Misfire 2, 4, 6 and 8 (1 Viewer)

[camino70]

'98 LX with +300

Truck started to run rough and CEL. Felt like A bad coil pack. Great, we can pull the code and swap one, should be done in 10 minutes.....

Pull codes and we get P0300, P0302, P0304, P0306, P0308, P0171 and P0172, uhh, what?!

We swap all four, truck still runs poorly and throws the full bank misfire again.

No obvious signs of a critter, but could probably use some more digging around.

We have access to another truck to swap parts. Thinking of swapping O2 sensors, what/where else should we be looking?

 

[trdcorolla]

Any maintenance done recently? I had similar codes (if I remember all one side) a few weeks after I had my timing belt replaced. It turned out that the timing belt moved a notch during install and my timing was off. Everything went back to normal after the timing belt was reinstalled correctly.

 

[camino70]

Nothing too big recently. I fear something somehow got in and got the timing to move a tooth or two. Is it just pulling the cover to get access to see?

 

[trdcorolla]

I'm not sure, I think you can pull off a cover to see the condition of the belt, not sure of the timing. I think I read here that a rodent got in one of the covers (because the small cover on the bottom is frequently not reinstalled during a TB change) and the rodent got the belt to jump a tooth.

 

[camino70]

Any other advice?

 

[gatormark91]

cam position sensor.

 

[jgray]

Another vote for timing off! I had the same thing happen and 2 local shops misdiagnosed the problem. I was convinced the timing was off and finally took it to Toyota. They called me within an hour of looking at it and confirmed timing gear was 2 teeth off on one side of the engine. The timing gears have an arrow stamped on them and a T stamped on them as well. The shop that had done my timing belt misaligned one side with the T and not the arrow. I my case cylinders 1,3,5,7 (passenger side IIRC) were misfiring. I went down many rabbit holes trying to find other reasons for misfiring. I would recommend taking it to Toyota - I don't think there anything else that can cause the whole side of the engine to misfire except timing being off...

 

[camino70]

Thanks! I don't think I understand how to tell if the timing is off?

 

[bigredmachine]

Thanks! I don't think I understand how to tell if the timing is off?

you would have to pull the timing covers off and look at the timing marks, there is a mrak on each cam gear and one on the crank. I would expect that if the belt had jumped a tooth that you would have cam codes instead of misfire and lean codes.

 

[bigredmachine]

how many miles are on the truck, if your close to needing to do the t-belt might as well do it a little early

 

[jgray]

I also swapped coil packs and installed new 02 sensors (all 4) which ultimately didn't fix the misfire problem. Misfiring continued exactly as you describe in your original post. There are some good detailed write ups on here for doing the timing belt job yourself which show the marks that need to be aligned, etc. As mentioned above you can pull the timing covers and inspect yourself. I still vote timing is off on the driver side of the engine! Please post the answer to your problem after resolution!

 

[camino70]

We pulled the covers today. Records say 50k miles and 16 months ago.

What the:

Bad belt

• camino70
• Feb 24, 2019

How did this happen? How much time am I looking at for a shade tree?

 

[Eicca]

Best to redo the entire thing. New water pump, idlers, tensioner, etc. Make sure it's all fresh. It's lucky that didn't snap.

 

[Ager Venator]

Exact same issue. Jumped 4 teeth on ONE cam. Drove it 4000+ miles this way. Thanks Toyota!

 

[JDWCruiserMS]

Mine just did this a month or so ago... thought it was bad coil packs but it turned out to be that the timing belt "jumped".

 

[JT4runner]

Mine just did this a month or so ago... thought it was bad coil packs but it turned out to be that the timing belt "jumped".

Yeah here is another pic of the problem. It is weird because the timing belt was replaced 11/2017 and has less than 50k miles since then.

 

[JDWCruiserMS]

Holy cow... mine did the same thing... I lost the whole bank (2,4,6,8)... he said it was 4 teeth off... is this a chronic 100 series thing?

 

[dnp]

Best to redo the entire thing. New water pump, idlers, tensioner, etc. Make sure it's all fresh. It's lucky that didn't snap.

^^THIS^^
That photo of the destroyed belt is CRAZY! Holy cow! You dodged one there!

Buy the following:

Aisin TKT-021
Aisin FBT-002
Aisin THT-015
Aisin THP-108

That'll get you started with the difficult stuff.......

Yeah here is another pic of the problem. It is weird because the timing belt was replaced 11/2017 and has less than 50k miles since then.

View attachment 1915529

 

[JT4runner]

^^THIS^^
That photo of the destroyed belt is CRAZY! Holy cow! You dodged one there!

Buy the following:

Aisin TKT-021
Aisin FBT-002
Aisin THT-015
Aisin THP-108

That'll get you started with the difficult stuff.......

Yeah I already purchased the Aisin TKT-021 kit and OEM cam and crankshaft oil seals, new thermostat and thermostat gasket and new OEM coolant.

 

[Wilsil]

How can it suddenly jump 4 teeth?