How long is the typical life expectancy of a distributor cap and rotor? I will be changing the spark plugs and wires on my 2001 Mitsu Eclipse GT, which has about 56,000 miles on her...just wondering if it's worth another $40 to change the distributor cap and rotor..or wait til the 120,000 mile mainteance...
On modern cars equipped with a distributor cap and rotor...
- Thread starter Chuck1986
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That's one expensive cap and rotor (whew!
) ..or are you including the wires in that mix
Does it have to be NOW or 120k ..or do you only consider maintenance on that schedule?? You're doing less then 10k-11k a year (assuming that you bought this in the 2001 model year - not a leftover). I'd say another 5-6 years is a long time from now. I would have changed it out by now
..but that's just me.
To tell you the truth, I've never noticed any improvement with a new cap and rotor on a modern engine ...ever ..but it seems to be a sensible thing to do. Now I've had wires degrade and cause real issues...but the OEM wires work very well for a long time. Aftermarket wire sets ..that's variable.
Does it have to be NOW or 120k ..or do you only consider maintenance on that schedule?? You're doing less then 10k-11k a year (assuming that you bought this in the 2001 model year - not a leftover). I'd say another 5-6 years is a long time from now. I would have changed it out by now
To tell you the truth, I've never noticed any improvement with a new cap and rotor on a modern engine ...ever ..but it seems to be a sensible thing to do. Now I've had wires degrade and cause real issues...but the OEM wires work very well for a long time. Aftermarket wire sets ..that's variable.
Why don't you just inspect it. At 60K mi. you would expect the wires to need changing but as long as the car isn't missing under load due to cracks or tracks in the cap I'd leave it for now.
My experience is similar to Gary's. When all else failed, I replaced a distributor cap that looked good, and it didn't help a bit.
Kestas
Staff member
I understand the cap and rotor are replaced because the gap between the two can grow and become excessive, robbing voltage that is needed to jump the spark plug gap.
Probably cracking was exclusive to those Bakelite caps, which was such a material prone to cracking no matter the application. I've never seen an ABS craked cap. Apart from that my understanding is that they're replacement items mostly due to the carbon tracking, which -unlike with the crude switching of the points- takes very long to happen on an electronic ignition. I share the Gary's observations about the performnce. I've changed mine after changing all other expensive components as an insurance against a possible problem propagation, but I wouldn't change otherwise.
Gaps may effect the performance, but for example GM HEIs are about 1/5" when fresh, so in the worst day of the cap they shall be widened by %5 max. I guess, and I observe erosion on the rotor rather than the cap. For the gap sense, may be replacing the rotor twice as much (between the cap change intervals, or with the plugs) would worth the effort with a small price.
Gaps may effect the performance, but for example GM HEIs are about 1/5" when fresh, so in the worst day of the cap they shall be widened by %5 max. I guess, and I observe erosion on the rotor rather than the cap. For the gap sense, may be replacing the rotor twice as much (between the cap change intervals, or with the plugs) would worth the effort with a small price.
I woul dlook for wear on the contacts on the cap and rotor and if it looks like its worn bad. then I would change it. or if you see hair line cracks in the cap its self. but if your not having anu miss fires or other wierd problems. then prob the cap and rotor is fine.
Thanx for the advice guys! This sounds like something not exactly worth doing just yet...
My NGK wires with iridium plugs last 60k miles (easily) so I don't plan on doing any ignition work until the change after the next one coming up, which would be at 120k miles.
My NGK wires with iridium plugs last 60k miles (easily) so I don't plan on doing any ignition work until the change after the next one coming up, which would be at 120k miles.
My first reaction to this thread was that modern cars don't have those trouble makers. Then I remembered all the coil packs and housings I replaced on my Grand Am. The originals did outlast the replacements I bought at AAP. Lesson?
I'd look for tracks not crack and the rotor to decide on the cap and rotor. Tracks show arcing.
I repalce wires at 5 years but if you don't I'd look for white dust arching signs on those. I take the plugs out and inspect because if you leave that plug in 10 years in an aluminum head they are very hard to get out without damage then. There is a thread on these plugs nearby for a honda
I repalce wires at 5 years but if you don't I'd look for white dust arching signs on those. I take the plugs out and inspect because if you leave that plug in 10 years in an aluminum head they are very hard to get out without damage then. There is a thread on these plugs nearby for a honda
When removing a cap and rotor for inspection, it's a good idea to dress the contacts with a small file or sandpaper. This removes corrosion and gives a nice clean path for the spark. It's also a good idea to clean the inside of the cap to prevent tracking. It's easy to 'recondition' this stuff and get many more miles out of it.
