LD28 lifespan, how to know when to rebuild

[blueeagle]

I have a 81 maxima with the LD28 at around 280,000 miles still starts in the cold and gets great fuel mileage, I only have to add about 1 quart of oil between oil changers every 3000. I was wondering how you know when it is time to rebuild a diesel, and where to get a rebuild kit?

I am going to be building a 1976 280z 2+2 turbo LD28 hybrid electric out of the engine in the maxima in the near future. Would it be advisable to rebuilt at that time?

How many miles can a cared for LD28 go?

[diesel-man]

I have a bunch of Maxi diesels but I only have a few over 200K. I personally saw one that had 348K on the speedo.

I would say that the logical answer is that there are more running Maxi diesel engines than there are licensable cars. It is cheaper to get a used engine than to rebuild one.

The "rebuild kit" is all individual parts. Some posts on this forum are about head gaskets being had to find. I would say that you have another hundred thousand to go. Buy a running engine for $500 and sell your old crank for $300. Here on the East Coast rust makes the decision for us. Anyone in an area that gets a lot of snow, or is very near to the ocean, is in this boat. Maybe in California or Arizona etc. they may have the car outlast the engine, but for the other 75% of us...this is not the case.

[asavage]

The cars fall apart before the engines do around here in the Great Pacific NorthWet.

However, I seem to see a few in JYs with stripped IP belts, so they may get to a certain level of decrepitness, and one morning when it doesn't start and the local shop shrugs and says, "Injection pump rebuild, $1500," the car gets scrapped.

The simple answer to the Q, "when does a diesel need to be rebuilt," is

• a) when a compression test reveals that the comrpession is low enough that it is hard to start. This is beyond mere "hard starting", because a lot of factors can affect diesel starting. A compression test's result is the determining factor;
• b) when the oil consumption (leak(s) or blue smoke) reaches your "ouch" threshold;
• c) when the bearings are making a racket (and low oil pressure).

Anything else, you can deal with separately without regrinding the crank or re-linering the top end. For example, IP belt replacement, camshaft timing chain replacement, head gasket issues (corrosion due to lack of cooling system maintenance), etc.

Hard parts for the LD2x are still available (pistons, liners, rings, bearings), but soft parts are drying up fairly quickly (gaskets, hoses, sensors).