bought a wreck....repaired it...pulled it out of the garage only to find out!

Wow... that's a big hole... There's no way to reliably weld that... Do you really mean it when you say engine runs? If this car runs with no error codes that's amazing! You must be a magician! Hopefully u can recover costs and pass it on to someone with an engine for it....

 

I didn't know it was possible to weld aluminum.

Why not buy a used engine from a salvage yard and have that installed. Then you'll have a reliable drivetrain.

 

To my knowledge, aluminum welding is just as reliable as steel welding, done by a capable craftsman. I had a split welded in a water heater, years back. They would probably cut an insert patch and weld around the edges. The issues will be the oil coated components immediately behind the broken case. A machine shop deals with welding cracks in aluminum heads on a continual basis. I had a Peugeot head welded, back in the eighties. The shop cut a hole in the head in order to reach the hidden crack and then welded the hole. However, there were no movable parts in the head at that point. No machine shop would work on the assembled, installed engine but that doesn't mean that there aren't some qualified welders that won't. The engine can be washed out with mineral spirits, for a start. I'll be interested in seeing if you can get a decent repair done without removal. I'd be checking with those that routinely do quality welding.

 

Why not DIY? Rent a welder from Home Depot, practice on some scrap until you get good. If you can do all of what you did, you can do this too. It looks like there's room to do it. My biggest concern would be, how to avoid getting metal dust in the engine when prepping the metal for welding. I think it can be done but, wow!!!, what a pain in the a%#.

 

Easier that welding is JB Weld epoxy.

Since the hole does not appear to diminish the structual intregrity of the bottom part of the engine, I'd just get a piece of 16 gauge aluminum, Make sure that it overlaps the entire area, drill a few 3/16 holes into the overlapping area, mark and drill the engine casting with the samew 3/16 inch holes, coat the overlap in the patch with JB Weld , and then rivet it into place.

The rivets hold the patch in alignment, and the JB Weld seals the oil in from leaking.

The oil filter will catch the aluminum swarf, so change the oil and filter after a couple of hundred of miles or so.

 

My only concern about this type of repair would be... Will the JB Weld hold up over time? The constant heating and cooling of the engine (moreso in a Prius than other cars) could result in leaking. The JB weld will expand/contract slightly different than the base metal. Whereas a weld will result in even expansion/contraction. I'm not totally discounting this as a fix b/c, it just may work.

 

I repaired a BMW 7series a few years ago with very similar damage. Repaired it with a propane/oxygen torch and some special aluminium welding rods from a welding supply company. Had to take the sump off and heat the whole thing up before it would weld. There is now I believe a gas and wire you can use in a mig welder to repair aluminium castings.

I also repaired back in the 60's an Austin mini sump casing, those had the gearbox in the engine sump (ran in the same oil). All I did to repair that was degrease the area and fill it with epoxy resin. worked without leaking for 4years until it got written off.

 

With a thick enough piece of aluminum as the patch, and sufficient rivets to hold it in place, perhaps a handcut gasket will do the trick? (I'd never have the guts to try this, and am suggesting something only because I'm "riveted" to the thread to find out what will happen. I'm sorry for the misfortune of the OP, but I imagine he is going to figure out a great solution.)

 

If the damaged casing is thick enough I think drilling and tapping would be better then using a plate with a gasket and sealer. This makes the job more serviceable in case of future leaks. It is possible that with care a steel plate drilled and tapped could be slid inside the sump for extra clamping.

 

I wasn't saying that you "can't" weld up the hole, I'm saying it won't be a reliable fix... The only thing crazier than not seeing damage that severe before you decided to fix the car is thinking that patching the hole is going to be the end of the nightmare. The kind of force it takes to put a hole in that casing means there is most likely other damage you aren't aware of yet. Microscopic cracks in the casing, motor mounts, internal parts, etc. What happened to the metal that broke off? Perhaps if you pulled the engine and removed the casing and had a qualified machine shop repair and inspect for additional hairline cracks / other damages you might be able to pull it off... But swapping with a used engine/transaxle is the only way you'll insure future owner will have a reliable vehicle.

 

I feel the same way when certain posters send people to the dealer when there are independent hybrid shops around.

Anyways, the hole is in the upper oil pan which I believe can be removed on the car. Keep in mind you will have to remove the timing cover and water pump as well. The dowels that center the engine to the trans are above the upper oil pan, so the upper oil pan should slide down and be removable.

The part number for the upper oil pan is 12111-21060 with an MSRP of $136.16. Considering that, you may want to re-think any welding.

Avi

 

This will prob be ur best bet.

Great info Avi

 

You're the man Avi.

 

If you guys wanna read a good story about holy engine blocks and JB Weld, look no further: LeMons Good/Bad Idea of the Week: Toyota Fun With JB Weld and Shattered Engine Blocks

Aluminum bicycle frames have been available since the 1970's. How do you think they were assembled, with super glue?

 

Aluminum airplane and wing parts have been "glued" for years with adhesives including epoxies and cyanoachrylates. Rivets hold the alignment, while the "glue" spreads the stress evenly.

The DH-1 De Havilland Comet of the 1950's as well as the new 787 Dreamliner is "glued" together.

You'll be very surprised how much 3M VHB double stick tape is also used.

In the case of the oil sump, there is very little pressure there. The crankcase is vented by the PCV valve to the intake manifold. Oil used to lube the piston rings and the bearings drain back to the sump by gravity. Your only intent is to close up the hole to keep the oil from spashing out and road debris from getting in.

 

Normally there is little pressure there, but the force that put the hole there likely torqued the casing and there are probably more pressures on it than normal, not to mention cracks that aren't easily visible. But it's awesome that the casing replacement part is only $100, which solves most of the problem... At the same time... What else might be still broken on this car?