Worn piston rings: now what?

[Avetiso]

So, the M54B30 from my parts car has low compression in cylinders 3, 5, and 6. All other cylinders are ~200psi, these are at 60-90 psi. Added oil to those cylinders, shot up to around 200 (except for 6, which only went up to 150).

So... what do I do with it? Probably not worth rebuilding... but I'm now caught staring at an engine that isn't really worth anything as a whole, and I'm kind of stumped.

Any worth to rebuilding it?

[wertyu78]

Rebuild it. It's a ton of fun. Feel free to ask me any questions. You can rebuild it 85% with all machine work for $1,200 or even less. Doesn't hurt to have a backup engine.

[Avetiso]

Rebuild it. It's a ton of fun. Feel free to ask me any questions. You can rebuild it 85% with all machine work for $1,200 or even less. Doesn't hurt to have a backup engine.

What did the machine work cost? My dad is a machinist so he could help me with it.

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[wertyu78]

What did the machine work cost? My dad is a machinist so he could help me with it.

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$500. If you use aftermarket bearings you could do it for $500 or so.


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[PirateZHP]

Do it, Dario!

[Avetiso]

$500. If you use aftermarket bearings you could do it for $500 or so.


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Not bad. So what exactly did you have to buy?

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[wertyu78]

Let me get on a PC and make a list


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[Smolck]

I'd rebuild it with forged rods and VAC pistons. Your crank is forged and can take a LOT of abuse, might as well beef up the weaker points. ARP bolts and hardware, a little head work, you now have a daily driver that will hit 8000rpm...

[midlandtech]

I'd rebuild it with forged rods and VAC pistons. Your crank is forged and can take a LOT of abuse, might as well beef up the weaker points. ARP bolts and hardware, a little head work, you now have a daily driver that will hit 8000rpm...

Yes make it a beast

taptalk + Note 3

[Avetiso]

I'd rebuild it with forged rods and VAC pistons. Your crank is forged and can take a LOT of abuse, might as well beef up the weaker points. ARP bolts and hardware, a little head work, you now have a daily driver that will hit 8000rpm...
I think I'd also need solid lifters.

The problem is that I was simply looking to sell the engine. I can't afford to build a performance once (as much as I'd love to), for all intents and purposes, I need to get this engine to be reliable with good compression and then just get my money back for it. I'll be asking much more for it than I was previously, so I don't think I'd lose money on the rebuild, it's just the time/work that I don't want to do.

[QC_ZHP]

If rebuilding is out then I say part out what you can and do this:

http://forum.e46fanatics.com/picture.php?albumid=5444&pictureid=33837
http://forum.e46fanatics.com/picture.php?albumid=5444&pictureid=33834

http://forum.e46fanatics.com/showthread.php?t=1028612

[wertyu78]

^this


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[slater]

that is awesome. really awesome.

[Smolck]

I wonder if it is a head gasket or valve issues. I have never seen piston rings wear out on these engines. Have you done a leak down test?

[Hornung418]

Get it tested professionally. See what the expert says. I would rebuild it. If tou need the cash sell it for what you need...or sell it to a shop who will rebuild it and use it as a replacement engine.

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[Johal E32]

How much would you sell it for as is?

[Avetiso]

I wonder if it is a head gasket or valve issues. I have never seen piston rings wear out on these engines. Have you done a leak down test?
No leakdown yet. I'm also hesitant to believe that 3 piston rings are gone at 109k, and 3 are good. The addition of oil made it seem like it was the rings, but further testing will be done.

Get it tested professionally. See what the expert says. I would rebuild it. If tou need the cash sell it for what you need...or sell it to a shop who will rebuild it and use it as a replacement engine.

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Who exactly would test it? I'm not hauling this thing around. The only way to even crank it is to hotwire the starter. :rofl I don't think any shops would be interested in it locally because there is a huge concentration of junkyards within 50 miles. You can find plenty of engines, so long as the price is right

How much would you sell it for as is?
Shoot me an offer via PM. This is pending further investigation, though, so I won't be selling it just yet.

[Hornung418]

Mmm.. understand now. Here there are only a few salvage yards. And definitely no e46s show up! I would rebuild and sell as an upgrade to the e36 crowd. If you have all the electronics it would make a good swap for an e30. I have a full DME EWS and locks/keys for a swap if you know someone locally

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[JupiterBMW]

Honestly, the time and money you'll invest just to get it torn down, source and purchase all the parts, would make it almost worthless.

Parting cars (or engines) almost never adds up when you consider the time and energy you spend getting dirty tearing stuff apart. Honestly, I would just dump it as is fairly inexpensively to someone else that wants it or needs it. I've parted out too many cars and engines to know that its just not worth it in the long run.

[Avetiso]

Honestly, the time and money you'll invest just to get it torn down, source and purchase all the parts, would make it almost worthless.

Parting cars (or engines) almost never adds up when you consider the time and energy you spend getting dirty tearing stuff apart. Honestly, I would just dump it as is fairly inexpensively to someone else that wants it or needs it. I've parted out too many cars and engines to know that its just not worth it in the long run.
I'm considering selling it as is. I'm still hoping I tested it wrong, so that is still pending, but I might rebuild it just for the heck of it during the summer. It'd be good mechanical experience.

[Asiah119]

I had, if I remember correctly, cylinders 2,3, and 5 fail compression and leakdown on my engine with 65k on the clock. I found a well spoken of and skilled shade-tree guy who used to work for a dealer but got downsized to work on my car. The two options that he presented to me were to pull the engine, tear it down, and see what all was wrong. Option two was to look for a salvage yard w a zhp engine and do a swap. He estimated both to run somewhere in the $4,000 range (parts labor, everything). I went with a swap, and told myself that I would be able to sell the old engine to a track guy or e36 guy who would want a zhp engine and recoup at least a decent portion of my money. The tear-down and rebuild had the potential to cost less, but also had the risk of being a lot more if it wasn't just the rings. He managed to find an engine with about the same mileage from the same year.

We did the swap, and other than the salvage yard dragging their feet on shipping the motor, the swap went pretty quickly. I tried to sell the old engine for about a year and a half before my mechanic found someone at a CCA meeting who was interested. At that point, I was so glad to have someone who wanted it, and wanted to get the motor out of my mechanic's garage that I let it go for significantly less than I had initially hoped. I had gotten a couple of bites on e46fanatics posts trying to sell, but it usually ended up being a guy who was just thinking about doing a swap, but not really interested in doing it now. There were PLENTY of people who just wanted the cams.

All things considered, if I could do it again, I would do the rebuild. I was getting to the point where I was considering hauling the old engine back to my house and doing a rebuild in my basement for the experience, and to try to sell.