79 240D Crankshaft seal replacement - PeachParts Mercedes-Benz Forum

mbzr4ever · #1 06-15-2007, 02:44 AM

I think everyone is familiar with my 79 240D on another thread I started. My ex-mbz mechanic wanted to replace the whole engine.

Finally got another mechanic to check it out to diagnose the problem with it not cranking over. First he said it was a massive algae problem, and I agreed to have him clean out the whole fuel system. After all, this is Hawaii, and the car was sitting for over a year. Total so far $434 plus the $60 tow.

Ok, so he got it to run, but the idle was very rough and there was smoke coming out of the exhaust. Then we saw the oil leak underneath. Looked like a quart lost. He checked it some more and said the crankshaft seal needed to be replaced, and their shop could not find one anywhere. So I said I would find one and have him put it in. Fair enough.

What would cause a seal to fail like that? He said age, but I'm thinking if the car was under tremendous stress to break a seal like that, what else can we suspect that should be checked out? Why was the idle so rough/irregular? Didn't have the usual rhythm - would a new seal actually fix that? I'm wondering if there is something else in the crankcase that is damaged to make the noise that it does.

Should we replace any other seals while he is in that area? Gaskets are cheap, I'm thinking of ordering a whole crankshaft gasket set, since they are light, and shipping anything here is such a pain in the you-know-where.

Thanks everyone for your support. I really have learned a lot from this forum.

t walgamuth · #2 06-15-2007, 05:59 AM

Changing the crank seal is a huge job if done correctly. It is not the cause of irregular running. Get the car running correctly before addressing the oil leak problem.

Where is the other thread? Additional info would help diagnose.

Tom W

toomany MBZ · #3 06-15-2007, 06:24 AM

Age and stress will cause a failure, it's not a big deal, just time consuming. As you have to start at the rad, and remove everything back till seal. Take your time with the balancer bolts. Parts, you may only need to replace the "soft" seal, can be ordered from above Buy Parts button, or else where. Rough running can be many things. Clogged fuel strainers, filters will be a problem. There is a gasket on upper oil pan, tank, something, the manual says to remove engine to access, unless you have a problem there, don't worry.

barry123400 · #4 06-15-2007, 09:29 AM

Quote:

Originally Posted by toomany MBZ

Age and stress will cause a failure, it's not a big deal, just time consuming. As you have to start at the rad, and remove everything back till seal. Take your time with the balancer bolts. Parts, you may only need to replace the "soft" seal, can be ordered from above Buy Parts button, or else where. Rough running can be many things. Clogged fuel strainers, filters will be a problem. There is a gasket on upper oil pan, tank, something, the manual says to remove engine to access, unless you have a problem there, don't worry.

He did not say if it was front or back seal. Front seal is easy usually compared to pulling the engine for the rear seal. As Tom said find the cause of the rough idle before moving on at least. Engine may not be worth even a front seal. Or if it needs major work before pulling motor he should know what it is.
Sounds like a situation that he would be better off adressing himself with the information on the forum if possible. A mechanics bill could grow and grow quite easily. He has over 400.00 into the algea problem already. Engine may or may not be tired. Do a compression check.

JimSmith · #5 06-15-2007, 10:56 AM

I had a massive oil leak at the front of the engine on my first W123 240D, and it sure looked like the crank seal to me. I took it to the local dealer to have the seal replaced. It ended up being a bolt that fell out of the air conditioner support bracket. The bolt hole penetrated an oil passage and allowed oil to just run out when the bolt fell out. I paid for a steam cleaning and a $0.50 bolt.

I would invest some time and effort into finding out what the problem actually is, and address any expensive fixes after you are sure the car is a keeper. Jim

kerry · #6 06-15-2007, 11:05 AM

I agree. I wouldn't put any money into seal replacement before determining if the engine was good enough to warrant the investment. At the moment, I'd say it isn't until the smoke and rough running problems are resolved.

mbzr4ever · #7 06-15-2007, 12:49 PM

Quote:

Originally Posted by t walgamuth

Changing the crank seal is a huge job if done correctly. It is not the cause of irregular running. Get the car running correctly before addressing the oil leak problem.

Where is the other thread? Additional info would help diagnose.

Tom W

7 pages, 95 posts...basically pros and cons of keeping it, the sad situation about not being able to find any qualified mechanics here in Hawaii (Big Island), so it has taken me this long to determine what is wrong with it. My worst case scenerio was a cracked block, threw a rod or blown headgasket, or all of the above....

Pro and cons of rebuilding the baby....

I also found a very good article on replacing the front crankshaft seal in the DIY section I was going to show the mechnic, just in case he did not have the special tool.

mbzr4ever · #8 06-15-2007, 12:52 PM

Quote:

Originally Posted by JimSmith

I had a massive oil leak at the front of the engine on my first W123 240D, and it sure looked like the crank seal to me. I took it to the local dealer to have the seal replaced. It ended up being a bolt that fell out of the air conditioner support bracket. The bolt hole penetrated an oil passage and allowed oil to just run out when the bolt fell out. I paid for a steam cleaning and a $0.50 bolt.

I would invest some time and effort into finding out what the problem actually is, and address any expensive fixes after you are sure the car is a keeper. Jim

I wish it was just that, but I don't have a/c. I understand what you are saying...taking this car to this shop yesterday is a big step in trying to find out what is wrong.

