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Engine Rebuild Costs or Used Engine

15K views 10 replies 5 participants last post by  Lapelas 
#1 ·
I posted this thread in the general forum, but thought I would get some additional inputs from this forum. It was my first track day and when I noticed the oil light on I got off the track as soon as I could, but I did not want to just stop mid-track (I was already freaking out on how slow I was compared to the others):

http://forum.e46fanatics.com/showthread.php?p=8141918&posted=1#post8141918

Anyone on this forum have some guesses on costs to have an engine rebuilt due to oil pump failure, or how much it cost to drop in a used engine? How do you even go about finding a used engine? I am still waiting for the dealer to give me a diagnosis, but I think I will need to do one of the two alternatives.
 
#2 ·
Yo Jeff, sorry to hear. I know someone who's oil pump nut backed out twice on the same track at the same turn!

The lesson learned isn't so much as to not track your car, but rather knowing what to expect. Some 330s have the oil pump nut issue. It's all over the forums. Apparently, the 325s might gone under the radar on that interestingly enough.

Rebuild or used engine? I could give a little advice.

I recently rebuilt my M54B25 engine. Nope, nothing to do with the oil pump nut but rather after some 55 track events, one of the cylinders decided to give up. And this is a supercharged engine as well. 5 years running. 55 events. A good run.

I had several options:

1. used 3.0
2. new 3.0
3. used S54
4. new 2.5
5. used 2.5
6. rebuild mine

I dropped a 3.0L . I didn't want to deal with a 3.0 and a supercharged setup, since I am running on steptronic.

I dropped all "used" engine options. Why? Because you never know the true history of a used engine.

I dropped the S54 as well because I don't want to deal unforeseen issues, although the transplant is possible.

I dropped the new 2.5L, because I simply can't bear to let my engine go.

I went with the last option. And even more shocking, I went with all OEM parts. Bearings, pistons, rods etc. Why? Cos certainty is a crucial piece of information IMO. I know that on a OE engine setup with my supercharger, the car lasted for 5 years, 55 events. Now I know 5 years and 55 events from now, the car may need another rebuild. If I had replaced the internals with different aftermarket parts, that certainty will become an uncertainty.

That being said, I am not sure how committed are you to your car. If you just want to drive another couple of years, grab a used 3.0 from the junkyard and call it a day. If you want to work on a project car, perhaps rebuilding the 3.0 is the key.
 
#3 ·
Yo Jeff, sorry to hear. I know someone who's oil pump nut backed out twice on the same track at the same turn!

The lesson learned isn't so much as to not track your car, but rather knowing what to expect. Some 330s have the oil pump nut issue. It's all over the forums. Apparently, the 325s might gone under the radar on that interestingly enough.

Rebuild or used engine? I could give a little advice.

I recently rebuilt my M54B25 engine. Nope, nothing to do with the oil pump nut but rather after some 55 track events, one of the cylinders decided to give up. And this is a supercharged engine as well. 5 years running. 55 events. A good run.

I had several options:

1. used 3.0
2. new 3.0
3. used S54
4. new 2.5
5. used 2.5
6. rebuild mine

I dropped a 3.0L . I didn't want to deal with a 3.0 and a supercharged setup, since I am running on steptronic.

I dropped all "used" engine options. Why? Because you never know the true history of a used engine.

I dropped the S54 as well because I don't want to deal unforeseen issues, although the transplant is possible.

I dropped the new 2.5L, because I simply can't bear to let my engine go.

I went with the last option. And even more shocking, I went with all OEM parts. Bearings, pistons, rods etc. Why? Cos certainty is a crucial piece of information IMO. I know that on a OE engine setup with my supercharger, the car lasted for 5 years, 55 events. Now I know 5 years and 55 events from now, the car may need another rebuild. If I had replaced the internals with different aftermarket parts, that certainty will become an uncertainty.

