Tune-Up Advice

[realness]

Hi all,

I am planning on changing my spark plug wires, spark plugs, distributor cap and rotor this weekend. These parts are all BOSCH. Is there anything I need to be aware of when doing this? I am not sure if the BOSCH wires have numbers on it. I will check later when I get home. If not, I plan on using color string or tags.

Which one should I tackle first? I’ve change spark plug wires and plugs in other cars before. I’m just not sure if there is something I need to know when changing all these things.


Any tips or advice would be great!

[Rustam]

Hi all,

I am planning on changing my spark plug wires, spark plugs, distributor cap and rotor this weekend. These parts are all BOSCH. Is there anything I need to be aware of when doing this? I am not sure if the BOSCH wires have numbers on it. I will check later when I get home. If not, I plan on using color string or tags.

Which one should I tackle first? I’ve change spark plug wires and plugs in other cars before. I’m just not sure if there is something I need to know when changing all these things.


Any tips or advice would be great!

I am guessing the evaporative purge valve maybe same in your car as in mine. You should be aware that when it clogs with pieces of charcoal from charcoal canister it gets stuck in open position introducing unmeasured air into the manifold:

http://www.bimmer.info/forum/showpost.php?p=163720&postcount=18

This part is not covered in Bentley manual it seems. Too bad!

[joshua43214]

Dont use Bosch platinums, they suck.

[Rustam]

Dont use Bosch platinums, they suck.

I use them. What exactly is wrong?

[joshua43214]

I use them. What exactly is wrong?
You need a microscope to find the electrode. I have seen the electrode on them burn down into the insulator in under 10k miles. The ones that you get from BMW are of a higher standard and will perform as well as NGK.

They also cause running problems on many cars, those mostly the domestic ones. I have yet to have a good experience with aftermarket Bosch plats, and I have had more bad experience with them than any other plug including the Mighty ones made by Champion. There is a very good reason they are 1/3 the cost of NGK's, they are poorly made.

[Rustam]

You need a microscope to find the electrode. I have seen the electrode on them burn down into the insulator in under 10k miles. The ones that you get from BMW are of a higher standard and will perform as well as NGK.

They also cause running problems on many cars, those mostly the domestic ones. I have yet to have a good experience with aftermarket Bosch plats, and I have had more bad experience with them than any other plug including the Mighty ones made by Champion. There is a very good reason they are 1/3 the cost of NGK's, they are poorly made.

So I take it you would advise NGK as "the best"? What would you advise as "most practical"?

Do you have part number for "the ones from BMW" ?

[Qube]

So I take it you would advise NGK as "the best"? What would you advise as "most practical"?

It's the ye old Platinum debate... Rustam, you've been around since these and many other posts... strange you'd ask why most do not like Platinums in the e34 ;)

http://www.bimmer.info/forum/showthread.php?t=20732&highlight=spark+plug+platinum

http://www.bimmer.info/forum/showthread.php?t=2422&highlight=spark+plug+platinum

http://www.bimmer.info/forum/showthread.php?t=8372&highlight=spark+plug+platinum

[joshua43214]

I would go with bosch coppers before the plats unless they came form the dealer. The plat # is 12 12 172 189 5 they are a W8 LPR.

In general I prefer NGK's, but I have no complaints with Bosch in German cars at all. Bosch makes a huge amount of aftermarket parts. The stuff that is made by bosch that has a BMW label tends to be of much higher quality than the stuff that does not, even if they are the "same" part. Bosch is the worst company I have seen with this double standard on parts. Even Delco maintains high quality on aftermarket parts, and considering that delco is OEM for GM and Bosch is OEM for BMW,MB and others its, its just sinful.

[Bill R.]

every real mechanic on here agrees on. Bosch platinum equals bad. Ngk conventionals are good and reasonably priced. My local import parts place sells ngk iridiums for 5.99 apiece which is a pretty good price for iridium plugs.
I've put them in a couple of cars now and i am very pleased with the results in my own cars and the 2 customers that i've installed them in are also happy with them. I put the iridiums in a toyota tundra v8 last friday and he's quite pleased with the mileage,smoothness and power increase... of course i was replacing old plugs that had 90k miles on them.





So I take it you would advise NGK as "the best"? What would you advise as "most practical"?

Do you have part number for "the ones from BMW" ?

[Rustam]

It's the ye old Platinum debate... Rustam, you've been around since these and many other posts... strange you'd ask why most do not like Platinums in the e34 ;)

http://www.bimmer.info/forum/showthread.php?t=20732&highlight=spark+plug+platinum

http://www.bimmer.info/forum/showthread.php?t=2422&highlight=spark+plug+platinum

http://www.bimmer.info/forum/showthread.php?t=8372&highlight=spark+plug+platinum

Well, it's not always possible to read everything. Thanks for the links...

[Rustam]

Thank you Joshua, Bill, Qube...

[632 Regal]

$1.99 each good? go for the supers.
http://wrenchead.carparts.com/servlets/WebEPC35?ns=Ignition%20Spark+Plugs+and+Glow+Plugs% 201989%20BMW%20525i&cl=jcw-carparts35&vc=1989|12|525|7914&grc=11010&grd=Ignition&JCWRETURN=store.carparts.com&storeId=10401&catalogId=10101&sgc=12081 (http://wrenchead.carparts.com/servlets/WebEPC35?ns=Ignition%20Spark+Plugs+and+Glow+Plugs% 201989%20BMW%20525i&cl=jcw-carparts35&vc=1989%7C12%7C525%7C7914&grc=11010&grd=Ignition&JCWRETURN=store.carparts.com&storeId=10401&catalogId=10101&sgc=12081)

[realness]

I have the BOSCH Supers which I plan on using. Is there anything else I need to be aware of as far as changing the distributor cap and rotor?

[Qube]

I have the BOSCH Supers which I plan on using. Is there anything else I need to be aware of as far as changing the distributor cap and rotor?

It was a pain to change them on mine... I had to remove the fan, etc, to get to it properly! :)

[BillionPa]

I loves my Denso iridium plugs.

when the mechanic removed the old ones, they were NEW (no wear) bosch platinum + 4 plugs.

The iridium plugs are much better when the accelerator goes down, and 0 gas drips out of my tailpipe.