My sisters 2004 rx330 165k miles lost all of its coolant on her way to have me check out her car. She initially called me to diagnose the ac not working. The second call was for the suv not accelerating over 15mph with the gas pedal down. I had her pull over and shut down immediately. I'd estimate she drove for at least 15 minutes with no coolant. The temperature gauge was on cold. I assume the temperature gauge reading cold was due to lack of coolant. The engine was smoking hot once she shut it off. The dipstick was even too hot to touch.

We let the car sit for a few hours. Then we added some coolant into the radiator. It came out of this plastic fitting which the radiator hose attaches to. The hose does not appear to be leaking. The leak is from the plastic piece the hose slides onto that attaches to the engine. I'm wondering if this was the initial cause of the overheating. I suspect the heat may have caused it to melt.

The suv still starts and drives. It takes a bit longer to start than normal. There was a firestone repair shop in the parking lot she pulled into. They are taking a look at it. I could fix it but if the head gasket blows in a few hundred miles I don't want any harsh feelings toward me.


I'm wondering how difficult it is to replace this fitting?
Has anyone heard of this plastic fitting leaking. It's on the side of the radiator cap. It definitely has some play as I can wiggle it and the hose around. The location where it mounts near the cylinder head looks difficult to access. I had to stick my phone in there to get a clear picture. Otherwise it's not easily visible from above.

It's worthy to note she made a few other stops before driving over. One of the times it took her a few tries to get it to start. This hard to start moment was before she started the 15 minute drive to where the car is parked now.

She had a "tune up" done a week ago. Plus 4 new tires
I told her once the leak is repaired there is a 50/50 chance the engine may need major work. If not right away maybe after a few hundred miles.

What are your thoughts?

 

 

Is it the thermostat housing? (Lexus calls it water inlet)
https://www.japan-parts.eu/lexus/us/...et/2?pnn=16321

Possible the housing got so hot it cracked or the gasket got baked and/or hose. That sounds like a severe overheat I'll be impressed if the engine survives. Replacing the thermostat on this engine is a bit of a pain but not too bad.

 

Thanks. Yes that is the area leaking. 16321 is the pipe which has coolant pouring out of it. I'm impressed with my picture and description you were able to narrow it down.

I just asked my sister if they replaced the thermostat with her "tune up" last week. She is checking.

 

Nope, thermostat wasn't replaced.

 

Most common failure is the radiator gives out do you see coolant leaking at the seam between the top tank and core?

 

I didn't notice any other leaks when I looked at it briefly yesterday. I expected to see some dried coolant or splatter. After it cooled off we dropped the coolant cap to the bottom of the radiator. While retrieving it I didn't see anything obvious.

I agree with your earlier post. I'll also be surprised if the engine survives.

 

Firestone is replacing the thermostat housing. They claim it is cracked which makes sense since I could move the pipe around. They also wanted to tack on a $200 coolant system flush. I laughed. Eventually they agreed to simply fill it afterward.
I noticed that pipe on some lexus vehicals appears to be metal. Unfortunately on the rx330 it is plastic....planned obsolescence.

 

Too funny. lol
It was already flushed when all the coolant in the system dumped out on the ground.
Wallet flush

 

In the automotive world it is called weight savings.

 

The car was finished yesterday. It is running normally for now. My sister pointed out even the ac is blowing cold lol. Hopefully it stays that way.

 

Wow that's amazing, big fat fail on plastic parts. I wonder if it's possible to use the aluminum parts from a 1MZ, there are two pieces instead of the one plastic housing. edit - just checked the 3MZ in the E330 it also has aluminum parts.

 

I am happy for your success and the car is running.
Please don't think i'm being negative but if it was my car and it is now running again I would trade it in today.
Your concerns above have merit.

 

Margate330 no worries. If it were mine I might consider selling it to carmax. Unfortunately, with the new tires, "tune up", plus the firestone bill I'd estimate they have spent $3k in the past 2 weeks on it. I doubt carmax would offer much more than that.

I have another sister with a different 2006 RX330. I'm going to recommend they replace their thermostat housing as preventative maintenance.

 

Yeah that's a tough call.
Poor engine took one hell of a punch!