Does anyone know how to prevent an oil leak from the oil pan on a 1994 4Runner with the 3.0L engine. I replaced the oil pan gaskets and put sealant on both sides but I’m still getting a leak.

 

Are you 100% sure the leak is coming from the oil pan?

You might have a leak higher up that collects around the oil pan.

Clean the oil pan area really well to be sure where the leak is coming from.

According to Toyota, the 3VZ-E just uses a Form In Place Gasket (FIPG), also called Seal Packing (both names used by Toyota).

This thread has some helpful information: https://www.yotatech.com/forums/f116...g-both-201485/

 

+1

Clean the pan gasket surface with a wire wheel in a drill motor until it shines. Then degrease it thoroughly. Then use the Toyota brand FIPG and nothing else. No gasket! Don't over tighten the bolts! Use a torque wrench to specs. Also, check the pan lip with a straight edge and make sure it's level.

 

Personally, I wouldn't use a wire wheel on any sealing surface (it will damage the metal). The oil pan isn't a very critical seal, so whatever you do, be careful.

The reason mechanics like FIPG is because it sets up REALLY fast. Important if you have to get one vehicle out of the bay and get onto the next one. But I'm no professional, and sometimes it takes me a little longer to get everything lined up correctly. So I prefer RTV or Permatex. I just have to let my truck sit overnight before starting it.

Your choice. Just remember that if you use FIPG and end up spending 10 minutes trying to get stuff aligned, you need to start all over.

 

Very good point! Permatex is more forgiving for a DIY'er.

 

Actually scope, those fears are unfounded. The wire wheel polishes instead of scratches. I know that sounds counter-intuitive but it's the same principle as lying on a bed of nails. The nails are so close together that no single nail can penetrate. It also takes all of the old gasket material and sealant off without killing yourself or trying to scrape it off with a tool. Scraping the old gasket by hand with a tool will cause gouges in the surface. I wish I would have taken pictures of my oil pan and block surface so I could show you guys. It was pristine! It looked brand new when I got finished.

 

Wire wheel is the perfect tool for cleaning silicone off an oil pan. Won't hurt the oil pan at all. Makes a mess though so clean out the pan well. It would work great on the bottom of the block but the mess it makes would be hard to clean out of all the nooks and crannies around the crank, rods, and inside of the block if you aren't doing a total teardown and rebuild. Wire wheel works great on steel/iron. Works fine on aluminum too if you're light and fast. Too long in one area will start to eat into the aluminum though.

 

Just a small example of the cleaning power of the wire wheel. I use it on all my carburetor rebuilds to clean up rust and dirt. This took a couple minutes.

 

When you had the pan off did you make sure it was flat where it needs to be?

When the bolts get torque down the pan can deform and the area around the bolt.hole will be proud of the rest of the surface which makes it difficult to get a good seal on the gasket. You can lay a straight edge front to back along some of the holes and spot it right off. Just tap these high spots down with a flat faced hammer and you get a much better seal.

 

Hey guys thanks for your input, it was actually the oil cooler that was leaking. It’s been fixed and the leak has stopped 👍🏼