Oil Pan replacement

The simplest and most permanent option would be to drill out the opening with a half inch drill bit, tap out the hole with a M14x1.5 tap, and replace the plug with a Honda, Mitsubishi or Mazda OEM plug. The 14mm hex will be exactly the same as the Toyota OEM plug it replaces. Make sure to remove the swarth of the tap with a magnet.

The oil pan is "glued" with an RTV silicone compound and a PITA to remove and replace.

The replacement M14x1.5 plug will have stronger, larger and coarser threads than the original Toyota M12x1.25 JIS threads. Thus, they would be less likely to cross thread on future use.

 

@Georgina Rudkus 's method is probably best, but if you do go for new pan, here's some info.

The spec'd form-in-place gasket is:

Toyota Genuine Seal Packing Black, Three Bond 1207B

The following stuff is more readily available, recommended by Gasket Masters*:

Permatex Ultra Black RTV Gasket Maker (alternate, readily available)

* The guys doing the cheapo head gasket replacements in SF.

 

I think what they're saying here, is place a bead all the way around the perimeter, and at the bolt holes be a little more generous, and go around the inside side of the holes.



Gasket Masters application technique is somewhat contrary" go around the perimeter placing closely spaced dabs, then spread it out evenly with a finger, and apply a few extra dabs if there's any apparent thin spots. Probably works as well as anything. I believe the permatex stuff they're using has a longer set up time too. Read the instructions.

Again, go a little heavier at the bolt holes.

 

The nut that is welded or brazed to the inside of the oil pan was originally threaded with a tap the same way that re-tapping it with a hand tap will do.

 

It is very important that all old gasket sealant residue be removed from the blind holes in the aluminum upper oil pan adapter into which the oil pan bolts are screwed into. If not removed, residue in the blind holes would be squeezed under high pressure and crack the aluminum casting.

 

Before forging ahead with the tap and die method or oil pan replacement, you may just try a longer M12x1.25 drain plug. I had a similar problem with my son's HONDA. Stripped thread on the oil pan made the OEM plug not to tighten. Fortunately stripped thread was just the first 1/2 of the oil pan drain hole. The OEM drain plug was quite short. All I had to do was to replace the OEM drain plug with a longer drain plug of the same diameter and pitch. It caught the last half of the thread remaining in the oil pan drain hole and I could tighten the new longer plug to the specified torque.

 

Unfortunately, the weld nut does not have that many threads.

 

Bead size is 4.0 mm consistent, centered. At the holes bead center should be 6.0 mm from center (of hole), is how I interpret it.

 

I’ve done this before. It’s a pain, but it’s very do-able.
First, do not use a helicoil or similar, because you’re trying to prevent leaks.

Second, if the new threads aren’t perfectly perpendicular to the mating surface on the pan, it will leak.

I recommend the Lisle 58850. I’ve used it, and it works. I’d let you borrow mine if you were in Oregon.

58850 Oil Pan Plug Rethreading Kit | Lisle Corporation

There are two steps: Drill out the larger hole, then tap the new threads. Both come with the Lisle kit. To drill the hole, operate your drill VERY slowly, and keep the bit packed in heavy grease, like wheel bearing grease. Drill just a little, remove the bit, and clean it off with a rag. Apply fresh grease. You’ll do this about four times, going through lots of rags and grease. You want to keep the shavings out of your engine.

When you tap, don’t use grease, use thread tapping oil. I used WD40. Tap by hand, with the collar of the Lisle tap pressed against the oil pan to keep the threads aligned properly. Thread by hand until it won’t go further, then use a ratchet to finish the tap. As before, remove the tap, clean it off, and re-lube frequently.

Reach a pick tool inside to remove any grease or shavings, then flush two quarts of cheap motor oil through to remove any possible shavings. Put the new plug in, included with the Lisle kit, add the fresh oil, and you’re done.

 

A much better price,

 

Well, yeah, nobody pays retail for anything.

 

I want to hear back from the OP.

In addition to being a more intrepid than average shade tree mechanic, I'm a machinist. The idea of trying to do decent quality drilling and tapping on the bottom of an oil pan fills me with skepticism. (side note: WD-40 is a water dispersant, it's the world's worst lubricant, any machine or motor oil is better)

I replaced the oil pan in my 06 Highlander V6 last Summer. I called my local independent mechanic when it developed a leak and I had a long XC trip coming right up, he would not even call me back. That's a clue. I patched the leak with JB Weld, bought a new oil pan, threw the oil pan in back of the car with sealant and a jug of oil in case of problems (oil to get me to a shop, new pan so I don't lose a day hunting parts in bumblefork North Dakota), eventually changed out the pan at my "liesure" some months later. It's a tedious job, but not as horrible as I expected. The hard part is breaking through the sealant. You can't lever the pan off. You will probably break a plastic tool trying to cut through. I used a steel carpenters pry bar with this shape. I had to figure out a way to apply great force with a 36" lever to slowly push the thin edge through the sealant. I recommend against hammering. Once through, you can work your way around with sturdy nylon interior body tools.

Agreed with the other poster above: you must run a tap through all holes to clean out old sealant.

Installation of new pan is easy. Follow sealant directions exactly. I used Permatex 82180. Easy to use, perfect results... but requires 24 hrs to cure before refilling (only downside).

There's a significant difference in quality between OEM and aftermarket oil pans. I was able to come up with a 'yota (Highlander) oil pan for $125 (retail is 2x that) which seemed worth while over the tinny $45 aftermarket jobs.

 

Not interested in your snide remarks. The tool I used worked fine. No leaks. On the car I worked on, removing the oil pan was not an option, and the procedure sounds like an awful lot of work on a Prius.

Lisle is a highly regarded tool company. The Lisle solution works.

 

Yeah you're right. And I was a draftsman...

 

Just trying to read the instructions properly. (Didn’t mean to step on anyone’s toes. I’m sorry if I did).

I would never make it to 3 minutes with the Toyota stuff. I’m guessing at least the 1st quarter of my bead would be dry by the time I fit it, if not half.....

 

This link shows $52 CDN for the Toyota oil pan for me:

Buy cylinder block for Toyota Prius XW30 (01.2009 - 11.2011) - Amayama

Plus $24 CDN shipping for me. I've done a few orders from them, and found it's good to keep all shipments from the same country (to incur only one shipping charge), and throw a few small extras in (say wiper inserts, or other consumable), the shipping price will stay the same or barely budge.

I've used them 3 times now; never any sales tax or import charges.

 

This time of year I'm always wearing my steel toed boots, lol.

I was a checker, not the best one though, too fuzzy.

Yeah, the permatex ultra black has a much more leisurely cure time. I'd much rather have to wait 24 hours before oil fill and use (as mentioned by @Nor'easter, it's the same stuff he recommended), than be racing against the clock.

 

I still prefer the use of the M14x1.5 tap and a standard oil plug. If the special plug from the Lisle kit is damage or lost, you would not readily find a replacement anywhere like the standard plug.

You could easily make the drilling guide out of a block of aluminum with a drill press. The same goes for threading an M14x1.5 black on the same drill press.

 

Love the "bumblefork" reference!! I'm stealing it if you don't mind. Much cleaner but says the same thing. Yeah, bumblefork Egypt.........