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1987 BMW 735i 3.5l cranks with spark but will not start

Code reader for 1987 BMW 735i 3.5l? What brand, model, and where can I buy one? OBD I or OBDII is for 1988 and up. Without going to dealer for diagnostic I need to know the failing code and equivalent meaning.

The neighbors 735i will crank, has spark, has fuel smell when plug removed but will not start. I can't tell what the solution is without a code reader. It could be a sensor, fuel pressure regulator, fuel filter, etc. I have a BMW maintenance manual but it refers to the dealer for service. Otherwise it's tow it to dealer for diagnostic and perhaps repair. The vehicle had a water leak. I replaced the leaking radiator/heater hose ($144 dealer/ $79 auto part) and water pump ($59 auto part). Now it won't start. Had to charge the battery since neighbor had cranked engine for so long it was near 0v. I haven't checked compression on all cylinders yet. It may have a bad head gasket leaking water as well.

Thanks.

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Reply to
<volkswag
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M30 head gaskets and heads fail if you just look at them funny, let alone over heat them.

IF it was running fine before you did the work, and not overheated, youve probably just disconnected something inadvertantly.

Id first be checking the air flow sensor, then the 2 crank position sensors, which are connected at the rear of the engine. one is for injection and the other for spark.

Reply to
TPr

Is the temperature sensor working and plugged in properly?

Reply to
John Burns

Update: I pulled the BMW's oil drain plug today and about 2 or 3 gallons of water came out followed by another 2 and 1/2 gallons of water and oil mixture. You were right about the head gasket. Tomorrow I will begin to replace head, intake and exhaust gaskets. The gasket set is $159 at local auto parts store. I hope it's only a head gasket and not cracked cylinder head. It was surprising how fast the engine would absorb the water. It must be a large leak. How it gets past the piston and rings is even more surprising. If left overnight it would completely drain of course. I also wonder what damage was done by running vehicle with water in oil both driven 20 miles and idled for 5 minutes. Bad cam, crankshaft or rod bearings and oil pump damage? The 1987 BMW has well over 100k miles.

I have not experienced the BMW way to torque the heads: 43 lb ft and wait

20 minutes; 57 lb ft and run engine for 25 miles and finally torque 80 degrees from last position (not anymore lb ft measurement). I don't have the degree wheel but think I could adapt something similar. The Germans definitely do things differently. This torque is something like my motorcycle but nowhere near the 95 lb ft of my truck or van nor 105 lb ft torque of aluminum heads on my Corvette.
Reply to
<volkswag

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