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Discussion Starter · #1 ·
So i got an SES light today and the car started running very bad (misfiring). I get it home to find the spark plug cover all busted up on the left side. I pull it and see that a spark plug had been shot out of the cylinder and the coil is shot. I'm going to replace the coil hopefully tomorrow. Will there be more to it than that? Do i need a rebuild? Car is a 99 540i, intake, exh, stage 2 soft. Thanks in advance
 

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clean540i said:
So i got an SES light today and the car started running very bad (misfiring). I get it home to find the spark plug cover all busted up on the left side. I pull it and see that a spark plug had been shot out of the cylinder and the coil is shot. I'm going to replace the coil hopefully tomorrow. Will there be more to it than that? Do i need a rebuild? Car is a 99 540i, intake, exh, stage 2 soft. Thanks in advance
This one sounds a bit extreme...... I have seen spark plugs take flight...however only after they were improperly installed. You gave no short term service history so I have to speculate.

As for other concerns, huuummmm.... if you were fortunate to have the plug leave and not take the threads within the head with it during the process you should be fine...... look closely at the threads....... awkward...... and if all looks good...... properly install the spark plug, torque it to spec......and consider yourself "Lucky"

Take care

Shadowman
 

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I have seen this happen on a couple 540s. All needed to have the heads be rethreaded. If this is the case, you can buy a new head ($$$$) or try to have a machinist rethread the spark plug hole for you. Also, be sure to inspect the piston head for any scaring from shards of the coil plastic and or spark plug pieces. Please let us know how you make you.
 

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Discussion Starter · #5 ·
well it turns out that the threads are shot and i suppose i will need to pull the head off and take it to a machine shop. Would it be easier to have the car towed or take the head off myself? Is there a price range for this job? Thanks again.
 

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The head needs to come off either way. So probably best to try and remove it yourself and save the hassle of the towing. Not sure about the pricing of the machinist but as long as it is under the cost of a new head, you should be ok. Please keep us updated with how you make out.
 

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Maybe you should talk sweetly with BMW NA? Threads failing like that on a not-very-old car is indeed extreme. Good thing the injector was shut down so you didnt get petrol sprayed all over and had a fire.

I would definitely think of getting a new head. The other threads could be weakened too.

David
 

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ray540inyc said:
there has been a set of 540i heads on ebay off and on for the last 3 months or so , try to search past auctions if it isnt listed.
i think they wanted 300 for the set.

good luck
If it look like it would seal well, I would definitely go with that rather than renovating the damaged head.

David
 

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Wow, how many miles on the car, what kind of plugs, how old were they, who replaced them. I wonder if it would be possible to re-tap the plug hole with the head installed. heavy grease on the tap to catch metal shavings etc. This might depend on you future plans for the car...
Mike
 

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Discussion Starter · #13 ·
there are 121xxx miles on the car and i just replaced the plugs with bosch platinum 2's and torqued them all to spec. They were replaced about 2 months ago. i might sell the car. It depends on how this whole ordeal goes.
 

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clean540i said:
well i had bosch 4 prong's in there and i got an SES light, pulled the plugs and all the prongs were missing when i got it out. .
Where did the missing prongs go??? hmmm
Regards,
Jerry
 

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Are you positive the Bosch plugs are approved for S62 use?
(I thought only the NKG plugs were ok. BTW the missing electrodes are a very good reason not to use that kind of plugs.)

David
 

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Discussion Starter · #18 ·
Keep in mind it's a 540i with the m52 i believe.


To update everyone, i took it in and they got the head re-threaded in 1 day and had it up and running BUT.....the power steering pump brackets broke, the serp belt shreded and took out an idler pulley. They charged my 175 for the original problem and then it turned into an 1100 dollar job. Sucks for me. On an up note the car is running great and no problems so far. I also had them put NGK's in while it was in there just to be safe. Now i just have to fiqure out that **** clunking noise from my right front suspension haha. Thanks for all the help guys.
 

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clean540i said:
Keep in mind it's a 540i with the m52 i believe.


To update everyone, i took it in and they got the head re-threaded in 1 day and had it up and running BUT.....the power steering pump brackets broke, the serp belt shreded and took out an idler pulley. They charged my 175 for the original problem and then it turned into an 1100 dollar job. Sucks for me. On an up note the car is running great and no problems so far.
I'm not a mechanic and not that familiar with your engine, but wouldn't they normally take off those items to make it easy to get the head off?? Steering pump bracket breaking seems unusual...........On the other hand, $175 for taking off the head and rethreading the spark plug is basically a freebie...
Regards,
Jerry
 
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