Should a 4500 hour engine be rebuilt? 336d

[RickB]

The furthest I would go is to adjust the valves and have the fuel injectors checked. Improper valve lash can cause all manner of expensive problems, is easily corrected and should be checked at these hours. Same goes for fuel injectors with plugged or worn or leaking injector nozzles. Symptoms may be present but not apparent.

 

[radios1]

make sure you know if they use a metric or inch measurement for the valve lash!.. also, when you check the oil, look for metal particles, larger sizes mean trouble(excessive wear). it's normal to get very tiny particles due to wear.. you shouldn't be having wear problems at 4500 hours..

 

[bmaverick]

Seafoam is your friend. Clean the injectors and clean the valves. Change the fluids and filters. Give it a good once-over. Grease all the fittings. (there are plenty.) LOL

Hours on the meter are not actual hours of run time use. The run time use would actually be MORE. Hours on a tractor are based on almost WOT or a very high rpm. Much of the time a tractor operates around 1/2 of the higher rpm. When I brush cut my fields, It's at 1,600rpms and not the 2,400rpms. Less high rpm wear on the engine.

There are plenty of Yanmars out there with 40 years on the clock and no rebuilds. Some have been extremely abused and others tend to fair alright. Still others used with special care from new. Like the others stated, you'll be good to about double the hour meter or more.

 

[CoyPatton]

Seafoam is your friend. Clean the injectors and clean the valves. Change the fluids and filters. Give it a good once-over. Grease all the fittings. (there are plenty.) LOL

Hours on the meter are not actual hours of run time use. The run time use would actually be MORE. Hours on a tractor are based on almost WOT or a very high rpm. Much of the time a tractor operates around 1/2 of the higher rpm. When I brush cut my fields, It's at 1,600rpms and not the 2,400rpms. Less high rpm wear on the engine.

There are plenty of Yanmars out there with 40 years on the clock and no rebuilds. Some have been extremely abused and others tend to fair alright. Still others used with special care from new. Like the others stated, you'll be good to about double the hour meter or more.

Some swear by seafoam and others say avoid at all cost. Use your best judgement. Check the valve lash, and adjust if out of spec. The OEM spec would have been metric, so if possible get and use those specs. Any additives that you use, be sure they are diesel safe! Also avoid starter fluid like a plague! Even if it has diesel safe on its label. If you have a decompression lever use it to get the engine spinning faster, when released, your engine should catch quickly.