Age of sparkplugs??

JimIsbell · 03-14-2010, 02:36 PM

I bought my Insight with 170K on the clock. It was running like a top and now at 210K it is still running great. Maybe even better than it was 2 years ago. I am getting 67mpg in town and much better on the highway.

As an engineer my general inclination is "If it aint broke, dont fix it." So I have never pulled the plugs to look at them. There is no need to, I reason.

But after 40K miles and "who knows how many before I bought it" I wonder if there is some lifetime to consider with these special plugs. Or do I just run them till mileage shows a decline and check them then?

joecvt · 03-14-2010, 09:09 PM

Scheduled maintenance for spark plugs is every 105K so assuming the owner of the car when there was 105K on the odometer changed them, you are due for a replacement right now. Also, now would be a good time to replace them to get back on track of the maintenance schedule even if you are not sure when the originals were changed.

I'm going to change mine soon since I am at 102K now.

JoeCVT = Just your average CVT owner

RobertSmalls · 03-14-2010, 09:20 PM

I have a related question.

My car has 45000 mi, so I presume the spark plugs have been in there since the car was made, ten years ago. Should I pull them out, apply anti-sieze, and torque them back down, or should I leave well enough alone?

joecvt · 03-14-2010, 09:34 PM

I would at least remove the single bolt that secures each coil.....Mine were so corroded that I had to drill 2 out of 3 bolts out and the one still in tact wasn't pretty. Swapped them all out with new bolts and antiseize.

I don't see the harm in removing the spark plugs as well and re-coating and torquing since you have such low miles in 10 years.

I only removed the coils to check the letter for the spark plug so I could order them ahead of time. Should be a few more months when I change them.

JoeCVT = Just your average CVT owner

aisbell · 03-14-2010, 10:35 PM

Quote:

Originally Posted by joecvt

I would at least remove the single bolt that secures each coil.....Mine were so corroded that I had to drill 2 out of 3 bolts out and the one still in tact wasn't pretty. Swapped them all out with new bolts and antiseize.

Did you consider replacing the bolts with stainless steel bolts?

joecvt · 03-15-2010, 11:07 AM

Quote:

Originally Posted by aisbell

Did you consider replacing the bolts with stainless steel bolts?

That is exactly what I did this time (and put antiseize compond on them as well).

The project started out just replacing the rear exhaust (muffler portion). Something I did years ago when I modified the internals. All exhaust bolts were corroded so much that they either rounded out or just broke away. I did try liquid wrech and heat treatment and let it sit overnight. I ended up taking the whole exhaust off due to having to repair snapped bolts. That is when I noticed that the coil bolts were doing the same thing.

I replaced all bolts with stainless steel bolts. I have read how stainless may work their way loose on exhaust parts over time but I also used lock washers. I would rather tighten them if they work loose compared to what I went through last fall (a couple of days) trying to get corroded bolts out. The two long special bolts inside the springs (near the bottom front) were the hardest. It is like they became one part of the metal of cat converter flange. I ended up grinding the special bolt flange portion off, then used heat to work the inner threads loose.

Something that only took about 20 minutes (changing out the rear exhaust) the first time ended up taking 2 1/2 days swapping out corroded / broken bolts.

Besides the exhaust and coil bolts....All others look fine....The special coated (green) bolts look brand new on other areas of the car.

It is almost like Honda used bolts on the exhaust desined to meld into one unit with heat and moisture over time. It sure keeps the system air tight

JoeCVT = Just your average CVT owner

JuiceMcGoose · 03-15-2010, 12:05 PM

I agree with Joe. Even if your spark plugs work great you need to remove them once in a while. Spark plugs have a coating on the threads to help prevent galvanic corrosion but it brakes down over time more so than most of the bolts on a car due to the temp. fluctuations the metal goes through.

Aluminum is not very strong stuff in relation to steel and those threads are pretty small. I'm going to be pulling my plugs this summer just to see what they look like.

Leeper · 03-15-2010, 02:40 PM

My philosophy is simple - when I buy a used car I always do all the maintenance due at that mileage regardless of what the owner says may or may not have been done. I always replace ALL the fluids (oil, oil filter, air cleaner, cabin filter, brake fluid, clutch fluid, trans fluid) even if they have receipts of such services being done. It is cheap insurance and peace of mind - those that do not never know if it was done or done properly. Why spend several thousand dollars on the purchase then be cheap on @ $100 of preventative maintenance? Makes no sense.

JimIsbell · 03-15-2010, 04:36 PM

Quote:

Originally Posted by Leeper

My philosophy is simple - when I buy a used car I always do all the maintenance due at that mileage regardless of what the owner says may or may not have been done. I always replace ALL the fluids (oil, oil filter, air cleaner, cabin filter, brake fluid, clutch fluid, trans fluid) even if they have receipts of such services being done. It is cheap insurance and peace of mind - those that do not never know if it was done or done properly. Why spend several thousand dollars on the purchase then be cheap on @ $100 of preventative maintenance? Makes no sense.

40 years of being an engineer, i dont screw with things that are working.

aisbell · 03-15-2010, 04:59 PM

Quote:

Originally Posted by JimIsbell

40 years of being an engineer, i dont screw with things that are working.

I agree with Jim (and not just because he comes from a good family

I am frequently tempted to "improve" or "fix" something that is working fine. On many occasions when I have yielded to this temptation, I have regretted my actions which caused unexpected problems.

So unless an action can be described as "preventive maintenance", I tend to leave well enough alone. But maybe inspecting for corroded ignition coil bolts would be worth doing. If I had read about lots of problems with seized spark plugs in Insights, then removing them to apply anti-seize compound might be good preventive maintenance.

Which reminds me … what is the "everyday" product that can be used as a good anti-seize compound? It was mentioned in the Insight Central forum, but I have been unable to find it again.