Branson 3510 Motor Issue

[Wadmalaw]

Hey Guys,
I've got a Branson 3510 with the 3T90L-ATC motor. It cranks and runs, but it's making a metal-on-metal loud tap-tap-tap that I think is isolated in the front cylinder. My feeling is it's a broken connecting rod. I don't have the cash to pay a mechanic at the moment, and a buddy who's just rebuilt his diesel boat motor are going to give it a shot.

The last time I ran it, I noticed it was running hot, so I parked it and mentioned it to my wife. Before I could check it over again, she used it (and said) it was running fine, not hot. She parked it and the next time I went to crank it.. this.

Would running it hot cause this problem? Let me know what your ideas are before I pull the top off this thing!

 

[DavesTractor]

Doesn't sound promising, but a bad injector nozzle will cause a sound like this. If it is injecting a bunch of fuel, it will nearly hydro-lock and sounds really bad. You can loosen the line to that injector and see if the knock greatly reduces. Of course it will miss, but ignore that for the moment.

How hot did it get? Any water in the oil or oil in the water?

 

[Wadmalaw]

Thanks for your input.

The temp gauge got almost to the redline, but it was still running ok. I drained the radiator and flushed it to make sure nothing was clogged.. I thought it might be the water pump at first. (it may be failing also, need to test it).

The oil is clean, no water at all, don't think there's any oil in the water either.

I'll test the injector as you said and see what happens -

 

[DavesTractor]

Generally when a tractor overheats the first place to look is coolant level, the second is the air side of the radiator. You should be able to see light through the radiator and I bet you can't on most areas of yours. They plug up and need to be washed.

 

[Wadmalaw]

I'm sure that radiator needs to be cleaned.. As I get more into this, I'll probably post some photos (or maybe even video clips) of the work-in-progress for advice and maybe it will help someone else here as well.

 

[Zork]

A broken connecting rod will probably make a louder noise than a tapping sound and it will be running on 1 less cyl than you have. The radiator generally has a removable screen to catch larger debris but I did my service this summer and washed all kinds of dirt from my radiator. The engines I have seen that were run "past hot" usually ended up with a leaking head gasket (whether it was the cause or not) damaged rings, and a warped or cracked head. Never have I seen an engine that was run hot and did not loose antifreeze or boil over somehow.

First thing I would do I'd pull the valve cover and inspect the intake and exhaust valve springs, retainers, and valve keepers to make sure the tap isn't valve related and prevent further damage (although this isn't related to overheating). Its hard to make a diagnosis because I'm not looking at it. But a valve cover gasket and inspection is cheap insurance in case you're getting ready to eat a valve and destroy your engine. Your engine may have been running hot because you weren't running on all cylinders due to fuel, compression (rings/ piston travel, valves) or running hot due to blocked airflow in radiator or cooling fluid problem (belt, hose, pump, clogged radiator)

Good luck and keep us posted.

 

[Monkman Harry]

Have the same issues with my Century 2535, found the waterpump impeller blade was erroded away, also center cylinder of the head has a crack in it from intake valve to injector port, take the time to remove the water pump and check it out. If you can find a water pump see if thereare 2 of them, I need one and cant seem to be able to locate anything from the dealer or here on the net.

 

[DavesTractor]

Have the same issues with my Century 2535, found the waterpump impeller blade was erroded away, also center cylinder of the head has a crack in it from intake valve to injector port, take the time to remove the water pump and check it out. If you can find a water pump see if thereare 2 of them, I need one and cant seem to be able to locate anything from the dealer or here on the net.

The heads tend to crack on the Bransons (and most tractors for that matter) if they get really hot. So if a guy thinks he just has a blown head gasket, the head really needs to be checked for cracks. Water pumps are available through any Branson dealer, that shouldn't be a problem. We bought one for a customer last weak due to a leak in the wp seal which caused the bearing to fail. I've not yet seen an eroded impeller on one, but that is a good thing to check. But 95% of the time over-heating is caused by a clogged radiator on the air side. If you can't shine a flashlight from the backside and see light through the front in all areas of the core, then it must be cleaned.

 

[Zork]

The heads tend to crack on the Bransons (and most tractors for that matter) if they get really hot. So if a guy thinks he just has a blown head gasket, the head really needs to be checked for cracks. Water pumps are available through any Branson dealer, that shouldn't be a problem. We bought one for a customer last weak due to a leak in the wp seal which caused the bearing to fail. I've not yet seen an eroded impeller on one, but that is a good thing to check. But 95% of the time over-heating is caused by a clogged radiator on the air side. If you can't shine a flashlight from the backside and see light through the front in all areas of the core, then it must be cleaned.

@ Dave- Do these tractors incorporate solid head bolts? Or Stretch head bolts? When you do a head/ head gasket job do you reuse the head bolts or buy new ones?

The reason Im asking is if the head bolts are solid and you reuse them then the head bolts should be re-torqued at so many hours of use. I asked this question some time back and did not get any answers. My thoughts are that the head gaskets will blow and heads will warp and crack if this simple maintenance procedure isn't followed. I checked my manual and did not see any information on the matter. Can you help with this topic?

 

[Zork]

Have the same issues with my Century 2535, found the waterpump impeller blade was erroded away, also center cylinder of the head has a crack in it from intake valve to injector port, take the time to remove the water pump and check it out. If you can find a water pump see if thereare 2 of them, I need one and cant seem to be able to locate anything from the dealer or here on the net.

