Wetstacking

[CuttingEdge]

Not a very good description I know, but after getting my idler back on and kind of working the dozer hard making some new ditches, the engine started to make a helicopter like sound. It goes away at low idle, but also goes away when at high idle, but no load on the engine. But full throttle pushing some dirt, oh yes, it sounds like a helicopter overhead.

I checked the front end for a loose fan belt "flapping", and to see if the bearings seemed alright in the alternator and water pump; both were fine. I have not checked the lovejoy coupling for the hydraulic pump however, but it would seem that would not be an issue if it sounds okay at high idle, but not under load (pushing dirt) since a hydraulic pump is constant load?

I hate to think it was a stuck valve, but maybe?

The only other issue may be a blown head gasket? The engine was not overheating though (actually on the cold side) with good oil pressure and power. Also the oil consumption on this machine is non-existent; neither losing oil nor making oil.

My only other thought...as remote as it may be, is that mud somehow got on a fan blade and stuck? I was in wet gumbo clay and at one point got a face full of mud-water spray.

[CatD8RII]

Might not be a bad idea to take a closer look at your pump coupling. My loader made a similar noise (I think!) . It should be a splined coupling, there are 2 different sizes depending on what size pump you have. Depending on your s/n (or if the coupling has been replaced) the coupling is held in place with a c-pin or with 2 E-clips. If the coupling stays free on the shafts (or if it was assembled with some spline grease) and doesn't rust up, the coupling can bounce back and fourth off of the 2 clips and make the noise you're describing. If you slide a flat washer in between the coupling and one of the e-clips it fixes that noise. Don't make it too tight as it needs some room to move. My noise only showed up when the machine was hot, and was really tough to tell what it was, sounded mainly like the fan hitting the shroud, kind of like what you're describing.

[Stan Disbrow]

Hi,

Are we talking 350? If so, then we also have the isolator noise....

Stan

[jtrichard]

Stan He has a 350D ..... IS a "D" past that isolator mess???

[Stan Disbrow]

Hi,

I think the main item that made a D from a C was the redesigned isolator. Not to say they can't have their own issues.

Stan

[CatD8RII]

Cutting edge can answer for himself, but I'm pretty sure he has a D. Off topic, but you would be supprised how similar a D's isolator sounds to an early C machine. That being said, since he is checking his fan belt, fan and alternator I guessed his noise is in the front of the machine, not near the middle (like under your feet) where the isolators tend to be noisy. Its also should be alot easier to check that coupling then take the machine in half to inspect the isolator. The other big difference in the D from the C is they used the 3179 engine as opposed to the 3164.

[CuttingEdge]

Yes I have a 1988 John Deere 350D.

It has been a long time since I was in diesel tech school, but the wet stacking example we were giving was the city of Bangor using a dozer to pull a sidewalk paver at idle that wet stacked. Mine was hardly at idle, but being the miser that I am, in the interest of saving fuel I have always run the dozer at about 1/2 to 3/4 throttle. Obviously due to loads it would lug down, but it never was worked for long periods of time at an idle or without a load. Since going to full throttle for all work, I have not been able to reproduce the helicopter noise though.

I really should not be concerned with fuel consumption anyway. There is no doubt that it burns more fuel then my little Kubota, but it also does an amazing amount of work in very little time. Honestly I am not sure how a farmer could be without a bulldozer. I have put in an insane amount of ditching, graded fields, built a new driveway for the barn, and that was all in one week. Next week it is off to the woodlot!