As you surmised that spark plug was by far the loosest. Probably got lazy on the back corner.
When to replace Ignition coils.
- Thread starter 2001LC
- Start date
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Is that hard on coils; idling in Park with AC on a hot day? Basically been doing that all summer in So.Cal! Got code P0306 tonight.
Extended idling under any conditions is not ideal. Should not throw codes after just 30 minutes thought.
- Thread starter
- #304
In a properly running engine where spark plugs are tight, idling is not hard coils per se! But is hard on the CAT's.
So I replaced my spark plugs today. My LX470 has 236k on the clock and here's what I found:
The plug heads looked ok, but all the threads were pretty gunky. Maybe from people using anti seize in the past?
They were all pretty snug except for one was much looser than the others, and the corresponding coil was much browner.
Also, every single one of my coils had a crack in the plastic tube
None of the little rubber boots were cracked
I had one spare Denso coil so I swapped out the worst of the 8. Now I'm wondering, should I replace all the other cracked ones?
The plug heads looked ok, but all the threads were pretty gunky. Maybe from people using anti seize in the past?
They were all pretty snug except for one was much looser than the others, and the corresponding coil was much browner.
Also, every single one of my coils had a crack in the plastic tube
None of the little rubber boots were cracked
I had one spare Denso coil so I swapped out the worst of the 8. Now I'm wondering, should I replace all the other cracked ones?
- Thread starter
- #306
Looks like a good burning plug on one you show. Nice!
Does not look like anti-seize on threads to me. Just carbon from gasses passing threads.
Those look (hard to see) like they say JAPAN. Which either old stock or factory. Gap will tell you if 236K miles factories. Over 1.2mm (is what find at ~250K). If so, then likely factory.
No halo on the one plugs, suggest; They snug up at operating temp. Which is fine. It's the ones not sung, once at temp, that cause blowouts.
Coils run hot. As gap grows they run hotter. That hotter running heat, sometime show as cracks. If not misfiring under load, they're fine.
But they'll not firer as effective or evenly as new coils. IMHO.
Like spark plugs, buy coils from trusted source only.
The bootleg spark plugs, can damage your engine by metal falling in cylinders.
So much bad stuff from China these days. Smog/climate change, is the price we pay for their cheap junk!
Does not look like anti-seize on threads to me. Just carbon from gasses passing threads.
Those look (hard to see) like they say JAPAN. Which either old stock or factory. Gap will tell you if 236K miles factories. Over 1.2mm (is what find at ~250K). If so, then likely factory.
No halo on the one plugs, suggest; They snug up at operating temp. Which is fine. It's the ones not sung, once at temp, that cause blowouts.
Coils run hot. As gap grows they run hotter. That hotter running heat, sometime show as cracks. If not misfiring under load, they're fine.
But they'll not firer as effective or evenly as new coils. IMHO.
Like spark plugs, buy coils from trusted source only.
The bootleg spark plugs, can damage your engine by metal falling in cylinders.
So much bad stuff from China these days. Smog/climate change, is the price we pay for their cheap junk!
I blew the third coil in 3 years. Seems like clockwork they are crapping out at 18 month intervals, one at a time. Seems like the original Denso's are going out and have a slightly larger boot than the new Denso replacements. 2000 LX with 182k. I think I will be going from the change them when they die camp to change them out at the same time camp. Just need to do 5 in this case. A re-evaluation of the process might be warranted due to age and plastic parts and heat cycles etc. Anybody else feel the same?
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I went through a little bit of this, had one fail, shop replaced, shortly thereafter had another couple, had a different shop replace the other 7, one of their replacements failed pretty quick, they fixed it. A couple years later, 2 more went bad. Finally came across this forum..........replaced all of them with Denso a little while back, did plugs, valve cover gaskets, tube seals all at the same time because there was some oil leaking into them. No more issues of course, all that stuff is really really simple to do. Just depends how much you want to get into it and how much you want to spend at the moment.
- Thread starter
- #309
Key to health of coil is spark plug gap & health. As plug gap widens it draws more current, which in turns runs coil hotter. If spark plug walking out, it also draws more current. It's the heat that damage the coil..
Eyedaho
SILVER Star
I'm not clear on how a higher resistance results in a higher current, but I know the ECU and coil pack don't create a simple DC circuit. Can you please explain how the larger spark plug gap yields a higher current through the coil?Key to health of coil is spark plug gap & health. As plug gap widens it draws more current, which in turns runs coil hotter. If spark plug walking out, it also draws more current. It's the heat that damage the coil..
- Thread starter
- #315
This is such an important component to the regular maintenance of these engines.
I love this thread. I'm about to replace all of my coils and plugs. I have 263k miles on the OG Toyo Denso's. I already have the Denso Iridium OG plugs new, and after a great debate within me, I've decided to go with Hitachi Coils from Rock Auto so I will save about a hundred bucks by not buying the OG Denso's again.
They tout using welds instead of soldering, but I suppose all the good coils do. Rock Auto sells the Hitachi coils in their premium section. If the coils perform like their outboards do, then I think the Hitachi will exceed expectations.
They tout using welds instead of soldering, but I suppose all the good coils do. Rock Auto sells the Hitachi coils in their premium section. If the coils perform like their outboards do, then I think the Hitachi will exceed expectations.
More Information for HITACHI IGC0123
www.rockauto.com
The OG Mass Airflow (MAF) sensor on my 1999 and 2002 models 100s were made by Hitachi. Since you are changing all coils with a matching replacement, I wouldn't have a problem with it. I've see problems on other cars when only one or two coils are replaced with an aftermarket. Let us know how it turns out.
I will for sure.
I just replaced 2 coils that had pending codes for random misfires. I believe the old one is possible a fake denso? I noticed it looked different when I rebooted the other coil packs and put it back together, I said to myself wait for it to give me a problem. Didn’t take long though.
Plugs were done about 1k miles ago. Will replace the other 6 later this weekend. My new ones are OEM from PartSouq.
Plugs were done about 1k miles ago. Will replace the other 6 later this weekend. My new ones are OEM from PartSouq.
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