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Welding on the engine

ephect

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I need some advice, I went to renew the thermostat, and ended up with 2 sheared bolt heads. I've tried soaking with CRC, easy outs which broke in one of the bolts. I'm avoiding drilling out the other one.

I just finished renewing the LIM gaskets so I don't want to remove the manifold if possible

So I'm here going to weld a washer to the thread first, then a nut to them remove the remaining bolt.

My question, besides the battery, do I need to disconnect the ecu, bcm, abs etc before I begin welding?
 

woteva

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Drill it out and install some helicoils.
 

losh1971

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My question, besides the battery, do I need to disconnect the ecu, bcm, abs etc before I begin welding?
Disconnecting the battery is a wives tale. The current in the welder looks for the shortest possible route to earth. You are more likely to damage the PCM or BCM. If you want to be really safe unplug the modules.
 

ephect

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Drill it out and install some helicoils.
I broke an easy out in it already, tried drilling and stuffed several drill bits in the process.

I have read another member slightly twisting the thermostat housing and drilling new holes. Want to avoid this also

Disconnecting the battery is a wives tale. The current in the welder looks for the shortest possible route to earth. You are more likely to damage the PCM or BCM. If you want to be really safe unplug the modules.
I'm going to clamp the welder earth strap as close as possible to the bolt.
 

immortality

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Old wives tale or not, I'd disconnect the battery.
 

shane_3800

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Disconnecting the battery is a wives tale. The current in the welder looks for the shortest possible route to earth. You are more likely to damage the PCM or BCM. If you want to be really safe unplug the modules.
No this is incorrect information. Stray current can cause all sorts of issues.
 

losh1971

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No this is incorrect information. Stray current can cause all sorts of issues.
Please tell me how many batteries you have heard that exploded from a stray current? Doesn't hurt, but wrong info I think not. If you have some credible evidence please share because I am happy to be wrong. A professional in welding that worked on my old 4b at various times told me it's BS. Like I said the stray current is more likely to affect a module than have any chance of destroying a battery, disconnecting the battery will do SFA to protect the modules.
 

shane_3800

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Please tell me how many batteries you have heard that exploded from a stray current? Doesn't hurt, but wrong info I think not. If you have some credible evidence please share because I am happy to be wrong. A professional in welding that worked on my old 4b at various times told me it's BS. Like I said the stray current is more likely to affect a module than have any chance of destroying a battery, disconnecting the battery will do SFA to protect the modules.
It's not about destroying the battery it's about removing the ground path for stray current. You disconnect the battery and every circuit in the car is now open circuit.
 

losh1971

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It's not about destroying the battery it's about removing the ground path for stray current. You disconnect the battery and every circuit in the car is now open circuit.
You may be right but I'd like to see some evidence from a professional or two on what you are saying. I have just read that leaving the battery connected can actually protect the modules as it can absorb the stray current.
I have been told that because the modules are still grounded regardless of whether they have 12v running through or not they could still be damaged, hence why you would unplug them if you want to be sure.
The battery and welding theory has been around since before I was born, so it's not just to protect modern electronics obviously?
 
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shane_3800

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You may be right but I'd like to see some evidence from a professional or two on what you are saying.
I've done it my self and survived but had a car at work the panel beaters fucked, now this shop uses ground straps to earth points in the shop.
 
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