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Discussion Starter · #1 ·
I've had my 2000 M5 for about two years now. About a month ago I noticed occasional loss of power and white smoke coming from the tailpipes. I had the car towed to an independent shop that specializes in BMW repair and my mechanic found the intake full of oil. He did a compression check and found low compression in two cylinders. He says there is clearly leaking by rings/pistons, so a pretty major repair is going to be necessary. Anybody been through this experience before? I spoke with my local BMW dealer service department and the cost of a new engine (part only) from BMW is $23,500! Not a good investment for a car that's worth mid-teens at best. Anybody have a good USA source for used engines that they'd recommend?
 

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Its a big decision and possibly a huge cost so investigate carefully on your options. You need at least 2 rings but you might as well do them all and you'd have to consider if there was wear on the bearings or crank due to what I assume is coolant in the oil (white smoke).
 

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You have low compression on two cylinder,power loss.
The options are:

If we are talking about white smoke,it burns water.That means either head gasket or c rack in the cylinder or head.
If it is blue smoke:piston rings,piston or cylinder issue...

A CO test to the coolant reveals if it burns water...

Are the cylinders that have compression loss next to eachother?
 

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My recommendation is getting a complete compression test performed WITH a print out stating the exact measured compression values, before you determine it is the engine.

Questions:

1. Any coolant loss?
2. Oil loss?
3. What oil are you using?
4. What is the milage on the engine?
5. What is the product date of the car?
6. What do the spark plugs look like? Worn out? New? White colored? Dark black?
7. Any check engine light code?
8. What octane level fuel are you using?

The S62 engine is very reliable; it has a dual head gasket. Unless the engine is abused, seen oil starvation, or ran to lean, it shouldn't be a cause of failure.
 

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If you have the time and some experience, replacing pistons isn't a hugely challenging process - but you have to be confident in yourself. If you're not, it could make things way worse. But if BMW is going to charge you $23,000 to replace the engine, you might as well give it a shot. If not, I call the intake cover!
 

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Discussion Starter · #8 ·
Time for Replacement Engine?

Thanks for all the good feedback. I did get a compression test report that reads as follows:

Cylinder
1 125
2 200
3 160
4 110
5 150
6 160
7 160
8 160

I didn't notice any coolant loss, but there was oil on the garage floor. Not much, but enough to show leakage.
I have been using the Castrol oil available from BMW specially made for the M5
Mileage is 90,000
Not sure of the production date of the car. It is still sitting at the repair shop so I can't check it right now.
Regarding spark plug condition, I haven't looked lately, so I'm not sure.
Fuel octane has been 89
Engine codes that were read involved the secondary air system and engine misfires on cylinders 2, 3, and 5.
The obstructed secondary air codes have come up before, but the mechanic doesn't think that issue is related to the current problem.

I've looked online for replacement engines but am leery of buying another engine with problems. Who knows where some of these engines come from. Some were clearly from totaled M5s and I assume the engine could also have damage. Some come with no warranty at all, others offer 30 days.

Found one from an auto parts company out of Florida. They located a replacement engine in Ohio-- 30,000 miles on it with a one-year warranty for $10,000. Better than the BMW price, but still a lot of money.

If this happened to your M5, what would you do? Looking for any advice you have to offer.

Thanks!
 

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Well, do you feel like you have the mechanical know-how to pull an engine, replace the piston rings, and put it back in? If you properly label everything, it's really not that daunting of a task - but it certainly seems that way when you peer under the hood. But that requires time, and it's time most people don't have.

For $10k, you can buy a pretty nice (used) car. Personally, I'd probably invest in a DD and set the M5 aside for future fixes or a part out. I couldn't justify spending $10k on a new engine just randomly. It would either be a slow fix-it process, or a part out.
 

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First I would start with a diagnosis!Boroscope inspection will reveal alot how the combustion chambers and cylinder walls look like!
Pressure test on the cooling system also if there happens to be CO in the coolant.
Run a leakage test on all cylinders.

If the block is ok,I would rebuild the engine,less than the 10k for another engine.And you know what you deal with!
 
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