P0304 Cylinder 4 Misfire - Headgasket Replacement

Nince work on tackling it yourself, I remember reading this thread when you started it and was pretty damn sure it was the HG.

I had a shop do my head, they pulled .003" off IIRC and cleaned them up nice. I was $800 all in, but ordered everything online, sounds like the dealership is taking you for a ride unfortunately.

I have notes and parts list in my build if you are interested. Did the work two years ago and running strong.

https://www.tacomaworld.com/threads/wishbone-runners-build.238998/page-16#post-9549520

From this:



To this:

 

Just saw your full list. I didn't do the O2 sensors, oil pump, chain guides or idler pulleys (had done the idlers previously). My guides looked fine, so did the oil pump, are yours showing any wear?

 

That does look mighty nice..

 

Did you overheat and warp the head before the rebuild? .003 seems like quite a lot but I've only dealt with 4 cylinders before.

 

turn of nut style, I noticed that in the manual. Good ol' one time use structural bolts

 

I remember coming across your thread while researching. Nice work! Your thread was useful in prepping, thanks for all the pics and details!

Yeah the dealership still has me reeling from the costs. To be honest, my first list with them totaled $3,200, then I whittled it down to $2,600, then the guy gave me a break on the pricing to drop it to $2,200. I didn't go the internet or aftermarket route because 1) I've had mixed results in quality with some of the aftermarket products and this truck wasn't cheap, want to to last a long time 2) my truck is my daily driver, I'm in a rental truck now and need to be back on the road asap. I ordered parts yesterday at 11:00, picked them all up at 3:30 today, and I know they are the right parts, and not damaged from shipping. I'm sure I could've purchased at least some of the parts online or aftermarket and saved I'm guessing around $400-$500 fairly easily. But time is money. Damn though, $2200!!

Oil pump looks fine, guides showing only normal wear. I went for the oil pump mainly because I read another thread about a fault in some of the oil pumps causing oil starvation on the driver's side. That post showed discoloration on that side of the engine, which looked very similar to mine. That was enough to scare me into the pump replacement. They do have new part numbers listed for the pump (and body) as well, hopefully an "upgrade".

 

[/QUOTE]
The machine shop's make things look pretty! I dropped my heads off this afternoon, hoping to pick them up tomorrow. I asked for the IIRC (do I have that correct?) to be checked, clean them up, and pressure test. The machinist will call me tomorrow and will decide whether to take the sealing surface down and replace seals (I will likely have this done, I gave them the seals from the master kit while dropping off). I also gave them the timing cover, it needed a bath.

 

Parts and costs so far:

Beer - don't remember
Coil (Denso) - $99
Spark plug Set (NGK) -$35
Crankshaft Pulley removal tool that I butchered and still didn't work - $47
10 cans brakeclean, electrical connector spray, throttlebody clear -$70-ish
12-point bi-hex bit - $15 (local auto store)

OEM parts (will post pictures of receipts, too many items to list) including:
Oil Pump and Body
Master Gasket Set
A whole bunch of vacuum and coolant hoses because of cracked ends or I ripped them apart trying to remove them
Thermostat (includes body)
Timing Chain Idler assembly
Chain Dampener
Chain Guide
2x Drivebelt Idler #2
Drivebelt Tensioner
Drivebelt Ilder #1
Various plastic clips I broke
Radiator and hoses
Radiator Cap
PCV Valve and both hoses
Drivebelt
Water Pump
Head bolt set
Driver's side primary O2 sensor
Replacing some of the rusted exhaust bolts (particularly the bracket bolts)
FPIG sealant

Still need:
Toyota coolant
Mobile 1 syn. oil and filter
air filter

I'm taking a risk on the driver's side catalytic converter, had the p0430 code showing up due to the misfire. I was also considering the timing chain tensioners, but figured that was overkill.

 

Here is a clearer picture for reference. There are three, or four, machined spots where the timing cover bolts to the center of the block.

Three are under the chains idler pulley, and I believe the other is near the driver head oil port.

Don't forget to hit those with silicone as well.

 

I did not, never overheated, as soon as I heard the gurgling, took it out of commission.

 

Thanks, glad I could help out others with this unfortunate issue.

I went all OEM, but did shop around for everything as cheap as possible, I wouldn't recommend using aftermarket for this job either. But yeah, sometimes you need to bite the bullet for convenience, I had the luxury of taking my time as I work from home (took me about 2 weeks start to finish).

Gotcha, better safe than sorry, especially when you are balls deep in it and have easy access to everything, ripping it apart again would suck.

I will second removing the studs on the cover to seal the oil pan, I had to later drop the oil pan and reseal everything which was a MAJOR bitch.

Good luck, it is not an overly difficult job, just time consuming with LOTS of parts to keep track of.

 

My friend's tC hit 240ºF. Warped it .006". 4 cylinder.

 

Two questions for you guys: You think I'm safe with the catalytic converter? Honeycomb appeared to be intact. What kind of gas mileage are you guys getting? And did you see any improvement after rebuild? I was getting around 13.5-14 mpg which seems pretty bad, i thought 16+ was more normal for the 4x4 V6's..

 

My cats were fine, I am 16-18 with 34s and a shit ton of steel. To answer your questions, yes, I did see an improvement after the rebuild and the motor ran much smoother and quieter. While is was a bitch to do, it was probably a good midlife cleaning for it.

 

Nice, thats a good pic. Fingers crossed I get a good seal. I like to scrape old gasket material, then use fine steel wool to polish the sealing surfaces super clean. I forget why, but when I did my car I forgot something simple and had to rip the freshly seal timing cover off, clean again and reseal (I had not bolted everything else back on yet luckily though!). Let's hope that doesn't happen this time!

I read that! I really don't want to drop my front diff and steering rack! I hope my resealing goes smoothly...

Cool! I'm hoping I get some improvement for my efforts and money beyond just a non-leaky HG (although I will be happy enough if I reassemble with no leaks and no problems with a fixed HG that lasts). I'm replacing the O2 sensor on the driver's side, and hoping with the fixed HG the cat burns itself clean.

 

Picture time:
Before:


After:






Fresh out the machine shop. I got lucky, I think they forgot to charge me for the parts cleaning... $125.00 out the door from the machine shop. Heads were pressure tested, no cracks luckily. Had them R&R the valve stem seals, but no valve job. Hehe, valve job. Made me laugh when they asked me if I wanted a valve job. Interestingly, the machinist told me these heads cannot get lathed on the HG sealing surface otherwise the valves will contact the pistons. I told him others have had it done without any problems, but he said that he knows from first hand experiance that it shouldn't be done on these heads. I do trust him somewhat as this machine shop is the one the Toyota dealership send their heads to get worked on. He said Toyota specs allow up to 0.004 out of flatness, and mine were not out of spec. When I did my car, I had bolted on a "fully remanufactured head" from a reputable shop, and ended up ripping them off again because the pistons contacted the heads, so I didn't argue with the guy.

Okay... time to get to work, here we go!

 

Parts turned out great.

 

Just spent the entire day scrubbing sealing surfaces and cleaning parts. If anything leaks, I'll probably blow a gasket.

 

Nearly there.