Hesitation / judder...

deMort · 28 Dec 2019

This is not sounding too good

Can you get a photo of the snapped earth strap if possible .

Im guessing its the large earth strap o/s/r .. this is the main engine earth so not only do i think the car will not start i dont think its a good idea to attempt starting it either .

You can't really drill and fix this lead as its a box chassis section it fits to , it needs a stud welded on really .

I think it needs to goto a garage .. that will require being recovered or using a jump lead inside the engine bay to give it a temp earth .. a little risky i feel .

the above is assuming the snapped lead is the engine earth strap though .. hence a picture if possible .

rob_p · 28 Dec 2019

Oh dear... thanks for the reply. I will try and post a photo later.

rob_p · 28 Dec 2019

Thanks DeMort,
Photos below, one showing the sheared stud (there might be enough left to get some kind of nut extender onto it?) - is it M8?,
and one showing the strap hanging down.

Also note the bumper bracket bolt next to it where it has also sheared (obviously less urgent than the earth strap....)

Any advice welcome!

thanks

deMort · 28 Dec 2019

I see what you mean by bumper bracket now .. you can drill a hole and use a self cutting bolt / screw to reattach that .. it's no problem if left off for now .

As it stands and after thinking about it your car won't start .. i remember leaving off an earth lead on an engine drop in the past .. it wont start .

Fixes .. a welded stud is best .. body shops have this sort of equipment but that doesn't really help you atm ..

My suggestion if you want to try it ..

You use the kit in the link below ..

You basically drill a hole , insert the collapsable threaded rivet nut and use the tool to compress it .. you then have something to put a bolt into for the earth lead .

Access is the only problem with the tool .. it will stick out at a right angle from the chassis .. if you have the clearance then this is the best diy i can think of .

https://www.ebay.co.uk/itm/Blind-TH...926036?hash=item1ef31f2f14:g:g7YAAOSwUMBcSJGb

Btw .. im happy to chat on the phone should you wish to , just say and ill PM you my number .

P9XX · 28 Dec 2019

Rob_p. I think you've already thought of this idea.
As a temporary or even permanent fix for the earth strap stud, you seem to have about 4 to 6 threads showing. If so, I would try a stainless rod coupler nut with Loctite onto the cleaned threads. Check electrical continuity from the coupler to the chassis. Then a short, M8 X 12 say, bolt to re-attach the earth strap.

jl-c · 28 Dec 2019

If you try it this way use Loctite 3888 as it is the conductive one.

rob_p · 28 Dec 2019

P9XX said:
Rob_p. I think you've already thought of this idea.
As a temporary or even permanent fix for the earth strap stud, you seem to have about 4 to 6 threads showing. If so, I would try a stainless rod coupler nut with Loctite onto the cleaned threads. Check electrical continuity from the coupler to the chassis. Then a short, M8 X 12 say, bolt to re-attach the earth strap.

Thanks. Yes I found something similar on eBay for £2 and wondered if that would work. I assume this will be M8?

I have also ordered one of DeMort's nut rivet guns. It's always good to have options.

rob_p · 28 Dec 2019

deMort said:
I see what you mean by bumper bracket now .. you can drill a hole and use a self cutting bolt / screw to reattach that .. it's no problem if left off for now .

As it stands and after thinking about it your car won't start .. i remember leaving off an earth lead on an engine drop in the past .. it wont start .

Fixes .. a welded stud is best .. body shops have this sort of equipment but that doesn't really help you atm ..

My suggestion if you want to try it ..

You use the kit in the link below ..

You basically drill a hole , insert the collapsable threaded rivet nut and use the tool to compress it .. you then have something to put a bolt into for the earth lead .

Access is the only problem with the tool .. it will stick out at a right angle from the chassis .. if you have the clearance then this is the best diy i can think of .

https://www.ebay.co.uk/itm/Blind-TH...926036?hash=item1ef31f2f14:g:g7YAAOSwUMBcSJGb

Btw .. im happy to chat on the phone should you wish to , just say and ill PM you my number .

Thanks DeMort. Rivet gun ordered. I may well take you up on your offer of a chat on the phone. Thanks!

rob_p · 29 Dec 2019

Quick update.
I have ordered some of the nut rivets and a nut extender.
Looking again today there is about a nut and a half of thread on the sheared stud and I can get an M8 nut on it. Turns out I can therefore get the earth strap and about half a nut of thread on it. Not ideal but will get me to a garage if i need to.
I think the nut extender idea should work quite well.
There is also another whole with a blanking plug in it next to this which presumably I could use for a new earth connection of I needed to? (Using the rivet nut).

I have also drilled out the bumper bar connection snapped stud. This looks a lot like Porsche used their own version of a nut rivet so I am hoping a new one will just slot right in. The original was M6 but if I need to I could do up to M8.

Thanks for the help so far, once the parts arrive I should be able to get it all back together.

rob_p · 29 Dec 2019

Quite an interesting video for anyone interested in nut rivets...

https://youtu.be/qhzVDvnN_yM

deMort · 29 Dec 2019

If that blanking hole is M8 or 8mm then you should be able to use that.

The video .. dam clever .. i don't often use this tool as its more of an emergency repair but i never even thought of using a bolt / nut

learnt something new today :thumb:

darkhorse · 29 Dec 2019

One word of caution. I used the DIY nutcert tool. It took some faffing to make it work.. but if space is tight it is a good option. It needs a grip spike washer onto the nutcert top, then the rest of the bits.
If you use stainless steel nutcerts as I did, M8 ones are VERY hard to compress using this method. It took me a lot of swearing to get them compressed and locked in, and I wished I had ordered the nutcert tool.

rob_p · 1 Jan 2020

Quick update.

I fixed the earth terminal issue with the "nut extender". It went on pretty firmly in the end and i think looks like a pretty good permanent solution.

Everything is back together and the car is running well. The original misfire has been resolved so confirmed this was a faulty coil pack on cylinder two.

I still need to fix the bumper bracket which is the hole to the RHS of the earth terminal. I will do that when the rivnut parts arrive - probably this weekend.

thanks for everyones help with this - especially Demort who has been legendary as ever!

I also managed a quick oil change today while I had the spanners out.

rob_p · 9 Feb 2020

Quick final update on this thread.
Having fixed the earth strap I then received the "riv nut" kit that Demort recommended.
The tool included (just like a rivet gun) broke the first time i tried to use it - the tool is nowhere near strong enough for the job required. So i made a DIY tool like i had seen on youtube (photo below).
Advice - just buy the riv buts on ebay and make your own tool.
That was pretty much it. I used an M8 instead of an M6 to hold the bumper bar on - but no big deal. All back on the road.

chowgar · 9 Feb 2020

I admire your tenacity in pushing forward to get this job completed.

Hesitation / judder...

Monaco

Suzuka

Suzuka

Attachments

Monaco

Silverstone

Attachments

Montreal

Suzuka

Suzuka

Suzuka

Suzuka

Monaco

Spa-Francorchamps

Suzuka

Attachments

Suzuka

Attachments

Spa-Francorchamps

Similar threads

Porsche Model Range

Porsche 911

Porsche Hypercars

Other Current Porsche Model

Porsche Legacy Models

Forum statistics