Loud Tapping, Rough Idle, Had to Tow - Page 4 - PeachParts Mercedes-Benz Forum

Maxbumpo · #46 05-15-2015, 10:27 AM

I still think the OP should put it all back together and see how it runs. Depending on the quality of the oil and how long/hard it was driven, the engine may just survive. The metal in the pan looks bad, but the short idle time with no noise and smooth idle gives me hope.

If the engine sounds fine and runs fine, I'd drive it for a thousand miles or so with a fresh oil / filter change, and then send an oil sample for lab analysis and you'll have a very good idea of the internal condition of the engine.

biopete · #47 05-15-2015, 12:23 PM

And when you need to rotate the engine for valve adjustment , use the starter , either the jumper box under hood or have a friend turn the key on and off for you. Way easier

kalikar85 · #48 05-15-2015, 08:29 PM

closed it up after valve adjustment, battery charge, new oil filter, 6 quarts Delo 400LE 15W-40.
The NSS is still down which failed a couple days before the tapping/ knocking.

https://www.youtube.com/embed/GsWpVpcLDk4

still appears to have a pronounced knock.

DeliveryValve · #49 05-15-2015, 09:56 PM

Have you used a stethoscope to locate the sound?

Also crack open each of the injector lines one at a time while running to see if the noise goes away on a dead cylinder. If it does, it might mean a bad wrist pin or rod bearing.

.

kalikar85 · #50 05-15-2015, 10:36 PM

Probably a polarizing choice on here but planning to remove the upper oil pan with the engine in to get a good look at my new boat anchor. Best case would be bearing replacement.

Anyone have experience doing this? I do have the FSM document from charmalu's post.
What risks do I run?
Would removing the head be easier?
Correct sealant/ torque?

Thanks

leathermang · #51 05-15-2015, 11:08 PM

We take strong stances on things.....but that is so others reading the thread in the future have a good idea of the ups and downs involved...
but it is your car..... and your labor.....and your money.....so don't worry about ' polarizing' effects of choosing to do any particular thing...
What is nice if someone tries something against the general advice... and comes back after a reasonable time to report on the results.... however it works out...that can really help future readers.....
I think you have little chance of success doing it from underneath... for reasons which have been mentioned already....

You risk bigger failure which might make any chance of rebuilding those parts you have impossible.... a broken rod for instance can ruin a crankshaft....

charmalu · #52 05-15-2015, 11:39 PM

I would remove the engine if I were going to remove the upper pan.
You will have to remove the Dip Stick Tube, or you will not be able to remove the pan. It is pressed fit in with that Knocker in Tool.

There is that cross frame that will be in the way.

Best of luck to you in removing it.

I posted this in another thread. Check the link to the dealer in Monterey, Ca.
for their price on it.

Dipstick tube troubles

Charlie

kalikar85 · #53 05-16-2015, 10:17 PM

From inspecting with the lower pan removed there is no play or visible damage to either 1 or 2 rod bearings or wrist pins.

Someone is suggesting motor mounts due to the excessive shaking in the video.
Had a buddy look at it today.

Quote:

Originally Posted by DeliveryValve

Have you used a stethoscope to locate the sound?

Also crack open each of the injector lines one at a time while running to see if the noise goes away on a dead cylinder. If it does, it might mean a bad wrist pin or rod bearing.

I have not used a stethoscope yet, no. Used a long torque wrench today to listen to no avail.

The injector removal is also worth a try. Where do you disconnect the lines to deduce the cylinders one at a time?

charmalu · #54 05-16-2015, 11:27 PM

You don`t need to remove the Injectors. Loosen the Hard line where it screws onto the injector, with the engine running.

Loosen #1, listen, tighten the fitting, go to #2 etc... this would be similar to pulling off a Spark plug wire to see what cylinder is dead or misfiring.

In this case taking the fuel away from each cylinder, you are looking to see if the knocking will go away. then you know that is the problem one.

You do not have to completely remove the hard line, just loosen it. Fuel will flow out from the threads, not a problem.
Use a 17mm wrench.

Charlie

Maxbumpo · #55 05-18-2015, 12:50 PM

That knock sounds to me like top-end, so could be bad injector, or maybe a bad valve-train component. I know a rod knock is a deep sound, and typically shortly after you hear it, the rod will exit the block.

As suggested, try disabling injectors one at a time to isolate the cylinder. Move the indicated injector to a new hole to see if the noise follows. Carefully inspect the valve followers etc. for that cylinder.

kalikar85 · #56 05-18-2015, 01:38 PM

Yep, checking the mounts today. Injectors next. Thank you

rscurtis · #57 05-19-2015, 09:43 AM

The noise is a moot point. With that debris in the pan, that engine is on its death bed.

Maxbumpo · #58 05-19-2015, 10:54 AM

Quote:

Originally Posted by rscurtis

The noise is a moot point. With that debris in the pan, that engine is on its death bed.

Unless that debris is left over from an earlier casualty, which was repair but not entirely cleaned up...

kalikar85 · #59 05-19-2015, 01:59 PM

Quote:

Originally Posted by charmalu

You don`t need to remove the Injectors. Loosen the Hard line where it screws onto the injector, with the engine running....

In this case taking the fuel away from each cylinder, you are looking to see if the knocking will go away. then you know that is the problem one....

Quote:

Originally Posted by Maxbumpo

That knock sounds to me like top-end, so could be bad injector, or maybe a bad valve-train component. I know a rod knock is a deep sound, and typically shortly after you hear it, the rod will exit the block.

As suggested, try disabling injectors one at a time to isolate the cylinder. Move the indicated injector to a new hole to see if the noise follows. Carefully inspect the valve followers etc. for that cylinder.

The new mounts are definitely helping isolate the sound but did not fix it. Wow what a difference they make. It really seems now, as maxbumpo said, that it is on the top end.

Loosening/cracking/disconnecting each injector where it meets the the hard line with the 17mm nut clearly caused the engine to misfire beneath each injector -except #2 injector-. #2 made no difference connected or not.

Im assuming this means the injector or nozzle on #2 is a culprit.
What exactly does this mean?

Thank you

DeliveryValve · #60 05-19-2015, 02:13 PM

Quote:

Originally Posted by kalikar85

....

Loosening/cracking/disconnecting each injector where it meets the the hard line with the 17mm nut clearly caused the engine to misfire beneath each injector -except #2 injector-. #2 made no difference connected or not.

Im assuming this means the injector or nozzle on #2 is a culprit.
What exactly does this mean?

Thank you

It should misfire with each opening of the injector line. You basically killed the cylinder by doing so.

Since #2 made no difference, it's dead. I suggest to investigate further and get a compression reading. You most likely have no compression on that cylinder, either valve related or piston related.

.