can coolant get from here... to here...

[BKFZ1]

4th gen 4Runner/V8/Sport
Coolant leak, eventually dripping from the flexplate/flywheel housing.
Expecting the leak to be emanating from the hoses/pipes coming out of the back of the engine, using mirrors and an inspection camera, everything is bone dry back there.

With the gathering of the coolant at the bottom of the flexplate housing, I removed the flexplate cover. After drying the area of any moisture/residue, I stuffed a paper towel in both sides of the bottom of the flexplate housing. By the next day, the paper towels were saturated with coolant, and the surrounding exterior areas were dry.

So... it appears the coolant is traveling down into the flexplate housing from... where? After hours and hours of searching many resources, I have yet to find this same scenario on any forum.

Question/title: Before I remove the intake manifold for inspection of the coolant pipe running through there, is it possible for coolant to leak from that pipe, down (internally) into the flexplate/flywheel housing?

The last image (not my vehicle) shows a glimpse of the top of the flexplate/flywheel from where the starter (?) would normally be.

 

[4Reak Show]

Yeah that's where the starter sits. I've seen the valleys fill up with coolant from multiple sources. The 2 likeliest are the crossover pipe gaskets that go from head-to-head in the front and rear, and also where the water pump bypass pops onto the pipe is an O ring that can get folded if not properly lubed with WATER based lube like hand soap not Vaseline. I'd take off the intake and get a pressure pump on the system to see.
Good luck

 

[mattkc16]

Hey Guys,

Im a new member to the forum and am having major powerloss @ the engine. I'm not able to post a new thread, so im replying to this one to see if you can help. I took my 5th gen to the dealership (twice), and to a second mechanic and they haven't be able to nail down the issue. Currently the engine is operating at about 30% power, they checked clogged cats, mass air flow sensor, fuel pressure. They are thinking the knock sensor is causing the engine to pull timing, hence the lost of power. they did check the sensor and wiring harness and both have good continuity (i.e. no issues with them) They didn't identify any knock or issue with the engine, but are recommending disassembly of the engine for a inspection to see if there are any issues $$$. Does anyone have any recommendations of other things to check, or any applicable threads?

Thanks

 

[BKFZ1]

Yeah that's where the starter sits. I've seen the valleys fill up with coolant from multiple sources. The 2 likeliest are the crossover pipe gaskets that go from head-to-head in the front and rear, and also where the water pump bypass pops onto the pipe is an O ring that can get folded if not properly lubed with WATER based lube like hand soap not Vaseline. I'd take off the intake and get a pressure pump on the system to see.
Good luck

Thanks 4Reak!
That's exactly what it was - both crossover pipe gaskets and replaced the O ring since we were in there. And to think 2 different shops wanted ~$800 (to start) just to drop the transmission to see where it was coming from.

Awesome board, awesome people - thanks to members like you!

 

[4Reak Show]

Glad it worked out.

Now you have extra beer money.