Look what i found beneath my intake (could this be causing my head gasket symptoms?)

99 Tacoma 3.4 extended cab. 278k miles.
I am replacing the head gasket currently and got down to this point. I noticed the heavy coolant corrosion on the middle pipe and there’s quite a bit of engine oil pooled in the valleys below. I’m wondering if it’s possible that this leaking/corrosion could be what’s causing the billowing white smoke out my tail pipe. Other symptoms include the engine running rough, gradually worsening coolant loss. I’ve had multiple misfires in the past and always fixed it with new plugs/wires.

I already have the new head gasket kit and I’m prepared to send off the heads for resurfacing (and maybe a valve adjustment) but I am wondering if this corroded, leaking pipe/seal could be the primary issue instead of the head gasket or cracked head. I am planning on replacing the O ring and possibly the pipe if its corroded enough. I would love any advice if ya got any.

This truck has had two previous owners before me, and looks like they’ve been in here before (these felpros were already in there)

This is my first time attempting this heavy of a job, if you have any pointers I’d love to hear them. Thanks!

 

I think that's the heater bypass pipe. And it's leaking coolant. If it leaks coolant into the combustion chamber, then yeah, that will be your white smoke problem.

 

How would it be getting from there to the combustion chamber? Worsening coolant loss says head gasket to me.

 

This is my thought as well.

But the corrosion on the pipe is pretty evident of a major leak…unless the steam is getting sucked back into the chamber through a leak in the intake gasket, then coming out the exhaust/tailpipe? (Just brainstorming here with my limited experience) I’m taking the heads off tomorrow so I guess I’ll find out wether or not this leaking pipe is the only issue causing the coolant loss.

 

Regardless, it's still obviously an issue. Water is getting into the combustion chamber somehow...

 

is there a gasket made to fit that connection to the block, or does it just use FIPG.

 

You have 2 separate issues. The pipe has probably been leaking for a while. The headgaskets are the cause of the smoke.

There's no way for coolant from that pipe to get into the cylinders.

 

Most likely a head gasket giving away......

worst scenario is a crack(s) in the head between valves(s)

 

Other than the seepage the only other this I see is the jiggle valve on the thermostat is at the 12 o'clock position… multiple posts and much debate regarding the 12 or 6 o’clock positioning.

 

From minds greater than me.....

Jiggle....

2.4 & 2.7 = Up (+ or - 15)
3.4 = Down (+ or - 15)

 

That's not the cause of your white smoke/headgasket symptoms, but Fel Pro headgaskets certainly could be.

Get an OEM gasket set. Pull the heads. Have the machine shop check for cracks as well...these like to crack between the valves.

 

Yeah unfortunately the rusty frames and cracks between the valves seem to be the Achilles heel of the gen 1's...


See @ 13:00 min mark...

Engine Head Gasket / Cracked Head Repair (Toyota 3.4L V6 5VZ-FE ) - Part 4 - YouTube

 

This was the original diagnosis and then I found this corrosion/seepage from the heater bypass pipe and thought maybe it could be contributing to the head gasket symptoms.

Last time I replaced the thermostat i looked at as many forums I could find and never truly found a solid answer of which direction to go with. So you’re saying I should put the thermostat jiggle in the ‘6o’clock’ position on my 3.4?

 

Yes, previous owner put the felpros in. I already bought an OEM kit. Sending the heads off on Monday.

 

Yes, so much debate that I never found a solid answer haha. Do you have a preference for the 3.4s?

 

Thanks for all the replies, guys. I ordered a new pipe just to be on the safe side. Pulling the heads tomorrow and sending off for machining on Monday. I’ll keep this thread updated with results. I’m really hoping there are no cracks. If so, does anyone have a favorite place to get new heads from? I saw some recs on other threads but thought I’d ask here too.

 

Yeah I've always had a 4-banner.....and mine has always been 12 o'clock...
I always told the 6's (5vz) is always 6 o'clock...




As far as heads if want the best without going boutique.
these guys have the best warranty I've ever seen...5 yrs..



Cylinder Heads Catalog - Powertrain Products

 

the jiggler exists as an air bleed. Air is lighter than fluid. Jiggler goes on top...just like bleeders on brake calipers. There is no reason I can think of why it would be on the bottom....it would be pointless on the bottom.

 

..FOOD FIGHT

 

right...makes no sense.