Help Deciphering Misfire Inspection Report

[Kb1982]

My 2001 was running rough/misfiring so I took it to a shop and got the below report. They recommended rebuilt/reman head for engine replacement. I have no reason not to trust their assessment and I am not mechanically knowledgeable so my own inspection, but a 2nd opining would be appreciated.

Minor backstory: it was running ok, but I hadn't driven it. Bought it semi-recently and was working valve cover leak and chasing electrical gremlins.
Technician's Notes: P0300 random misfire, P0301 P0303 P0305, Cylinder 1 3 5 misfire. Vehicle barely runs, has spark and fuel on the affected cylinders. Checked cam timing since the misfires are confined to one bank, cam timing is good. Removed the spark plugs and found two wet with fuel and one fuel fouled. Did a compression test and found zero compression from cylinders 3 and 5. Leak down test indicated a problem with the intake valves. Removed the valve cover to inspect for valvetrain damage, everything looks good, next step would be to remove the cylinder head to inspect for a bent valves or valve seat issues.

 

[Sparky 97Runner]

The technicians notes look solid to me. I agree the next step is to pull the head and dig deeper. They recommend a rebuilt or remand head because your head may not be rebuildable.

 

[brillo_76]

Sure sound like the head gasket or head on the one bank has issues. How about the other side 2,4,6?? As if you going to tear it down on one side. The the side of the engine may need some TLC. Its running so bad because half the engine isn't working. Might be best to use OEM head gaskets etc.. Unless you want have to redo it.. Sadly, we just had a member here have his heads redone and didn't use OEM head gaskets and had to redo it 6 months later. :-( Maybe your mechanics are aware of this but Toyota can be very particular with their gaskets and parts. I just hate to see folks have to redo things because bad parts...:-(

 

[Kb1982]

Thanks for the replies. I appreciate it. It ran fine when I test drove it, but suddenly stopped after it ran out of gas so I was hoping for maybe a simpler/cheaper solution.

Not sure what's the status on the otherside, but the shop said they'd rebuild/repl ace both sides if they were going to do anything, though even they said it's a coin toss if that'd fix the issues.

 

[alia176]

That is a great report, i thought. Kudos goes to the mechanic and the service writer.

Remember, even as newbies, we have a lot of love and interest in saving money while DIY fixing our junk. It might be something not too expensive to repair but finding it will take a considerable effort.

I have the heads on my dining room table so let me know if you have questions that I can answer. Visual answers are MoBetta than bunch of words!!

Before anyone wonders, yes, I AM divorced. I also use the dishwasher to wash car parts.

My take: At this time, the valve seats maybe so foulded/dirty that they're not seating perfectly and closing tight. So, the air/fuel mix is seeping into the cylinders and fouling the plugs.

Another thing might be the injectors. Couple of them might be leaking and dripping when they're not suppose to. This is an easy fix but to remove them requires a fair amount of work. The odds of three injectors leaking is quite low but maybe the wiring to them is suspect. While doing my daughter's head gasket project, I'm also cleaning/testing her injectors. Yup, on the dining table!!

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I had to put in spaces in the report to make my brain hurt less.

Technician's Notes: P0300 random misfire, P0301 P0303 P0305, Cylinder 1 3 5 misfire.

Vehicle barely runs, has spark and fuel on the affected cylinders. Checked cam timing since the misfires are confined to one bank, cam timing is good.

Removed the spark plugs and found two wet with fuel and one fuel fouled. Did a compression test and found zero compression from cylinders 3 and 5.

Leak down test indicated a problem with the intake valves. Removed the valve cover to inspect for valvetrain damage, everything looks good, next step would be to remove the cylinder head to inspect for a bent valves or valve seat issues.