Is it worth rebuilding? Or should i buy a new motor?
Posted July 16, 2014 - 09:38 PM
Posted July 17, 2014 - 12:36 AM
Depends on how many hours are on it. When you start getting over 4,000 hours you can figure the injection pump and injectors are running on their last legs. It also depends on what is wrong with the engine. If it just needs rings and bearings it could easily be worth rebuilding.
You didn't give us much information to go on.
- speedex99gt said thank you
Posted July 17, 2014 - 07:48 AM
It has less than 1,000 hours on it. it smokes and has a bunch of blowby.
Posted July 17, 2014 - 09:35 AM
In that case it would surely be worth taking the time to open up and see what is going on. I know I would.
Buy yourself some zip-lock bags and a felt pen. Place parts in a bag and mark where they came from. Will save you or the person who puts it back together a lot of head scratching down the road.
Posted July 17, 2014 - 11:54 AM
Have you ever had one apart before?
Posted August 17, 2015 - 09:59 AM
Posted August 17, 2015 - 08:35 PM
Check the bores before signing up for machine work. We had one came in that was overheated and all it needed was the head checked for cracks, honed and new rings as the old ones had lost thier temper. Kubotas are designed so that when ran hot, the rings loose their temper and lower the compression, sometimes to the point she wont run at all. This is the protect the engine from more severe damage. Sometimes you will find the middle piston slighly melted if the overheating persisted for a longer duration of time. First step is to tear her down as far as getting the pistons and rods up and out, then start measuring for size by the book and looking for damage. Only and only then will you know if machine work is needed/required or if it can be fixed fairly easily. At minimum you need to plan on a bearing set, new rings, head gasket, taking head to machine shop for magnaflux to check for cracks, new thermostat and associated gaskets. If its starting ok, I would probably first start with a compression test and leak down test to see what the cylinders are doing. Do you know if it was run hot? Has it just sat without use for a long time? Sitting without use can cause rings to stick, this can cause loads of blow by till either the engine gets a top end rebuild or sometimes working the engine hard will free up sticking rings in a diesel. Bottom line is, yes it worth rebuilding, but you need to do some more homework to see whats going on and then go from there.