Saving a S54 From Parting Out.

[Anri]

Clean parts and clean assembly is a must providing the best service to customers.

[sapote]

Short skirt piston like S54 tends to have more wear due to higher rubbing force.
You are right that the grooves around the piston retain oil and helps.

[sapote]

Anri,
I believe you have found the root cause of the gasket eating problem: engine high temperature due to cooling channels blockage.
The question is how to heat sink the multiple stacked gaskets to offset the 0.021” machined block, in order to keep the gaskets eating monster away.

[Anri]

Short skirt piston like.

Far more important to say is the lower 1.52 Rod Ratio which is very bad
for the piston trying to cock the cyl wall. On top add the short skirt.

But this proves that if you do coating and the groves there is no problem at all..

On S38 B35 with Connecting Rod ratio of 1.71 (were S54 will only dream to get)
the damn skirts have scores on the exhaust side...and less on the intake.

S38 pistons have no coating, and the groves are Coarse and the reason to get
scored.

Regards,
Anri

[Anri]

Anri,
I believe you have found the root cause of the gasket eating problem: engine high temperature due to cooling channels blockage.
The question is how to heat sink the multiple stacked gaskets to offset the 0.021” machined block, in order to keep the gaskets eating monster away.

Sapote,

The blockage was not the primary reason but certainly does not help.

The main reason as I mentioned above is the fact that the left over impeller
count like may be 2max I don't have the broken water pump infront
of me but I found 2 impeller pieces in the engine block and 1 in the head.

So from total of 5 blades only 2 left! At 2 the water flow is disaster and with
the combination of the 2Bar cap to keep the cooling system under hi pressure
in order to raise the boiling point makes the water move slow to almost none
and this is the pure evidence why the engine suffered maaaaasive overheat but
with water inside. I'm sure that the pressure exceeded 2Bars and the expansion
tank was releasing/splashing coolant but the engine never lost water.

When I put the head to inspect it as-is the natural warpage was nearly none!
I don't remember already but it was 1-2thou across...which gives me the indication
that the engine never lost water/coolant, or otherwise the head warpage would
have been far more than what I found.

Shortly I will compare the water pump and why S54/M3 owners should NEVER
use any other water pump than OEM.


Regards,
Anri

[Anri]

For the last 10-15engines I started doing Molybdenum skirt coating
in-house mandatory on my std engine rebuild/s. Its either to restore
the S54 OEM or aftermarket unless they are ordered with.
Many good benefits to be had.


Moving forward.


Regards,
Anri

[Anri]

Coating piston skirt and coating bearings is std
in my builds.

Regards,
Anri

[Anri]

The crankshaft gear/snout has been cleaned/machined for the new
seal to sit on brand new surface.

[cobra]

Big respect for the attention to detail.

I have an N52 powered bmw that currently has a leaky head gasket from overheating one time. Been running for 20,000 miles like this, it leaks combustion gasses into the coolant and requires topping up with water every 1k miles. I'd like to do a proper repair but worried now what would be involved. Machine both the head and block? It's a magnesium block.

[Nate047]

Great thread with great info, thank you for sharing all this.

[Anri]

Big respect for the attention to detail.

I have an N52 powered bmw that currently has a leaky head gasket from overheating one time. Been running for 20,000 miles like this, it leaks combustion gasses into the coolant and requires topping up with water every 1k miles. I'd like to do a proper repair but worried now what would be involved. Machine both the head and block? It's a magnesium block.

Thanks Cobra.

The thing with engine/s in general is that you never know
how much damage has been done...and what parts can
be saved?

All comes down to do you want to keep the car...? If you
have a space to freeze the car and you decide to Wrench it out
on your own sure why not.

Something interesting I monitor and collect statistic and fact is
how much people let those New BMWs go...
If you go to the LQK parts web page and look at the Inventory you
will be shocked....just pay attention here and there. You will see
2015 cars end up in the scrap yard all intact cars some with
accident sure but most end up there with Engine problem and
not worth to fix..

All BMW M Cars/Engines are special and they keep value and its
worth the sweat to save, repair, restore them.

New cars are throw away item. Engines are absolute crap
with short life span and nothing but issues. The Value of
those cars determine if it's worth spending money or not.

I have lady customer with E90 4 door and she lost compression
on 2 cyl 1 owner man, never overheated the damn thing...and
now she is on the line to scrap the car and get the New BMW.
If decided to rebuild her engine its 8-10k ticket...

Scott's, wife got brand New 15' X3 drove it hard 100k miles the engine
lost compression same story....what do we do ? We got short block
from BMW swap accessories and keep going. Me rebuilding this
N20 engine?....It does not make financial sense.....

I still have connections in the old BMW dealer I use to work
long time ago. The Mechanics are telling me they had cases
when they replace remanufacture engines shipped from Germany
when they install them few cases they start with a knock !!!!

This Industry has become nothing but one large joke and
BMW certified technicians are simple parts replacer people !!!!

I never had a call for M54 engine rebuild....people sent to junk
yard and get New Honda or New BMW etc..

It's the reality.

Regards,
Anri

[sapote]

it leaks combustion gasses into the coolant and requires topping up with water every 1k miles.

If combustion gas leaking into the coolant is confirmed, then the coolant tank should rupture by the high pressure.

I don't think the block needs to be machined for flatness, but check the head for crack between the valve seats and water channels, and its flatness. Worst case just replace with a good used head from ebay.

[George Hill]

Big respect for the attention to detail.

I have an N52 powered bmw that currently has a leaky head gasket from overheating one time. Been running for 20,000 miles like this, it leaks combustion gasses into the coolant and requires topping up with water every 1k miles. I'd like to do a proper repair but worried now what would be involved. Machine both the head and block? It's a magnesium block.

Anri, is sharing a bunch of wisdom for sure.

Rebuild an S54? Yes! An N52... it would have to be for the love of the job IMO. Those engines are really solid, I would be hard pressed to justify all of that when you could get a used engine and just swap them.

I just quoted a HG on an M54 vs replacing with a used engine... slightly cheaper to do a used engine. And both of those options were about 2/3 a brand new reman engine from BMW.

[eacmen]

Coating piston skirt and coating bearings is std
in my builds.

Regards,
Anri

Are these rod bearings? Never saw s54 rod bearings with a groove in them like that.

[Anri]

Are these rod bearings?

These are Main bearings.

Regards,
Anri