Clark

I've seen plenty of threads on the topic of stripped-out oilpan threads, but mine's cracked.

I've done all the oilchanges myself, and I don't use a torque wrench so it's plenty possible that I've over-torques the nut. I always use a new crush washer and usually torque it until I feel that "give" of the crush washer deforming.

In any case, I'm just curious to see if anybody else has come across this.

As I now, overly sensitive to the situation, look at my oilpan it appears there are many small surface cracks, but it's really hard to tell if they are really cracks or just casting marks.

xviper

These aluminum crush washer don't "crush" all that much with the designated torque. If you are cranking on it till you feel it give, you are most likely putting way too much force on that bolt and this could be the reason why your casing is cracking. I even consider the designated torque to be too much considering the short amount of thread the bolt is going into.

Clark

xviper,

It's entirely possible that I've done this myself I suppose. I've had Hondas/Acuras for the last 15 years and never stripped pan threads or anything like this before. The give I describe in the crush washer though has always been noticable to me. It's really less "give" I guess, than it is that there's a point in tightening when the torque applied remains constant but the nut turns about an extra 1/8th a turn.

It just seems strange to me that the casting actually cracked rather than stripping the threads. This made me wonder about the other crack-looking marks as well. I track the car quite a bit, and the pan looks somewhat structural (well, that might be overdoing it. It certainly is used to stiffen the block though), so I was looking to see if this problem existed elsewhere.

Oh well, I've got a new Mugen oilpan in the mail, so this will be just a memory soon.

xviper

I don't recall seeing any other posts about cracked oilpans at the drain bolt, so yours is a rare case. It's entirely possible that you have a weak oilpan and in conjunction with your track activities, this may result in a hairline fracture. I put mine on with about 25 lb/ft, which seems on the high end to me. The recommended 30 or so is a bit too high IMO. My washer has never shown signs of compression.

Voodoo_S2K

When I did the oil jet bolt upgrade to my engine, I was suprised at the size and construction of the oil pan. It would seem to be used to stiffen the block. As I recall, part of the tranny actually bolts to the oil pan.

slalom44

Are you sure that it is actually cracked? The oilpan is injection molded out of aluminum. this means that liquid aluminum is injected into a mold made of steel or cast iron. Over time, thermal stresses cause the mold to start to craze (surface cracks). When it gets bad, they usually take the mold out of service. The mirror image of the cracks shows in the casting, but they are cosmetic.

It might appear to be cracked, but the "vein" actually sticks out. Check to make sure that it's actually cracked. If so, I'm surprised. Did you happen to have any dents from bottoming out?

slipstream444

My '03 experienced a hairline crack at the drain ... and the threads came out - as in cracked and came out as if they weren't attached. Honda said it was due to a possible bad casting. This was the cars' first oil change and was covered under warranty.

Clark

No marks on the oilpan from bottoming, although I have been in the gravel once or twice

Oilpan is indeed cracked as slipstream describes. I had a very slow oil leak from the drain bolt, and saw the crack there. I removed the bolt and could just barely see the crack all the way through from outside to the threads on the inside.

When I replaced the bolt, I heard the "tink" of the crack widening. I put some oil in to verify and it was leaking faster this time.

Unlike slipstreams' case, my car has 37k on it with plenty of oil changes. Also, my threads are undamaged (well, as much as can be said for threads with a crack in them).

Hopefully I'll have my Mugen oilpan in time to replace it this weekend.

mikegarrison

You aren't driving with it in the meantime, are you? If the crack grows and your oil dumps itself out while you are driving, you might lose your entire engine in the blink of an eye.

Clark

Hmm, I don't know whether to be thankful that you are looking out for me, or offended that you think I'm such a dumbass

No, I'm not driving it. It is parked with the oil drained out of it so as not to leave a big oil stain in the driveway.

My new oilpan is sitting here as I speak, so I'll be replacing that this weekend.