Hi,

I have a GP 1.4 8v, the exhaust has been blown for a while, I finally had the time and money to fix it. Decided to replace the whole exhaust including the cat and manifold because I got the parts for fairly cheap and it's relatively easy to do.

We went to remove the manifold and not only noticed that nearly all of the studs were loose, and one was missing. We thought it was a bit odd but carried on otherwise. The bolts were fairly easy to turn, we weren't putting very much force on them at all.

But the bolts kept shearing. One went, then another, then another. 3 bolts sheared... At this point we decided to stop, because we had no way of getting the broken bolts out at that time, and no bolts to replace them with anyway.

We did up the rest of the bolts that are holding it on and that's how it's sat at the moment. We're planning on trying to fix it next weekend, and I don't plan to drive the car much if at all between that time.

I've seen a few posts and a few sources say that the bolt size is m8? It was 10mm when we were doing it. I'm wondering is that the right size for a 1.4? Or has some clueless mechanic put the wrong size bolts in at some point... do I need M8 or M10?

Anyways any help will be greatly appreciated

Thanks.

What spanner size did you used ? Here are some standardized sizes for normal strength (8.8) hexagonal heads nuts/bolts

M4: 7mm
M5: 8mm
M6: 10mm
M8: 13mm
M10: 17mm
M12: 19mm
M14: 22mm
M16: 24mm

BRs, Bernie

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I've realised my stupidity now... This is the last time I make posts at 2am haha

The thread size is m8, the bolt is obviously bigger. So we used a 10mm socket.

While I'm on the subject. Does anyone have any tips on how to remove the broken studs?

I've heard drill extractors can work but there's a good chance you can break them off in the hole, giving you even bigger problems... Another suggestion was welding a bolt onto them, but I think they're going to be too far down in the block for anything like that to work :/

Again any help will be appreciated

Thanks

A 10mm socket would correspond to a M6 thread nut or screw head, while M8 requires a 13mm tool . It's far from 2am but there is still Something unclear … ;-)

Br's, Bernie

The 8 nuts holding the exhaust on the head should be 8mm thread,needing a 12mm or 13mm spanner or socket. Two of mine snapped flush and I got a mate round with a MIG welder,once the setting was right,the snapped studs came out very easily,and was astounded how cool the head stayed.

That's the right (and only ?) way to do it: the MIG welding will NOT stick to the aluminium but the heat generated will un-seize the strud from its thread. The other way is using a milling machine but that needs head removal; drilling and "strud remover" will probably not work: very difficult access and the conical shape of the extractor would stuck the strud even more ! If one can reach the broken strud and drill a hole in it, I'd suggest to tap a LEFT thread in the strud, but left taps are not found easily (nor are left thread screws)…

BRs, Bernie

If someone here helped You fix -or better, understand- your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)

I managed to remove a stud once a few years ago, with the conical left-hand extractors... but when i had to do it on my t-jet the stud would not budge.
Was a difficult one, broken 4-5mm below the surface.
Had my dad weld on to it ... stick welding ... it took a few minutes slowly building up..eventually welded a bolt on to it.... then slowly moving it back and forth.
The bolt broke off a few times.. but eventually he managed to get it out.
a few threads were slightly damaged.. but ran a tap/thread chaser through all of the holes... and seemed fine.

Thanks for your help guys.

The studs have sheared fairly deep in each of the holes. At least 5mm maybe more.

So the recommendation is to use a MIG welder, weld a bolt to the top of the studs and slowly back them out?

I know a few people who may have MIG welder. I'll speak to them see if it's a job they'd be comfortable to do. I've had very little experience with welding and my engine block probably isn't a good place to practice lol.

The process consists of adding material to the strud so it finally protrude from the hole (slice by slice), then slip a nut on the protrusion and weld all together. Heating the strud will un-seize it and the nut will allow removal with spanner/socket …

BRs, Bernie

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Bernievarian said:

The process consists of adding material to the strud so it finally protrude from the hole (slice by slice), then slip a nut on the protrusion and weld all together. Heating the strud will un-seize it and the nut will allow removal with spanner/socket …

BRs, Bernie

If someone here helped You fix -or better, understand- your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)

Click to expand...

Done this a couple of times now. Much greater chance of success than other methods I've tried. Works well on steel studs in Ally and Cast Iron as the weld doesn't stick to the parent metal and the heat frees the stud. You need the weld current quite high (I crank my Cebora 130 turbo up to not far off max) as you only have a very short melt time, unlike running a bead, and you need to aim the wire carefully at the stud otherwise the arc will strike to the casting. It's not that difficult but needs a bit of concentration. I also like to give it a good couple of squirts of Plus Gas before attacking it with the spanner/socket.