Threads came out with oil plug

[mjoekingz28]

Hey, I was changing the oil on a 2006 Toyota Sienna LE and the drain plug came out fine. Last time I changed it I torqued it to 20-25lb-ft and this time I didn't even get to put 5lb-ft on the plug before it started spinning.

I got the car warmed up first for obvious reasons, but I heard when you change spark plugs you can strip the threads if you change them while hot. So, does this apply somehow, because I can't figure out how or why the oil pan's threads would come out on the drain plug when it hasn't been overtorqued, for future purposes.

My first time for stripping an oil pan and the only other time I stripped something was on my dirtbike when the suspension bolt came out very stubbornly and when retoruqing I misread the sheet saying 50lbft instead of the 25 it was supposed to have. My bad.

As of now, the plug will go in and come out fine, you just cant put any torque on it. I got some blue threadlock on the plug and we're letting it set now. Should we try a helicoil or something or maybe a new oil pan?

What do you think?

 

[Pablo]

Nothing to do with heat, oil isn't hot enough to cause a problem.

Are we talking about an aluminum oil pan? (or steel?)

 

[robshelton]

Sounds like who ever did it last time may have messed it up. Look for an over-sized self-tapping plug.

 

[nfs480]

If it's a steel oil pan i'd retap it first trying to use the same size plug but if it's too damaged i'd tap it out and use a larger plug. If it's an aluminum pan, i'd replace the pan.

 

[simple_gifts]

http://www.cgenterprises.com/drain_plugs_oversize_repair.htm

I, or more correctly, the numerous places that have messed up my oil drain plug, have used a device like the one here. Scroll down. Item is above the "1030" cell. Non destructive, unlike the chimps who used to service my car.

 

[nfs480]

We have a bunch of those at the VIOC I work at, frankly I don't trust them. I'd want a more permanent fix.

 

[simple_gifts]

Your call of course. There really isn't any cutting edge engineering there, materials would probably handle 20x the stress needed to keep the oil in the pan.

I definitely can appreciate the "no way" aspect of a fix like that.

 

[2003f7]

20-25lb-ft Wow. Should it have ben inch pounds?

 

[lipadj46]

Originally Posted By: 2003f7
20-25lb-ft Wow. Should it have ben inch pounds?


My truck's shop manual calls for 24 lbf.ft on the oil drain plug and that is for an aluminum pan. Try a helicoil or just drill it out to the next sized plug and retap it.

 

[labman]

I don't think Helicoils work good where you are removing it repeatedly.

 

[tig1]

Take the pan off and bring it to me and I will weld up the drain hole and re tape. Alum or steel.

 

[holla]

Originally Posted By: labman
I don't think Helicoils work good where you are removing it repeatedly.


Personally I don't see how you strip an oil drain plug in the first place (air tools?) but I disagree with this, helicoils (or any similar thread insert) work great. And I'm not sure you're really wearing it out (4x/year x 10 years is only 40 uses).

Helicoils should only be used where going up to the next thread size is not an option (when the clearance hole in the part that's being bolted is hardened, or when there's not enough clearance for the larger head that accompanies the larger screw). But if going up to a larger thread is possible, you save yourself one step by retapping over using a thread insert (plus the cost of the insert which ain't cheap if you have to buy a set just for the one that you need). Rent the taps at OReilly's for free.

Oh, but I would avoid self-tapping drain bolts. Leave the self-tapping screws for the sheet metal work where they belong.

 

[holla]

Thought of a problem with a helicoil, when you punch out the tang where does it go....into the pan. If you go the thread insert route, theres better ones than helicoil but like I said, if there's no interferences, going up the next thread size is easier.

 

[willix]

NPT 1/8 or 1/4.

 

[defektes]

Originally Posted By: robshelton
Sounds like who ever did it last time may have messed it up. Look for an over-sized self-tapping plug.


+1

 

[Eddie]

Cross threaded during the previous insalls?

 

[mechtech2]

No Helicoils there!
I find that the drain plug is usually softer than the hardened pan threads. See for sure which one is stripped.
ANd like mentioned, there are aftermarket oversized drain plugs.
They are the same thread pitch, just slightly larger diameter.

 

[nfs480]

Did you ever try a replacement plug of the same size? Maybe the threads on the plug are what are messed up and the pan is fine (has happened to me before).

 

[Kiwi_ME]

Me too, on a BMW M60 engine, steel pan. Brand new stock plug worked fine.

 

[mjoekingz28]

The plug looks perfect (not even a scratch) so does that make it an aluminum pan? I did the last oil change and like I said, I torqued it just as much as any other oil pan (20-25lb ft). But the one before that Firestone did, but I didn't notice anything out of the ordinary when doing the next oil change.....didn't feel over-torqued or anything.

I thread by hand until it wont allow any more hand turning. This maybe helpful, when rethreading, after a turn or two by hand it acts like there is threadlock on it, meaning its impossible to turn by hand and requires a decent amount of torque with a ratchet. Its not crossthreading because it does this with the plug coming out as well.


So far its holding with the blue locktight, but I don't want to lose an engine over something so simple and if we got another drain pan, maybe this would just happen again. I don't know, but maybe its time to give up. Since if we took it somewhere and it happens again then they'll get to clean it up. They got $20.10 oil changes at a tire shop nearby, but I'll continue to do my own.

Its possible its my fault, I just dont see where I made a mistake.



The neighbor has a welder, so we can just find out the material and weld it closed then rent the appropriate sized tap at O'reilleys and put it in a drill and reuuse the same old drain plug?

thanks

Mechtech2, we thought about a bigger drain plug, but thought since the threads were pulling out then there'd be nothing to hold it in....or would it make its own threads.