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#16
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Decided to have the connecting rods examined, and found that the number 4 connecting rod upper bearing housing was slightly bent, and the upper bearing was not sitting square on the crankshaft and would wear on one side, then after a few miles, would start to knock. The machine shop corrected the connecting rod flaw, and the car ran great from that time on. Good luck
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96 E300d |
#17
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Mains can be plastigauged then oiled with the crank in the block. After checking and cap is removed, dribble some oil down the sides / edge of the bearing then put some assembly lube on the lower bearing. Main bearing load is mostly down so the assembly lube will do just fine. If there is still a concern about oil, some can be dribbled through the rod oiling drilling to the mains. I'm not sure why you have rod bolts sticking up and no cap when working on mains. The crank does not get turned when plastigauge is on the bearing so even if the rod caps are off , there isn't an issue here. |
#18
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Plasti gauge should have found that problem as the entire rod would be bent and a full strip of plasti gauge would show taper. |
#19
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As suggested, I checked the wrist pins today. I turned the crank so each piston was loaded against the crank, and then tried to push the piston down in the cylinder. There was no play at all in any of them, and I even went back and did it over again. I can say beyond any doubt that this engine has no wrist pin problems. I just don't know what else I can do or could have done to this one to fix it.
I once had an OM617 Turbo that had a knock. I pulled the head, and pushed down on all the pistons, and the front one went down in the bore what seemed like a quarter of an inch, making the knocking sound. I also noticed that the top of the piston and combustion chamber of the head looked polished, and no carbon was present. I assumed that the piston was hitting the head on it's rebound, and that is what was responsible for the knock. I suspected on the engine I am now working on, that if it did in fact have a bad wrist pin, It would have felt and sounded similar as the turbo engine that had the bad wrist pin. I now have no other tests that I can perform before putting the engine back together and testing it. As far as I can tell, there is no problem with any of the rods that might cause a knock. If it turns out that there is still a knock, the only thing that may make the noise is injector nailing. I had an engine once that sounded exactly like a rod knock, but after replacing the injectors, the sound went away.....Rich
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All Diesel Fleet 1985 R107 300SLD TURBODIESEL 2005 E320 CDI (daily) LOTS of parts for sale! EGR block kit http://www.peachparts.com/shopforum/diesel-discussion/355250-sale-egr-delete-block-off-plate-kit.html 1985 CA emissions 617 owners- You Need This! Sanden style A/C Compressor Mounting Kit for your 616/ 617 For Sale + Install Inst. Sanden Instalation Guide (post 11): http://www.peachparts.com/shopforum/diesel-discussion/367883-sanden-retrofit-installation-guide.html |
#20
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Ummm - I'd be checking piston protrusion before putting the head back on...
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1992 W201 190E 1.8 171,000 km - Daily driver 1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone 1965 Land Rover Series 2a Station Wagon CIS recovery therapy! 1961 Volvo PV544 Bare metal rat rod-ish thing I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior Don't leave that there - I'll take it to bits! |
#21
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That would mean that I would have to remove the head first. All the work I have done so far to this engine has been with the head on, and the pistons still in the block. The original job was to reseal the entire engine, and replace the rod bearings. Since I have had experience changing the rear rope seal without removing the crank, I was enlisted to do that job as well as the front seal and all the other gaskets. This engine is going back in a low mileage coupe that is undergoing a complete color change (that is a whole other discussion that does not need to be started). I am out of options, and the only thing I can do now is put it back together and hope and pray it is fixed for good.....Rich
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All Diesel Fleet 1985 R107 300SLD TURBODIESEL 2005 E320 CDI (daily) LOTS of parts for sale! EGR block kit http://www.peachparts.com/shopforum/diesel-discussion/355250-sale-egr-delete-block-off-plate-kit.html 1985 CA emissions 617 owners- You Need This! Sanden style A/C Compressor Mounting Kit for your 616/ 617 For Sale + Install Inst. Sanden Instalation Guide (post 11): http://www.peachparts.com/shopforum/diesel-discussion/367883-sanden-retrofit-installation-guide.html |
#22
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I don't want to make work for you but a cross your legs and hope approach might not be the best now that the engine is out...