I do the same thing with plugs: clean and regap, and check the resistance. If it's somewhere in the range of 5K ohms, the plug's still good.
You can't recondition wires however. When they build up resistance, it's time to change.
I do the same thing with plugs: clean and regap, and check the resistance. If it's somewhere in the range of 5K ohms, the plug's still good.
You can't recondition wires however. When they build up resistance, it's time to change.
arcing points and contact corrosions are the main issues inside typical cap and rotor setup and as time goes by, the gap grows due to erosion. You'll also get a whole lot of oxidised metal flakes on points that are non conductive (electrically-speaking).
Yes, scraping the oxides (white powder) off the points with a fine screwdriver makes good sense but eventually, your cap and rotor will be worn out-of-spec. and that would simply call for a replacement.
While you are at it, consider checking/replacing the cap and rotor with factory units (applicable to imports such as Honda, Toyota, etc. for many so-called aftermarket OEM units are not perfectfit, causing all sorts of performance and reliability problems).
Also, consider replacing the seal (a big o-ring gasket) where the cap mates the distributor body. This seal has to be replaced on a regular basis for if you don't and moisture/water seeps in, you'll be in trouble.
Lastly, I don't clean/gap spark plugs. I simply throw them away after they have fulfill their job: i.e. copper typically gets replaced every 35kms, platinum typically every 50~60kms. Even though some might argue that the plugs are still somewhat "salvagable" but IMHO it's not the electrode erosion that concerns me but the minerals deposited onto the electrode and the ceramic body (maganese, etc.) that may lead to all sorts of drivability problems (some may even cause spark leak along the ceramic nose).
Yes, scraping the oxides (white powder) off the points with a fine screwdriver makes good sense but eventually, your cap and rotor will be worn out-of-spec. and that would simply call for a replacement.
While you are at it, consider checking/replacing the cap and rotor with factory units (applicable to imports such as Honda, Toyota, etc. for many so-called aftermarket OEM units are not perfectfit, causing all sorts of performance and reliability problems).
Also, consider replacing the seal (a big o-ring gasket) where the cap mates the distributor body. This seal has to be replaced on a regular basis for if you don't and moisture/water seeps in, you'll be in trouble.
Lastly, I don't clean/gap spark plugs. I simply throw them away after they have fulfill their job: i.e. copper typically gets replaced every 35kms, platinum typically every 50~60kms. Even though some might argue that the plugs are still somewhat "salvagable" but IMHO it's not the electrode erosion that concerns me but the minerals deposited onto the electrode and the ceramic body (maganese, etc.) that may lead to all sorts of drivability problems (some may even cause spark leak along the ceramic nose).
kestas-
Many moons ago, I was taught by a wise man (master mechanic for an import stealership, still a good friend of mine) that grit-blasting is so "yesteryear" for 2 reasons:
(1) no need to grit-blast platinum tipped plugs for it makes no use if your tip is eroded due to natural causes (yes, rate of platinum plug tip is between copper and iridium, and when they erode, they erode. See Bosch platinum tip plugs for more info after running some 30+kkms) (2)Besides, the biggest concern is that there will be blasting grits stuck inside the bottom of the ceramic nose and they will dislodge after you reinstall that plug into your engine...imagine the "unintentional" introduction of abrasives into your prized engine/cylinder.
As for wire brush, my experience told me that if you brush the center ceramic nose too hard in an attempt to remove those combustion-borne deposits, there will be a slight dark/metallic deposits left behind on the ceramic body which is somewhat conductive (test it! it has a measurement of roughtly 4~15Mohms) which may become a contributor to spark leak (not jumping across the electrode gap but to "leak" away along the ceramic nose down ).
Because of that, I don't go for "reusing" spark plugs... Simply go buy a new set of plugs (for 4 cyl with 4 plugs, it would cost me 20CAD for a set of 4 NGK plats which is more than reasonable, for copper V-tip NGK would still costs me 16CAD for 4) every 40~50kkms interval and simply throw them away when they are not firing optimally...
Afterall: the reduced fuel economy and the negative effects to an engine due to poor combustion ignition condition( spark misses, inconsistent sparking/flame pattern, inconsistent acceleration due to weak spark, quick fouling of plugs, cat, EGR valve, etc.) far outweighs the cost of a much more frequent replacement of sparkplugs on a regular basis, even platinum plugs for example.
