Larger drain bolt second time round?

[Falcon_LS]

This story actually dates back a decade, when my father was having the Mitsu maintained by the dealer. For whatever reason, they would tighten the oil drain plug with an impact gun. When we went back because of a leak, they would simply replace the drain plug and it would stop.

When I took over the maintenance, I had a bigger bolt made by a shop, because no matter how many times I replaced it with an OE bolt, it would still leak.

Finally, it got to a stage where I had to use Teflon tape to prevent it from leaking. Luckily, with the mileage this vehicle covers, oil changes are every 9 months and this seemed to be working for me.

When I last changed the oil a week ago, I ran out of Teflon tape, so I used RTV instead. Unfortunately, the bloody thing is leaking again. It really got on my nerves, because it's fresh PU which isn't exactly cheap over here.

Long story short, would I be able to resolve the issue by getting an even bigger bolt made? Changing the oil pan is anything but an easy job, because of the differential right under it. Even if I unbolt the mounts and lift the engine, clearance is too tight. Only way to do this is to pull the engine out and I don't have the means to do that, would need to take it to a shop. Thanks!

 

[jsnyder49090]

I Believe Dorman makes an oversize one as they do caliper bolts just for circumstances like these.You will probably have to go to a real parts store to inquire or check Dorman site.

 

[Kruse]

I wouldn't recommend it for everything, but do a search for "piggyback oil drain plug". Basically, it's a plug within a plug.

 

[LeakySeals]

I have experienced a difference in tightness recently with the same manufacturer. The 00 Corolla was tight till the last turn on the way out, no leaks. Didn't have to worry about how tight the drain plug was, would never back off or leak. The Camry, one turn and its loose, oil drips. Have to replace the washers often to keep a good seal.

You have a washer on there right? There are a few different kinds. I use metal, but there are other ones that squash. Some even made of rubber. Maybe trying a few different kinds of washers will help.

 

[chevys10]

Shop a family member used to take their (now mine) Civic to stripped out the origial drain plug. They covered it up with some sort of molly bolt looking plug with a big rubber gasket on it. When I took over the oil changes I got an oversized drain bolt and it has worked fine since. I think I actually got it at the Honda dealership. It is self tapping and cuts into teh old stripped threads. You need to find the original thread configuration on the existing bolt and go from there. Yes I believe Dorman also makes them.

http://www.amazon.com/Dorman-65217-AutoGrade-Oversize-Drain/dp/B000COCX0E

 

[LeakySeals]

Like a time sert?

http://www.timesert.com/html/drainplug.html

 

[yonyon]

Originally Posted By: Kruse
I wouldn't recommend it for everything, but do a search for "piggyback oil drain plug". Basically, it's a plug within a plug.


This probably is a good choice for your situation. They're available in single and double oversize. The whole thing screws in like an oversized drainplug and you just leave it there. The inner drain plug is the one you use for draining the oil (it's small so the drain is slow) and can tolerate a bit of overtightening because it uses tapered pipe threads. If you overtighten it once, just overtighten it again the next time and it will still seal.

If you may ever be having your oil changed by someone other than yourself, be sure get some urethane adhesive or epoxy and glue the outer plug in place. Goober it up but good so it looks like some sort of accident waiting to happen, but leave yourself some place to put a backup wrench on it. It won't actually do anything to help other than make someone think before they unscrew the outer plug instead of the inner one.

 

[doitmyself]

I don't understand the original post.

The threads don't create the seal to prevent leaking, the washer does that.

The idea that teflon tape stopped the leak implies there was no washer. Or, maybe the pan surface where the washer mates to it is damaged?

What is meant by "I had a bigger bolt made by a shop"?? Bigger bolt head only (same thread size)? Bigger thread size/diameter? Did you retap the female threads to match??

It just doesn't add up.

 

[Falcon_LS]

Thanks very much for everyone's input. The piggyback plug seems like a great idea, and so does the Timesert. I'll pull the plug and have a look at the threads on the pan carefully to see how bad they are. Maybe get the Timesert and the piggyback plug.

Originally Posted By: doitmyself
I don't understand the original post.

The threads don't create the seal to prevent leaking, the washer does that.

The idea that teflon tape stopped the leak implies there was no washer. Or, maybe the pan surface where the washer mates to it is damaged?

What is meant by "I had a bigger bolt made by a shop"?? Bigger bolt head only (same thread size)? Bigger thread size/diameter? Did you retap the female threads to match??

It just doesn't add up.


Sorry, the thread on the pan was stripped after a tech didn't fit the drain plug in properly by hand, and forced it shut with an impact gun. Have had problems ever since, because of the threads on the oil pan.

The bigger plug has a larger thread size, with a fixed, metal washer/crusher on the bottom. When I had the plug made, they redid the threads on the pan to match, but now the threads on the bolt are stripped. So you basically cannot tighten the drain bolt enough to secure a seal. I used to wrap Teflon tape over the threads on the drain plug to be able to do that. The RTV just didn't work.

 

[yonyon]

Don't use both the time-sert and the piggyback. Use one or the other.

The time-sert is the better repair, being as it is an actual repair. The result is that the pan is restored to a condition where an original style drain bolt will work and the new threads are stronger that original so they won't likely be stripped out again. It does require a little bit of skill and patience, but not much and should be well within your abilities with room to spare.

The piggyback is quick, easy, and cheap. It's not so much a proper repair as a modification type fix. It's probably easier to find. I expect you could get one today if you wanted to. Anyone with a socket wrench and extension can install it and it's probably very easy to find. On the down side, it's ugly and it drains very slowly.

 

[Falcon_LS]

Thanks, Yonyon. Ended up going with the Timesert, which should be here within the next two weeks and address the problem permanently.

 

[JZiggy]

O ring under the bolt flange. Has worked for me before.