Repair advice? Blown head gasket on 4th Gen 4Runner?
- Thread starter cbradley
- Start date
keezer37
Explorer
I had replaced the thermostat & coolant at 100k. I used Amsoil coolant which does not have silicates. My limited understanding is I am not endangering the o2 sensors/cats on the affected side. I've recently read, it's the silicates that does the damage.
I've got a Block Tester and I do test positive.
Pulled the connector on number six coil, ran it for about five minutes and tested again...still positive. I intend to run this test again, having it run longer. Number six is my fouling plug.I borrowed a pressure tester from Autozone and ran the check this weekend. Cooled the motor down, topped off the radiator, pumped 18 psi in and it managed to drop to 15 psi but it took four hours to do it, so I'm calling it good. Note: That 45mm OEM brand adapter can really maul a plastic radiator neck if you're not careful.
I get air bubbles immediately at cold start up, lots of them, so...haven't figured that one out yet.
I'm inclined to monitor the coolant and oil and not spend the money at this time. I'm loosing confidence in this vehicle.
shortbus4x4
Expedition Leader
Sounds like you have done your home work. Based on what you have done I would say you have a bad head gasket/head on #6. You see lots of bubbles when its cold because things expand when they get hot so you don't have as much of a breach then. I have seen coolant leaks where I put 15 psi to them and not a drop leaks, I put 7 psi and presto it leaks. Sometimes leaks only happen at lower pressures, put operating pressure on the cooling system and the leak seals itself up. Head gaskets on a 3.4 are easy, especially compared to a 3.0. If its not a high mileage engine I would recommend head gaskets, usually its cheaper than a whole motor. Make sure you get the heads pressure checked though.
Pictures of the culprit
I finally got the job done. See attached for pictures. The gasket on top was the passenger side head gasket which was okay (They replaced both since they were already doing one) the bottom is the driver side gasket. The next picture is a close up of the culprit. see the bits of paint chipped off between the two cylinders. that is where the small amount of coolant was leaking into the cylinder causing the spark plug in Cyl 6 to misfire. As the engine warmed up the gasket expanded and sealed itself back up. This allowed the spark plugs to ignite burning away the coolant that leaked in.
The mechanics actually removed the engine out of the truck as it was easier to work on with more space to maneuver around the engine. They told me that they ordered the new gaskets direct from Toyota as there is an updated part. Apparently Toyota knew of this issue with the 1GRFE motor and produced an upgraded gasket but since no one has died and there aren't many instances of this they decided to save some money and not conduct a recall. I guess this type of practice is common in the auto industry.
Hope this helps some of you. This thread has been invaluable to me. Thanks everyone for your input.
I finally got the job done. See attached for pictures. The gasket on top was the passenger side head gasket which was okay (They replaced both since they were already doing one) the bottom is the driver side gasket. The next picture is a close up of the culprit. see the bits of paint chipped off between the two cylinders. that is where the small amount of coolant was leaking into the cylinder causing the spark plug in Cyl 6 to misfire. As the engine warmed up the gasket expanded and sealed itself back up. This allowed the spark plugs to ignite burning away the coolant that leaked in.
The mechanics actually removed the engine out of the truck as it was easier to work on with more space to maneuver around the engine. They told me that they ordered the new gaskets direct from Toyota as there is an updated part. Apparently Toyota knew of this issue with the 1GRFE motor and produced an upgraded gasket but since no one has died and there aren't many instances of this they decided to save some money and not conduct a recall. I guess this type of practice is common in the auto industry.
Hope this helps some of you. This thread has been invaluable to me. Thanks everyone for your input.
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keezer37
Explorer
Thank you.
Good to know there is an upgraded gasket. Hopefully they also assigned a different part number so as not to be confused with any old stock. Have to check my local dealer.
I think I'll give one more shot at trying to get Toyota to pick up some of the cost now that I know they've recognized the problem.
Interesting that you should mention pulling the engine. I know on the Tacoma, the manual states to drop the entire front driveline (transfer case forward) and I cannot figure why other than to perhaps access to the lower exhaust manifold bolts?
-Was any resurfacing necessary?
Good to know there is an upgraded gasket. Hopefully they also assigned a different part number so as not to be confused with any old stock. Have to check my local dealer.
I think I'll give one more shot at trying to get Toyota to pick up some of the cost now that I know they've recognized the problem.
Interesting that you should mention pulling the engine. I know on the Tacoma, the manual states to drop the entire front driveline (transfer case forward) and I cannot figure why other than to perhaps access to the lower exhaust manifold bolts?
-Was any resurfacing necessary?
They didn't have to pull the engine but they said it would be a whole lot easier and faster to work on with it out. No resurfacing was necessary as it was a small leak and the engine never overheated to cause warping. The shop I took it to actually already knew about the HG on this moter he said he worked on 3 others before mine.
keezer37
Explorer
Stopped by the local dealer yesterday. Talked to the parts guy and yes there is a new part number: 1111631011 superseded 1111631010. Though he could not specifically say why. Said it may just be a vendor change.
Talked to a mechanic while I was there. He says he hasn't had any incidences of head gasket failures.
I sent one email to Toyota regarding this back in January. I think I'll piggyback on it and ask why the superseded head gasket.
Talked to a mechanic while I was there. He says he hasn't had any incidences of head gasket failures.
I sent one email to Toyota regarding this back in January. I think I'll piggyback on it and ask why the superseded head gasket.
cbradley
Adventurer
Please do. I'd like to know what they have to say. My failed head gasket cost me an arm and a leg in repair costs.
keezer37
Explorer
Email went out on the 14th. The turn around time for an answer on my previous email was four days. Will post their response as soon as I get it.
Dave Bennett
Adventurist
The dearly departed (she looks so young)
I hope you kept this for spares Chris, I see lots of good bits there :drool:
cbradley
Adventurer
Sadly, I had to give it back as a "core" charge. I would have done things a bit differently if I had to do it over again.
maclean216
Observer
For the OP. Did you replace your water pump or was it the original one?
keezer37
Explorer
Toyota/Keezer Email
I asked:
-"...is this new head gasket due to the failure? If so, will Toyota now, at least
in part assume some financial responsibility for the repair?"
Their response:
-"Special Service Campaign involvement would cover repairs past the manufacturer's warranty. We checked your Vehicle Identification Number, and did not find any Special Service Campaigns for the condition you have described. If the 2005 Tacoma happens to become involved in any future Special Service Campaigns involving the head gasket, then owners would be notified by Toyota via U.S. postal service at that time."
Make of it what you will.
For my part, while I expect problems as a vehicle ages, I do not expect internal problems of a well maintained engine. Further, they did not answer the specific question of "why the new head gasket".
cbradley
Adventurer
I replaced the water pump, hoses and radiator.