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1992 W201 190E 1.8 171,000 km - Daily driver 1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone 1965 Land Rover Series 2a Station Wagon CIS recovery therapy! 1961 Volvo PV544 Bare metal rat rod-ish thing I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior Don't leave that there - I'll take it to bits! |
#23
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Hey Rich -
Best of luck on this! Dan |
#24
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What else is there to do? If I were building this engine from scratch, I would check using plastigauge the same way, and would have come up with the same results. For all intents and purposes, the rods check out well within spec. There is no wear on the thrust bearings, and the mains look very good (nothing like the rod bearings). The tests I did or the wrist pins check out positive (no detectable play). If I had an expert tell me of some other test or procedure to do before putting the pan back on, I would do it now. Knowing what I know, and seeing what I see, this engine should not knock when I get it put back together. Again, I don't know what else to do. The guy that enlisted me to do the work is in agreement with this, and I will get paid either way. I have done everything I was asked to do, and it was his call to put it back together. If it does turn out that the knock is still there, this engine will NOT go back in the car. He will have to find another one, and is prepared to do so if need be....Rich
__________________
All Diesel Fleet 1985 R107 300SLD TURBODIESEL 2005 E320 CDI (daily) LOTS of parts for sale! EGR block kit http://www.peachparts.com/shopforum/diesel-discussion/355250-sale-egr-delete-block-off-plate-kit.html 1985 CA emissions 617 owners- You Need This! Sanden style A/C Compressor Mounting Kit for your 616/ 617 For Sale + Install Inst. Sanden Instalation Guide (post 11): http://www.peachparts.com/shopforum/diesel-discussion/367883-sanden-retrofit-installation-guide.html |
#25
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That being the case, I think you're doing the right thing...after all the customer is always right, and sometimes it just makes sense to cut your losses and move forward. Hopefully, the knock will be gone. And if not, it will be a shame to not know what the cause is.
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Current Stable
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#26
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After consulting my local experts and the experts here, I have done all I can. Now I just need the motivation to put it back together!
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All Diesel Fleet 1985 R107 300SLD TURBODIESEL 2005 E320 CDI (daily) LOTS of parts for sale! EGR block kit http://www.peachparts.com/shopforum/diesel-discussion/355250-sale-egr-delete-block-off-plate-kit.html 1985 CA emissions 617 owners- You Need This! Sanden style A/C Compressor Mounting Kit for your 616/ 617 For Sale + Install Inst. Sanden Instalation Guide (post 11): http://www.peachparts.com/shopforum/diesel-discussion/367883-sanden-retrofit-installation-guide.html |
#27
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No , the customer isn't always right. A customer seeks out the services of others because they can't do the job themselves and are relying on those with greater knowledge to help them. Letting them make poor choices is a disservice to the customer and unethical. When I had my shop some wanted a patch that would not last, the conversation went like this. Customer: I just want the car patched up by doing X Y Z , I'm getting rid of it. Me: ( Thinking, no, you aren't getting rid of it after spending some $ to make it go. Or you will tell whomever the buys it that so and so just "rebuilt the entire car", here is the receipt. ) The repair you suggest isn't going to last. C: A patch up is what I want. Me: So you just want it patched up knowing it won't last, correct? C: Yes Me: So when it breaks, . . .I get to fix it the right way. . . for free. . . ~~~~~ Logical customers got it fixed the right way, the others when off to some low rent hack shop making my days much brighter. |
#28
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Roller:
There is one (or two) additional possibilities; if a rod has a twist it will not be detected by plastigage as the centerline of the rod will not be out of square with the journal. Statically all will appear to be well, but dynamically a torsional oscillation will occur that will produce a knock. The second possibility is that there is a small fore-and-aft bend in the rod close to the pin end; piston clearance will allow for a slight tilt of the pin and piston in the bore. Again, all will appear OK statically, but dynamically an oscillation will cause a knock. |
#29
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All Diesel Fleet 1985 R107 300SLD TURBODIESEL 2005 E320 CDI (daily) LOTS of parts for sale! EGR block kit http://www.peachparts.com/shopforum/diesel-discussion/355250-sale-egr-delete-block-off-plate-kit.html 1985 CA emissions 617 owners- You Need This! Sanden style A/C Compressor Mounting Kit for your 616/ 617 For Sale + Install Inst. Sanden Instalation Guide (post 11): http://www.peachparts.com/shopforum/diesel-discussion/367883-sanden-retrofit-installation-guide.html |
#30
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Chapter 03.313 shows how to check for it
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1992 W201 190E 1.8 171,000 km - Daily driver 1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone 1965 Land Rover Series 2a Station Wagon CIS recovery therapy! 1961 Volvo PV544 Bare metal rat rod-ish thing I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior Don't leave that there - I'll take it to bits! |
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