Oil Change Gone Wrong
 

I've always been wary of overtorquing anything on my 85 300d given its age. I'd read on this forum how people had sheared off bolts by accident while doing routine maintenance... Well, it's happened to me. I was snugging up the filter housing bolts and one of them sheared off almost immediately, and the car is undriveable without it. :(

I've searched low and high on the forum, but can't find a relevant thread. What's the best way to go about fixing this? How do I replace the bolt without damaging or replacing the housing?

If it's not siezed in there, you could drill into it w/ a left hand bit, and then an easy out. Just talked w/ a friend about similar problem, he said you got no idea how many broken ez outs he's pulled out of engines. He says if an ez out would work, you wouldn't have broke the head off loosening it.

Good prevention: Whack it hard w/ punch & 2-3 lb hammer before loosening- this will break the bolt loose from any corrosion/galling before you loosen it.

You could also drill out and rethread w/ heli coil.

I just took the head off a bolt in my suby's thermostat housing, drilled into it, ez out didn't work, and I broke a drill in the hole trying to go next size up. Flange was open on both sides as opposed to a blind thread, so I drilled thru w/ a 3/16 masonry bit, and then a 1/4. Carbide insert on the masonry bit ground thru the drill. Don't work it too hard and check it, if it gets hot enough the braze holding the carbide on the drill will melt, and you are on the the next level of screwed. Obviously, no threads left in the hole, but I just nutted a longer bolt on the exposed far side of the flange. Not pretty, but back on the road.

The cover with the thru hole will act as a guide bushing, and center your drill.

Other suggestions:
Slot the protruding stub w/ cutoff wheel, remove w/ flat screwdriver
File flats on the protruding stub, grab w/ visegrips, wiggle back & forth, use heat & penetrant.

Caution
 

Make sure that whatever you do, you take precautions to keep metal chips from drilling/grinding/whatever from getting into the filter housing itself. If you can, work with the cover on; if it broke off low, tape something like a sturdy plastic bag over every place except where the bolt pokes through. Or something like that. Just keep the chips out. I wouldn't use aluminum foil; it pierces too easily.

Kurt

If when you take the cover off there is bolt shaft protruding, you may be able to grip it with vice grips & unscrew it. The filter housing is alloy & it should come out easy.

ditto, those studs are replaceable.

I forget if all models unscrew and some are friction-fit from underneath.

but all replaceable, nonetheless.

worst case scenario, you could unbolt the entire oil filter housing from the block. it's a pain to get to, but it can be done.

Nothing needs to be "overtorqued due to age". That was mistake #1

If it is just one of the "buffers", you should be able to remove it with the afore mentioned vise grips.

If you're referring to the bracket bolted to the engine block, that will be more involved.

Don't blame yourself. Members have used an Torque Wrench and still snapped them off.

The Previous Owner/s or those Oil Change places might have previously over tightend them for your.
Also Previous Owners may not have realized that the O-ring does all the sealing and that if they had a leak tightening the Lid down more is not going to stop the leak if the O-ring is no good.

Since the above was done to the Oil Filter you might expect to find the Valve Cover Nuts/Studs have also been overtightened>

There is a few ways to fix your situation in our DIY Section.
DIY Repair Links
http://www.peachparts.com/shopforum/diy-links-parts-category/

http://www.peachparts.com/Wikka/DoItYourSelf

"Given its age" what does that mean?

I'm absolutely flabbergasted by this one. I can't even begin to count how many oil changes I've done and never had one of those bolts break, especially not "almost immediately" I usually snug them down until the vein in my wrist pops out (The John Muir method) and call it good, never a leak, never a broken stud...

The only broken bolt (from tightening) I can think of on an MB was one of the little thermostat cover bolts but they're teeny.

I think he's saying that he's worried about overtorquing things due to age. Not torquing them down more because of the age.

I typically use the three finger rule when tightening most oil related parts, ie valve covers, oil filters, oil pans etc. I put three fingers and my thumb on the wrench, and don't wrap my hand around the handle. Then tighten until it stops.

Those studs are knowns to break now and then. I've know a few folks that had that happen.

I think the mistake here might involve your interpretation of the OP's statement:

heh. I just brought home an 87 300D, and wish to do an oil change on it first thing before I unload it from the trailer... center bolt is totally rounded off, can't get any wrench on it. I heated it with a torch until it was very hot, then cooled it with a hose, hammered a 12mm (it's SUPPOSED to be a 13mm...) and it STILL spins off. I'm going to have to attempt pipe wrenching it or just grind it off, and order a new one!
I wonder if it'll come off if it's not under tension anymore... wait, no that won't work, it's threaded into the lid, not the housing... I'll HAVE to get it out to remove the lid. well, I guess I could move the fake firewall and get the entire lid off, then find a replacement at a pullapart...

Jiffy lube did this to the original engine in my car, thats why I got it for $400. :o

I did than once. I was able to grab onto the broken stud and unscrew it, I used a bolt in place of the stud until I was able to get a replacement from the dealer; I actually replaced them both.