4th Gen 4Runner Head Gasket (1 Viewer)

[Tentsontop]

I picked up an 05 that I think the PO put head gasket sealant in the radiator fluid before he sold it to me. I'm planning on having the HG done as soon as possible. Truck (V6) is sitting at 218k right now. My question is how long will this HG sealant work? I've already put almost 2K miles on it in the week that I've had it. I'm monitoring the rad, oil, temps and checking for codes. So far, all is clear.

 

[sean2202]

A fix in a bottle IMO really should not be used..... unless its an emergency. With that being said I have in the past used HG fix in a bottle as I was in a jam. What I had was a 96, 3rd gen 4 runner with the 3.4 V6. It did have a head gasket leak and I used the head gasket repair with the fibers in it. I used 1/2 the bottle and kept the other 1/2 in the truck "just in case". For the most part it sealed the leak up, never ran hot and I used it for about 20k miles before I sold it. I was going to fix the H/G but I just never did and kept running it. I had to top the coolant off every once in a while.

There are different kinds of H/G sealant. Mine had the fibers and beware that the fibers can play havoc clogging up passages in the system. I never had that problem but have heard others have.

What makes you think your H/G is bad? Why do you think the PO but sealer in?

 

[Tentsontop]

I can see whatever it is he put in there on the cap and in the reservoir. He said he was a Toyota tech a few years ago. He cleared the CEL, cleaned out the overflow reservoir and the radiator cap after adding the sealer then refilled the reservoir with clean fluid. I knew the little bit of rad fluid I saw below the radiator was a red flag. He said he must have spilled a bit while topping off the radiator. It drove great, the CEL wasn't on and I did not realized the PO306 code I brought up on my reader was what it is. I took it for what it said - random misfire. I've learned a lot about 4runners since that day. 3K+ miles later it's still running great. I have no idea how long I'm going to leave it in there. I'll get to the HG eventually. We're still trying to close on a house right now, so it will be a bit longer. The PO306 has not come up again.