Need help in diagnosing engine problem BMW E39 520i
Discussion
Hello everyone
I am new to PistonHeads so I apologise in advance if I'm doing something wrong.
I am very keen to buy a 520i E39 2003 model I found online but the owner stated that sometimes when the engine(M54B22) is cold it vibrates when switched on. But if it is switched off and switched on again the problem goes away. Hence I was wondering what the problem might be(I guess it's something electronic). I have already seen the car upclose and test driven it and did not find any issues.
Thank you
I am new to PistonHeads so I apologise in advance if I'm doing something wrong.
I am very keen to buy a 520i E39 2003 model I found online but the owner stated that sometimes when the engine(M54B22) is cold it vibrates when switched on. But if it is switched off and switched on again the problem goes away. Hence I was wondering what the problem might be(I guess it's something electronic). I have already seen the car upclose and test driven it and did not find any issues.
Thank you
That could well be an electrical issue, but could be easy or REALLY difficult to actually find the problem with.
From your description, it sounds like a missfire & would therefore likely bring up a fault code to assist with where to start at least.
Could be as simple as a plug not connected quite right, could be as big as an ECU replacement.
My personal advice would be if you are asking the question, that means you didn't know what I have said above & so my best advice to you would be to leave it well alone as I am guessing you would be paying someone else to do it. Intermittent faults are the hardest to diagnose.
From your description, it sounds like a missfire & would therefore likely bring up a fault code to assist with where to start at least.
Could be as simple as a plug not connected quite right, could be as big as an ECU replacement.
My personal advice would be if you are asking the question, that means you didn't know what I have said above & so my best advice to you would be to leave it well alone as I am guessing you would be paying someone else to do it. Intermittent faults are the hardest to diagnose.
Hello
Thank you for your quick reply and your advice. While my knowledge on cars is somewhat extensive I have to say I'm not as extensively prepared on the mechanical side. What boggles me about the misfire part is that I suppose the misfire wouldn't be fixed by a simple switching on and off. Also I was planning to bring an OBD2 reader with me next time I see the car to check the error codes
Once again, thank you
Thank you for your quick reply and your advice. While my knowledge on cars is somewhat extensive I have to say I'm not as extensively prepared on the mechanical side. What boggles me about the misfire part is that I suppose the misfire wouldn't be fixed by a simple switching on and off. Also I was planning to bring an OBD2 reader with me next time I see the car to check the error codes
Once again, thank you
More than likely a bad coil/coils; poor spark plugs or the intake boot from MAF to throttle body is split and letting air in after the MAF and the engine is running lean
a) get the codes read (INPA) and see the live data and b) check the air intake boots, vac lines and DISA for failing/failed rubber parts and replace as necessary
a) get the codes read (INPA) and see the live data and b) check the air intake boots, vac lines and DISA for failing/failed rubber parts and replace as necessary
Cristian02 said:
Hello
Thank you for your quick reply and your advice. While my knowledge on cars is somewhat extensive I have to say I'm not as extensively prepared on the mechanical side. What boggles me about the misfire part is that I suppose the misfire wouldn't be fixed by a simple switching on and off. Also I was planning to bring an OBD2 reader with me next time I see the car to check the error codes
Once again, thank you
What year is your 520i?Thank you for your quick reply and your advice. While my knowledge on cars is somewhat extensive I have to say I'm not as extensively prepared on the mechanical side. What boggles me about the misfire part is that I suppose the misfire wouldn't be fixed by a simple switching on and off. Also I was planning to bring an OBD2 reader with me next time I see the car to check the error codes
Once again, thank you
The OBD port will be there; but check to see if you've the 20 pin port in the engine bay too; it'll be on the drivers side. If so, you need the necessary cable and plug for that connection as the OBD port won't be fully active
d_a_n1979 said:
What year is your 520i?
The OBD port will be there; but check to see if you've the 20 pin port in the engine bay too; it'll be on the drivers side. If so, you need the necessary cable and plug for that connection as the OBD port won't be fully active
Thank you for the response. It's 2003 model yearThe OBD port will be there; but check to see if you've the 20 pin port in the engine bay too; it'll be on the drivers side. If so, you need the necessary cable and plug for that connection as the OBD port won't be fully active
Cristian02 said:
d_a_n1979 said:
What year is your 520i?
The OBD port will be there; but check to see if you've the 20 pin port in the engine bay too; it'll be on the drivers side. If so, you need the necessary cable and plug for that connection as the OBD port won't be fully active
Thank you for the response. It's 2003 model yearThe OBD port will be there; but check to see if you've the 20 pin port in the engine bay too; it'll be on the drivers side. If so, you need the necessary cable and plug for that connection as the OBD port won't be fully active
The OBD port under the dash will be fully active then
You need a decent code reader (ie Carly for bMW at a minimum) or ideally INPA so you can see the live data
But my bet is it's something that I mentioned in my first post
d_a_n1979 said:
Cristian02 said:
d_a_n1979 said:
What year is your 520i?
The OBD port will be there; but check to see if you've the 20 pin port in the engine bay too; it'll be on the drivers side. If so, you need the necessary cable and plug for that connection as the OBD port won't be fully active
Thank you for the response. It's 2003 model yearThe OBD port will be there; but check to see if you've the 20 pin port in the engine bay too; it'll be on the drivers side. If so, you need the necessary cable and plug for that connection as the OBD port won't be fully active
The OBD port under the dash will be fully active then
You need a decent code reader (ie Carly for bMW at a minimum) or ideally INPA so you can see the live data
But my bet is it's something that I mentioned in my first post
Once again thank you for the help
Gassing Station | BMW General | Top of Page | What's New | My Stuff