head.

Interesting technique. Before I gained confidence with my welder I'd always drill and use an extractor, however, as you say, unless you drill it absolutely dead centre you can end up with the drill drifting into the casting. Then the extractor won't work anyway. I've tried, in situations like this, then using a tap to clean it up but what often happens is that the remains of the steel stud rotates a bit in the hole and traps the tap! I've ended up with then with a tap stuck in the hole which breaks if you try to unwind it! However, as with many things in life, you go with what you've found works for you and I've found welding a nut on works for me. I'd like to look over your shoulder when you're doing it your way though as I like the simplicity of the idea.

 

[Pugglt Auld Jock]

You might be lucky and the studs may just have vibrated loose. When the manifold is removed (for the sump, amongst other tasks that might require it) you can find that the nut is so rusted to the stud that the whole stud unscrews rather than the nut only... so the stud/nut combo act like a regular bolt.

They're supposed to be Loctited in place but it's 99% likely that whoever did that job probably just screwed in the stud/nut and that was that.

Stick a small screwdriver into the hole to see whether there is any stud still in the hole, or whether the hole is empty (you might be able to feel the screwdriver running over the threads).

Buy new manifold studs and new nuts. Buy a new bottom clamp.



Ralf S.

Hadn't thought of that possibility. However, when the garage did my boy's clutch they failed to refit one of the gearbox mount bolts! Maybe the chap doing the job just forgot it or maybe lost it and couldn't be bothered to go to the stores and get a new one. Luckily I had one that did the job.

 

[JerryRJ]

When I got my wife's 500, 3 of the exhaust manifold studs were sheared off. due to other work been done the front was off the car so I had good access to the head. (Full disclosure my background is engineering maintenance) literally 10 min per stud, pilot drill the stud, drill to tapping size, 6.8mm for m8 and clear out with a tap.( you could try drill the stud and use stud removers but I've had limited success with these in the past)

This should NOT be done by someone with out the necessary experience, if the hole is not properly centered the drill bit will drift badly into the aluminium of the head, away from the steel stud and possibly destroy the head.

Hi mtimm thanks for your comments. Interesting that you have had bolts shearing off too. I will pass your advice to the garage to do. Cheers

 

[John202020]

Never looked at ours, and we had a new sump 7 years ago

 

[mtimm]

Interesting technique. Before I gained confidence with my welder I'd always drill and use an extractor, however, as you say, unless you drill it absolutely dead centre you can end up with the drill drifting into the casting. Then the extractor won't work anyway. I've tried, in situations like this, then using a tap to clean it up but what often happens is that the remains of the steel stud rotates a bit in the hole and traps the tap! I've ended up with then with a tap stuck in the hole which breaks if you try to unwind it! However, as with many things in life, you go with what you've found works for you and I've found welding a nut on works for me. I'd like to look over your shoulder when you're doing it your way though as I like the simplicity of the idea.

I've drilled out hundreds of sheared bolts/studs over the years. Once the drilling goes right your basically only left with the threads of the bolt which in some cases you can literally pick out.
But like everything it can go horribly wrong.
I've just never found anything easy about "easi outs"

 

[Pugglt Auld Jock]

I've just never found anything easy about "easi outs"

Oh yes, I agree with that.

 

[JerryRJ]

If it's had the sump replaced then the manifold needs to come off, and at that age ther eis a good chance it will have been done (at least once!). More than likely someone broke the studs then.

We've had the car for 12 years now since it was 18 months old and have never had to work on the engine or sump, so this is a surprise. Thank you