I fixed the @#&% oil door!

My method is to replace the large 9mm plastic rivets with M6 rivet nuts. The rivet nuts fit the 9mm holes without drilling.

Then, using two stainless M6x1x20 stainless steel bolts and fender washers, I secured each flap (one on the rear edge of the main undercover and one on the rear of the oil change door) so there is no chance of either coming undone.

 

I’ve taken off and reinstalled ours maybe 25 times; could almost do it with my eyes closed.

 

In the diagram in #18, I think I'm only seeing two types: a bunch of the 90467-07220 (7 mm ones) and a couple of the larger 90467-09227 ones. Am I missing something? Or is it possible someone had been at your undercover before and changed some of the clips for a different type already?

 

There were three types that I recall. Maybe two sizes? One type I noticed went into metal piece in the back. One was obviously bigger. Everyone else went into plastic (this is vague in my memory). The number matched the available # of holes with the back that I mentioned.

Had the first two oil changes at the dealer (Toyota Care) then did all oil changes and work that I am aware to the area. (There was a significant hit to the rear but I do not think they touched the front)...

I hope I can take a peek tomorrow. (I need to do an oil change on my iQ so I'll be dirty anyways so I can lay down and peek).

 

I think for the oil change flap itself one is bigger than the other two...

This is for a v though...

 

The v is a Gen 3. The components of the undercover and oil change door are identical. Using the rivet nuts and bolts in only two locations means that any other adjacent plastic rivet will not be tensioned to result in them being torn off.

 

That is the exact diagram I was looking for. I have no idea where I saved it, but I used it to figure out what sizes and how many to buy if I ever wanted to replace all the plastic clips. The idea now is to take the bottom cover, and paint arrows to the holes where the plastic rivets go, with a "7" for the 7mm holes and a "9" for the larger holes.

I like the idea of your favorite type. I simply bought enough of the 07220 rivets (perhaps a bag of 50?) that I can replace any that get the least bit damaged during removal. I think the 6 sided 10mm socket trick would work for those rivets where you can reach the other side during removal. Maybe intentionally put them in backwards, so the socket trick would always work?

 

What I want to do is be proactive. I have one of those permanent paint pens that wrecking yards use to label parts. I bought it originally to lable my 6 rims with their TPMS ID. I might feel more motivated to pt the cover back on if I had the holes nicely labeled.

 

It's not hard. I even had a metal shield off that I think is for the exhaust. (It's possible that's where the third type came from). I also had a side panel off to pull off the oil filter housing.

 

it is hard when you are me, and are too lazy to jack the car up high enough Also, it would just the sort of anal thing I would like label, so humor me.

The diagram above does specify three different plastic Rivets. Most are the 7mm variety. About a half dozen are 9mm, and they
mostly hold on a smaller back panel between the converter and the back. Somewhere there is a third type. It is a single unique rivet, but my memory is failing on what made it so special.

Then there is always this solution:

(stenciled above the windshield on the inside of a UPS truck I worked in last Holiday season)

 

I replaced that large plastic rivet that attaches to the little strap to the oil change door with a special one that has a steel parts that expands. I did that nearly 10 years ago and have gone through nearly 20 oil changes. I have a larg bag of them, but have never replaced it. On and off for nearly 20 times, and it is still good and holding.

 

Sorry. I was hoping to be encouraging/motivating. I haven't had a good look underneath the Prius, to see what could be damaged by road debris while off. We/My wife has a vehicle with a plastic transmission pan, which is shielded by a felt-like shield that takes 21 screws to hold in place. That plastic pan has a built in filter and costs in the $$$ (I think $200+). Not only that, it takes around 10L (dry, I think I used 8.5 L on a drain and fill) of $20/L ATF fluid. I had the panel off because I was monitoring a small oil leak from the drain plug. But I drove it around on eggshells and didn't want my wife to drive it during that time....

(In the words of my wise son, now a sophomore: I'm just "jelly" about your great idea to mark each hole. )

 

I just hate over engineered components that only satisfy the designer's ego ant the expense of cost and practicslity.

It's like the yellow plastic $15 oil drain plug on the plastic oil pan on many new Ford engines.

 

The third kind is a pair of plastic-to-plastic fasteners, along the side edge of the smaller flap at oil pan. If you’re always taking the whole panel off, then you never deal with those; just leave them be.

In the TSB attached to my post #19, they’re ID’d.

 

Just sticking my head underneath on the front left (driver side, LHD) I pulled out the corner push pin which is not in the diagram and the one next to it (which happens to drive into metal in the back).

I started blindly rearranging my box in the background of NEEDA? PARTS but regret it...

...(No longer allowed to post pictures)...

One that pushes into metal I suspect is part # 90467-07201 4 prong with flat side head (vs perfect circle)
Front left corner suspect 90467-10183. Short 3 prong (real fragile) perfectly round head.

 

Thank you! And thank you for reminding us you posted this!

It is more detailed, but I see one difference at least in our v

On the right side of the image (which is the front left corner I dropped my head under) there are four in a straight line that go as oriented /. (A little slightly more towards straight up). The one on top is a tiny one on mine. Confirmed the other three are probably -07201 I pulled one out....

 

Oh, I see, and that's why they're not even called out in the diagram in #18, because it's a diagram concerning the whole panel, so you don't deal with them. And to open the oil flap, you only ever need to deal with one of them.

(I'm pretty sure on mine the one holding the other end of that 'strap' doesn't even look removable.)

 

Let me try this...

 

Yeah think you're right; I found a shot of ours, flap is to the left of the seam. Fastener on right looks to have regular jaws, while left side has some sort of bar: