92 850i - Overheat

I'm looking at buying a '92 BMW 850i for $5000 with only 94000 miles. But the catch is that it has been overheated due to a broken aux wyer pump. The water pump has been replaced by the current owner whom I'm possibly buying from but now the engine is acting up. He says that some of the cylinders aren't firing, but I don't think that's it. There is a "clank" noise when the car runs every 10 seconds or so. Can anyone diagnose this or have any ideas on what could be damaged from it overheating. Other than that, the car is amazing. He has Remus cat-back exhausts, ac shnitzer(?) lowering kit, cross drilled rotors, and a short throw kit. I really am interested in trading my e34 540i for this car. Can someone please tell me if this will be a fix that would be less than $1000

Originally Posted by cmellios16

I'm looking at buying a '92 BMW 850i for $5000 with only 94000 miles. But the catch is that it has been overheated due to a broken aux wyer pump. The water pump has been replaced by the current owner whom I'm possibly buying from but now the engine is acting up. He says that some of the cylinders aren't firing, but I don't think that's it. There is a "clank" noise when the car runs every 10 seconds or so. Can anyone diagnose this or have any ideas on what could be damaged from it overheating. Other than that, the car is amazing. He has Remus cat-back exhausts, ac shnitzer(?) lowering kit, cross drilled rotors, and a short throw kit. I really am interested in trading my e34 540i for this car. Can someone please tell me if this will be a fix that would be less than $1000

Don't walk, but run AWAY from this car. An "overheated" 850 is a very likely candidate for cylinder problems. What happens is the cylinders become oval instead of being round, and you wind up with loss of compression and very high oil usage. The "fix" can be well into the several thousand dollar range.

Yeah true, but instead of keeping the current engine. Would it be worth it to buy another v12 engine? The car is pristine other than that.

It is not that easy to determine based on the assessment of a non 8 owner. What might seem to be perfect except that one "little" thing might actually be very expensive in the long run.
The only problem I see with what you have described is that if you did indeed need another engine, you are left with getting one that potentially has the same problem.
A "decent" engine is in the neighborhood of $2000 - $2500 and unless you can install one of these yourself, it can get pricey. I have done a number of engine swaps on these cars and can remove an "old" one and install a new "one" in about 9-10 hours.
Take the car to a BMW dealer and have them do a leak-down test. This will help determine if there are any major issues with the car. Also a hook-up to the diagnostic computer will tell you if there are any other "issues" with this car. There is also a "Pre-Purchase" checklist available online that can give you a hint of what you need to look out for ( http://www.wuffer.ca/index.php/downl...ellaneous.html ).
As for the Auxillary Water pump causing overheating - that really only happens if the outlets on that pump break and you loose all the coolant from it. The Aux Pump is really only for the heater and A/C on these cars.

Originally Posted by TxGr8White

It is not that easy to determine based on the assessment of a non 8 owner. What might seem to be perfect except that one "little" thing might actually be very expensive in the long run.
The only problem I see with what you have described is that if you did indeed need another engine, you are left with getting one that potentially has the same problem.
A "decent" engine is in the neighborhood of $2000 - $2500 and unless you can install one of these yourself, it can get pricey. I have done a number of engine swaps on these cars and can remove an "old" one and install a new "one" in about 9-10 hours.
Take the car to a BMW dealer and have them do a leak-down test. This will help determine if there are any major issues with the car. Also a hook-up to the diagnostic computer will tell you if there are any other "issues" with this car. There is also a "Pre-Purchase" checklist available online that can give you a hint of what you need to look out for ( http://www.wuffer.ca/index.php/downl...ellaneous.html ).
As for the Auxillary Water pump causing overheating - that really only happens if the outlets on that pump break and you loose all the coolant from it. The Aux Pump is really only for the heater and A/C on these cars.

Sorry I didn't specify. The auxiliary water pump hoses "blew" causing the drainage of coolant which then led to the overheat. The reason I'm still somewhat interested in this car is because it'll be worth almost 3 times the amount because it only has about 94k miles and everything cosmetic on the car has been changed or modified. If does help, I can post a video of what the engine sounds like. It's only 12ish seconds but you get the full understanding of what I'm trying to describe

Sounds like a potential disaster. If i was you don't buy teh car. period. An overheated engine can have a warped head.