I was making good progress today and then . Damn! Cracked the oil tank by over tightening the drain plug. I didnt even think I was making it that tight just trying to snug up the drain bolt and crush washer. Does anyone know the torque value for the plug? I thought the plug would strip before something broke. Im now wondering what my options are New oil tank? Or can it be welded?
I decided I didnt want to wait until I could get it repaired and ordered a used one instead. Ill sell the broken one after I have it repaired or maybe as is. Now I have to get the tank out of the car without taking out the engine. Anyone done this before?
So the drain plug on a 355 is threaded directly onto the tank itself, rather than onto a separate plate, as on the 348?? That's......dumb.
Hmmm...Appears to be a Helicoil in there. Bad Idea... Never do that near a oil port. Recommend replacement of the coupling entirely. Your problem was likely caused by poor installation of the coil.
Ferrari uses helicoils for oil ports all the time! Including the ones on the engine oil pan and tranny pan.
Helicoils are wound wire inserts. Over time and due to heat and excessive torque the wire can crack causing the coil to become smaller pieces of wire. When the plug is removed it is not uncommon for the coil to fall out in pieces. As a result, pieces of coil can end up in the oil. If you need to re-size a hole in a sump or other place where metallic pieces cannot be tolerated, consider a one piece insert similar to the timesert. I cannot imagine why Ferrari would need to re-size a hole. I could add an over sized plug as an alternative to replacing the entire coupling but I certainly would not install a wire coil (Helicoil) in any sump. In fact, When I did the gearbox on my 348 due to a bad synchro I had one removed from the transmission dip stick plug. Pieces of wire were missing that I never found. I installed a timesert.
I think the threads are originally tapped into the aluminum bung. Mechanics over the years invariably tend to crossthread or overtighten, not realizing they're dealing with threads in aluminum, thus ruining the threads. The helicoil, while not the ideal fix, was undoubtedly inserted to repair it. I would tend to say overtightening was the culprit here, agreeing with the OP.
I believe that all drain plugs on 348 and 355 were helicoiled from factory, but hey, what do I know, seems most cars through here are anywho..... Edit, sorry, missed your post above Mitchell
That's an easy 30min fix. Cut the bung off and weld on a new one. You can buy weldon bungs that have a foot on them and everything to make a clean TIG weld to the tank. http://www.jegs.com/i/ARP/070/800-8112/10002/-1?parentProductId=762716
Oil tanks have a contaminated surface that's true. I have found if you cut them off and hit the part you need clean with a propane torch and wire brush you burn off all the smooge. Follow up with some brake cleaner and you are ready to weld. There is also a setting on most TIG welders that is more negative or positive I forget which that cleans the surface more vs. deepens weld penetration. On contaminated surfaces I just us more clean
Remove the heli-coil......clean the cracked area thoroughly with brake cleaner, then IPA....Epoxy filler in the crack.....re-tap / thread chase for the helicoil.....re-install the helicoil.....coat the threads with sealant.....install the plug under light torque....go driving ....that would be my half-assed approach for a quick, easy, cheap fix until you decide what you want to do later for a more "high-end" solution ---- and one which you can coordinate with other down time for the car (winter, major service, etc.).
Just in case there's anyone that doesn't know about this, NEVER use non-flammable brake cleaner (tetrachloroethylene) on a surface you are going to weld or heat with a torch. It turns to phosgene gas and can be quite deadly. Here's an article that explains further. http://www.brewracingframes.com/id75.htm
Oh so true Tim! ...I grew up wearing no helmet, skiing off cliffs, playing with "lawn darts" , having BB gun fights, and I used to drink out of the water hose.
Yes but if you live by people there is someone who can weld. Most pro welders start at about $15 bucks for a little job like this. You can cut the bung off with a hacksaw and buy another one to fit. Take it to your local welder and ask him to Tig weld it....Done!
Just FYI...not trying to argue any point. Just making sure the info is out there. For the readers who would use helicoils near oil sumps please google "helicoil fell in sump". You will find a great many people who have experienced a problem with either failed helicoils or issue's removing the installation tang. The Timesert design specifically addresses this issue. I understand that the issue raised by the photograph provided by the OP is on the underside of the tank at a drain and is therefore less likely to end up inside. I just don't like the practice.
