1994 M50 Detonation Issue

[joeoldschool]

Help - 1994 M50 Detonation Issue

Hello all - could one of my fello do it yourself nerds help me with some advice? I have narrowed down a detonation problem with my m5o motor in my 1994 525i to two things. Faulty Knock sensors or a Faulty crank position sensor. I'm experiencing detonation at light loads and when the engine is at normal running tempreture. I'm fairly sure I have a too lean of a fuel misture that is being caused by a faulty in put. I'm to cheap to by the code reader becasue flatly - I need the money for the new sensors. Any advice on other possible options? bye the way - it isn't a fuel or an Octane issue, and my plugs are spec Bosch plugs that are recomended OEM units. THANKS

 

[m5runner]

if the crank sensors were bad, your car wouldn't even start. check engine light perhaps? how's the mass air flow sensor? what else have you checked?

 

[joeoldschool]

thanks for the reply. My Check Engine light comes on intermitantly. The pinging does not occur until the engine is near opperating tempreture and occurs between 1,700 and 2,500 RPM with light loads. I do not have any diagnostic tools at this point. You mentioned Mass Air Flow sensor... how would I check this?

 

[m5runner]

if your check engine light comes on you have an emission issue. you are going to have to get the codes pulled to narrow down the issue. i'm not sure how to check the mass air flow sensor but maybe you can do a little research on it. if i were you, i'd buy the reader, pull the codes and sell it back if you need to buy parts with the money.

 

[joeoldschool]

Many thanks for the input. It helps solidify my direction. Code reader it is and besides - I'm sure I'll need it again.

Joeoldschool - kepping the 5 ALIVE!

 

[Big Daddy]

Actually it is possible for the engine to run with a faulty Crankshaft Position Sensor, here are some of the codes that indicate you have a problem with that sensor, but M5runner is correct in that you need to obtain the codes as it could be a number of things.

1243 Crankshaft Position Sensor This code is triggered when the crank angle sensor is disconnected, or generates a signal that is not accurate when compared to the other engine sensors.

1244 Camshaft Position Sensor Displayed when the signal from the camshaft pulse generator is out of spec or absent. May indicate a problem with the injector side of the DME output stage.

 

[m5runner]

good choice. keep us posted