Damned oil drain bolt won't come out!!!
 

Ok people, I have done many difficult technical/electrical jobs so far on my car, but this is the most rediculous thing I have ever encountered. Last night, I decided to change my oil for the first time. For over 4 hours, I tried to get the damn oil-drain bolt off the oil pan! I tried everything....the correct sized metric socket wrench, then the standard wrench, then vice-grips, then a chisel and hammer, and then I tried drilling a hole through the bolt head to put a metal rod through it to twist it off, but nothing worked. I tried all these things many many times before giving up. I now have a worn-down nub where the bolt head used to be. Any ideas on what to do here? -- Mikey

until you get real help
 

try this posting sequence:http://www.peachparts.com/shopforum/showthread.php?threadid=45865&highlight=starter+bolt

Hey - I'm not the only one!!! I had exactly the same thing. Gave up in disgust and took the car to the Mercedes Dealership for an oil change. The mechanic also rounded the head of the bolt trying to loosen it using big vise grips. After trying using the hammer and chisel routine - that didn't work - he put an air chisel on it and pushed the chisel on the side of what was left of the head of the bolt in a counter clockwise direction. 30 seconds later - the bolt let go. I paid for an oil change and $3 for a new bolt. Well for the money!

Maybe your car came from that mountain in Mexico where they put a hex on vehicles and all the repairable/removable portions of the vehicle are fused together

I had the same problem when I got my 95 E320 about 4 months ago.

It's too late now, but next time use a 1/2 6-point socket and you will never have this problem again.

Have you tried a big pipe wrench yet?

special Vice-grips!!
 

Vice-grip makes a specialty wrench for stubborn bolts. It's for hex-head bolts and is a life-saver when some one has rounded of the bolt head. I would consider this a must have for the tool kit.

the jaws of the vice grip pliers has a "V-shaped" upper jaw and an inverted "V" on the lower jaw. These clamp down on three sides of the hex head and make short work of tough bolts!

Intruder

when I had the lower pan off my SE I noticed that the inner square nut was held by four small spot welds was tempted to it braze for more shear stregth but didn't.It's not hard at all to take lower pan off at least on the V8's (about 10 minutes) then you could safely heat it to get that devil out .give you a chance to clean pan of thoses nasty looking meatal particles that hide in the bottom of pan and put a fresh gasket on........
William Rogers.....

agree 6 point 1/2
 

I think he's well beyond a socket selection at this point but I agree with Mr. Latos. Just changed the oil and found that the 1/2" 6 point works the best. After getting it off it needed a little dressing up from all the past strippings.......

The last time the oil was changed it was at the dealer. They did'nt tighten the bolt down. I kept getting thin oil strip leaks on the garage floor when I backed out of the garage just going over the kick plate. Didn't happen noticably anytime else. At first I thought it was brake fluid but it wasn't pulling the floor paint up.. A little head scratcher.... Oil level off the stick seemed fine. Finally I dropped the brush cover and had a very slow leak.

On my 190E-2.3-16 the oil drain bolt the threaded part is about two inches long, and the first three times I changed oil the bolt got mutilated. It has the beginnings of the underbody fairing, and between that and the fact that I ended up changing the bolt/plug every other oil change, I bought a Topsider. I still have an extra bolt in the glove box, just in case I need to change oil and there is no Topsider around. Anyway, it solved my problem on that car, and all the later models have a bigger, harder to work around or remove encapsulation part under the engine, so I do them with the Topsider too. Jim

I've been there. As CSNOW suggests, try a good pipe wrench first. If that fails do what I did - cut the bolt head off and out it comes.

The old hammer and chisel routine has worked well for me dozens of times. You need a big hammer, sharp chisel, and aggresive blows from the hammer. Of course I have always had the convenience of a hoist. That makes the job easier.

PS: Now might be the time to invest in an oil sucker. The car was designed to have the oil changed that way. That dipstick tube goes to the very bottom of the pan.

Peter

got it
 

Well, I gave up and took the car back to the place I had the oil changed at three months ago. They took the old bolt off ( I could hear the mechanic pounding on it for a while from the waiting room) and put a new one on for free. I took the car home and changed the oil myself. Thanks fir the suggestions - Mikey

That is good news.

These plugs are unusual in that the threads are very long, and the hex head is very small relative to the diameter of the threaded portion. The aluminum pan causes the steel threads to corrode in place by electrolysis.
BTW, I have tried 2 methods to prevent the plug from seizing, and both worked equally well:

1) Grease the threads (multi-purpose grease).
2) Teflon tape.

One would think that the residual motor oil on the threads would be enough to prevent seizing, but this appears to get washed away, where the grease sticks.

Also, there is a tendency to over-torque drain plugs in general ('just to be sure'...).
With so much thread, very little torque is needed for a tight seal.

I love it pipe wrenchs and cold chiesels on MB engines .maybe we have a chance yet........
William Rogers........

William,

Why not? They're built to take it.

Peter

yust because they are cherman does not mean they can not be fixed with amareicun precisun tools!

This problem would never happen if people would just do 3 things correctly when they change their oil:

1) If the head of the bolt is even slightly worn replace it!!!

2) Make sure the washer that is supposed to be on the plug is there when you put the plug back in.

3) Don't over torque it when you put it in, instead of a big ratchet, extension and a socket use a short combo wrench you have to be real gorrila to overtorque it with a little combo wrench.

Now if I just had a solution for the stubborn oil filter!!!!

Does the euro 190 have a spin on replacement or a cartridge that fits in a cannister?

For Spin on units, the reluctance to come off is often the same overtorqueing problem. However, if you collapse the top you'll need to get right down to the flange end where the threads are. I only had a few that I had to dismember to remove if I could get at the base flange.

There is a special that plops down on the filter, and you use a 22mm socket and ratchet to spin it off.

Peter

Apparently the "quicky lube" goobered plug syndrome has spawned a new industry .

http://www.cgenterprises.com/index.htm

Check out the "temporary" and oversized plug selection.