With the price of gas these days, the $$ I saved by maintaining ignition systems/fuel systems at it's peak pays back nicely over time--I have an original cat converter that is in excess of 180kkms clocked and other than being a bit lazy, the cat still works like new and passes emissions control like a charm.
This one of the cheapest insurance I can buy for over the long run!
Many moons ago, I was taught by a wise man (master mechanic for an import stealership, still a good friend of mine) that grit-blasting is so "yesteryear" for 2 reasons:
(1) no need to grit-blast platinum tipped plugs for it makes no use if your tip is eroded due to natural causes (yes, rate of platinum plug tip is between copper and iridium, and when they erode, they erode. See Bosch platinum tip plugs for more info after running some 30+kkms) (2)Besides, the biggest concern is that there will be blasting grits stuck inside the bottom of the ceramic nose and they will dislodge after you reinstall that plug into your engine...imagine the "unintentional" introduction of abrasives into your prized engine/cylinder.
As for wire brush, my experience told me that if you brush the center ceramic nose too hard in an attempt to remove those combustion-borne deposits, there will be a slight dark/metallic deposits left behind on the ceramic body which is somewhat conductive (test it! it has a measurement of roughtly 4~15Mohms) which may become a contributor to spark leak (not jumping across the electrode gap but to "leak" away along the ceramic nose down ).
Because of that, I don't go for "reusing" spark plugs... Simply go buy a new set of plugs (for 4 cyl with 4 plugs, it would cost me 20CAD for a set of 4 NGK plats which is more than reasonable, for copper V-tip NGK would still costs me 16CAD for 4) every 40~50kkms interval and simply throw them away when they are not firing optimally...
Afterall: the reduced fuel economy and the negative effects to an engine due to poor combustion ignition condition( spark misses, inconsistent sparking/flame pattern, inconsistent acceleration due to weak spark, quick fouling of plugs, cat, EGR valve, etc.) far outweighs the cost of a much more frequent replacement of sparkplugs on a regular basis, even platinum plugs for example.
With the price of gas these days, the $$ I saved by maintaining ignition systems/fuel systems at it's peak pays back nicely over time--I have an original cat converter that is in excess of 180kkms clocked and other than being a bit lazy, the cat still works like new and passes emissions control like a charm.
This one of the cheapest insurance I can buy for over the long run!
sorry typo:
I mean "passes emissions testing", not "emissions control"....
We have a province-wide annual emmissions testing for all vehicles operated here and you have to shell out some $$ to get it tested. Cars that fail the emissions testing will have to display/show some effort or spending in hopes of improving an already failed engine/emissions to get a condition pass (that works out to be a rather costly affair over time).
I mean "passes emissions testing", not "emissions control"....
We have a province-wide annual emmissions testing for all vehicles operated here and you have to shell out some $$ to get it tested. Cars that fail the emissions testing will have to display/show some effort or spending in hopes of improving an already failed engine/emissions to get a condition pass (that works out to be a rather costly affair over time).
Kestas
Staff member
If you replace your plugs because of mineral deposits on the electrode and ceramic insulator, why wouldn't cleaning be acceptable? I grit-blast my plugs and reuse them until the erosion is too noticeable. Or are you talking about cleaning with, say, a wire brush?
Otherwise, I agree with your cap/rotor observations.
Otherwise, I agree with your cap/rotor observations.
My rotor was toasted when I just changed it last month, it was quite corroded. After giving it a new cap/rotor the engine seems to run a bit smoother. Although if the contacts arent corroded I would agree generally.quote:
Originally posted by Gary Allan:
That's one expensive cap and rotor (whew!) ..or are you including the wires in that mix
Does it have to be NOW or 120k ..or do you only consider maintenance on that schedule?? You're doing less then 10k-11k a year (assuming that you bought this in the 2001 model year - not a leftover). I'd say another 5-6 years is a long time from now. I would have changed it out by now..but that's just me.
To tell you the truth, I've never noticed any improvement with a new cap and rotor on a modern engine ...ever ..but it seems to be a sensible thing to do. Now I've had wires degrade and cause real issues...but the OEM wires work very well for a long time. Aftermarket wire sets ..that's variable.
A worn cap/rotor will actually INCREASE the voltage to the plugs, when firing.
This is good until you need more, and it misfires.
If there are no cracks/carbon tracks, clean and dress them.
This is good until you need more, and it misfires.
If there are no cracks/carbon tracks, clean and dress them.
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