(no subject)
NOV 10 - DEC 11
SURGERY
For the next month I would be embarking on a journey through the heart of the car.
BMW M42 motors are notorious for what they call "timing profile gasket" failures. The engineers decided it would be a wonderful idea if they made this gasket very susceptible to failure and extremely difficult to replace. Left unattended, coolant would disappear into the timing case areas, car would overheat, aluminum head would crack, etc.
Having no service records of the car, I think the best thing to do would be to assume that it has not been done. Odometer reads 136,074km; apparently these fail around 100,000km. I wasn't going to take any chances.
LETS GET STARTED!
There's a jungle of vacuum and coolant hoses I must battle through. The hoses don't look their best:
Not to mention according to various sources, the hoses are connected incorrectly. So whoever last put it back together didn't bother labelling or referring to a diagram and just put it back however his/her mood suited them. There's also this ugly thing:
What looks like a urinal is actually a throttle body heater installed on M42s sold in colder climates. This supposedly prevents the throttle plates from icing up in the winter time. I couldn't give a damn and decided that there was too much associated plumbing and mess to warrant me to keep this. I really wanted to removing it outright, but the 4 studs holding the intake to the throttle body were too long, so I just kept the heater plate as a "spacer". Plus if I decide I want to reinstall it in the future, it won't be so difficult.
So anyways, I pull off the intake manifold and take a peek into the valves:
The engine had been sucking in lots of oil from the crankcase vent into the intake, which made it very dirty and sad. Notice how oil managed to seep through the manifold gasket from the bottom. Replacing those gaskets.
Moving on to the top side:
Once the valve covers and timing case covers were removed, it was just a matter of rotating Cylinder 1 to TDC, marking and removing the cam sprockets, making sure the timing chain doesn't fall into the timing case (or death will ensue), removing the cams, exhaust manifold and finally the head bolts. Then we get this:
My genius way to keep the timing chain from falling was to zip tie them to the cam sprockets, thus also keeping their relation. THEY MUST NOT FALL.
My head gasket was in pretty decent shape for a 20 year old (assuming it hasn't been changed) and my profile gasket looks pretty good too:
Looks like the updated one. No matter I suppose, better safe than sorry. Although the safe side is definitely the expensive side. I went SUPER safe and replaced all important matters with OEM BMW stuff. That stupid little rubber gasket cost me $14. Head gasket, $120 (and backordered for a week). Head bolts, $93. My sanity, priceless.
Here's half the engine placed in my trunk:
They say rear-engine, rear-wheel-drive is the way to go anyways.
SURGERY
For the next month I would be embarking on a journey through the heart of the car.
BMW M42 motors are notorious for what they call "timing profile gasket" failures. The engineers decided it would be a wonderful idea if they made this gasket very susceptible to failure and extremely difficult to replace. Left unattended, coolant would disappear into the timing case areas, car would overheat, aluminum head would crack, etc.
Having no service records of the car, I think the best thing to do would be to assume that it has not been done. Odometer reads 136,074km; apparently these fail around 100,000km. I wasn't going to take any chances.
LETS GET STARTED!
There's a jungle of vacuum and coolant hoses I must battle through. The hoses don't look their best:
Not to mention according to various sources, the hoses are connected incorrectly. So whoever last put it back together didn't bother labelling or referring to a diagram and just put it back however his/her mood suited them. There's also this ugly thing:
What looks like a urinal is actually a throttle body heater installed on M42s sold in colder climates. This supposedly prevents the throttle plates from icing up in the winter time. I couldn't give a damn and decided that there was too much associated plumbing and mess to warrant me to keep this. I really wanted to removing it outright, but the 4 studs holding the intake to the throttle body were too long, so I just kept the heater plate as a "spacer". Plus if I decide I want to reinstall it in the future, it won't be so difficult.
So anyways, I pull off the intake manifold and take a peek into the valves:
The engine had been sucking in lots of oil from the crankcase vent into the intake, which made it very dirty and sad. Notice how oil managed to seep through the manifold gasket from the bottom. Replacing those gaskets.
Moving on to the top side:
Once the valve covers and timing case covers were removed, it was just a matter of rotating Cylinder 1 to TDC, marking and removing the cam sprockets, making sure the timing chain doesn't fall into the timing case (or death will ensue), removing the cams, exhaust manifold and finally the head bolts. Then we get this:
My genius way to keep the timing chain from falling was to zip tie them to the cam sprockets, thus also keeping their relation. THEY MUST NOT FALL.
My head gasket was in pretty decent shape for a 20 year old (assuming it hasn't been changed) and my profile gasket looks pretty good too:
Looks like the updated one. No matter I suppose, better safe than sorry. Although the safe side is definitely the expensive side. I went SUPER safe and replaced all important matters with OEM BMW stuff. That stupid little rubber gasket cost me $14. Head gasket, $120 (and backordered for a week). Head bolts, $93. My sanity, priceless.
Here's half the engine placed in my trunk:
They say rear-engine, rear-wheel-drive is the way to go anyways.