93fourunnerSR5

Hey everyone. So my 93 4runner started throwing a knock sensor code. Last year I noticed it using a little bit of coolant but could never find a leak. Well I started it up this year after sitting all winter and was amazed at the massive leak coming from the back of the motor. I had a hard time trying to pinpoint the source and actually ended up using a borescope. What I found was coolant leaking out under the sheet metal cap to the coolant line under the intake plenum. So I tore it apart and found that the valley was flooded with coolant and my knock sensor was under water! I didn't get far enough to actually find where the leak is but I'm suspect of the metal tube. Has anyone ever seen these do this? Anyone have a good used one for sale?

Thanks

scope103

Looks like it's about $68. http://www.toyotapartsoverstock.com/...rimLevel=18292 Keep that in mind when you're looking at used pieces.

cr@ves4wheelin

On the heater bypass pipe under the intake, there is a gasket for where the pipe meets the block. That's probably where, I would guess, if the pipe doesn't have any cracks. When I swapped my motor to a 3.4, the gasket for the same pipe was messed up. Filled the valley full of coolant, etc.

93fourunnerSR5

Well here Is what I found. I think the FIP gasket failed.The mating surface, twords the bottom of the valley , is rusty with what looks like dried coolant residue. Its not clean metal like the upper mating surface. Also its interesting that the hole drilled for the coolant passage is offset quit a bit. Maybe this contributed to the failure. I'm replacing the coolant pipe anyways just to be on the safe side. This pipe was off about 4 years ago when the heads were rebuilt. What's everyone's opinion?

stefanc

@93fourunnerSR5 Hey,looks like i'm having similar symptoms. After replacing the FIP gasket, did the Knock Sensor code go away? Did you also replace the knock sensor and/or pigtail connector?
Appreciate the response!