Toyota/Lexus 3.3L V6 Water Inlet (Valley) Plate Coolant Leak

[The Critic]

Tip: if you own a Toyota 3.0 (1MZ-FE) or 3.3 (3MZ-FE) V6 and you see a buildup of pink crust around the thermostat, your water inlet plate is leaking. If it is leaking badly, coolant will drip down the transmission.

This issue seems to be common on older 3.0/3.3’s after 120k. For some reason I see it more often on the 3.3s.

This plate is sealed using RTV. In order to perform this re-seal, you must remove the upper and lower intake manifolds, both knock sensors and the knock sensor studs. When doing this job, I suggest replacing the bypass water hose, the knock sensor wiring harness, thermostat and all intake gaskets. You will also need 2 gals of Toyota SLL coolant and 1 tube of FIPG Black.

Labor time for this repair is 4.5 hr, but many shops will bump this up a bit. There is quite a bit of cleaning required.

Our local Lexus dealer gets around $1300 for this job.

I recently did the job on a 05 RX330 with about 138k miles. This one had been leaking for a while.

1) The coolant leak was obvious once the lower intake manifold was removed.



2) Water inlet plate removed:




3) Cleaning and Reassembly:


Gasket dissolver was soaking on the surface:

 

[Charlie2015]

Thanks for sharing!

 

[MONKEYMAN]

Having a Lexus is nice until you need to get it serviced or repaired. $$$

 

[JC1]

Critic is the stealership charges $1300, what are you charging for that?

 

[MaximaGuy]

The intake manifolds removal on a 3.3L is a PITA, there are some bolts that hold the housing to the rear and almost blindly you will have to remove and put it back. No fun.

The Lexus is much simpler since the entire manifold is held with studs w/o the bolts to the rear (or atleast that is what I have seen on the 3.5L when I extended my arm behind the manifolds).

Oh yeah, replacing the plugs is when you really wonder how hard it is on a Highlander vs. Lexus. You pay a 10K more for ease of replacement on a Lexus from plugs, mounts, LCA etc.

 

[andyd]

The Rat's long-wise V6 is awkward enough to wrench on. I won't own a transverse V6. I've been living in a fool's paradise working on inline 6s .What is the deal with leaky intake manifolds, etc on V6s?

 

[supton]

Originally Posted By: MONKEYMAN
Having a Lexus is nice until you need to get it serviced or repaired. $$$
Wasn't the same mill used in a number of Toyota products?

 

[dishdude]

I see the hood struts are shot too, had to double vise grip it!

 

[michaelluscher]

Originally Posted By: supton
Originally Posted By: MONKEYMAN
Having a Lexus is nice until you need to get it serviced or repaired. $$$
Wasn't the same mill used in a number of Toyota products?


Pictured is the same engine that powers many Sienna's/Highlander's, and the Camry in my signature

I'm just passing 105k and didn't know about this

Will keep an eye out, but I haven't seen a drop of coolant anywhere yet

 

[The Critic]

Originally Posted By: MaximaGuy
The intake manifolds removal on a 3.3L is a PITA, there are some bolts that hold the housing to the rear and almost blindly you will have to remove and put it back. No fun.

The Lexus is much simpler since the entire manifold is held with studs w/o the bolts to the rear (or atleast that is what I have seen on the 3.5L when I extended my arm behind the manifolds).

Oh yeah, replacing the plugs is when you really wonder how hard it is on a Highlander vs. Lexus. You pay a 10K more for ease of replacement on a Lexus from plugs, mounts, LCA etc.


The Toyota 3.3L and the Lexus 3.3L engines have the exact same intake manifold setup. No difference. There are 3 stays which keep the upper intake manifold secured. I have not removed the intake manifold on a 3.5L so I am not sure on that one.

Originally Posted By: andyd
The Rat's long-wise V6 is awkward enough to wrench on. I won't own a transverse V6. I've been living in a fool's paradise working on inline 6s .What is the deal with leaky intake manifolds, etc on V6s?


The RTV seal failed. I hate RTV.

Originally Posted By: dishdude
I see the hood struts are shot too, had to double vise grip it!

Yep, but I did install a new hood strut. It only uses 1. I also had some fantastic luck that day and the bolt to the lower hood strut bracket decided to break off as well. But I did drill out the bolt and fix it properly.

 

[Supersonic]

Revisited, being I just did this job and this thread may up on a future search for others.

At 12:50 here the bolt is right where the bracket bends over the top, best to use a ratcheting wrench, spread the bracket as necessary and then you'll likely need fingers from both hands to free it and when reassembling to get it started, not hard but tricky.


Suggest watching several videos on knock sensors, spark plugs and valve covers to help unveil the procedure, it wasn't real difficult, just keep your parts grouped/binned to each section of removal and allow for a couple of days especially when sealant has to cure 24 hours. I used the Permatex Ultra Gray, and this video linked here helped on how to apply it,

More Information for AISIN AB1207B1

And the only special tools I remember is the external torx sockets E8 for easier removal of the intake plenum and E6 for the coolant plate stud to better clean the gasket surface. Vacuum cleaner, gallon jug, and a 1/2 inch tube about 2 feet for a extraction of the about 2 cups of coolant under the coolant plate. The jug contracted some but allowed for enough vacuum to clean out the coolant a couple of times and the vacuum cleaner didn't get any coolant in it. 4ft LED corded garage light from Harbor Freight, best trouble light ever when rigged with bungees for under-the-hood repair. If I can think of more I'll add later.

 

[haawkyle]

Anyone got the torque specs and torque sequence for those bolts on the inlet plate?

 

[The Critic]

Anyone got the torque specs and torque sequence for those bolts on the inlet plate?

Water inlet housing torque values for bolts

www.siennachat.com

 

[haawkyle]

Thanks!

 

[nthach]

I just done this repair on a 05 Sienna. It was more or less the same as this job. Except I used Toyota’s $70 RTV for cooling systems(ThreeBond FIPG 1282B) and did a switch over to Prestone for coolant. I also replaced the radiator hoses as PM, and one water bypass hose between the valley plate to the throttle body was replaced with the proper molded Toyota piece. I used a piece of 5/16” heater hose as a contingency.

 

[DV0993]

Bumping an old thread... Suspect I have a valley plate leak on an rx330.

Anything else I should do while everything is apart? Im thinking plugs and coilpacks (rear bank) but wondering if there are any gaskets or hoses that are worth doing.

Sitting at about 120k miles

 

[malibuguy79]

Valve cover gaskets. I resealed my 06 HL last year but my plate wasnt leaking (i probably should of just did it anyways)

Be prepared to replace some coil connectors or use zipties

 

[The Critic]

Maybe knock sensors if you're feeling wealthy?

 

[michaelluscher]

Maybe knock sensors if you're feeling wealthy?

Do you feel it's the sensors themselves or just the harness?

I had a ghost P0333 on my 3MZ last year, cleared it and hasn't come back in 6 months

 

[The Critic]

Do you feel it's the sensors themselves or just the harness?

I had a ghost P0333 on my 3MZ last year, cleared it and hasn't come back in 6 months

It can be either.