02 745i - To buy or not to buy?

[hacksaw]

Hello,

Beamer newbie here looking to purchase my first one. I've driven Chevy's fords and Jeeps my whole life.

I have the opportunity to buy a 745i for a smoking deal of a price. The problem is that the gentleman that owns it says he ran it through some water and it won't roll over anymore. My first assumption would by a hydraulic lock. He is selling the car not running.

I am very mechanically inclined but, once again, have no experience with BMW's. How difficult is swapping a motor if there is internal damage? I am assuming that pulling the motor it comes out through the top since it is a RWD car (like every truck and American sports car I have owned.)

How susceptible are these motors to internal damage to hydro-locking? I know in the old jeeps and trucks we would submerge them, pull the plugs crank it over and spray some WD-40 in the holes and we were good to go after an oil change.

The problem: I have no idea the tendencies of these cars. I have looked online and only found a few hydro-lock stories.

I have also read that the motors in these cars are quite expensive to replace compared to other BMW motors (looking at remans online they are ~6k.)

I have built many engines in the past, SBC, SBF, BBC BBF and varios inline 6 motors for jeeps, like I said I feel I am fairly well versed when it comes to turning wrenches.

Is there anything that I should be aware of when looking at this car. However, I don't want to pull the plugs at this gentlemans place of residence and attempt to get it running before purchasing for obvious reasons. So, I guess that leads me to be in quite the pickle.

I would be getting the car for about 1/3 of the NADA book value on it. Car has 110k miles on it and comes with Asanti 22" wheels and is in mint condition.

Thoughts?

[marti5]

Has he indicated how much water he ran through ?, at a 1/3 of the price I would buy it anyway and if the engine was shot I would break it and sell the parts....but even with a hydro lock it can be repaired.....ive done one before, drained if etc like you have said above...

[brettski]

Ask for more information about the depth of water, the speed he was doing, whether it was fresh or salt water and how long ago this happened. Even as a parts car it will be worth the money if you can afford the time and space.

[Torque]

An engine is an engine, rebuilding one isn't any more difficult than what you're used to: what I am worried about though is all the electronics (both the ones associated with the engine and all interior as well) ... are you sure it wasn't in a flood somewhere instead of just "being driven through water"?

Either way, just be sure everything else works at the minimum ... engine parts can be purchased for a decent price: it's the electronics that will make it cost 3 times the book value if they're gone.

[marti5]

Also be aware that the early e65/66 had a lot of electrical gremlins,the predominant one being the idrive.

[Ashot]

do not buy 02-03 7's. all the problems and the headaches you will deal with is not worth any smoking deals. do your research before buying. and dnt even thin about it. if you do buy it, and part it out, pm me i could use some parts.

[beamers4life]

Yeah thats what ive heard to is that 02-03 had serious electronic problems but a deal that good i might would chance it

[darkhorse737]

Bimmer engines are pretty much waterproof till the water level reached cylinder head height. I would lean more to flood damage than "ran through water".

Hydraulic lock or a waterlogged engine will show abnormally high oil level or water actually in the crankcase.... if we assume the oil hasn't been drained yet.

If it hasnt... then how long has it been sitting in that state? The longer it stays waterlogged, the more rust internally you need to contend with also Consider also tranny has a breather pipe/hose. Does that mean the tranny sustained damage too????

Flood damage of course connotes a horde of electrical probs that you will have to deal with, and that will not be an easy task.

P.S. If your assumption is hydraulic lock... IRREGARDLESS of what seller claims, consider hydraulic lock resulting from a blown head gasket where water collects in 1 or more cylinders - that mishap results in bent or broken con rods and pistons.