P0300, P0301, P0305 Codes..

So, I limped home after a flashing engine light came on. Luckily only had to drive about a mile. Also just bought a code reader & these popped up. I recently replaced an O2 sensor & had a Walker Cat installed. Wondering if these are related? Or did I just happen to blow 2 coil packs? BTW, I have 2008, 5.7L with 183K relatively trouble free miles on it. Had the plugs replaced at 120k & have the original coil packs on..

Appreciate any feedback, as I am taking a 5k mile trip in a month towing a 7k camper.

 

Sometimes the computer can't tell exactly what cylinder it is and attributes it to a different one and it'll set multiple codes...

The best way to do it would be to look at misfire counters on a scan tool, but if you don't have that you can just unplug each one and see if it makes a difference.

 

Thanks! I’ll give that a shot, kinda new to the scan tool thing. I assume it’s under live data. I just recently purchased a Innova 3040 scan tool.

 

Well, I swapped #1 & #3 coils & reset the codes. Then started & got the same codes again for cylinder 1 & 5 misfire. Going to try new plugs on 1 & 5 next. BTW #1 plug looked okay, but had a little oil on the coil when I pulled it.
Am I on the right track?
Advice appreciated!

 

At the age and mileage, it's not unreasonable to just replace all of the coil packs. Yes, it's a lot of money (don't get the cheap ones!), but once you have one dead coil, you're likely to have more in the near future.

 

yeah, I would swap 3 and 5 now and see if it moves to 3. like I said, the code on 1 might be a ghost misfire caused by cylinder 5. you just proved that it's not caused by the coil on 1, time to rule out the coil on 5.

 

Ahhhhh, the plot thickens. First I put cyl 1 coil back to original position. Then
Swapped cyl 5 & 3 coil & changed plugs on cyl 1 & 5(original misfire codes)....then it happened
Misfire’s now on Cyl 4,5 & 6.

 

I’ve thrown in the towel. Getting towed to the Toyota dealer on Monday morning. Spoke to the tech and related the above information. He was stumped also & wanted to diagnose on their equipment. He was stumped also, possible crank sensor maybe etc. I will update this thread after I hear from the dealer. BTW, this sucks. First time in 12 years I had an issue & had to call a tow truck. Hopefully its only a sensor and not a major engine failure.

 

Did this issue happen after you changed the plugs? Also what brand of plugs did you install?

 

I used Denso plugs. The misfires on 1 & 5 occurred prior to me changing plugs. But had misfires on 4,5 & 6 after changing plugs on 1 & 5.
It barely idles & sounds like the timing is way off.
Recent work has been a new O2 sensor, new Walker Cat, cleaned mass airflow sensor. Everything ran fine for 2 weeks after this work was done. Then I lost power close to home the other night.
Gonna go inspect my cam/crank sensors today. Hope its not a major engine issue.

 

Watching for updates. Thanks for sharing.

 

This has been driving me crazy. The only thing I can think of is that the Walker Cat installed 2 weeks ago has caused my Tundra to throw all these misfire codes. Is that possible? A new factory cat is about 2k.
Will find out tomorrow, after going to the dealership.

 

It's unlikely a cat issue causing a misfire unless it plugged. You can test the back pressure before the car to confirm. Things that can cause misfire codes are spark plugs coils, injectors or a mechanical condition. I know that your bring it in to the dealer now and they should be able to figure it out. Techstream has the ability to see which cylinders are misfiring. When the plugs are out have them do a compression test or better yet a cylinder leak down test. Where did you buy the new Denso plugs? Ebay and Amazon are a good source for counterfeit plugs that fail often.

 

Appreciate the feedback. I always respect your opinion and experience.
I bought my two plugs from Advanced Auto, so they should not be the problem. I will speak with the dealership in the morning & update this thread when I hear back.
Been driving nothing but Toyota since 1998 & this is the first time a tow truck has shown up at my house. Kind of a punch in the gut for me. The thing is, I really don’t want a new Tundra right now. And the used car market is so crazy it’s the wrong time to buy used & good luck finding new. So, if this is not a catastrophic engine failure, I will probably lick my wounds and put some $$ in the old girl as she has been good to me.
Feel like a family member is going under the knife...

 

It's unlikely a mechanical issue even with 183k on it. It's a very reliable engine. I'm betting coils, injectors or spark plugs which really shouldn't cost that much. Look at it this way, you have drove it for 183k and it has cost you very little.

 

it could have jumped timing due to a failing timing chain tensioner (which is semi-common on high mileage 5.7s), but you should have heard the rattle of that going bad a while back.

It's probably just a bad coil that the computer is having a tough time tracking down for some reason. especially since the codes changed when you swapped them around.

My bet is that #5 coil. but at this point since you don't have the equipment to properly diagnose it, I think the Toyota dealer is a good call.

 

Have you tested your battery??? I mean sometimes low idle can be attributed to low idle.. I get it every now and then and do stall out of I don't watch the idle.. this is only a 30 minute issue once the battery gets recharged by the alternator it should be good to go... I suggest you test this first as it's free and you may be good to go.. I'm at 230k. No issues, original coil packs, batteries I'm on #20.. more or less...

 

Just got word back from dealership. Misfires on all cylinders except #8. Compression test acceptable levels but at low end (150) on a few.
At 2500rpms the misses go away.
Tech is still not sure & wants to run a few more tests. I gave them the go ahead.

 

I'm thinking clogged, dirty injectors. If he comes back with replace the injectors have them perform a fuel system clean before you replace.

 

Well, tomorrow they are taking the driver’s side valve cover off to inspect. At 2500 rpm’s no misfires on passenger side(2,4,6,8 cylinders) but a clicking noise on the driver’s side with misfires on 1,3,5,& 7. Will update as I hear back form dealership. 2 hrs shop time today and 3hrs for tomorrow...

 

Broken exhaust valve spring, cylinder #5! Problem solved.
3k to replace with new valve spring & head gasket etc. that is the grand total with all labor up to this point.
Sound fair??
I told them I need a few to think about this & I’ll call them back.

 

All new valve springs? Or just the broken one? For that price, I would want all new springs, might be a good time to do a timing chain, tensioners water pump while they are in there. I would hate to see them change 1 spring, only to have it happen again down the road. As well as all the consumable parts they may be removing and reinstalling like timing chain tensioner‘s etc.

 

You had mentioned the compression being a little low. I'm not sure if I would want to dump that kind of coin into a high mileage motor. Another option would to replace the motor with a low mileage used one.

https://www.tundratalk.net/threads/5-7-valve-spring-fail.657018/

 

Leak down test went well. Good results on all cylinders. Wanted this test done before moving forward. Here are a few pics of the old girl. Techs mentioned that the engine looks very clean for the mileage. Royal Purple most of its life.

 

I would definitely do timing chains or at least the drivers side chain tensioner if they're that deep into it. It's known to have issues.

I just had to replace mine @177k miles. Chain slap had broken the guide and it was grinding the metal backing plate throwing metal shavings into the oil...

 

Well, all work complete! Got her back Tuesday.
Had them put in a new radiator, water pump, valve cover gaskets in addition to the four springs & valve(looked fine, but replaced). Talked to the tech for a while & he said it went smooth & used a ton of brake cleaner while reassembling.
Believe it or not, I have no more ticking/diesel sounding engine!
Truck drives great & I even towed a 7k camper 100 miles yesterday to test her out. My mpg on that tank was 12.5mpg with 270 total miles, 100 of which were towing! Not Prius #’s, but a big increase for my truck. Will keep monitoring.
Also, wanted to thank everyone for their input! Great Forum!
$3,600 Total