I have a Cat 3208 (210 hp) normally aspirated in a Massey 1505 tractor that suddenly quit and makes a loud bang I thought was a rod gone but I’m informed that when the injector pump on these engines go it’s loud. The engine cranks fine but makes the loud sound while cranking and the oil (I drained to inspect) looks new (I had just changed it about an hr earlier). It’s a “V” pump and I’m trying to learn more as to what happens when the pump goes out and info on repair in the south central Michigan area. So far if it is the pump I believe a rebuilt would be my least expensive option. I’ll have to use the backhoe to pull the hood to replace it so I want to be sure before I start that endeavor again. The last time I discovered the front windshield is $400 to replace. Thanks for all your help Dave.
Loosen all the belts and gently pry on the crank balancer to maybe see if it is loose. Pry up and down as well as in and out. Maybe the crankshaft is broke. I’ve never heard of those sleeve-metering pumps making a loud noise but maybe somebody else has. Maybe the Pump Guy will chime in
THATS a new one on me..?? I do like the crank and balancer idea tho..
Another idea while checking the crank and damper. Put a wrench on a bolt at the front and while someone watches the flywheel at the back try turning the front with the wrench. Never had much experience with a 3208 but had a couple 8V-71's that broke cranks and they still ran. But you could move the front half of the crank a few degrees in each direction before the rear moved. Bad thing is all the Detroits with broken cranks also damaged at least one of the main bearing casting in the block. Some might say that was actually a good thing!
Thanks guys. I’m going to pull an injector line off next and see if it’s delivering fuel. That will tell the pump tale. And I’m hopping that’s it. I’m trying to find what drives the injector pump now. I don’t think it would be a belt. I can’t get to the front yet (need to pull a side panel off) but it threw a fan belt at the same time. But no … it didn’t over heat.
I may be missing something here but wouldn't it be more logical to do the checks for possible crankshaft breakage as suggested above before going through the effort of pulling an injector.? Pulling an injector isn't going to get you anywhere if the crank turns out to be broke.
What everyone is saying is that its very unlikely the injector pump is the problem. It throwing a belt leads credibility to a balancer failure
Pull the engine oil filter and cut the canister off. Look for steel debris.
Almost certainly the injection pump is driven by a gear train that involves the camshaft gears and some idler gears. Do the cylinders make the same regular sound when cranking that they used to? Shouldn't be too hard to narrow down where the loud sound is coming from.