Cheap part woes

[pits]

Why do people buy and fit them? Mate of mine bought a lovely 36 328 sport, one day the radiator gave up so he went to the place where everyone goes for cheap parts, as opposed to spending a little more and using C3BMW or BMW themselves.

Radiator
Water pump
Thermostat
Thermostat housing
Someone fitted them, car overheated again, so someone else had a look and it overheated again.

Convinced him the block was cracked or head gasket was gone, and it was only a passing conversation that I decided they were talking bks and agreed to have a look at it.

Removed all the parts and refitted, go to bleed and it won't bleed, no heat out of heaters, so check heater valves, both dead...Replaced them, but still after 45 minutes idling away the car didn't overheat

Pressure tested it and it held pressure for 10 minutes, started it up and it created no pressure on tester, so head gasket ruled out and block not cracked, still baffled, took bottom hose off and got a small dribble out of it.


So went through it all again
New water pump is so stiff and really compared to BMW one, the wrong shape, so replaced it with second hand BMW one.

Checked thermostat housing, the little feed hole from left to right is partially blocked by swarf/cast scrap so it can't flow.

Checked thermostat, and it doesn't open, checked old BMW and it works.

So this car has been off the road a year, done 50 miles all because of cheap st parts, turns out it's the second faulty thermostat from same place.


Spent hours of my life going through this car, only to find cheap parts that don't work and have airlocked an engine that is a nightmare to bleed as it is.

Vent over.