966D with a 3306 making a little slapping noise, so says the operator!

[HDR]

So the the operator of a 966D at work says he heard a bang and saw some white smoke that eventually went away. When I got to it I put my long screw drive to the block (checking one cylinder at a time) and could hear the #6 cylinder was the one making the noise. I pulled the valve cover off and watched everything while it was running and everything looked good except there wasn't too much oil up there. I started to think a rod bearing went. So I drained the oil and dropped the pan!! And Bob is your uncle. I started to pull the motor today and when I see the crank and rod I'll post some more pics.

 

[Wayne M.]

How many hours? Sorry to hear. Is it your machine? 3306 is a nice engine. I ran a fleet of marine 3304's. They withstood lots of abuse. I remember changing some Water pumps and oil coolers on them.

 

[HDR]

The loader has 36000 hours and the motor has about 16000 since last rebuild. Not my loader just fix them, dozers, excavators, and cranes.

 

[Wayne M.]

Those are big numbers!

 

[HDR]

I was finally able to tear down the 3306 and hear are some pics of what I found.

 

[HDR]

 

[HDR]

I was the #6 piston and the rod bearing was spun. I still haven't found why. Although all of the rod bearings looked like crap. Also here are some pics and reasons why we should all have coolant filters.

 

[Wayne M.]

The bearing shots are deceiving to me. The separate shot with the 2 bearings and cap is #6 rod? The others look like they have issues, possibly long term contamination (?) but it's hard to tell unless you handle them. I'm wondering what happened to the piston/ sleeve, are those scores all the way around the cylinder? Great shot of the water jacket scale, does it have a coolant filter? the 3304's we had were marine w/ keel coolers and only had zinc anodes. The crank don't seem bad. Did you measure?

 

[HDR]

All the bearings showed wear and tear. A question I had is why they were all black on there back? The cylinder had and piston had a scores maybe . 003-. 005 deep. I'm thinking something clogged the oil squirter maybe. It doesn't have a coolant filter. I haven't looked at the cam let but all the lifters looked great.

 

[Mikey-KE7LBB]

I say kudos to the operator for noticing a change.



I often drive the truck I'm assigned to with the windows down and radio off to listen for even the slightest change from "normal".



Not my personal truck, but I still care enough to do my part in keeping it running.

 

[Wayne M.]

All the bearings showed wear and tear. A question I had is why they were all black on there back? The cylinder had and piston had a scores maybe . 003-. 005 deep. I'm thinking something clogged the oil squirter maybe. It doesn't have a coolant filter. I haven't looked at the cam let but all the lifters looked great.

I've seen black on the backsides. It could be just the imprinting/ brunishing from the the cap/rod, it could be a sign of heat. Did the bearings fall out of the caps? A clogged squirter is a good thought, maybe that caused a ring to stick? Usually that would cause a more regular pattern- not gouges. Haven't seen that before. Either way, if the crank looks good (did you pull a main?) You might be able to save it.
I'm thinking it ran with bad oil or something. What's the PM history on the machine? How did the oil look when it came down? you have to think about the white smoke you described in the first post. The lack of oil up top is another clue. Did you note the oil pressure previously? Does it have a shutdown system (kysor, lengard, etc)?

 

[HDR]

I pulled the crank and the #7 main bearing was as bad as the #6 rod bearing. The PM on the machine is good. The oiler does a good job and keeps good records. I have the block striped and I've started to mic everything. So far the cam is no good and I'll have cat check the head.

 

[Jim W]

That is an old machine might have been built around the late 90's? When I retired they were designing the K and building the H's in Aurora. I spent my last 20 years designing the big boy toys such as the 5130, 5230, 993K and 994F's.

Were oil samples taken and sent in to a lab for analysis? Were the oil filters cut apart for abnormal wear material in them now? I would think abnormal wear material would have shown up sometime before the 16,000 hour engine failure. The 3306 Cat engine was in used in a lot of Cat products and was will excepted before it was replaced with the Tier II emission engines.

Jim W.

 

[HDR]

I've worked on alot of 773's and 5110 at an open pit in Indio, Ca. that was alot of fun and that 5110 could move ALOT of durt.

The place I work at now doesn't do oil samples! They're the "Run it until it blows up" crowd. So I just keep fixing them and they just keep breaking them break them. I didn't cut the filter because the oiler just did a oil change by the time I got to it.

 

[Wayne M.]

I pulled the crank and the #7 main bearing was as bad as the #6 rod bearing. The PM on the machine is good. The oiler does a good job and keeps good records. I have the block striped and I've started to mic everything. So far the cam is no good and I'll have cat check the head.

Let us know how it goes.