Problem is, I have yet to find someone here (Big Island) that really knows this engine that has earned my trust and confidence. Why do I feel like shark bait when I go to these car repair shops around here??? (Rhetorical question, no needs to answer...

)

mbzr4ever · #9 06-15-2007, 01:00 PM

Quote:

Originally Posted by toomany MBZ

Age and stress will cause a failure, it's not a big deal, just time consuming. As you have to start at the rad, and remove everything back till seal. Take your time with the balancer bolts. Parts, you may only need to replace the "soft" seal, can be ordered from above Buy Parts button, or else where. Rough running can be many things. Clogged fuel strainers, filters will be a problem. There is a gasket on upper oil pan, tank, something, the manual says to remove engine to access, unless you have a problem there, don't worry.

Clogged fuel strainer, filters? The whole fuel system was supposedly cleaned yesterday. Looking at the receipt, I got 2 new fuel filters, was I supposed to get a new strainer?

mbzr4ever · #10 06-15-2007, 01:02 PM

Quote:

Originally Posted by barry123400

He did not say if it was front or back seal. Front seal is easy usually compared to pulling the engine for the rear seal. As Tom said find the cause of the rough idle before moving on at least. Engine may not be worth even a front seal. Or if it needs major work before pulling motor he should know what it is.
Sounds like a situation that he would be better off adressing himself with the information on the forum if possible. A mechanics bill could grow and grow quite easily. He has over 400.00 into the algea problem already. Engine may or may not be tired. Do a compression check.

The mechanic is asking me to order the front seal.

Update: I just asked them to do a compression check, said probably Monday they can do it. Crankshaft seal ordered, will get here anytime between Monday and Wednesday next week.

About how much would be reasonable for the compression test? Or how many hours would be reasonable, they are charging me $92.00 per hour.

kerry · #11 06-15-2007, 01:31 PM

Quote:

Originally Posted by mbzr4ever

, so it has taken me this long to determine what is wrong with it. My worst case scenerio was a cracked block, threw a rod or blown headgasket, or all of the above....
.

After looking at that thread and reading this one, I don't see anywhere where the problem has been diagnosed fully. The car is running, but it is smoking and missing. It has a lot of miles on it so I wouldn't put anymore money into it until the reason for the poor running engine is fully understood. The oil leak will not cause the engine to run poorly. The compression test is a good start. It shouldn't take more than an hour or two to do it.

The mechanic should have run the engine on an alternative fuel source directly fed into the primary filter before making the diagnosis of a plugged up fuel system.

toomany MBZ · #12 06-15-2007, 03:00 PM

Quote:

Originally Posted by mbzr4ever

Clogged fuel strainer, filters? The whole fuel system was supposedly cleaned yesterday. Looking at the receipt, I got 2 new fuel filters, was I supposed to get a new strainer?

Depending on how much, high tech term coming up, gunk, has accumulated, you may need to flush more than once. Was the tank removed and thoroughly cleaned? Strainer can be reused, must be pulled and reverse flushed. Agree with ke. barry... has a good point about $$$.

mbzr4ever · #13 06-15-2007, 03:09 PM

Quote:

Originally Posted by kerry edwards

After looking at that thread and reading this one, I don't see anywhere where the problem has been diagnosed fully. The car is running, but it is smoking and missing. It has a lot of miles on it so I wouldn't put anymore money into it until the reason for the poor running engine is fully understood. The oil leak will not cause the engine to run poorly. The compression test is a good start. It shouldn't take more than an hour or two to do it.

The mechanic should have run the engine on an alternative fuel source directly fed into the primary filter before making the diagnosis of a plugged up fuel system.

You are correct, we still do not know the exact problem. My original statement should have read something like:

..so it has taken me this long to get a mechanic to look into why the car won't run. My original mbz mechanic didn't even want to determine what was wrong, he just wanted to just replace the whole engine. This lead me to believe the problem was major like a cracked block, thrown rod or blown head gasket.

And yes, not trying to use an alternative fuel source before cleaning the fuel system FIRST is a perfect example of the talent quality (mechanic) I have to work with here. This is like the blind leading the blind. Would I have known any better if it wasn't for this forum? No, but I am learning a whole heck of a lot, thanks to everyone.

mbzr4ever · #14 06-15-2007, 03:16 PM

Quote:

Originally Posted by toomany MBZ

Depending on how much, high tech term coming up, gunk, has accumulated, you may need to flush more than once. Was the tank removed and thoroughly cleaned? Strainer can be reused, must be pulled and reverse flushed. Agree with ke. barry... has a good point about $$$.

From the receipt:

Tech inspected vehicle found fuel system heavy contaminated and fuel filter plugged.
Remove old diesel (fuel) contains excessive amount of contamination, clean fuel lines and pump. Replace fuel filter then recheck system. Tech removed contaminated diesel fuel, replaced both fuel filters. Cleaned fuel lines and bowl, bleed injectors. vehicle started and ran.

Front crank seal leaking excessively, vehicle shouldn't be driving on long distances.

mbzr4ever · #15 06-15-2007, 03:56 PM

Bad news, or maybe good news, cause now I'm moving the car...

Shop just called me and said they do not have the equipment to do a compression check on diesel engines. Suggested I go to the dealer to have it done. I guess I should not be surprised about this shop. Just made another appointment at another shop for a compression test Monday.

OK, another tow just cost me $50 to move it one mile. It's there ready for Monday's test.