a little preventative maintenaince for you guys

[tnt525i]

hi guys i thought i'd share some info for those interested, recently i was having an intermittent loss of power from my car, i checked everything from plugs, filters, battery ( i bought a new one) sensors, vacuum leaks etc anyway one day i decided to do an obd test 9 while driving, strange enough i noticed that everytime the car would lose power, the voltage would drop to 12.xx coincidental huh?
the alternator is brand new only 2 weeks old, so i thought it couldnt be that the diodes were going so i swapped the voltage regulators, no change
cleaned and changed the battery terminals and the jump start lead at the front, no change,,, so i decided to check all grounds, thats where i found the gremlin, there's a negative ground on the left side chasis near the front of the car,( im right hand drive) and this connects to the engine mount, i took it apart and found some corrosion there,, cleaned it and restarted, right away the car felt as if it came alive for the first time ever, obd reading is in the area of 13.6 lowest to 14.24 highest, she now pulls extremely strong in ED before i would have to switch to SD to get that kind of performance, so guys if your car feels sluggish, try the grounds, it worked for me.

[Incantation]

hmm..

is it possible for you to post a photo of the problem area? I would like to check this out anyway..

[AllGo'n'Show]

me aswell, even tho im a 7

[HDhandyman]

Me too!--Love to see that photo

[632 Regal]

congrats on the fix! What made you think to check voltage while driving?

[genphreak]

hi guys i thought i'd share some info for those interested, recently i was having an intermittent loss of power from my car, i checked everything from plugs, filters, battery ( i bought a new one) sensors, vacuum leaks etc anyway one day i decided to do an obd test 9 while driving, strange enough i noticed that everytime the car would lose power, the voltage would drop to 12.xx coincidental huh?
the alternator is brand new only 2 weeks old, so i thought it couldnt be that the diodes were going so i swapped the voltage regulators, no change
cleaned and changed the battery terminals and the jump start lead at the front, no change,,, so i decided to check all grounds, thats where i found the gremlin, there's a negative ground on the left side chasis near the front of the car,( im right hand drive) and this connects to the engine mount, i took it apart and found some corrosion there,, cleaned it and restarted, right away the car felt as if it came alive for the first time ever, obd reading is in the area of 13.6 lowest to 14.24 highest, she now pulls extremely strong in ED before i would have to switch to SD to get that kind of performance, so guys if your car feels sluggish, try the grounds, it worked for me.More power from fixing rust? Sounds SUPERCOOL, pls do show us what to look for dude... if this works for even a few peeps you will really be starting something here...

[tnt525i]

hmm..

is it possible for you to post a photo of the problem area? I would like to check this out anyway..
ill try to get a pic as soon as possible

[tnt525i]

congrats on the fix! What made you think to check voltage while driving?
i guess i ran out of options as to where to look for that gremlin, you could say out of frustration lol

[tnt525i]

More power from fixing rust? Sounds SUPERCOOL, pls do show us what to look for dude... if this works for even a few peeps you will really be starting something here...
i dont know if it would help everyone, but its worth a try, it worked like magic for me, the car runs so powerful now that i just ran a friend of mine , he has a turbocharged corolla, man i got 1 car length from the word go and we ended up with me 2 carlengths ahead of him, by no means my car is super fast after the fix, but my car is at least 1000 lbs heavier than his, and oh he's manual

[tnt525i]

hmm..

is it possible for you to post a photo of the problem area? I would like to check this out anyway..
i pulled this off real oem's site its #16 in the diagram one end mounts to the chasis, and the other to the engine mount, not sure which side it is on LHD cars but mine is on the right near the steering box

[genphreak]

i dont know if it would help everyone, but its worth a try, it worked like magic for me, the car runs so powerful now that i just ran a friend of mine , he has a turbocharged corolla, man i got 1 car length from the word go and we ended up with me 2 carlengths ahead of him, by no means my car is super fast after the fix, but my car is at least 1000 lbs heavier than his, and oh he's manualHey that's normal dude, we normally eat Ricers for breakfast... :D

