Toyota ignition coil questions

[lukejo]

Time to replace spark plugs and have a leaking valve cover gasket on the 2005 Corolla.
Going to replace ignition coils while I'm at it.
1) I haven't checked coil prices yet, but should I stick with OEM for the coils?
2) Besides the plugs and coils, are the wires connecting the coils (don't know the name for them) usually changed, or left alone?

(Just background—the car has 291,000 miles. We have owned since new. While it has received plugs, I'm 95% sure the coils have never been replaced. In the last few months, it is a little slow to start...new battery, but sounds like the original starter might be getting tired. Also, on some days, it has been idling a little rough at stops. Accelerates and drives fine. The above are due anyway, so I'm hoping they'll also fix the slower starting before I try to address the starter.)

 

[SatinSilver]

I think the slow starting is normal as long as it starts on the first try. The 05 Matrix with 149k here has always been like that since new. As far as idling rough at stops has the intake manifold gasket been replaced? There's a new updated gasket for it. Below is a link to some common issues with the Corolla including the intake gasket

http://carspecmn.com/?s=corolla&lang=ICL_LANGUAGE_CODE

I'd almost be tempted to leave the coils alone unless there's a misfire happening. You may consider using some CRC GDI Intake Cleaner on it. That's what I'll be using soon. A guy on here has 360k on his 04 Corolla with basic maintenance.

 

[lukejo]

Thanks. No that gasket has never been replaced. It has never thrown any codes since an O2 sensor was replaced over 200k miles ago. Starting takes two tries about half of the time now...although I don't let it crank for more than a couple seconds usually.
So, even after 14 years and 290k you think the coils are probably okay if I'm not getting misfire codes? I was kind of hoping this was what would fix my two minor issues.

 

[anndel]

Change the coil packs when you start having misfires and/or P0301-0304 codes. Just replace the valve cover gasket for now. I always go with OEM or DENSO for ignition parts.

 

[Lubener]

The coils are not considered a maintenance item. No codes, engine runs good, I would continue to use the originals.

 

[Gebo]

I would leave them alone. But, if you change them please use OEM as first choice. Denso as second.

 

[PeterPolyol]

If you had a 1ZRFE Corolla, I'd keep an extra coil on hand for convenience..just did a coil on my neighbour's 1ZR Corolla couple months back. Not sure about how often they go out on ZZs though

 

[eljefino]

Get yourself a spare coil and throw it in the glove box along with a cheap code reader and tools to change it out (probably just a 10mm socket & driver.)

What's your oil consumption like? Oil burning can muck with your idle. On a car that old I might run copper plugs like autolite 3924s or the equivalent NGK.

The OE coils will be marked Denso.

 

[lukejo]

Originally Posted by eljefino
Get yourself a spare coil and throw it in the glove box along with a cheap code reader and tools to change it out (probably just a 10mm socket & driver.)

What's your oil consumption like? Oil burning can muck with your idle. On a car that old I might run copper plugs like autolite 3924s or the equivalent NGK.

The OE coils will be marked Denso.

Oil consumption is 1/2 quart in 5k miles.

 

[clinebarger]

Originally Posted by eljefino
Get yourself a spare coil and throw it in the glove box along with a cheap code reader and tools to change it out (probably just a 10mm socket & driver.)

What's your oil consumption like? Oil burning can muck with your idle. On a car that old I might run copper plugs like autolite 3924s or the equivalent NGK.

The OE coils will be marked Denso.


Some Toyota OE coils are made by Diamond Electric.

Never been a believer in carrying an spare coil.....Where does it end? Extra Crank Sensor, Cam Sensor etc? If you worry about catalyst damage, Unplug the offending cylinders fuel injector.

 

[WyrTwister]

Originally Posted by lukejo
Time to replace spark plugs and have a leaking valve cover gasket on the 2005 Corolla.
Going to replace ignition coils while I'm at it.
1) I haven't checked coil prices yet, but should I stick with OEM for the coils?
2) Besides the plugs and coils, are the wires connecting the coils (don't know the name for them) usually changed, or left alone?

(Just background—the car has 291,000 miles. We have owned since new. While it has received plugs, I'm 95% sure the coils have never been replaced. In the last few months, it is a little slow to start...new battery, but sounds like the original starter might be getting tired. Also, on some days, it has been idling a little rough at stops. Accelerates and drives fine. The above are due anyway, so I'm hoping they'll also fix the slower starting before I try to address the starter.)



One step at a time . I would do the plugs first & visually inspect the coil & boots , while you are at it . Then go from there . Unless the coils are VERY difficult to get to .

But , have a Plan B if one needs replacing .

I would consider the throttle body cleaning that has been suggested .

Check for vacuum leaks and check all the electrical connections to sensors .

Has the MPG decreased ?

Best of luck to you .

 

[rustypigeon]

I agree with the others who said they would not change the coils. I have never had a Japanese coil fail in my small sample of 3 Toyotas and 1 Mazda, all with over 200,000 miles on them.

If this were a BMW however, I would carry a spare coil. I have had 2 of 6 coils go bad in only 130,000 miles on my BMW.

 

[OhioMazda]

Originally Posted by rustypigeon
I agree with the others who said they would not change the coils. I have never had a Japanese coil fail in my small sample of 3 Toyotas and 1 Mazda, all with over 200,000 miles on them.

If this were a BMW however, I would carry a spare coil. I have had 2 of 6 coils go bad in only 130,000 miles on my BMW.


"German engineering" is the biggest crock of you-know-what ever foisted on the motoring public. Most of them drive great, but are totally unreliable moneypits.

 

[ka9mnx]

Yep, one step at a time. Plugs first. That should be a big improvement. If you replace the coils ALWAYS replace the wires.