M3 MOTOR SWAPS? 01'X5 3.0

[bcredliner]

At the risk of getting blasted--

The lowest cost and the biggest gain would be with a nitrous package. I know of several 6 cylinder BMWs that use nitrous. Your gain in torque will be almost as much as horsepower.

Since you control when the nitrous is injected there is no addition stress on the engine when it is not in use. In addition, just by changing the jets you can increase or decrease the amount of the shot. A Nitrous package increasing horsepower by 100 and torque, say, 70-80 would be about a third of the price of a SS package. I don't know if there is a kit out there for similar engines to yours but if there is the cost will be even less.

Depending on what package you choose the install could be done in less than a day. You probably won't need a special tune or need to make other modifications like larger injectors or different plugs so it is very straightforward install.

A 10lb. bottle refill is abut $40. It is hard to estimate how many bottles you would use a month. On the average I use about a bottle and a half a month for a 150 shot. I only use it from stoplights, on ramps or sometimes on the freeway.

[Bmwtvboy]

Sorry, should have clarified. I am concerned about the possibility of having to choose replacement engine over 180k mile original rebuild issues. Engine is old, so I am curious about replacement values vs. rebuild value for another 5 year run. Quite happy with this motor selection although I would much prefer a diesel.

[bcredliner]

The only way I know to be sure which way to go is to disassemble your existing engine and prepare a cost to repair estimate. You can get some perspective of the shape your engine is in from compression and leakdown tests.

I suggest you will be more comfortable with rebuilding your engine as you know what it has been through and you should be comfortable that there should be not major work necessary over the next 5 years.

Unless the used engine is torn down you won't be sure of the condition and you won't know if it received TLC or was abused. You can have the same tests done plus a pressurized smoke test to get some idea. If I decided to go with a used engine it would have a warranty of some type and I would want to run it on an engine stand to cycle it to operating temp a couple of times and rev it to see if there are engine sounds that mean trouble lurks. It is likely the used engine won't be a plug and play swap. There will likely added costs.

Odds are the used engine will cost the least now but cost more to maintain over the 5 years. I don't know a way to determine which route the overall cost will be less.