MyEs300Yea

The car is a 95 es300, and the issue is that the antifreeze comes out of the cooling reservoir.
The PowerSteering pump is leaking from the banjo bolt, could this be what is causing the reservoir to overflow by over heating the antifreeze?
or is it 2 different issues.

PolishJoe

What kind of mileage do you have on your car? Overheating and overflowing into the reservoir can be caused by many things.

Bad radiator cap, clogged radiator, thermostat sticking, fan not working, low on coolant and worst case senario a blown head gasket which what happened to my car.

My car had over 200,000 miles when mine blew. I posted about it here and I'm currently in the process of fixing it. https://www.clublexus.com/forums/es3...-93-es300.html

MyEs300Yea

Actually it was a friend of mine looking to buy that lexus, but after i showed him something similar to what you told me here, he change his mind about it.

HDSC300

just to add note for those that have this bubbling issue... I check to see if my fan was working? (which it was idle at low speed before the car warmed up and increase as the temperature came up to normal level and remained increase when the car's temperature needle started to rise above mid point)

I took off both radiator and blow off caps and check their gaskets and overall condition of the caps themselves. I noticed the blow off cap ( located passenger side of the engine, right on top) gasket looked worn, I replaced that with a new one and then PROBLEM SOLVED.. PLEASE DO NOT REMOVE RAD OR BLOW OFF CAP WHEN ENGINE IS HOT... *** FYI *** I ran the engine again after filling coolant and then top it off, car remained within normal operating temperature and NO MORE bubbling reservoir........

Understand this may not solve all bubbling reservoir issues, other things within the engine can create the same symptom.

enterconne

Whats the level of your power steering fluid? If your low, there might not be enough pressure to run the fan. Tighten the bolt or replace the hose so it doesn't leak. I replaced the hose on Sunday since the rubber was cut near the fan.

EEngineer

coolant and ps fluid are two systems they don't interfere with eachother.

enterconne

That's good to know. What do you think it can be?

MyEs300Yea

Just so that you guys know, my buddy decided not to bother with trying to buy the car because he thought the seller wasn't being honest about the issue.

CUMan

That is true with most vehicles; however, the mid-90's ES models have a unique setup that creates a relationship between the two.

The radiator fan on these vehicles is powered by fluid pumped from the power steering pump. There is a control unit underneath the glove box which controls the fan speed by raising or lowering the volume of power steering fluid moved through the fan. As more fan speed is needed (e.g., when the card is idling or moving slowly), the power steering output is increased, thereby increasing the fan speed.

There is a wiring harness which connects the control unit to the power steering pump. A lot of overheating problems with these cars involves this connection being defeated by service people failing to reconnect this harness after doing work involving the power steering pump and/or other engine components in this area. Since this radiator fan setup is not common, it seems that service people don't attach the importance to this connector that they should.

I could see where low power steering fluid volume could cause a problem with proper cooling fan operation and thereby cause overheating problems.

Somewhere along the way, the ES models got an electric radiator fan; but I don't know what year the change was made.

BK4293

Beat me to it.... My 92 used to do the exact same thing. Seems there was a little plug unplugged on the top of the power steering pump that was causing my bubbling and overheating issues. Stuck my hand down there, plugged it back in and I was good to go!

rcpeters

I went through an expensive drawn out process to solve overheating that usually occurred on highway trips with long grades. In summary here is what I had to do, but not all at once (in between overheating incidents):
1. Rebuilt radiator and new aftermarket thermostat and pressure cap.
2. New hoses
3. Replaced water/coolant solution with 100% coolant.
4. Rebuilt heads, new gaskets and ground valves.
5. Removed hydraulic fan set up and converted to electric fan from a Jeep Cherokee.
6. Replaced thermostat and pressure cap with original from dealer.

No problems since, always stays in middle of gauge but when fan comes on you know it because of slight vibration, it is a turbine type blade!