That being said, I am not sure how committed are you to your car. If you just want to drive another couple of years, grab a used 3.0 from the junkyard and call it a day. If you want to work on a project car, perhaps rebuilding the 3.0 is the key.
Awesome advice! :bow:

From my experience, stock blocks are grossly under-rated.

The reason why 2.5s aren't having the same oil pump nut failures as 3.0s is because of the M54B30 crank has an undamped harmonic node at higher RPM. (Which happens to be the exact same crank found in the S52...see a trend here?)
 
#4 ·
Thanks for the advice, Paddle.Shift. However, I am not mechanically inclined. If I even pick up a wrench I will end up with a knuckle bleeding. I would like to keep the car at least another 4 or 5 years, so perhaps the used engine might be the way to go.

When the nut backed out on the person you know, did it toast the engine? Were the symptoms just the oil light coming on, or did it lock up the engine? More details, please, if you have any.

TIA
 
#5 ·
I've seen my fair share of oil pump failures. Anyway, I do know that my car was able to run for 116 seconds without oil pressure. At that point, #1 rod kicked itself right out and #6 was ready to go next. I've seen this exact scenario over and over for the past 5 or 6 years. Surprisingly, the valvetrain and head are never damaged (the lifters are usually shot).

If it was my car, I'd pull the pan and then take off the rod caps. That'll tell you the whole story.

As for the oil pump failure, you probably just have a case of the nut backing off. If you have a 330, then the shaft shears off. What is the fix? A. Buy the updated shaft that some people have made on their own. B. Go with the whole BMW Motorsport setup and plan on spending about $3K. Once you see the BMW Motorsport setup, it makes you wonder why BMW didn't do this right from the beginning. It's actually cheaper to make (when you look at the machining) over the street unit.
 
#6 ·
I had the dealer pull the pan and they did find the nut sitting there. They think the pump itself looks OK and the oil didn't show signs of anything suspicious (e.g. no metal filings). They are suggesting putting the nut back on, putting her back together, and see what happens. The dealer will only replace parts with OEM parts as far as I know. I am not sure I like this 'fix one thing and see' way of doing things. I never did hear anything bad sounds from the engine before it died, so hopefully I didn't throw any rods.

Is taking the rod caps off a straight-forward thing to do, or do you need to pull the engine out, or something complicated? I am calling the dealer in the AM, so if you can respond quick, that would be great!

TIA
 
#7 ·
The mechanic put the nut back on with loc-tite. They said they couldn't safety wire it (probably against their policy). Once the pump was working, they checked compression. Way low on all cylinders. They said the camshaft had serious signs of wear (metal shavings). I believe he said the bearings. The camshaft timing was way off causing the low compression. He didn't think it was due to the camshaft position sensor fault, which is what the error code is. He said it is a mechanical alignment issue. He does not know what could have caused this to occur.

Any thoughts? Could this be the position sensor failure causing low compression, even though the mechanic doesn't think so?
 
#8 ·
Pulling off the rod caps is really easy when you have the pan off. You just have to replace the rod bolts (they are cheap).

From your last post, you sound like you are in a typical dealer situation. They are just going to give up and give you the easiest thing they can do (replace the engine). If they end up replacing the engine, I'll take the block and timing cover as I have a block that's worn out and I need a decent one.
 
#9 ·
I thought I posted my latest findings from the dealer, but can't seem to find it, so here is what the dealer has found so far. The camshaft and bearings are compromised. 11 of 24 lifters need replacing. They mentioned something like a ledger, or something (?), too. They did a scope probe (camera on fiber) to look at the walls. They still had signs of the original cross-hatching so they think they are fine and have no reason to believe the pistons or rings are bad. Parts should be in and they are working on putting them in. I forgot to ask if these bad parts caused the low-compression on all cyclinders, or if there may still be problems (??). I hope this solves it! I am into this $5K so far (out of warranty). Get your oil pump nut re-tightened, or replaced with a third-party part!
 
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