P0301 Code

Had a second diagnostic done from a different mechanic and they said they did a compression test 5 times and cylinder 1 is 100-110 while 2-4 are 170-180 so they believe it’s a valve or head gasket...

How does one diag. get this result while the other yesterday said my compression is fine and it’s a plugged up fuel injector?

Is it worth the cost to get the job done if it really is a compression fail?

 

So the code says cylinder 1 and the compression test shows an issue with the same cylinder. I am assuming during the diagnostics they checked spark and fuel. My best guess is a valve. Getting a rebuilt head installed would require a new head gasket anyway, or you can ask the shop what a valve job would cost, which would also mean removing the head and replacing the head gasket. Rebuilt head: http://www.alliedmotorparts.com/00-...GjVICXKs4vTbczzG7N38yECBJg45w9K0aAut4EALw_wcB

Plus new bolts and gaskets for another $150 plus the labor . . . whether it is worth it depends on what shape the rest of the truck is in. You'd probably be in for at least a grand, and the bottom end (block, piston rings, crankshaft bearings, etc.) would still be original. A long block (block and head) looks to be about $4K. Ouch.

What did the shop recommend?

 

Man oh man...people say my truck looks great. The only issue I know besides what’s going on right now is a rear main seal leak that is very manageable. I’ve attached images on what I’ve done with the truck since purchasing it in 2014. So it could be more than a head? They are going to call me back for quotes. I need to make sure they ran everything I guess but if it’s the same code and that’s the compression test results than it must be the valve.

 

Looks like you've addressed a lot of wear and age parts. I didn't see ball joints or wheel bearings, but I can't think of a ton of other things. Looks like you have a manual transmission, so doing the rear main seal when doing a new clutch makes sense unless it gets really bad, so you can wait on that until you need a clutch.

I would wait to see what the shop says, but with its age, needing a valve job is not a big surprise. That may be all it needs. They could quote just a head gasket, get the head off and see that it needs the valve job, so you need to be prepared for the full valve job. Hopefully they can get it done locally for cheaper than getting a remanufactured/rebuilt head, but it will probably take a few days. Injectors may eventually fail, but #2 injector just doesn't sound right for what you are seeing.

 

I just did this on my 2rz. OEM reman cylinder head from Allied Motor Parts (highly recommend them, website is cylinderhead.com they do have a head for the 3rz too) $455 shipped to my door, including camshafts, and everything needed. No core charge up front, just send the old one back within 30 days.

I would very highly recommend going OEM on the head gaskets and bolts. Contact Gunny1005, I got mine through him for right at $250 (gaskets and bolts)

Not a bad job to do but time consuming. If you cant do it yourself it will be expensive though. Pays 11-12 hrs to do, so at $80 and hour you are looking at $950-$1000 labor plus parts. If its just a burnt valve you could fix that for probably only $300 in parts...and thats OEM parts too.

About the first shop and saying it was injectors...obviously the first shop didnt do a comp test for yours. I thought mine was injectors too, but the comp tesr dont lie. I would think it would fire though even with 100 psi.

 

All good I appreciate your help.

I took it back to the first mechanic who diagnosed it and they cleaned out all of the fuel injectors to where #1 is performing like it’s new. The pressure increased by about 20% but it’s still 40% lower than the other cylinders. We’ll wait and see if the light comes back on but looks as it is a damaged valve from when my radiator cracked. Too bad my car didn’t communicate a hot engine when it happened before it did damage...

 

Good to hear it is working a bit better, but that's a big difference between cylinders. Did you get a quote on fixing the valve?

 

Yeah it is quite the difference. He said “$1,800 to $2,200. Could be less if things look good inside.”

I guess with doing that everything they pull out to get to it from under the hood gets inspected and all the valves get cleaned and replaced (or something like that).

Sounds like a good deal I think to run another 200,000?

 

Just FYI, back to your coils, these older trucks have an ignition system known as a "waste spark" system. 1 coil controls 2 spark plugs and they both fire at the same time, while 1 cylinder is on the combustion stroke and the other is on its exhaust stroke. So if you have a failing coil, you will have a misfire on 2 cylinders, not just one.

 

Right. So would the engine light be pulling up cylinders 1 and 4 and not just one? One is the only one having pressure issues. The problem wouldn’t be the coil because of that, correct?

 

That's correct. You'd have 2 misfire codes if it was a failing coil.

 

Okay thank you. So that even says this issue is definitely a valve job in cylinder 1. Joy

 

Most likely if you've got low compression on cylinder 1 and you're not losing coolant (head gasket failure) then you've probably got a burnt valve. Have they done cylinder leak down test or checked your coolant for combustion gasses?

 

Yep, they did that in the diagnosis and the coolant was good. They said drive for the next week to see if the light goes off on its own and if not I’ll have to make the decision on whether I want them to do the job or not. That’s a hard one to chew.

 

Yeah, this is why I was saying to look for a 304 code as well. Good news is, it looks like your problem is identified. Bad news is it ain't cheap. But, it's not terrible. You might get another 100K out of the engine if you fix it and take good care of it.

 

My current thinking right now is they find other issues as they’re taking it all apart then it may be a money pit...super frustrating this happened.

 

Looking into it, it's going to be more money than it's worth so I'm looking into another truck. Which of these would you guys recommend getting when it comes to mileage, mpg, price and longevity:

https://www.ksl.com/auto/listing/4472458?ad_cid=44
https://www.ksl.com/auto/listing/4372795?ad_cid=2
https://www.ksl.com/auto/listing/4488103?ad_cid=9
https://www.ksl.com/auto/listing/4519623
https://www.idriveutah.com/vehicle-details/used-2005-toyota-tundra-sr5-orem-ut-id-22864964

 

^That one. Price/milage. But they are all close enough in milage that I could go for the color and best price.

2005 Toyota Tundra SR5
Mileage: 108,936
Lindon, UT | Posted March 18, 2018
$12,500

 

Yeah the green one has almost 25,000 less miles for $500 more but not sure if that’s a good deal compared to the other Tundra. My biggest thing is looking for a vehicle that can tow more than my 2006 Honda Pilot for a 2,000 lb camper, which my Pilot specs say 3500 lbs but idk if it’s doing more harm than good compared to a 2005 v8 Tundra.

 

I'm very picky if I look at/for a Tundra. 2005-2006 only. '05 is when they moved to the newer VVTi and 5-speed Auto (A750)