Bosch 4303 Platinum spark plugs good?

[m1943]

I saw these at Wal Mart for about $5 for a pair or less. THEIR manual says they're good for an M50 engine. Is it cool to use these, should I go get some NGKs from the dealer or other autoparts place? Please let me know I may need to change them soon since I'm going on a 5-hour trip for Thanksgiving. The runs ok but fuel economy is down, so I figured might as well change the plugs. Let me know, thanks y'all.

[LouieD]

I'm a big fan of standard copper NGK plugs. I've fixed more drive ability issues on many cars by just replacing fancy aftermarket plugs with standard NGK's. Also if your fuel mileage has taken a turn for the worse, you may want to consider also checking your O2 sensor. They are a maintenance item and as the get old/lazy the fuel mileage will suffer.

GL

[5mall5nail5]

Get ngk bkr6e from advanced auto. Copper plugs are great and CHEAP!

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[Bwaterman]

just get standard copper cores

[trive2]

I can vouch for 02 sensors. Mine was running a constant 0.7 voltage and almost blew my motor. Unplug the stupid thing.

[seraphim]

Get ngk bkr6e from advanced auto. Copper plugs are great and CHEAP!

Sent from my iPad using BF.com

well not that cheap

[e34Croak]

BMW's HATE PLATINUMS

[m1943]

I can vouch for 02 sensors. Mine was running a constant 0.7 voltage and almost blew my motor. Unplug the stupid thing.

What do you mean unplug the stupid thing? I though most cars, once they lose the O2 sensors will run less efficiently, check engine light will come on and so forth. Then the cats may burn out. Could you elaborate?

NGK coppers, I got it. And yeah, they ain't THAT cheap, paid like $4 per plug at Pep Boys. Was kinda surprised, actually.

[5mall5nail5]

What do you mean unplug the stupid thing? I though most cars, once they lose the O2 sensors will run less efficiently, check engine light will come on and so forth. Then the cats may burn out. Could you elaborate?

NGK coppers, I got it. And yeah, they ain't THAT cheap, paid like $4 per plug at Pep Boys. Was kinda surprised, actually.

Toldja to go to Advanced Auto. $2.20 ea. I get 6 for about $15 with tax.

[cleansti]

BMW's HATE PLATINUMS
Agreed, you've seen it as many times as I have I am sure.
NGK coppers > * anything else

[m1943]

Toldja to go to Advanced Auto. $2.20 ea. I get 6 for about $15 with tax.
K, I'll go to Advanced Auto, and will just return these here back to Pep Boys. Both stores are pretty much in my neighborhood, no biggie. Where do I get the boots though, or what do you call them, little connector wires between the coil and the plug? I don't have time for eBay, as I have to be on the road by Wensday, going to be a fun couple of days at the recently estranged step sister's house, ha-ha :) 5 hours driving, so I want to get the plugs and all prior to the trip.

[5mall5nail5]

The plug boots aren't very available in stores. Have you measured yours? Whats the resistance on each one? 1.8 - 2.2k ohms is good.

[e34Croak]

Agreed, you've seen it as many times as I have I am sure.
NGK coppers > * anything else
:lol at customers that are like 'Bro, your techs are recommending spark plugs and a factory air filter cause my car runs like shit? I just put brand new Bosch Platinum 4's in this puppy... are you sure I don't need a new DME, cause I was reading the forums and..'


:confused

[trive2]

Ahhh I forgot you guys get tested for emissions!

Over here we don't. When I get my Beemer's I scrape the cats out when I pull the exhaust to do the centre bearing's. Taking out the 02 sensor does little for or against efficiency but it WILL destroy your cats.
Haha you guys have to pay $100 for new sensors! Yuck!

And yeah I put awesome platinums from Pelicanparts in my M30 and it was NOT happy. The NGK's in the 323i look great and we're yet to see how the crap "champions" in the 520i are going to go.

[LouieD]

Ahhh I forgot you guys get tested for emissions!

Over here we don't. When I get my Beemer's I scrape the cats out when I pull the exhaust to do the centre bearing's. Taking out the 02 sensor does little for or against efficiency but it WILL destroy your cats.
Haha you guys have to pay $100 for new sensors! Yuck!

And yeah I put awesome platinums from Pelicanparts in my M30 and it was NOT happy. The NGK's in the 323i look great and we're yet to see how the crap "champions" in the 520i are going to go.

