GeorgeM

Passenger side block plug. I had previously attempted to tighten this to 35ft lbs, as per the WSM, but all it did was crush the washer, and it just felt too tight, so I backed off before I got there. Then, using the old washer, I used Dwayne's spec of 25.8ftlbs from his TB/WP job guide, and I get this. The torque wrench hadn't even clicked yet.

Any ideas on how to repair it? All I can think of is get a longer bolt and weld it shut. I'm up for ideas...

dcrasta

Yikes!

Is that the coolant plug? I would [I'm a bit of a desperate hack..] Probably get a welder in there like you said. I never remove those things (even when Doing my TB/WP) unless I am taking the block out of the car... Never seen one go like that usually they sheer the head off (iron block cars) ..

That looks like its gonna sting (in the wallet!)

Dean_Fuller

If its the coolant block plug I would think that system doesn't run at high PSI so JB Weld may work but you will never be able to drain that block side again...which isn't that bad. Could of been a lot worse.

WallyP

While I know that I will be flamed for a make-shift repair, I would clean the area carefully and start slowly layering JB Weld on the area. Apply the material to the broken area and bolt only, let cure. Sand with very coarse abrasive paper, clean the area and apply a coat over the patch plus 1/4", let cure. Sand, apply a coat over the patch and the bolt head plus 1/2". See what happens...

76FJ55

There have been enough successful welding on these blocks that I think this should be recoverable. I would assume you still have the piece that broke off. I would find a competent welder and have it reattached. Then you will need to retap or possibly helicoil to get good threads for the plug. Make sure he end is smooth and flat perpendicular to the hole, and reinstall the plug. For good measure you could use non setting sealant on the plug during installation. I know this has to be frustrating, but it is recoverable.

Note: make sure to disconnect the computers during welding.

Good luck.

GeorgeM

It is the coolant block plug. After draining the driver's side first, there wasn't that much left to drain out of this side, so I have no issues permanently plugging it.

Never used JB weld before. Is it that good? Good enough to trust not to give out on the road?

I was thinking to get a longer bolt that will fill the existing hole, then just weld the thing shut w/o even using the broken pieces.

Landseer

George,
Are there any threads remaining beneath the broken area?

pjg

This may be worth a shot.

http://www.aluminumrepair.com/aluminum_repair.asp

Herman K

I've used JB Weld on BMW and Mercedes radiator leaks and it has outlasted the cars life span if applied right you shouldn't have a problem.

Like Wally said you have to built it up in layers because of the location if applied to heavy it will just drip down.

I'm still surprised this happened can it be that is was over tight before the block is pretty strong in that area.

JBW will do the job but I know things like this will linger on your mind.

I would only consider to weld on this with the block out of the car.

Good luck

Erik N

Epoxies will chemically bond between coats if they are not cured yet. So you can avoid the sanding between coats if you do not wait for it to become completely hard before the next coat.

928 at last

Before applying the JB, the aluminium has to be CLEAN. I've had very good results with it on a snowmobile heat exchanger (front bulkhead, exposed to all the crap the track throws up), at full pressure. Several years and hundred miles on it now with no issues.

SQLGuy

I think my first choice would be to see if a job shop felt comfortable about welding the old piece back in place.

If not, but I still had the old piece, I'd try Muggy Weld (aluminum solder). It works at pretty low temps, but high enough to not weaken at block temps, and is quite strong. I'd trust it much more than JB Weld, which I have had problems with when heated.

Muggy Weld could also be used to solder a plug in place.

928mac

I know JB weld works because I've used it on a quad, but, I don't think I would feel safe knowing that if it started to leak I could be in the middle of nowhere and not catch it in time.

This really really sucks but I would check around for the best welder in your area and ask him to come take a look.

I don't know if there will be enough room for him to perform a leak proof weld with the engine in the car.

definitely remove the connectors from your computers and to protect the other modules remove the ground cable from the battery

SeanR

I'd just do similar to what Wally said.

Put the bolt back in, stuff some JB Weld in/around/on and try to put the old part back in place, followed by more JB Weld.

mark kibort

why people go so crazy at these types of bolts is amazing. just sinch it down and be done. its not like its under any pressure or anything!

anyway, what am i looking at here. it looks all wrong to me. i thought the freeze plug bolt was just a bolt that went into the side of the block. this looks vertical, or is it an optical illusion?
anyway, i would weld it shut. and never think about it. the ony time in 20 years of owning 928s that I have removed one of those was when i was using the block fixer liquid.