Can't budge the crankshaft bolt. - PeachParts Mercedes-Benz Forum

jmerc6 · #1 04-18-2009, 05:42 PM

Today I started on the repair of a '95 SL500. I was told by an indie that the head gaskets were blown. Before I got too far I decided I would see if I could turn the motor over using 27mm socket on the crankshaft bolt. I used a 2 foot breaker bar and could not budge it. Can I intrepret that as the motor is locked up and toast, and look for a replacement motor? Or should I continue with the disassembly of the heads, if so how do I get to TDC?

GaryF · #2 04-19-2009, 04:22 AM

The head gaskets in themselves wouldnt cause an engine to sieze, what happened leading up to the failure ?

jmerc6 · #3 04-19-2009, 07:27 AM

According to the previous owner the engine got hot so he replaced the water pump and thermostat. Then it got hot again, that's when he took it for a diagnositic and the indie told him it was the head gasket. He stored the car for six months. That's where I come in.

rowdie · #4 04-19-2009, 08:56 AM

Quote:

Originally Posted by jmerc6

According to the previous owner the engine got hot so he replaced the water pump and thermostat. Then it got hot again, that's when he took it for a diagnositic and the indie told him it was the head gasket. He stored the car for six months. That's where I come in.

Oops!, The storage may have caused the rings to sieze if there was moisture in the cylinders. Might as well pull the heads and see.

jmerc6 · #5 04-19-2009, 12:48 PM

rowdie, I think you hit it on the head. My question now is, what about not having #1 cylinder on TDC? Would I be better off to go ahead and pull the complete motor and doing a ring job?

rowdie · #6 04-19-2009, 02:23 PM

Quote:

Originally Posted by jmerc6

rowdie, I think you hit it on the head. My question now is, what about not having #1 cylinder on TDC? Would I be better off to go ahead and pull the complete motor and doing a ring job?

I have no experience with the late model SL. Mine is a cast iron block '73. I think your block is aluminum. I think finding a good used engine might be a better way to go if you have the boneyards in your area. Probably cheaper and faster since you are going to have to pull the engine anyway.

ctaylor738 · #7 04-19-2009, 05:29 PM

Actually, you bring #1 to 45 before TDC to remove the camshaft adjuster, according to Alldata. I'm not sure why it's done this way, but it's a step in the cylinder head removal job.

There are lots of good used engines out there.

jmerc6 · #8 04-20-2009, 08:24 AM

After mulling it over, I think the used engine route is the way to go. I live in the Nashville, Tennessee area. Does anyone have any good leads on a used 5.0 engine?
Thanks

jmerc6 · #9 04-21-2009, 12:16 PM

Update on my '95 SL500. An indie that I've used before and trust has found me a motor and has agreed to put it in for me. Total cost of motor and install $2,000. I'm supposed to take him the car next Friday. Anybody have a guess what a hardtop for this car would run?

rowdie · #10 04-21-2009, 05:33 PM

Sounds like a real good deal if the motor is sound. Good Luck!

jmerc6 · #11 04-23-2009, 09:17 AM

I'll let you know in a couple of weeks.

jmerc6 · #12 06-10-2009, 10:58 AM

Well it's been 8 weeks and the motor is finally in. Because the motor was locked up we couldn't turn the crank to get at the bolts to remove the torque converter, so had get another converter. Then the MAS was dumping too much fuel causing the motor to smoke like a mosquito sprayer. Replaced that and the motor seems to run fine. The first test will be this weekend when I drive home a 2.5 hour drive. Thanks for your replies. I'm sure I'll be back.