I beg to differ. No O2 signal means the DME will receive an "out of parameter" and will try and compensate. This can go either way. If it runs too lean you will run much hotter combustion temps and if it runs too rich not only will you suffer poor fuel economy but you run the risk of "washing" your cylinder walls with excess fuel which will lead to premature scoring of cylinders.

I can understand gutting a cat for the performance aspect, but I don't see how running no O2 sensor has any benefit. The O2 reports lean/rich mixture back to the DME, which in turn adjusts the mixture. This happens hundreds of times per second and ultimately levels as close to a stoichiometric ratio as possible. Without an O2 sensor I don't think that would be very possible across all operating ranges on the engine.

[5mall5nail5]

Ahhh I forgot you guys get tested for emissions!

Over here we don't. When I get my Beemer's I scrape the cats out when I pull the exhaust to do the centre bearing's. Taking out the 02 sensor does little for or against efficiency but it WILL destroy your cats.
Haha you guys have to pay $100 for new sensors! Yuck!

And yeah I put awesome platinums from Pelicanparts in my M30 and it was NOT happy. The NGK's in the 323i look great and we're yet to see how the crap "champions" in the 520i are going to go.

Uhhh...

Sent from my DROIDX using BF.com

[e34Croak]

Ahhh I forgot you guys get tested for emissions!

Over here we don't. When I get my Beemer's I scrape the cats out when I pull the exhaust to do the centre bearing's. Taking out the 02 sensor does little for or against efficiency but it WILL destroy your cats.
Haha you guys have to pay $100 for new sensors! Yuck!

False. Matey. :nono

[trive2]

You guys are the first people I've ever met that have tried to tell me that the 02 sensor is important for anything more than the Cat's and emissions?
As far as I've ever been told, the DME will simply compensate and run a less effective map without the sensor. It's not going to run dangerously rich or lean without it.

And there's no performance benefit in not running an O2 sensor, but its a $100 part that i'd rather not shell out for. Eventually I may get around to plugging in another one, but that's after everything that goes wrong in old BMW's is fixed... sounds like I have a boot full of old pots every time I go around a right hand corner at the moment... *MOAN*

[TSMacNeil]

The ECU runs in open-loop without the 02 input. Here's where it goes off the rails, unmetered air (VAC leaks) will go unaccounted for without the 02 signal. Emissions are just that...post combustion gasses. Without an 02 sensor the ECU just runs the same map regardless of the condition of the actual combustion. Not a great long- term plan.

[5mall5nail5]

You guys are the first people I've ever met that have tried to tell me that the 02 sensor is important for anything more than the Cat's and emissions?
As far as I've ever been told, the DME will simply compensate and run a less effective map without the sensor. It's not going to run dangerously rich or lean without it.

And there's no performance benefit in not running an O2 sensor, but its a $100 part that i'd rather not shell out for. Eventually I may get around to plugging in another one, but that's after everything that goes wrong in old BMW's is fixed... sounds like I have a boot full of old pots every time I go around a right hand corner at the moment... *MOAN*

dude...


seriously? It runs rich - it runs open loop which is a FAIL SAFE condition. Why would you do this lol. Its $100 to replace yet you'll waste hand over fist full of cash in gas lol.

[trive2]

Ive done three tanks without the sensor plugged in and my fuel economy has increased by 1L/100km. Considering it was running lean before, I would have expected that increase anyway.


Oh, and it never occurred to me that vacuum leaks could only be picked up by a downstream sensor. I'm gonna look more into that. Makes sense!

[5mall5nail5]

Ive done three tanks without the sensor plugged in and my fuel economy has increased by 1L/100km.

No it hasn't but ok

[trive2]

Are you serious dude? Your actually accusing me of lying? What the hell would I be lying for? How insulting and inappropriate.

I do about 1000km a week. 500km of that is traffic/highway and the other 500km is highway/suburbs. I was recording 8.5-9.0L/100km on the two tanks I did with it running awfully lean with the sensor plugged in. Since then I have recorded between 9.5L/100km and 10.0L/100km.
Note also that in the last three tanks I have also started to run 98 Octane instead of 95 Octane to avoid detonation just in case its still running lean, till I can get into an exhaust shop. Maybe that is helping?

If I'd known someone had enough attitude to accuse me of lying about something as petty as my fuel economy figures Id take pictures of the odometer and the fuel bowser every time I filled up.

