Another 2005 V6 4.0 1gr-fe Head Gasket Failure

Quick update, the truck is back together and running! The knock sensor code is gone, but now I’m having misfires on cyl 5, 6 and random...at this point the quarter tank of fuel in my truck is 3 months old, so I topped it off last night and added a bottle of fuel cleaner. It idles well, and revs through the RPM range smoothly when parked. It drives smoother with a heavy foot, if I accelerate aggressively when driving the engine seems to smooth out, but if I’m coasting at speed and lightly apply the gas it starts to shake and mis. It doesn’t seem to matter the RPM range either. I’m thinking it’s a fuel issue since it runs well at WOT, but I can’t entirely rule out the plugs and coils. I did replace the plugs with NGK iridium ones when I was trying to rule them out diagnosing the head gasket issue, I’m almost inclined to just throw the original plugs back in and see if that does it. I drove it 40 miles around town today, feels good to be back on the road!

 

I am glad to hear that you got it up and running again. Stinks about the misfires though. For some reason, which I don't know, most folks and mechanics that I have talked advise against running iridium plugs. Not sure if that would be causing your issue though. I know you did have misfire issues initially, albeit, on a different cylinder from what I recall.

I wish I had some suggestions to give you, but hopefully others can chime in.

 

No worries! I have a game plan, posted more for continuity than anything else. I know I’ve learned a lot from the forums in random threads. The Denso spark plugs weren’t in stock when I was buying, the first thing I’ll try is switching back to the OEM sparks, then check coils / wiring. I think I’ll pick up a compression test kit after that.

 

What nightmare. I went thru that a year ago exept I dont have that automechanic skill level. Mine was just one head 2.7 happend rite at 208k up till then It never had one failure at all. It got repaired and its back running like a champ thank God. Love that truck. Everything works as it should motor trany ac brakes etc.

 

Got the misfiring figured out! I got those NGK Iridium plugs out of my truck and cleaned up the original OEM Denso's, regapped them and torqued those back to 15ft lbs. The only 2 spark plugs the manual recommends are DENSO K20HR-U11 and

$10 NGK LFR6C-11 V-Power Spark Plug, Pack of 1

NGK LFR6C-11. The NGK I bought were NGK LFR6A...that was on me for not checking the service manual and relying on the parts guy at Oreilly's. Since I was having a pretty consistent cyl 5 and cyl 6 misfire code I swapped those coils with coils 1 / 2. Fired her up and the misfire followed to cyl 2. Called around and found a coil at a local dealer, and she's running like a champ now! Today, running an errand I got a new CAT code for bank 2, which I'll look into, but man does it feel good to be back on the road!

 

So glad you got that sorted. I been using K20HR-U11 for my spark plug changes. Could that P0430 be for a leaking exhaust manifold?

 

Could be! From the SM...I'm betting it's a leak from the exhaust where I disconnected.

 

After my head gasket failure I had to get a new cat. I tried the cleaners but nothing woud get rid of the code. I would reset and treat with cleaner and in a bit it would come back on. I found a new OE cat for that side and all is good since. They are a once piece manifold and cat. Expensive buggers too. The radiator fluid going through the cylinders and into the cat ruined it.

 

Dang that sucks! Hope it doesn't come to that. At first startup I had a ton of exhaust leaks that cleared up once the engine warmed up, not sure if that's normal after replacing an exhaust gasket, but the leaks seemed to go away after it idled for a while. I'll have to check them closely, and spray some soapy water on them to be sure.

 

I don't believe that is normal. I was lucky enough to not have any exhaust leaks on startup. I did spend sometime cleaning up the sealing areas on both the heads and the manifolds when they were out of the truck.

 

Quick update guys, haven’t figured out the O2 sensor / Cat issue yet, but I’ve been able to clear the code by adding a drilled out 18mm spark plug anti fouler spacer on the downstream O2 sensor. I did this primarily to keep an eye out for misfire codes or any others that could pop up after the repair. It does not appear to be a gas leak, I’ve sprayed the flange down many times now with soapy water before starting it up and the seal seems tight. No coolant loss, and I’ve put a few hundred miles on the truck now and I’m feeling more and more confident with the repair job each drive, so if anyone out there is debating on whether the head gasket is doable for non-mechanic types, do it! If you have a garage and the time, it really isn’t rocket science, just a bear of a job that is palatable in small chunks.

 

3,000 mile Blackstone oil analysis results:

https://www.tacomaworld.com/threads/2005-1grfe-blackstone-oil-report-post-headgasket-repair.810276/