Code P0302 - Cyclinder 2 Misfire Detected

I just checked my reservoir tank and it is low again. I filled it to the "Full" line 2 weeks ago.

So does this means that "coolant drains into the cylinder over night" per Bishop84 comment?

 

If you have a bore scope, you can check for a head gasket leaking into the combustion chamber by placing the camera into the spark plug hole. The top of the pistons should be fairly black. If their is one or 2 that the piston is oddly clean, theirs your issue. The coolant/water leaking into the combustion chamber will provide a sort of steam cleaning effect to the top of the piston. You may also be able to see it leaking in if at the same time you apply pressure to the coolant system via a pressure tester

 

Ok, so it looks like I will be doing either

1. driver side (cylinder 2) head gasket replacement

2. use Bar’s Leaks HG-1 Head Seal Blown Head Gasket Repair solution ->

$33 Bar's Leaks HG-1 HEAD SEAL Blown Head Gasket Repair

https://www.amazon.com/dp/B003RGIWO0

any recommendations on not using the Bar’s Leak repair method?

Thanks for everyone’s inputs!!

 

The leak repair just gums up everything but the leak, it will make things worse before better.

You need to confirm the leak first, park it hot, remove the spark plug on the missing cylinder and use a pen light to peak inside if you can.

Ideally a borescope if you can find one.

 

Thanks @Bishop84

As y'all know, cylinder 2 spark plug is a pain the *ss to remove due to where it is. It took me over 2 hours to get the connector back on the coil pack after I replaced the spark plug for #2.

Not sure why but it seems that there is not enough wires to make it easier for me to reconnect the plug into the coil. It has to be at a particular angle and turning clockwise etc. to get it to snap together.

many busted knuckles to get this one connected and I am fear of it to this day.

As you can see in the attached picture.

Is there an extended adapter that I can make or purchase to give me more wires so next time I replace spark plugs, #2 will not be a pain in the @ss? lol

@Bishop84 can I disconnect cylinder 2 spark plugs before I run the truck to get it hot and then just remove the coil pack and use a borescope? I know it will be close to impossible to remove the spark plug when hot since it is already a pain removing while cold.

 

No unfortunately you cant run with a coil unplugged, the engine shouldnt run like this.

You dont have to remove it immediately, but its best to see it in action. On really bad leaks you can see it mist in.

I usually connect the coil while the coil is loose, not while its bolted in.

 

also it is possible to remove spark plugs first thing in morning and use borescope to see leak mist that is causing rough idle? sine it at times start rough and the smooths out.

 

The mist only happens hot, as the metal has expanded and high pressure on the cooling system exists.

You can still peak inside the cylinder to inspect for moisture.

Again these arent sure things, but things to check.

 

@Bishop84, please help me to understand how the reservoir tank works.

If you look at the attached picture, it's identical to my truck.

1. please note that the suction line from radiator to the tank is connected on the top.

So, when overflow from radiator goes into the reservoir, it will fill it but not to the top. Then when it cools, it will be sucked back into the radiator.

It's hard for me to understand how air bubbles is not also being sucked back into the radiator since the suction line is at the top rather than at the bottom.

Thanks

 

In your other photos you can see inside the tank and the piping that is internal, it draws from the bottom.

 

@Bishop84 that's just the drain with clip. there is not tube beyond that I can take a picture of it closely in the morning and double check but I remember no tube beyond the clamper.

 

Look closer, the yellow inside the tank is the tube. It connects to the top.

 

@Bishop84 you are AMAZING!!! Thank you!!!

 

Happy Friday y'all!

@Bishop84 - I did the followings:

1. examined the oil dip stick NO milky or murky creamy substance
2. Did a block tester kit and it DID NOT turn yellow. Test was performed for approximately 15-20 mins to make sure that the engine is warm/hot and temperature gauge is in middle.
3. Taco does not over heat or nothing, temperature gauge steady at middle


Observations:

1. light white smoke coming out from tailpipe
2. small water drops dripped from tailpipe, I would say one drop per 5 or so seconds
3. drops confirmed as water, NO gas or coolant smell. Not greasy either
4. taco started rough and engine light came on. once smooth running the engine light went off.

Thoughts or recommendations?

Thanks Again!!

 

So while at Toyota I've seen many headgasket misfires, and tried the chemistry kit with no success.

What I found later on was this.

https://youtube.com/shorts/IzmOjpB5WFA

I'd be bleeding the coolant, and while reving it, I'd see a stream of little bubbles, not air, but combustion. And these stupid little bubbles wont change the dye on the kit, but they are clearly there.

This was a propane truck that had hard start misfire. Had other techs look at it and could not diagnose it. I have other 4.0's same issue, same bubbles.

These were all confirmed with borescopes and starting to get routine on 4.0's from before 2010.

 

@Bishop84, so maybe I should remove the cap to the radiator and look directly into it and see if there are any small bubbles?

I am thinking of maybe replace #2, #4, #6 fuel injectors even though #2 might be bad but go ahead and change #4 and #6 since I am already in there? Or maybe just #2?

 

Before you start replacing things I'd pull the plugs, presurize the cooling system with a pressure tester, let it sit overnight with pressure, the next day look in the suspect cylinder(s) with a borescope for coolant.

If there's coolant in them you 100% have a headgasket leak, if not your headgasket is probably fine and you need to look elsewhere.

 

@Dm93, thank you for the advice. I will do that on Monday and let you know my findings. Thanks

 

Here is another suggestion. Buy or rent a borescope with a side view. I will link one below. Pressurize the cooling system and use the borescope to inspect the cylinders. You should be able to rent one of these too. For example. If one or more are leaking, you should be able to see a leak coming from the head gasket and running down the cylinder wall. This is what I saw with the borescope while pressurizing the cooling system on my truck.

DEPSTECH 5" IPS Display Endoscope, Dual Lens Inspection Camera with Light, 7.9 mm HD Borescope, Sewer Camera with LED Flashlight, 32 GB, 5000 mAh Battery, Carrying Case, Detachable Snake Camera-16.5ft

DEPSTECH 5" IPS Display Endoscope

 

Thank you! I have purchased a borescope on Amazon and will use it when I pressurize the cooling system on Monday.