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.