i recently discovered this crack on my engine. Motor is a Cat 3406E 5EK. Motor runs and drives fine. Any ideas of what it could be or what parts are exactly located behind this crack.
Is that the mounting for an ECM..? It looks a bit like it but it's hard to see from the angle of the photo.
The crack is located directly behind the dip stick
What's the "fitting" with the 2 red washers on it right next to the crack..? Is it the left or right side of the engine, front or rear..? Pretty much everything we need to see is obscured by the wiring harness. The full engine Serial Number would also help. On-highway truck engines have a million & one possible configurations.
serial number is 5ek45588 its a 500hp factory motor
Got it now. I was right the first time, it's the top LH mount for the engine ECM. Why it cracked like that, no idea. The Parts Manual shows the threaded hole in the cylinder block as being a through hole, is it leaking oil..? Also if you look at the illustration below (Section B-B is the bolt where the crack is) it calls for a "sound panel" between the ECM mount and the block. I don't see anything like that in your photos ...... I wonder if something has been missed out at some time and the result is that the boss on the cylinder block has cracked from becoming over-stressed..? Or are we in fact looking at the sound deadening panel itself which is cracked, not the cylinder block..? Removing the ECM completely would be the best way to find out.
That almost looks like the sound panel. Grab it and see if it flexes. Usually those panels get brittle and crack or get saturated with oil.
I was wondering why that looked like black plastic with the paint peeling off, not rough or rusty like cast iron.
The motor has been leaking oil for a while now but I haven't been able to pin point the location of the leak. it has regular blow by nothing excessive. When the motor is idling i cannot see a leak but if i clean all the oil away from dip stick area and chassis rails and take the truck for a run when i get back to the yard and open the hood there is a mess of oil all over the chassis rail, dip stick, etc. I under the impression that while driving it was blowing oil out the dip stick tube but the dip stick handle is still fastened down over the dip stick tube when i get back. So its possible that it could be leaking oil through these cracks?
If it is leaking through "those cracks" you're going to have to do a certain amount of disassembly to find out. The ECM, wiring harness, fuel lines, and sound deadening panel are all going to have to come off for a start. How much else has to come off will depend on how large the sound deadening panel is. If those are through holes into the block as the Parts Manual suggests it's certainly possible that oil is leaking past the threads of one or more of the ECM holding-down bolts. Whether it's coming from the bolt holes or not, if the source of the leak is behind the panel then removing it is going to be the only way you'll see where the oil is actually coming from.
Thank you very much
I think it's the sound insulation panel cracking. The leak is probably something minor underneath, but as has been mentioned you'll need to do a little dismantling to remove it to find out.
You could start by taking that bolt out and seeing if there's oil at the end. That area looks too caked with dirt to be the source of oil, usually an oil leak will clean up the area closest first. Unless you pressure washed this before taking the pictures?
ya looks like sound insolation
I ran the same engine for 15yrs. Same crack in 3 spots. Not a concern. The one oil leak I had problem with was in behind compressor,small leak but messy.