3306 top end noise

gwhammy · Mar 21, 2017

I was running the 973 building a lake when it started missing and had real low power. Took my ear muffs off and it has a real hard rattle in the top end. Slowly backed it out of the cut to get it out of the way and by the time I shut it off it was really banging and starting to blow out the dip stick. I'm guessing a piston came apart, it has no water in the oil so it's contained.

It started a weird vibration several weeks ago and we thought the harmonic balancer had slipped. I'm guessing that isn't the problem. We haven't loaded it up yet, is there a bypass valve to free wheel this machine or do you have to pull the axles to move it. It is a 86g serial number machine.

I'm hoping to do a inframe overhaul if the crank looks good or replace if crank is hurt.

DMiller · Mar 21, 2017

Look very close at the rod journal of the one that failed should a piston have popped. Many times damage will appear slight but could be pretty severe over time.

kshansen · Mar 21, 2017

Well I guess there is no harm in starting out in the direction of an in-frame overhaul.

But if something like a piston did break-up first thing I'd want to check is the oil filter. Remove and cut it open and inspect. If there are any signs of metal parts in there I would strongly suggest removing and a complete disassembly of the engine. This would include replacing the engine oil cooler core with either a new one or a reman unit. Then I would strip block to the bare casting including removing all plugs that are related to the oil system and using a gun cleaning brush to scrub them clean. Don't for get the dowel at the rear of the block the oil for rocker arms has to go through. Next if crank is checked and found to be usable there are plugs in oil passages in it that should also be removed and cleaned out. Basically anything that has oil going through it needs to be completely disassembled and cleaned 100%.

This is by no means a full list of things that need cleaning but should give you an idea of what I personally feel needs to be done to prevent a second major failure in the near future.

Dickjr. · Mar 21, 2017

I just had to tow my 943 and opted to remove the axles. I think there is a way to charge the brake system but its about as easy to pull the axle. The only 3306 I was around that had a noise like that , the wrist pin bushing went on a cylinder. The weird thing about that was that morning no noise at all , 6 hours later sounded like a hammer floating around and kept getting louder. The owner shut it off before it let loose. Come to find out the previous dealer had remaned the engine but didn't fit new pin bushings. Hopefully you won't find much out of line. 3306 is a fantastic power plant , how many hours?

gwhammy · Mar 21, 2017

Engine looks like it's been rebuilt, really clean for the age of the machine that was one reason I bought it. Machine has around 11,000 hours on it. It's pretty tight for it's age. I'm hoping for an inframe but won't chance it if things look to bad when we get the head off of it. It's going to be awhile, I'm swamped with work and really don't need it till this fall for more lake work so it may set till wet weather will let me move it.

We will probably pull the axles, they aren't that bad to get out.

I hadn't thought of a wrist pin, when it started missing I'm guessing it hit the injector and shut that hole down. It also didn't start blowing out of the dipstick till the very last few feet. I'm hoping for the best but we all know how that goes. Are used 3306's hard to come by?

kshansen · Mar 21, 2017

Hope I did not sound too negative but just trying to point out potential problems. If as in Dickjr.'s case it turns out to be a bad wrist pin bushing and no noticeable amount of metal in oil filter you may get lucky with an in chassis repair.

Good luck and be sure to post updates as you find what the problem turns out to be and if you need any detailed information a full serial number on that 86G and the motor itself if it does have a separate serial number will help whoever is going to answer your question. Also a little info on the use you are looking to get out of it would be nice. What one might suggest for a machine running 2,000+ hours a year might be way different if you are only going to be running it 200 hours a year or even sell it when project now in the works is done.

gwhammy · Mar 21, 2017

I do alot of brush removal and build a few lakes and ponds a year. I'm going to say maybe 2 to maybe 350 hours a year. May not have it looked at for a couple months, working out of town when this job is done. Hoping for the best, it's been a long month, excavator burnt, dump truck rear end went out and now this. That's a lot for a one man operation!

Dickjr. · Mar 21, 2017

gwhammy , I feel your pain. If your read some of my posts from last year, it was rough. Maybe your 73 repair won't be to hard on the pocket.

