Pulling Engine Block Drain Plug Yields No Drainage
- Thread starter Ohmess
- Start date
Mario L.
Well-Known Member
I reviewed your pics . . t-stat housing corrosion is totally normal . . these have to be made from the cheapest aluminum . ..
water pump debris, a bit of rust
Coolant was green Prestone, perfectly compatible with the era of these engines.
The coolant drain plug on the block is at the very bottom of the coolant jacket, which is at the bottom of the cylinder bores. A bit of sediment in the bottom of the water jackets will likely not effect cooling capcity on a stock engine used on the street.
I suggest you try to create a drain flow path out the plug opening , not disturb what is in the block and run it.
Note that BMW coolants today are blue, and formulated for their new family of engines, which have all sorts of lightweight alloys in the cooling system.
That's also why it is so expensive . . . An older m30 has no exotic metals in the cooling system, so refill with distilled water to a 40% coolant and water mixture, top it off with a bottle of Redline Water Wetter. The later breaks the surface tension of bubbles on a boiling surface, which is the top of the combustion chamber. This aids in heat transfer by increasing the amount of water contacting the hot surface.
drive it and enjoy . .
Mario L.
water pump debris, a bit of rust
Coolant was green Prestone, perfectly compatible with the era of these engines.
The coolant drain plug on the block is at the very bottom of the coolant jacket, which is at the bottom of the cylinder bores. A bit of sediment in the bottom of the water jackets will likely not effect cooling capcity on a stock engine used on the street.
I suggest you try to create a drain flow path out the plug opening , not disturb what is in the block and run it.
Note that BMW coolants today are blue, and formulated for their new family of engines, which have all sorts of lightweight alloys in the cooling system.
That's also why it is so expensive . . . An older m30 has no exotic metals in the cooling system, so refill with distilled water to a 40% coolant and water mixture, top it off with a bottle of Redline Water Wetter. The later breaks the surface tension of bubbles on a boiling surface, which is the top of the combustion chamber. This aids in heat transfer by increasing the amount of water contacting the hot surface.
drive it and enjoy . .
Mario L.
Mario L.
Well-Known Member
In the shop to keep things simple, in all BMWs we use BMW Antifreeze . . and it's what we stock.
If I were looking to save a few dollars, on an older car, before BMW had it's own coolant , I used the Prestone that was compatible with aluminum, and never had any issues.
Mario
I am happy to report that I have pierced the galvavic corrosion crap and bright green coolant is all over the place! I used a dremel and a really tiny drill bit, then worked the little hole into a bigger hole.
The restoration is back in gear! Every thing is flushed, and the new water pump went in tonight.
The restoration is back in gear! Every thing is flushed, and the new water pump went in tonight.
restart
Well-Known Member
Xcellent solution!
At the risk of being a buzzkill-
I would still be concerned about those coolant passages that you can't easily get to. I believe the more restricted susceptible points for blockage would be at the head gasket. We recently replaced a burnt cracked valve in my son's car. It was due to a blocked coolant passage right at the gasket. For ease of mind, I would measure the head surface temperature at identical points over each cylinder and compare the results. No wide variance- no problems. Point and shoot thermometer laser pointers are real cheap now and easy to use.
I would still be concerned about those coolant passages that you can't easily get to. I believe the more restricted susceptible points for blockage would be at the head gasket. We recently replaced a burnt cracked valve in my son's car. It was due to a blocked coolant passage right at the gasket. For ease of mind, I would measure the head surface temperature at identical points over each cylinder and compare the results. No wide variance- no problems. Point and shoot thermometer laser pointers are real cheap now and easy to use.
Hi Ed - I am concerned, but I have met Mario, been to his shop, and talked with him several times, and for now I am going to trust his view. I have in the back of my mind the fact that the mfg date on my head is mid range in terms of coolant passages. I have a line on a better head, and perhaps may go that way.
Again, triage on the restoration of an older car is pretty complex, and I have to prioritize. So, for now, I am going to put this lower on my list and hope for the best.