Is my engine going to explode? (video) OM617 - PeachParts Mercedes-Benz Forum

jparker164 · #1 09-18-2008, 04:01 PM

Or has something happened already?

More then anything, can I safely drive this thing to a shop or should I have it towed? I don't seem to have the time to get it running on my own. . .

http://www.youtube.com/watch?v=NFSyUGIfwAY

Cervan · #2 09-18-2008, 04:11 PM

Quote:

Originally Posted by jparker164

Or has something happened already?

More then anything, can I safely drive this thing to a shop or should I have it towed? I don't seem to have the time to get it running on my own. . .

http://www.youtube.com/watch?v=NFSyUGIfwAY

Sounds like either a spun rod bearing, or bent rod. Both will end in disaster if not fixed imediately.

jparker164 · #3 09-18-2008, 04:30 PM

Awesome. I don't think this car likes me.

79Mercy · #4 09-18-2008, 04:42 PM

yeah, that soulnd's like rod knock, I don't think its a bad injector, that more of a really high pitch tap.

jparker164 · #5 09-18-2008, 04:50 PM

The whole engine shakes too. . . So I would imagine if it's the rod that's not a cheap repair?

Cervan · #6 09-18-2008, 04:53 PM

Quote:

Originally Posted by jparker164

The whole engine shakes too. . . So I would imagine if it's the rod that's not a cheap repair?

complete engine overhaul prettymuch. rod (lets say) 100$ for the rod, and another 100$ for the gasket kit and another 200$ or so in bearings and rings. (this is if your going to do it yourself) If your going to hand it over to a mechanic then expect 1500$ plus.

85300DT · #7 09-18-2008, 05:26 PM

Time to find a good donor engine and be done with it. Then bring the old engine to a metal recycler and get some cash to spend on a cheap dinner to celebrate.

DeliveryValve · #8 09-18-2008, 05:26 PM

That is inconclusive for me to hear off the video to say it is a rod or rod bad bearing. I would think it would be a harder knock. But anycase, I would dig into the engine a little bit. First off, find out which cylinder is making the noise. Crack open each of the injectors at the line one at a time. If the noise goes away, then you found the problem cylinder.(keep in mind it will still run rough) I wouldn’t dismiss a troublesome injector just yet. You might want to swap an injector with another one from a good running cylinder to see if noise follows to the new place. Also, remove the valve cover to and check on the valve lash adjustment. It might be a tight valve caused by the adjuster lock nut to come loose.

Cervan · #9 09-18-2008, 06:04 PM

Quote:

Originally Posted by DeliveryValve

That is inconclusive for me to hear off the video to say it is a rod or rod bad bearing. I would think it would be a harder knock. But anycase, I would dig into the engine a little bit. First off, find out which cylinder is making the noise. Crack open each of the injectors at the line one at a time. If the noise goes away, then you found the problem cylinder.(keep in mind it will still run rough) I wouldn’t dismiss a troublesome injector just yet. You might want to swap an injector with another one from a good running cylinder to see if noise follows to the new place. Also, remove the valve cover to and check on the valve lash adjustment. It might be a tight valve caused by the adjuster lock nut to come loose.

remove the injector and start the car, if the noise is still there then you have a rod knock.

Hatterasguy · #10 09-18-2008, 07:59 PM

Yep that engine is an anchor.

DslBnz · #11 09-18-2008, 08:49 PM

I have one that sounds similar. Actually, much worse. It's the one with what I thought was a bad lifter (and it was). It "blew up" the other day.

I'm tearing into it, currently, to see what I find. When I relieved cylinders of the fuel pressure, there was no change in sound on all six. But cranking out 3 particular lines had no effect on the engine whatsoever (no stumbling). 3 cylinders have very little compression suddenly, while oil is puking out through the coolant, and the right side part of the head is pouring oil everywhere when it's running. Got a stripped headbolt and two slide-rail pins left and up she goes!

jparker164 · #12 09-18-2008, 11:36 PM

Quote:

Originally Posted by Cervan

remove the injector and start the car, if the noise is still there then you have a rod knock.

Thanks for your replies, I'll try that in the morning. I take it removing the injector it relieves all compression in that cylinder to keep valve issues from affecting the engine? Sounds dangerous, is air going to blast out the injector hole dangerously? Should i just loosen it a bunch?

And yeah, replace the engine. THIS IS THE NEW ENGINE. I just had a depressed cylinder sleeve and swapped the engine with a newer one. This was the first drive longer then 2 miles on the new engine.

I tried loosening the hard lines to each injector in sequence, didn't change the noise.

TylerH860 · #13 09-19-2008, 12:02 AM

Your video brought forth a childhood flashback.

http://www.youtube.com/watch?v=ylNwSv6c7m0

Also one of my father's nicknames for my cars.

jparker164 · #14 09-19-2008, 12:23 AM

Quote:

Originally Posted by jparker164

Thanks for your replies, I'll try that in the morning.

I assumed the cylinder with the new injector was the problem one, and loosened the injector a bunch and started it up. Noise is louder.

Cervan · #15 09-19-2008, 12:43 AM

Do not loosen the injector part way and start the engine, you will pull the threads clean out of the head and cause the injector to go flying. Remove it completely and start the engine. Valves has nothing to do with this. If you remove the injector it takes the injector "nailing" out of the equasion and leaves only bottom end mechanical noise.