DMiller · Mar 22, 2017

Send me a PM where you are at gwh, I too am in MO and have such gracious results while trying to earn a little extra cash!! Sorry to hear the other miseries, I am awaiting my own physical repairs to seal up/heal over so I can return to some level of function. Docs PA stated may be up from 6-8 weeks dependent on my internal processes where I can lift more than 10 lbs. or turn my head up to look above my head! Then and ONLY then I can start 'easing' back into any sort of working.

Shimmy1 · Mar 24, 2017

Since we're guessing here, I'm going to vote for a dropped/broken valve. When you get everything apart, make sure you inspect the turbine on the turbo very closely. If things were coming apart in a cylinder, some shrapnel may have made it's way out the exhaust.

gwhammy · Mar 24, 2017

Pulled the axles today before it started raining to get it out of the field. Real easy, six bolts a side and a ratchet strap hooked to the bolt put in the center they came right out. Going to get it on a trailer this weekend between rains and find out whats wrong. Talked to my mechanic and he said he had seen seats come out and cause havoc on the 3406.
I'm north of you DMiller about 80 miles. Paris, at the west end of Mark Twain Lake. I know a couple people from your area, Merlin that runs a body shop and a guy we called Chunky, who was a laborer and then worked at the nuclear plant till he retired.

DMiller · Mar 24, 2017

Been to Paris a few times, had friends that loved the lake. I may have known chunky, I still(somewhat) work at the nuke in Operations. Being down with the back and neck has taken some wind out of that sail. Been there since 96.

oldirt · Apr 1, 2017

wish I lived over your way.. heal quickly, DMiller!

gwhammy · Apr 14, 2017

Got the head off, needs a total rebuild. The guy I got it from didn't run it maybe a couple days a year. It had gotten condensation in all cylinders and had rust in all. Couple of pistons tore up and I'm guessing took rod bearings out causing piston to hit head. I'm sure crank will need turned so out it will come.
I'm going to pick up a running motor this weekend as it will be more cost effective and faster. It's intercooled just hoping the intercooler on top of the intake will clear the cab.

DMiller · Apr 14, 2017

Sorry to hear but at least you stopped before destroyed the entire engine. Keep us informed on progress.

gwhammy · Apr 14, 2017

Got home with the new to me motor. Guy had it rigged up with a radiator and it was on a skid from the rock drill he got it out of. Fired right up and ran great. Picked this up for less than a rebuild kit. We are going to pull the pan and check a couple bearings while it's easy to do. May have to swap injection pumps as this one has solenoid on and off and the loaders use the throttle. That should put it back to stock horsepower also. One question, this is a deck plate motor and mine wasn't. Will that make a difference?

Shimmy1 · Apr 14, 2017

Any idea what hp the transplant is? I'm thinking somebody is going to throw a fit over the fact it might have different pistons than your engine.

kshansen · Apr 14, 2017

One quick question are they the same style pump, other than the solenoid?

While I'm asking, are they both the same type of injectors, Pre-chamber direct injection?

Okay, one more. What about flywheel housing? Wet/dry, pump mount/drive.

Cat is not as bad as Detroits but there can be many variations for some of the more common engines like the 3306. They have been used in everything from gensets to loaders and dozers. Each one may have variations that would not work well in another application. Just because it is Yellow and has the same model designation does not guarantee it will work!

gwhammy · Apr 14, 2017

Looks to be the same style pump. The loader motor and this motor are both dry flywheel. I'm thinking adapters and flywheels will have to be changed. I did notice this one has a different arrangement on pulley and harmonic balancer. Loader has the pulleys first then the harmonic balancer new motor opposite but just guessing they will interchange.

Replacement motor has the turbo near the rear of the motor and loader has it centered.

Both are direct injected I believe, replacement is like a 93 or newer as the guy that had it said the cat name on the valve cover was 93 or later.

As long as new motor is same hp or more I wouldn't think pistons would make any difference.

I wouldn't be against wiring up the shut off solenoid to a switch instead of killing it with the throttle.

DMiller · Apr 16, 2017

One caution stationary to machine engines, the stationary may not have the appropriate multi-pickup oil pump suction system and not ready for use in a mobility machine. Check with the parts guys as to major differences you may have to change; IE Oil pump and pickup, if the vib, dampers will interchange, if the cranks are the same, etc.

3306 top end noise

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