Broken oil pan bolt

96 XJ Country HO W/0630 head, AW4, D30/C8.25, NP231, 3in RC lift, 200+K miles

Short story: While tightening my oilpan bolts, to eliminate a "2 drop a day" oil leak, I snapped the head of the bolt off. The bolt is on the drivers side, at the pans half way point where it goes from shallow to deep.

Should I worry about this? Is it worth the trouble to drill it out and tap it if necessary.

Long story: I'm in the process of diagnosing an oil leak. Like everyother XJ, it APPEARS to be coming from the RMS. So to rule out the rear valve cover, oil sensor, filter adapter, oil pan, blah blah blah, I cleaned everything. So I cleaned the hell out of everything in the engine bay and underneath also. First, I wrapped the distriutor, both fuse boxes, and the IAC sensor with shrink wrap. I hooked the pressure washer up to the hot water heater and turned it all the way up (180F IIRC), and ran a bottle of dawn through the mix port. Before taking the pressure washer to it, I applied copious amounts of degreaser to everything in the engine bay. Took it on a quick trip to heat up the degreaser. Pulled into the driveway and took the pressure washer to it. Huge improvement as far as visibility goes.

I ruled out everything on top. It is either the RMS or ther rear of the oil pan. So I started tightening bolts. The two bolts closest to the RMS were 5/16 IIRC and the rest were one size smaller. I'm a small guy (not as strong as most) and using a 3/8 ratchet, I got 4-5 turns on every bolt on the oil pan, except for 1 obviously!!!!

Oddly enough, no more leaks. I have yet to drop the oil pan, and have no plans to as long it doesnt lean again. So I have no idea what the PO used for a gasket because theres nothing overlapping enough for me to see.

Anybody have any expierence with this??? Is that many turns on an what I believe to be the original oilpan/gasket normal??? Most important-Should I worry about that bolt if its not leaking?????

I'm kind of an anl type, but I eventually adopted the philosophy "if it ain't broke don't fix it" meaning if it isn't leaking don't mess with it.

If you ever do that job again, 4-5 turns is way to much. Reason being, you can crush the gasket and it may split. And you can deform the pan, especially around the bolt holes. The bolt holes get a cone shape and can split the gasket that way and/or when you do put in a new gasket the cone shaped holes may split the new gasket. I usually find something hard and flat and lightly hammer the bolts holes flat again, with feeling and carefully.

I never have had much luck tightening bolts (pan, valve cover or even thermostat housing) to stop a gasket leak, though you may have a silicon pan gasket (depending on the year and/or if it has been replaced before). Silicon gaskets have a lot more give than a composite gaskets do.

If the bolts loosen I usually pull them one at a time, clean off the bolt, blow out the bolthole with brake cleaner and put a small dab of Loctite on the threads, then re torque to specifications. This will work well with a silicon gasket, not so well with a composite gasket (depending on age). When they get old composite gaskets can shrink, which may require (trying) to re torque the bolts, but the composition gaskets tend to harden, another good reason not to overtighten them. The last composite pan gasket I took off was covered (both sides) in asphaltum or maybe Permatex type one gasket sealer and the bolts were kind of redundant. That sucker was really on there and would likely seal and stay in place with no bolts.

You may have gotten away with it this time, but I wouldn't count on tightening the bolts to stop a leak in the future. It may make it worse.

Check behind the harmonic balancer, I usually use a piece of wire wrapped around a small piece of rag. See if there is oil back there. The oil travels down the pan seem area and can fool you. It may show up as a seep at the back of the block (from the wind).

no leak, no worries.

8Mud said:

I'm kind of an anl type, but I eventually adopted the philosophy "if it ain't broke don't fix it" meaning if it isn't leaking don't mess with it.

If you ever do that job again, 4-5 turns is way to much. Reason being , you can crush the gasket and it may split. And you can deform the pan, especially around the bolt holes. The bolt holes get a cone shape and can split the gasket that way and/or when you do put in a new gasket the cone shaped holes may split the new gasket. I usually find some flat and lightly hammer the bolts holes flat again, with feeling and carefully.

I never have had much luck tightening bolts (pan, valve cover or even thermostat housing) to stop a gasket leak, though you may have a silicon pan gasket (depending on the year and/or if it has been replaced before. that has a lot more give to it than a composite gasket.

If the bolts loosen I usually pull them one at a time, clean of the bolt, blow out the bolthole with brake cleaner and put a small dab of Loctite on the threads, then re torque to specifications. This will work well with a silicon gasket, not so well with a composite gasket (depending on age). When they get old composite gaskets can shrink, which may require (trying) to re torque the bolts, but the composition gaskets tend to harden, another good reason not to overtighten them. The last composition pan gasket I took off was covered (both sides) in asphaltum or maybe Permatex type one gasket sealer and the bolts were kind of redundant. That sucker was really on there and would likely seal and stay in place with no bolts.

You may have gotten away with it this time, but I wouldn't count on tightening the bolts to stop a leak in the future. It may make it worse.

Check behind the harmonic balancer, I usually use a piece of wire wrapped around a small piece of rag. See if there is oil back there. The oil travels down the pan seem area and can fool you. It may show up as a seep at the back of the block (from the wind).

Click to expand...

Thanks for the input but thats why I mentioned that I was a smaller guy (not as strong as most). I have to put a breaker bar on nearly everything. It just seemed that sombody with my upper body strength, could get 4-5 turns with ease.....I guess my next trip to HF&T Ill get a torque wrench.....

