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Registered
Join Date: Jan 2004
Location: NY, NY
Posts: 149
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I'm planning on performing some routine tune-up work to my '93 325i, including changing the spark plugs.
My question: Is there a predetermined (or suggested) interval at which I should replace my coils? Although my car has 83,000 miles, I have no indication that any of my original coils are faulty. However, since I'll need to remove them to replace the plugs, should I take this opportunity to replace the coils as well? Should I proactively install a new set since my car's existing coils have over 83,000 miles on them? Is the $250 investment good insurance for any future damage? (I'm especially concerned about my DME and the Conforti chip I've installed- I've heard a faulty coil can adversely affect a DME) PS: I would just be looking to replace with stock coils - not Plasmas. Last edited by Ad Hoc; 05-10-2004 at 05:43 AM.. |
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Registered
Join Date: Jan 2003
Location: houston
Posts: 60
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wait for 1 to go bad.
unless of course you have a flush wallet, or stock in a coil company. |
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Registered
Join Date: Jan 2004
Location: NY, NY
Posts: 149
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Is it true, though, that even if 1 goes bad it could damage my ECM (and my Conforti chip)?
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Registered
Join Date: Oct 2002
Location: Atlanta
Posts: 549
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Its usually the DME that goes bad first>>replace all 6 coils & DME if one coil goes bad...but if ur not havn trouble>>let it ride
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Registered
Join Date: Jan 2004
Location: NY, NY
Posts: 149
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Quote:
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Registered
Join Date: Oct 2002
Location: Atlanta
Posts: 549
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If ur DME is new>>then replacing the coils would be a good idea>>but if you have chippd the old DME and arent having any problems I wouldnt worry about it>>>because its the DME that is the problem.
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Registered
Join Date: Mar 2003
Location: NY-Upstate
Posts: 207
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why not ohm out the coils? the bentley has the spec on what you should see. if there within specs and you have had no tell tale signs of misfire or the like, i'd say save your money for something else...
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Registered
Join Date: Jan 2004
Location: NY, NY
Posts: 149
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I'll refer to my Bentley manual and check them out. I guess my bottom line question was this: Do coils have a shelf life - should they be changed at a certain interval like an O2 sensor?
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Registered
Join Date: Mar 2003
Location: NY-Upstate
Posts: 207
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Interval change, no. coils can die slowly, the dielectric breaks down, the insulation can break down and what you get is a degradation of performance. TEST...
After talking with an EE here, do the test with a heat gun brining the coil temp up closer to what it would be in actual usage. testing a coil cold is NOT a true test. |
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Registered
Join Date: Mar 2003
Location: NY-Upstate
Posts: 207
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also"shelf life"
Shelf life refers to a coil thats sitting in storage...Under those conditions i.e. "NEW", they could sit there "Forever" and be OK... Its the constant temp fluctuation that will over time break down the "inards", again the dielectric, insulation and allow Moisture in and begin to create havoc.
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