Water Gone Into Engine

[jarance]

Hi Jarance,

Compression test will just tells you there is a wear on the piston rings and valve seats. Hardly to show there is leaks between the water jacket and the combustion chamber.

If the water really get into the combustion chamber, the mechanic will tells u is hydraulic lock!

Actually, if there is a hairline crack between the piston and the water line (jacket), the compression test can roughly tell there is a leak without having to remove the cylinder head. However, it is not conclusive until the cylinder head is removed and dye penetrant check is done or use flaw detection via ultrasonic devices.

Have to agree with you that the compression test is basically meant for piston rings and valve seats.

 

[prime5]

wanted to ask this..would opening the radiator cap to check the water level let the air in and cause bubble thus block the water to run smoothly?

 

[bimmerholic]

wanted to ask this..would opening the radiator cap to check the water level let the air in and cause bubble thus block the water to run smoothly?

Not if you opened it when it's cold. (anyways you are only supposed to open it when it's cold). But if you;re topping it up to the brim (full), its better to unscrew the bleed screw to let the air bubbles out. Better still have the engine cranked up while bleeding.

 

[prime5]

Not if you opened it when it's cold. (anyways you are only supposed to open it when it's cold). But if you;re topping it up to the brim (full), its better to unscrew the bleed screw to let the air bubbles out. Better still have the engine cranked up while bleeding.

u mean let the car runs idle while i put in water?and also unscrew the bleed screw while doing this so that let the air out?when it is full, just rescrew the bleed screw and the radiator cap and it is good to go?

 

[kgb]

u mean let the car runs idle while i put in water?and also unscrew the bleed screw while doing this so that let the air out?when it is full, just rescrew the bleed screw and the radiator cap and it is good to go?

i believe it is bests to screw back bleeder screw while engine is running and while you are still pouring water in.

 

[jarance]

i believe it is bests to screw back bleeder screw while engine is running and while you are still pouring water in.

No, prime5 method is the best to purge the airlock in the cooling system. but MUST do it while the engine is COLD.

I have seen my mechanic actually open and removed the bleeder nut. Then they start the engine and rev the engine hard. They will also put a plastic cap over the bleeder hole to prevent the water from shooting up in the air when the engine speed is high. When the water level is dropping they will keep adding water while purging the air the cooling system. Again while the engine is still COLD.

 

[bimmerholic]

u mean let the car runs idle while i put in water?and also unscrew the bleed screw while doing this so that let the air out?when it is full, just rescrew the bleed screw and the radiator cap and it is good to go?

yes exactly. you re-screw the bleed screw when you no longer see bubbles forming at the bleed screw hole.

P/S: Don't you think we're screwing a bit too many screws...we should look at other opportunities when talking about screwing

 

[conan]

Hi guys,

Anyone can recommend a mechanic in KL/PJ who can do the compression test?

Thanks

 

[fabianyee]

The M52 aluminum alloy block has this weakness whereby the cylinder headbolt thread will come off or loosen due to age and overheating... When this happened, the engine would overheat randomly and also water would find its way into the combustion chamber. The solution is to bore out the thread hole and put in a metal insert (or heli-coil) for the thread. And to do that means time for top or complete overhaul...

 

[initialM]

The M52 aluminum alloy block has this weakness whereby the cylinder headbolt thread will come off or loosen due to age and overheating... When this happened, the engine would overheat randomly and also water would find its way into the combustion chamber. The solution is to bore out the thread hole and put in a metal insert (or heli-coil) for the thread. And to do that means time for top or complete overhaul...

does this apply to M54 as well?

 

[alantiong]

YUP it does apply on all aluminumbased block & head by bmw!

The M52 aluminum alloy block has this weakness whereby the cylinder headbolt thread will come off or loosen due to age and overheating... When this happened, the engine would overheat randomly and also water would find its way into the combustion chamber. The solution is to bore out the thread hole and put in a metal insert (or heli-coil) for the thread. And to do that means time for top or complete overhaul...

 

[fabianyee]

YUP it does apply on all aluminumbased block & head by bmw!

Most or all BMW cylinder heads are aluminum alloy... only the blocks are made of lighter materials as the years go by... Most reliable is still the cast iron block... can technically last a lifetime.. Then alum alloy block came along due to lighter weight... After that is the magnesium alloy block... Haven't heard of any major weaknesses of the magnesium.. or maybe its time not come yet..

 

[infinityKL]

E39 528i 2000 Double Vanos

Same issue, cylinder head hairline crack, replaced the cylinder head(2.8K)... within months new cyl(no 5) head cracked again!!

this is even after change the whole freaking cooling system and other related parts...

!@#$$%%@@!!@%

 

[infinityKL]

 

[initialM]

Double vanos engine is more delicate. Mine is good as rock. The secret is preventive maintenance.
All must be done with a good & experience mechanic

 

[zank]

Wouldnt it better to replace with M54 half cut than spend RM5K for the overhaul??