Need you guys help with this one. What you guys think?


https://streamable.com/ug5k4

Sounds like metal to metal contact of a rotating assembly.

Alterrnator fan striking the housing?
Water pump bearings?
Seized/ failing AC compressor?
Bone dry power steering pump?
Failed harmonic balancer?

Remove one accessory v-belt at a time and retest.

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78 W116 300SD 'Desert Rose' new as of 01/26/2014
79 W116 300SD 'Stormcloud' RIP 04/11/2022

I was also thinking maybe the belts making noise or a seized ac compressor. So i removed all three belts and noise is still there.

Could it be the vacuum pump failing or possible engine rod bearings.

Is it a stick shift? If so possible throwout bearing.

More info to diagnose, please. It won't start- why? Insufficient fuel delivery is the first place to look; change the fuel filters. Check the whole fuel system. Next is air- check the filter. Valves been adjusted lately? Is there enough lube oil? Has the engine been running and now this or has it been sitting for years? Many diesels sound "bad" when they don't start but turn over and get close.

Automatic

I was driving and engine started to make knocking sound and i shut it off. Checked oil level it was 2 qts low so i corrected the oil level but that didnt help much. I can still start the engine but makes a lot of noise all the belts are off but noise is still present.

I might remove the glow plugs and see how hard it is to turn the engine with the crank bolt.

There may be too much mechanical resistance to start with the starter. I am not saying this is the problem but I would eliminate it as a possibility.

For example the first rod bearing may have spun. There are several possibilities.

First of all check for serious engine binding since you have removed all the belts. Where the problem remains. Others probably will suggest other things as well.

I think I can almost hear it trying to start. Just not able to overcome some internal resistance factor perhaps. I can be totally wrong.

Plus the noise when cranking indicates this perhaps as well. Removing the valve cover for a start to inspect in there if you encounter much more resistance than you should. While turning it over with the crank nut. It may be very tight.

So I hope I am wrong as well. I have repeatedly mentioned that very long life of the 616 engines may be dependant on having reasonable fuel pressure in the base of the injection pump. I also think it applies to the 617 to a lesser degree.

Never being able to really totally prove it. Yet worth checking as they run better,quieter, and slightly more powerful with it present. More than just an opinion at the same time. A lot of circumstantial evidence led me there years ago. While none has surfaced since to disprove it over the ensuing years. I still keep as objective as possible about this as well.

I believe they have to also run a long time with the low fuel pressure to create the damage that is reported time and time again. That being the destruction of the first rod bearing.

I totally believe checking that fuel pressure as a reasonable periodic maintenance check that should be preformed. Say about every thirty K miles. Under twenty dollars for a liquid filled pressure gauge and parts to hook it up for a check is a lot cheaper than this reoccurring scenario. These engines may become scarce soon and are a very expensive engine to rebuild properly.

I specified the 616 engines as this problem is far more common with them. The 617 you have can develop the same problem but it is not as common. On those engines usually. It is the first or second rod bearing. Again a check of the fuel pressure on them is a good ideal even though the problem is not as prevalent..

Personally I would cease attempts to start that engine. Until I was able to establish it does not have high internal drag. Plus there may be less damage to deal with if practical to repair.

You are right! It spun the first bearing. I haven't checked the rest but the first one looks pretty damage

How bad is the surface of the journal? You can access cylinder one and twos rods through the lower oil pan. If an undersized bearing is available for fairly minor damage you can resize the journal at home.

It is possible in many cases. By hand. A lot depends on what a plasti gauge check of the number two rod bearing reveals. Plus how much you have to remove to recondition the number one journal. If guy is fairly young. Has the time over money. It is possible. Although picking up a good running used engine cheap if the car is worth a replacement engine. Is a better choice.

I suspect that some members may not have heard of this. That is self restoring a crank journal in place at home. Please do not tar ad feather me. It is possible with decent results. If you pay attention.

@ Barry ;

Not to worry, there are still a few graybeards here who know what you're talking about .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

w114, if your crank is toast. I have a N/A crank you can have for shipping cost or local pickup and perhaps a donation of a case of beer.


Also, I would check the oil pump shaft to make sure it didn't wear itself down to the point you lost oil pressure. That could be the cause of the failure.

__________________
1983 123.133 California
- GreaseCar Veg System

Been working at this and that. Well out of sight of the public. Yes the whiskers are grey.


So I better go shave before attending to a few errands for the wife today. About the only razor I can use after about a week of growth is the old safety double edge blade types to hack this off. Or a straight razor but I do not feel that confident in using them.