[TSMacNeil]

I think it's safe to say that since a car running in open loop runs richer by default mapping, it's safe to assume your fuel economy will be worse.
There may be other factors that have affected your results... But the fact remains that you are running a richer mixture in open loop, and that is what kills the cats- and gives poorer fuel economy

[Mister6er]

Maybe his O2 was running on the rich side (extremely) therefore when unplugged, it actually is now running leaner off the base fuel map (open loop).

[mikemxbike4]

Of course pulling o2 sensors is going to affect performance negatively. If a car is designed to work with a closed loop emissions system and you unplug one of the sensors from that loop, it will not work properly.

[TSMacNeil]

OP change out the CTS. Then I recommend an 02 sensor before you destroy the cat... Which is much more $! Than the 02 sensor.
.02

[trive2]

@TSMacNeil. I think something else is still causing it to run a little lean, so forcing it to run a richer map by default is sort of compensating until I can find everything that's wrong. I mean, I baby it, but that fuel economy is still pretty fantastic considering the kays and driving I do so I'm a little worried she's still lean.

@Mister6er. It was definitely running very lean. That's why I got onto it so quickly. Rich is bad, but lean is REAAAAAAALLLLLLLYYYYY bad.


Oh and after all this discussion I ended up having to put "Champion" plugs into it, they're awful! They're like the Black and gold of plugs and cost more than the NGK's! Stupid shop had the wrong parts listings for the NGK's...

[TSMacNeil]

Only a few things cause a lean mixture. CTS, vacuum leaks, bad 02 sensor.

[5mall5nail5]

Are you serious dude? Your actually accusing me of lying? What the hell would I be lying for? How insulting and inappropriate.

I do about 1000km a week. 500km of that is traffic/highway and the other 500km is highway/suburbs. I was recording 8.5-9.0L/100km on the two tanks I did with it running awfully lean with the sensor plugged in. Since then I have recorded between 9.5L/100km and 10.0L/100km.
Note also that in the last three tanks I have also started to run 98 Octane instead of 95 Octane to avoid detonation just in case its still running lean, till I can get into an exhaust shop. Maybe that is helping?

If I'd known someone had enough attitude to accuse me of lying about something as petty as my fuel economy figures Id take pictures of the odometer and the fuel bowser every time I filled up.

Theres a difference between accusing you of lying and insinuating that you're wrong - in this case I am doing the latter. I know my fair share of automotive technical information (perhaps more than I care to sometimes) and there is absolutely 100% zero chance of your car running MORE efficiently without closed loop operation. Period. If your car runs better without oxygen sensors that means your current ones are toast. Imagine, then, how great it'd run with functioning oxygen sensors.

[trive2]

There is a difference between accusing me of lying and insinuating that I'm wrong. What you did there was accuse me of either lying or being unable of doing basic maths at the petrol pump.

And as to my 02 sensor, yes I know my old one is toast, which is why I chopped it up. It was putting out a constant 0.7 voltage. It's running much better without it. I never said a car would run better without a properly functioning O2 sensor. I began the discussion by saying that from what I've been led to believe, the 02 sensor is only most important to keeping the catalytic converter healthy and keeping emissions down.

In my case, I have no Cat and I don't get checked for emissions. I forgot that in the USA that's not a practical solution.

[5mall5nail5]

There is a difference between accusing me of lying and insinuating that I'm wrong. What you did there was accuse me of either lying or being unable of doing basic maths at the petrol pump.

And as to my 02 sensor, yes I know my old one is toast, which is why I chopped it up. It was putting out a constant 0.7 voltage. It's running much better without it. I never said a car would run better without a properly functioning O2 sensor. I began the discussion by saying that from what I've been led to believe, the 02 sensor is only most important to keeping the catalytic converter healthy and keeping emissions down.

In my case, I have no Cat and I don't get checked for emissions. I forgot that in the USA that's not a practical solution.

And again I am clarifying that I am not calling you a liar, I am saying you're wrong. An O2 (not 02) sensor helps the engine run at 1 lambda which is the most economic mode for cruising. With the O2 sensor you car is running on a closed loop map that is typically a full point or more rich in AFR. Whatever perceived "gains in mileage" you're experiencing is just that - perception. Your car is not running as efficiently and you will trump the $70 O2 price in only several tanks of gas worth of driving.

I don't want to say "trust me, I know" but... yeah.

[trive2]

I cave, I'm keeping the car long term so I may as well stick an 02 sensor on.

Problem being, the parts listing for the 520i and 525i are different. Are they compatible? Getting parts for a 520i specifically is difficult.