[tnt525i]

Hey that's normal dude, we normally eat Ricers for breakfast... :D
lmao :D

[Kalevera]

There are two critical grounds in the E34 engine bay. Having either corroded, disconnected, or otherwise compromised means big problems. A cracked/chaffed/corroded block to frame ground can prevent the car from starting (ex: a stupid me went crazy for a few minutes after doing an E21 323i pan gasket a few weeks ago -- thing wouldn't even crank, because I'd forgotten to reconnect the ground strap....oops).

http://www.bimmer.info/~lowell/e34ground1.jpg

http://www.bimmer.info/~lowell/e34ground2.jpg

best, whit

[632 Regal]

are you saying copyrights on these? lol

There are two critical grounds in the E34 engine bay.

[grease]

It's most always corrosion when everything else checks out, if not usually it's loose terminals. I glad that you found the problem and thanks for sharing. You said "one day i decided to do an obd test 9 while driving, strange enough i noticed that everytime the car would lose power, the voltage would drop to 12.xx coincidental huh?" I understand it all except for the OBD test 9, what is that?

[Kalevera]

haha -- nope. But I did snap them, so I expect to be credited for them. Savvy?


best, whit

[ArtemLepilov]

Well, one thing I do not understand is how can a piece of wire that is a ground from the engine to the car cause the car to perform better? It just doesnt sit right in my mind... I thought the engine was bolted to the rest of the car anyway, so its ground by default?

Hope this isnt a stupid question :)

-Artem

[mzarifkar]

Well, one thing I do not understand is how can a piece of wire that is a ground from the engine to the car cause the car to perform better? It just doesnt sit right in my mind... I thought the engine was bolted to the rest of the car anyway, so its ground by default?

Hope this isnt a stupid question :)

-Artem

The engine on most cars (if not all) is not directly bolted onto the body, but it is mounted on rubber "shocks" to keep the engine from vibrating the frame to pieces. Rubber is bad conductor so thats why we have ground cables

[Bill R.]

mounts. The ground cables are flexible wires also to avoid transmitting excess vibration and noise to the frame and the interior.




Well, one thing I do not understand is how can a piece of wire that is a ground from the engine to the car cause the car to perform better? It just doesnt sit right in my mind... I thought the engine was bolted to the rest of the car anyway, so its ground by default?

Hope this isnt a stupid question :)

-Artem

[Incantation]

thx

[ArtemLepilov]

mounts. The ground cables are flexible wires also to avoid transmitting excess vibration and noise to the frame and the interior.

Thank you all :) I just thought there was a way for the engine, etc to connect with the rest of the car in some way (tranny mounts, LSD mounts, etc..), I supose not. :)

-Artem

[romus]

grease, on your OBC, press 1000 and 10 buttons simulataniously and you'll see TEST on the OBC display. Then, using 1-button, press it to get 09 on the display, thats your current voltage. When you got 09, press S/R and you should get real-time readout of your voltage. For example, 07 is amount of fuel left in tank, 08 is current speed etc...Now! Mine doesnt work but people i talked to say their's does, so try it out.

also, look up my posts and find a thread i started on OBC recently, theres a list of all codes avaliable (some 21) and play around :)

[romus]

my idle is varying and it cant be anything but voltage, which is some 11. I've done everything i possibly could and nothing fixes it. I'd love to try this option myself. My 09 OBC test doesnt work but i messured voltage and found voltage to be below desired level, yet am NO GOOD with wiring so i was at a point where i gave up.

[uscharalph]

Great Post!

[tnt525i]

Great Post!
thanx dude

[Gene in NC]

bump for relation to post re sudden loss of power or stumble as I haev called it.

http://www.bimmer.info/forum/showthread.php?t=15700

[Visions]

Where are All the grounds for the e34,,, my 89 has the same sluggish problems as TNT535i

I see the one posted here but I would like to do maintance and clean all grounds including the fuseable link that causes problems... I'll have to look that up to find it again... If someone had links or pics to each ground including the fuseable link that they could post here I'm sure that would help alot of people...

Thanks!