2002 Rav4 burning through coil packs (1 Viewer)

[mudgudgeon]

My wife has a 2002 Rav4, 2.4L 2AZ-FE

It's been in and out of the local mechanic shop.
It has repeatedly had misfire issues. Intermittent stumbling, stalling, down on power

Mechanics have changed coil packs numerous times.
Replaced the cats twice (once under warranty).
Replaced the ECU. Had a bunch of random codes, and security system/ immobiliser code in a vehicle with no immobiliser.

Coil packs used have been a mix of NGK and cheap generic stuff.

Latest issue was coil pack #2 completely melting down.

Codes

I have no faith in the mechanics troubleshooting this to find a root cause.

I think coil pack failures are probably just a symptom, but not sure what to look for

 

[gnob]

id be looking for resistance issues in the primary side.

 

[Eyedaho]

My wife has a 2002 Rav4, 2.4L 2AZ-FE

It's been in and out of the local mechanic shop.
It has repeatedly had misfire issues. Intermittent stumbling, stalling, down on power

Mechanics have changed coil packs numerous times.
Replaced the cats twice (once under warranty).
Replaced the ECU. Had a bunch of random codes, and security system/ immobiliser code in a vehicle with no immobiliser.

Coil packs used have been a mix of NGK and cheap generic stuff.

Latest issue was coil pack #2 completely melting down.

Codes
View attachment 3566693

I have no faith in the mechanics troubleshooting this to find a root cause.

I think coil pack failures are probably just a symptom, but not sure what to look for

If it has a mix of junk coils, I think I would spend the $64/each for new Denso coils and install new plugs at the same time, just to eliminate any possible issues being induced by s***e parts.

 

[mudgudgeon]

I'm planning to start with basics.
Change coil packs, plugs ( gapped correctly), check wiring harness.
Compression test etc
Fuel filter
Air filter.

Do coil packs need to ground to the engine through the bolt?
One of the bolt holes is completely stripped out and needs a helicoil

 

[gnob]

coils(primary)ground through the ignitor. the spark plug obviously through the head. make sure that ground is there as well.

 

[mudgudgeon]

If anyone has access to Techstream and can sling me FSM & EWD, I'm more than willing to send beer money in return.

Or a lifetime supply of Vegemite

 

[gnob]

If anyone has access to Techstream and can sling me FSM & EWD, I'm more than willing to send beer money in return.

Or a lifetime supply of Vegemite

log onto TIS. it's like $15 unlimited for three days

 

[CondeCruiser]

My Honda civic commuter car kept burning through coil packs. I would keep two spares at all time. It turned out to be a blown head gasket.

 

[mudgudgeon]

log onto TIS. it's like $15 unlimited for three days

Thanks gnob. I'll check it out

 

[Kamran Khan]

A quick compression test will save you a lot of headache and money. I suggest you do a compression test on those two cylinders before spending money on parts. I have a 2011 RAV4 with over 300k miles on odometer. Furthermore, I had a misfire problem, but it was due to worn out spark plugs and coil packs. I ordered parts from rock auto and the replacement took me less than 10 minutes.
RAV4 basic tuning is easier than working on a bicycle.

 

[mudgudgeon]

A quick compression test will save you a lot of headache and money. I suggest you do a compression test on those two cylinders before spending money on parts. I have a 2011 RAV4 with over 300k miles on odometer. Furthermore, I had a misfire problem, but it was due to worn out spark plugs and coil packs. I ordered parts from rock auto and the replacement took me less than 10 minutes.
RAV4 basic tuning is easier than working on a bicycle.

Thanks.

Not fully familiar with coils on plugs.

Basic tuning and trouble shooting I've mostly got covered.

The car has been in and out of the shop with a somewhat trusted mechanic.
I've literaly been 10, 000 miles away. And my tools are on a ship coming 10,000 miles.

The shop it's been at are just a garden variety, oil change, basic repairs kinda shop. They literally said they don't know how, and don't have the time to find a root cause. So its been frustrating experience.

 

[gnob]

Thanks.

Not fully familiar with coils on plugs.

Basic tuning and trouble shooting I've mostly got covered.

The car has been in and out of the shop with a somewhat trusted mechanic.
I've literaly been 10, 000 miles away. And my tools are on a ship coming 10,000 miles.

The shop it's been at are just a garden variety, oil change, basic repairs kinda shop. They literally said they don't know how, and don't have the time to find a root cause. So its been frustrating experience.

real diag mechanics almost don't exsist. it's seriously bs.

 

[mudgudgeon]

Got access to TIS. 2 days for $25.

Is there a coherent way to look at complete sections of repair manuals EWD etc.

Can't see any way ordered way to see the different sections of manuals.

Been able to search by fault code and find relevant pages for some things which is helpful, but links to other relevant sections of EWD, diagnostics etc don't seem to work.

 

[gnob]

it's been a minute since I've been on.
it seems like it was system by system via pdf.
at least that's how I have them ripped to my pc.
not as easy as just thumbing a page. take your time it's worth it in the end.
iirc it was tabbed out showing repair, ewd, owners etc.
then you drill down

 

[mudgudgeon]

it's been a minute since I've been on.
it seems like it was system by system via pdf.
at least that's how I have them ripped to my pc.
not as easy as just thumbing a page. take your time it's worth it in the end.
iirc it was tabbed out showing repair, ewd, owners etc.
then you drill down

Thanks gnob, that helped. Had another look, and slowly working through sections

 

[mudgudgeon]

Kind of at a dead end with this for now.

Compression tested at 155psi on all cylinders, which is on the lower end of in spec

Plugs all look a bit fouled, but not too bad.
Gaps look big, but I don't have feeler gauges to check them. Will try and pick up a gap setting tool.

Tested all the wiring from coil packs back to the ECM. All tested ok.
Checked continuity of ECM ground. Checked for shorts etc.
Checked grounds where I could get to them.

Bought a multi meter with oscilloscope function. Tested the ECM signal for ignition IGT and IGF. All seems to test ok, but I'm no expert on electronics
Wave form, frequency, voltage etc was consistent across all four ignition circuits

Coolant and radiator cap are clean, no sign of oil contamination.

Listening to injectors with a long bar, they sound like they are firing consistently across all four.

Took it for a drive. Runs OK. No trouble codes.
Using an obd11 reader, all the sensors etc look normal.

For now, I suspect maybe there was a loose connection. Or an intermittent fault with the ECM.

Probably going to get a couple of spare coil packs to throw in the car just in case and get the car back into use.

 

[mudgudgeon]

Seems the problem with this was a simple as loose connections at the ECU which was replaced by the shop we've been using about a year ago.
Been running fine and code free for nearly 3 weeks, knock on wood

With me being out of the country, we spent hundreds on towing, and labour. The shop replaced coil packs multiple times, and the cat twice on warranty.

They basically said "we can't fix this, and don't want to see this car ever again"