New Adventure Needs Help

[dclin703]

Finally, I still decided to take this adventure even my known mechanic told me "Don't buy it" - bought 92 BMW 850i two days ago. Today I have a chance to take a closer view on it. No doubt, it is a beautiful car compare to what I have on hand. However, I don't know whether I am too exciting or too stupid to find out some dummy issues. To be a new member, please allow me to ask few stupid questions. Any comments are much appreciated.

1. How to open the trunk from inside? (Few minutes ago I couldn't open the trunk from outside keyhole either.) : I swear I checked everywhere inside but still can't find any button or handle to open the trunk. There is no video on YouTube to show any 850 repair.

2. Battery : The seller told me I have to jump the car, so I decide to buy new batteries instead of jumping each time. I removed the battery (left side in the trunk) in the morning. However, I forgot which side is the positive side. Is the short cable connected to negative (-) and long cable connected to positive (+)? I remember there is no color on the cable.
Also, what size of CCA (the website shows BOSCH 800 CCA and also 690 CCA. I am confused.) My current battery is too old to read.

3. If I want to do oil change by myself, what type of oil is better 0W-30, 0W-40 or others?

4. Many thanks to Tom for the help of spark plugs. However, I have never changed the spark plugs before, so I will keep posting the issues later. If I need to pay attention to something before I open the engine, please advise me.

This car will be my first DIY because my mechanic don't know how to repair it either. If this is a case, I prefer to do it by myself. Hopefully, my car can be seen on the road instead of sale for parts on eBay (if I don't screw it up too much). Sorry for all dummy questions. Please help.

[Timm]

Firstly, there are two batteries and take great care connecting them as shown here:

https://www.meeknet.co.uk/e31/E31_Ba...eplacement.htm

If the glove box is locked the boot (trunk) will not open - the handle is under the ledge above the licence plate as seen to the right of my hand here:



Here's my website for the E31:

https://www.meeknet.co.uk/e31/

[Belgiumbarry]

congrats for your courage.... a 850 sure is not a easy car as a first DIY... wish you luck and not to many gremlins in it

[dclin703]

Thanks a lot, Timm. Per your description, there is no handle to open the trunk from inside of the car, isn't it? So inconvenience!

[Alec Cartio]

This video is the easiest visual guide to solve the trunk problem!

https://youtu.be/oHbeBRpLhu8

As for the batteries. The negative (ground) is towards the rear of the car (by the tail light) and the positive is towards the “amplifier”

[72tpik5]

Congratulations on the purchase, and welcome. There is a wealth of knowledge here, enjoy.

[PabloRock]

Congrats on joining the fun of 8 ownership. The trunk can be a pain in the butt to open with just the key (I locked it earlier this year without the batteries, so put my charger on the hood terminals and opened it that way. Not really recommended, but works). I am (was) fairly new to work aside from the assorted repairs on other cars over the decades. But so far, with the help of this forum, have yet to run into to an issue I couldn't do myself. Aside from basic tune up stuff and easy fixes I have changed the master cylinder, sealed the intake manifolds, and a new fuel pump. All of those require a little knowledge (which is gather from this forum), but mostly just patience (and maybe a new tool here or there).

For the plugs, use the tool in the trunk for #12 (and use the NKG plugs not the bosch). Careful when pulling the boots, as the wires are probably original, delicate and expensive to replace. Do a forum search for oil, tons of opinions on that (but might was well use synthetic). And for batteries, I just went with autozone because they are local. If it's not a daily driver, your batteries will more than likely die in a few years if you don't keep on top of them. I think next I will go with Walmart brand because they have a 3 year warranty and will take them back no questions asked (a lot of opinions on that as well, so this is just mine).

[CaifanSC]

H8 batteries from Walmart...can't beat them. 850 and CSi both have those. Zero issues, Walmarts are everywhere and price is just right.

Welcome!

[rogbmw]

H8 batteries from Walmart...can't beat them. 850 and CSi both have those. Zero issues, Walmarts are everywhere and price is just right.

Welcome!

I too have the Wallymart H8's in my car. 3 year replacement warranty too. Can't beat them.

[Pneill316]

If batteries don’t solve the start problem check the fusible links by the the passenger side battery l, when I say check I mean replace as you can’t tell they are bad. Had an issue with a recent one I bought, would only start with a jump even with 2 fully charged batteries.

[Money Pit]

You will want to do a battery drain test as per Timm's website. If you have lead calcium batteries you will kill them quickly with high (450ma) current draw. Heaps of knowledge on the forum but it helps to find a local mechanic with experience on the E31's. Enjoy the ride
Regards,

[Stantz]

Congratulations and happy wrenching!
Here's some advice:
1. Always take pictures of stuff before you take it apart.
2. Don't rush things, and don't get too frustrated.
3. Read as much as you can on here - there's good information buried in years of posts. You have to dig sometimes.
4. Begin learning about Inpa - the diagnostic software you'll need to talk to your 850.

[clubE31]

I would start learning DIS (get a laptop with DIS), Inpa was never designed for the 850 en does less then half of what DIS can diagnose.

And yes..... take your time, rush means $$$

[Stantz]

See what I mean?
I didn’t know that DIS would provide more info and data than Inpa. I learn something new every time I visit this forum.

Thanks for the tip, I’ll start reading up on DIS.

[Chillax]

You can also grab a Foxwell scanner that can be loaded with the E31 code as well. Will need the adapter cable. Also be sure to join the Chapter more info about the chapter and the car (lots of how to info) is located here http://www.bmwccae31.com

-Bob

[dclin703]

I would start learning DIS (get a laptop with DIS), Inpa was never designed for the 850 en does less then half of what DIS can diagnose.

And yes..... take your time, rush means $$$

Thanks a lot. However, I just purchased a PEAKE R5/FCX-3-U BMW Reset and Scanner tool two days ago. Is it good for 850 also?

[8eights]

It's good for some codes and helps plenty at times, Some times you have to follow fourm members advice for issues that don't throw a code until you catch on, Dis is best but i would keep the R5 and DIS would complete your tools for Diagnostics.