I usually grab the ratchet by the head (thumb, forefinger and one gun salute finger) with my pinky and ring finger on the handle and tighten them this way. Then add an 1/8th-1/4 turn after they are snug.

I'm a moderately big guy and have snapped off many bolts, too many. I recently snapped off an exhaust manifold stud with a torque wrench (with a lower than book torque setting), sometimes bad stuff just happens.

8Mud said:

I usually grab the ratchet by the head (thumb, forefinger and one gun salute finger) with my pinky and ring finger on the handle and tighten them this way. Then add an 1/8th-1/4 turn after they are snug.

I'm a moderately big guy and have snapped off many bolts, too many. I recently snapped off an exhaust manifold stud with a torque wrench (with a lower than book torque setting), sometimes bad stuff just happens.

Click to expand...

Thanks for the input!!!

bugout said:

96 XJ Country HO W/0630 head, AW4, D30/C8.25, NP231, 3in RC lift, 200+K miles

Short story: While tightening my oilpan bolts, to eliminate a "2 drop a day" oil leak, I snapped the head of the bolt off. The bolt is on the drivers side, at the pans half way point where it goes from shallow to deep.

Should I worry about this? Is it worth the trouble to drill it out and tap it if necessary.

Long story: I'm in the process of diagnosing an oil leak. Like everyother XJ, it APPEARS to be coming from the RMS. So to rule out the rear valve cover, oil sensor, filter adapter, oil pan, blah blah blah, I cleaned everything. So I cleaned the hell out of everything in the engine bay and underneath also. First, I wrapped the distriutor, both fuse boxes, and the IAC sensor with shrink wrap. I hooked the pressure washer up to the hot water heater and turned it all the way up (180F IIRC), and ran a bottle of dawn through the mix port. Before taking the pressure washer to it, I applied copious amounts of degreaser to everything in the engine bay. Took it on a quick trip to heat up the degreaser. Pulled into the driveway and took the pressure washer to it. Huge improvement as far as visibility goes.

I ruled out everything on top. It is either the RMS or ther rear of the oil pan. So I started tightening bolts. The two bolts closest to the RMS were 5/16 IIRC and the rest were one size smaller. I'm a small guy (not as strong as most) and using a 3/8 ratchet, I got 4-5 turns on every bolt on the oil pan, except for 1 obviously!!!!

Oddly enough, no more leaks. I have yet to drop the oil pan, and have no plans to as long it doesnt lean again. So I have no idea what the PO used for a gasket because theres nothing overlapping enough for me to see.

Anybody have any expierence with this??? Is that many turns on an what I believe to be the original oilpan/gasket normal??? Most important-Should I worry about that bolt if its not leaking?????

Click to expand...

Torque on the oil sump screws is down around 7lb-ft/84 lb-in (for the 1/4"-20 screws) and 11lb-ft/132 lb-ins (for the 5/16"-18 screws.) DO NOT OVERTIGHTEN - with either the four-piece cork & rubber gasket, or the one-piece moulded rubber gasket.

Recommend applying RTV to the screw threads, as that will help keep the screws from vibrating loose and it may be retorqued.

However, unless your oil leak gets worse, one broken screw on the oil sump rail isn't anything to worry about. I don't recommend "overtapping" the screw (to 5/16"-18,) as you lose room. Drill & remove the screw, using a left-hand twist drill bit (which will probably break it loose.)

Since that's undercar hardware, carbon steel screws should be replaced. Anything may be used, but I prefer to use brass machine screws (1/4"-20x1/2" and 5/16"-18x3/4") because brass will not seize against iron or steel... And won't need to be replaced because they're rusted or corroded.

5-90 said:

Torque on the oil sump screws is down around 7lb-ft/84 lb-in (for the 1/4"-20 screws) and 11lb-ft/132 lb-ins (for the 5/16"-18 screws.) DO NOT OVERTIGHTEN - with either the four-piece cork & rubber gasket, or the one-piece moulded rubber gasket.

Recommend applying RTV to the screw threads, as that will help keep the screws from vibrating loose and it may be retorqued.

However, unless your oil leak gets worse, one broken screw on the oil sump rail isn't anything to worry about. I don't recommend "overtapping" the screw (to 5/16"-18,) as you lose room. Drill & remove the screw, using a left-hand twist drill bit (which will probably break it loose.)

Since that's undercar hardware, carbon steel screws should be replaced. Anything may be used, but I prefer to use brass machine screws (1/4"-20x1/2" and 5/16"-18x3/4") because brass will not seize against iron or steel... And won't need to be replaced because they're rusted or corroded.

Click to expand...

5-90, as always, your advice is greatly appreciated!

Anytime!

(I gotta get that other book plotted out sometime soon...)

Agreed with the others that I wouldn't worry about it too much but I would also recommend that you keep an eye on it. In many cases, particularly with something like an oil pan bolt, when the head breaks off, all tension on the remaining bolt disappears making it loose and really easy to back out. You would likely find that tapping a flat scewdriver into the end of it and using the resulting divot as a foothold may allow you to remove it quite easily. Failing that, leave it in and it may just vibrate out on its own.

If you want to be really creative, buy yourself a reverse drill bit, put your drill in reverse and try drilling it. 99 times out of a hundred it will back right out. The other 1 time it is either rusted into place or stripped which is too much like work to fix.

Well, I've put a couple hundred miles on it, way more than usual, in the 100 plus heat and NO leaks!!!! Ill keep everybody updated!!!!:thumbup: