Just replaced intake manifold due to a bad manifold runner solenoid, then did a test drive with a couple full throttle pulls. Now it is leaking coolant from the right rear of engine (pass side). So far I can't locate it and I didn't think I disconnected any coolant lines.
2008 IS250 AWD 130,000 mi

 

Did you disconnect the throttle body small hoses? I'm guessing at that milage the hoses are pretty much too stiff. For the oem small clamps to tighten down. There's the one from the back of the TB, and Front one.

 

Yes, disconnected all of them, I think. Just saw a thread about a coolant hose that connects to the throttle body...do you know which one that is?

 

See my photo ^ up top. It's right under the TB only 1 hose there on the back. The other is for the front along the manifold front.

 

When you find whatever is leaking make sure you bleed the coolant. The last thing you want is air trapped in the system.

 

Ok, I found the hose under the front of the TB, and the clamp was not even in position...easy fix. It stopped leaking, but now there is a pulsing sound coming from under the TB, like a distant helicopter - is that air? If so, how do I bleed the cooling system?

 

 

Thanks for all the help. It doesn't run hot, but I bled the system anyway. Over more than an hour, bubbles came out. Unrelated to this, the dealer had the engine out a year ago for the ZLA recall, where they replace rings and seals due to oil consumption. I'm thinking they did not bleed it then.

 

By any chance did you experience this from the links below?

https://www.clublexus.com/forums/is-...l#post10265832


https://www.clublexus.com/forums/is-...-solution.html

https://www.clublexus.com/forums/is-...-bank-1-a.html

 

Ouch, hindsight is 20/20. Originally, my mechanic at work said it was the intake manifold runner solenoid. I went to my trusted parts store, and they searched and searched, but could not find the solenoid to order. They said I can only buy it as a whole with the intake. They got a Toyota part number for the intake and I bought it on line at a Lexus parts distributor. Now that it is back together, it runs fine with all the power it originally had. For what it's worth, I just went outside and tried removing the two phillips screws form the solenoid of the old intake, and they won't budge. But I am thinking it is the same as what happened in the links you sent, where the nut worked itself loose.
I paid $597 for the aluminum intake, genuine Toyota parts. Two new gaskets for the bottom of the intake, re-used the upper orange ones.

 

For stubborn screws like that. I use some medium size long nose vise-grips. Just enough to break them loose. Then proceeded with a Phillips. It should do the trick.

 

 

Yep, I was a little baffled by the poor fit of the cross tip, but got it off with vice grips after soaking with penetrating oil. Didn't round it out. So I got the solenoid off and there was the nut - not on the shaft! Live and learn I guess. Thanks again for all the feedback, Mike Fig and Texas149. Anybody want to buy a used intake manifold..!