Eroded impellers and head gaskets can be avoided by using distilled water in your recommended antifreeze and changing it at the correct interval.

 

[DavesTractor]

@ Dave- Do these tractors incorporate solid head bolts? Or Stretch head bolts? When you do a head/ head gasket job do you reuse the head bolts or buy new ones?

The reason Im asking is if the head bolts are solid and you reuse them then the head bolts should be re-torqued at so many hours of use. I asked this question some time back and did not get any answers. My thoughts are that the head gaskets will blow and heads will warp and crack if this simple maintenance procedure isn't followed. I checked my manual and did not see any information on the matter. Can you help with this topic?

I do not think the Bransons use a torque to yield type bolt like we so often see now in cars, especially with aluminum heads. It is my understanding that torque to yield bolts must always be replaced, but others can be reused.

 

[Zork]

@ Dave- Got it. Thanks

 

[johnnyo1111]

i have a branson 3510i,,motor locked up,,was running hot as well,,the engine thrust bearings went out,,spun..the clank noise was the flywheel hiting the engine bolts,,

 

[Zork]

i have a branson 3510i,,motor locked up,,was running hot as well,,the engine thrust bearings went out,,spun..the clank noise was the flywheel hiting the engine bolts,,

Not sure how to follow this.

 

[Wadmalaw]

Last night we pulled the cover off the top of the engine and cranked it. Could not see any problems with the valves or pushrods. Put the cover back on and took some videos cranking / running.. maybe some of you guys will have some ideas when you hear it run.

My buddy said he thought the crankshaft looked like it had some play / movement in it when running.. possible a bearing went bad? I'm guessing that in order to access the bottom end I'll have to remove the entire motor?

 

[DavesTractor]

I think you can pull the pan without pulling the engine, but now that you know there is nothing coming apart under the valve cover, I highly recommend checking to see if the noise is coming from an injector failure. It really does sound like a rod is ready to come loose when an injector fails and lets a bunch of fuel in. It is nearly hydro-locking and the hammer is impressive. It's not an injector noise, but a noise caused by a bad injector. An injector tip should stay closed and only allow fuel in when the pump gives it adequate pressure, maybe 2000 psi or so, and it gives a little squirt at the right time. There is a pintle and a spring that keeps the tip closed untill it sees adequate pressure. If that tip is messed up, when the piston goes down it sucks fuel in from the injector and it gets way too much fuel at the wrong time. It's rare, we see it a couple times a year, but it is worth checking before you pull the engine. If you are worried about turning it over, then drop the pan first and inspect for carnage down there.

 

[Zork]

The second video looks like everything is jumping, even the radiator. From what I see that crank (via) pulley doesn't look problematic; plus if you had that kind of movement you would be loosing a tremendous amount of oil. A main bearing failure usually produced a slower cycled/lower pitched thumping-like sound, your noise appears too rapid to be a main bearing. The noise could be a rod bearing which has a faster cycle (rhythm) but the noise appears too high pitched to be a rod or rod bearing. I think it sounds like a valve tap.

Do you have a stethoscope to pinpoint the noise? Just observing the valves in operation may not be enough of an assessment.
When you removed the valve cover did you personally feel each intake and exhaust rocker arm at top-dead-center? When you have the cylinder in this position there should be very little, if any clearance between the rocker arm and the valve. Also, take some carb cleaner and inspect the valve spring keepers and upper spring seat (washer-like plate the keepers (X2) are seated into). (edit) Sometimes I have personally had to put my hand on the rocker arm while the engine is running to silence the tap.

(Edit) With Dave's good advice about the injector you should be able to isolate the cylinder by loosening the fuel line (maybe removing the nut at the injector or pump) one cyl. at a time while it is running and the noise should quit at the problem cyl.

 

[johnnyo1111]

my 3510i needs a short block,,70 hrs,,im a mechanic and i took the motor apart and metal all in the pan,,i think a yanmar will work,,cummins kakes the kukje engine,,a drop in motor for the 3510i is 9500.00,,so i needed a tractor and now i have also a john deere 4005,,working on geting a motor for the 3510i branson.

 

[Wadmalaw]

Hey guys, thanks for all of the advice.

A friend of mine works at Cummins Marine and he had an engineer watch the videos and here's what he had to say: "Best guess from here is a rod bearing. Generally happens if run hot because it gets oil second. Main bearings get the most oil first. Although those could be shot as well and you might not hear it. It sounds like it needs a total breakdown. You should see heat marks inside the engine once it is apart."

First thing I'll do is disconnect the suspect injector and see what happens..go from there. The valves do need some adjusting, there was a little bit of play in some of them.

 

[Wadmalaw]

Happy New Year to everyone. I've been moving slow so far, but deer season in the SC Lowcountry ended yesterday so I'll have more time as of right now.

I finally drained the oil and removed the inspection plate from the oil pan to get a look at the bottom end. Nothing looks to be out of place here. There were some very thin copper-looking shavings on the plate when I pulled it. This is probably the first time this plate has been removed so I don't know if that's an indicator of anything.

I also pulled the 3 injectors to take them for testing / cleaning. The injector from the front cylinder that's the problem has white corrosion around the bottom (one on the left in the photo). I'm starting to think that I might have a cracked head that's allowing coolant into that cylinder? I'll keep pulling things off until I find out.