325es not starting help :(

[JeLani]

so my 86 325es with m20b25 head / 2.7i stroker block wont start. it has a new battery which replaced a smaller one which gave me problems the day i bought it , since the car didnt run for ten years before the P.O. bought it , it would start up weird and idle kind of weird. but since i'm driving it every day now that issue hasn't popped up fortunately. But today after dropping one of my friends off i go to turn it on again , it starts up noticeably unusal , i turn it off to see if it would start like then , sure enough , it did. So i drop off my last friend at his house , turn it off , turn it back on again . doesnt start , wont crank or turn over . after i had my friend jump start it , she started like normal . I go back home , park it , turned it off , test started her again . same issue.

btw, the lights turn off when i try to start it and the sound it makes when you turn on the electronics fades down when i try to fire it up . what could this be? what can i do to fix this?

located in san diego.

[inferno27468]

your alternator sounds like its taking a dump. ur car will run when jumped until you turn on something with a heavy load like ur headlights or ac. soo bascally sounds like your alternator is not charging the battery... take it to autozone or get it tested?

[JeLani]

found on autozone an alternator , they dont have the es selection for alternator parts so i found one for a 325e , but under the criteria it says 1986 BMW 325E 2.7L FI SOHC 6cyl , but i know it isnt sohc right ? would that make a difference? i obviously need one for the specific 885 head or ?

[JeLani]

total $110? does it have to be that much? http://www.autozone.com/batteries-st...9_14962_10918/

[inferno27468]

yes your engine is single over head cam. you don't get into dual over head cam till you get an e36 or a chunkier engine. also is your engine stock? or do u have it swapped to a 2.7 stroker? if its stock get the one that it says to get if your not then ask for an 89 325i and youll either get a different part number or heck they might be the same. same base engine should be pull same amount from the battery. make sure you get it tested first before jus jumping into buying a new one.

[inferno27468]

and yes they are pretty pricey lol

[JeLani]

no the original engine is a 2.7i stroker but the head was upgraded to m20b25/885. so no not stock. so i understand what ur saying since its not stock find a criteria for a 2.5i head which is the 325i which is the m20b25 correct?

[inferno27468]

yeah and jus for kicks ask them to match P/N between the e and I. my e30 originally was an e and I swapped to an I and now I have an s50 lol but when I had the e I used to use parts off an I and they worked jus fine =]

[betsy325e]

What do the brushes look like on the alt?

[Regnar75]

first, did your battery light come on at any point?

next, what belt are you using for the alternator? like what size (should say on the belt something like 10x950) the stock 10x965 didnt work for me anymore when i converted to 2.7i, the toothed harmonic balancers have a shorter track for the belt than the smooth ETA harmonic balancer. maybe check the tightness first to make sure its not just visibly tight but slipping.

Also what is the CCA of your new battery?

I'm a firm believer in not throwing money at problems right away. first lets figure out if its something simple then look into buying replacement parts.

[JeLani]

early that night i noticed a very dim lighting of the battery light , but it wasnt starting up wierd then. i may have 9x950

[JeLani]

so first , talt is 10x965
Fanbelt size , one below the alternator? is 10x825 , and how do i check for cca , lol i'll be back.

[JeLani]

first, did your battery light come on at any point?

next, what belt are you using for the alternator? like what size (should say on the belt something like 10x950) the stock 10x965 didnt work for me anymore when i converted to 2.7i, the toothed harmonic balancers have a shorter track for the belt than the smooth ETA harmonic balancer. maybe check the tightness first to make sure its not just visibly tight but slipping.

Also what is the CCA of your new battery?

I'm a firm believer in not throwing money at problems right away. first lets figure out if its something simple then look into buying replacement parts.

so the battery CCA - 750
The reserve capacity is 140