Engine Hydraulic Fan stuck on full-steam

[rparker]

Hello guys/girls,
Just a little problem thats annoying the **** out of me. My hydraulic fan in front is stuck on 100% operation so on start up and with anything above 2k rpm its really noisy, now my lexus sounds like a oversized hoover. The amount of air that is pushed even at 2k is so high it will blow newspapers away from behind the car, yes BEHIND!. No its not the exhaust, its very big bore so not must air velocity.

Its also particularly bad when you stretch her legs on those long drives where it feels like something is going to explode coz the fan is spinning so fast and making such a god awful high pitch "hoover with a sock stuck up the pipes" sound.

I even opened up the exhaust a month ago and I can't even hear the damn pipes over that vacuum machine up front.

Now I did some research and the net tells me that the fan is indeed a hydraulic fan which uses ATF fluid to turn the fan. My question is where the heck the regulator is and where is the pump that runs the fan. Is there actually a separate Fan ECU?

Also if anyone knows where the temp sensor is or if its the same one the feeds the gauge and the ECU.

All I want is my quiet lexus back so I can hear the nice V8 burble, I don't want a hoover for a lexus :squint:

Please help!!

 

[Lextreme II]

It sounds like your hydraulic fan is bad. I think you can check if there is any fluid in there. However, if its making that type of noise its better to replace it. The hydraulic fan pump is not cheap. Retail price is about $275 from the dealer. However, there is another option would be totally eliminate the system all together to electric fans.

 

[rparker]

Firstly thanks for a extremely fast response!
The noise isn't actually a mechanical sound, rather its the sound of too much air being pushed along coz the fan is spinning really fast moving far too much air.

Ok, so how do I check if there is hydraulic fluid inside. It is actually in the coupling? or is there a reservoir someplace else?

I've actually read through how you used electric fans, and I thought about it but don't electric fans make a lot of noise too? Sorta like out of the frying pan and into the fire thing no?

Strangely, just for the benefit of everyone else, I actually went down to my local toyota dealer and a parts distributor whose software doesn't actually have the part in their system....hmmm....

Anyway, it'll be great if I can find out where the fluid goes, maybe I can just drain away the old one and put some new ATF and see how it goes before ripping off the system.

Thanks again!

 

[Lextreme II]

Please check this link... http://lextreme.com/forums/showpost.php?p=60852&postcount=2

 

[jibbby]

Well it sounds like your hydraulic pump cylinoid, heat sensor and or ECU (reads) are faulty...If the fan is running at full strength at all times I would say the fan and hydraulic pump are just fine, it's got to be the cylinoid, heat sensor, and or ECU that is a miss...Maybe a wire that is cooked... There is a "screw in" cylinoid Bolt on the lower right side of the hydualic pump that has a black wire connected to it....That cylinoid opens and closes the Hydrualic fluid push if I am not mistaken, that cylinoid is operated by an incoming electronic feed control sent from the cars ECU...The ECU is hooked in with the main engine heat sensor... (that sensor or wiring maybe bad)

The engine heat sensor tells the ECU (Computer brain) to operate the hydraulic fan speed in accordance to the cars temp (in lamens terms)....

I would guess that Toyota made it safe that when there is a break down in the electric and temp reads the hydraulic fan safety option kicks in and operates the fan at full blast so upon failure the engine does not overheat and blow...

Look into the sensor reads if you can find them...Or electric fans are always an option....

Use the search option and look up "10-20hp gains with electric fans" that thread shows you everything about the pump, fans, reads, swap, etc...It may help you better understand your problem....Good luck..

 

[Lambo]

Hydro Fan

Maybe these will help solve it

Regards
Lambo

 

[rparker]

Opps

Thanks so much guys,

You know what...I've been looking under the hood the whole day feeling really stumped. I couldn't find the reservoir, no lines, no cooler, nothing, just the fan connected straight to the engine.

The fan is just connected straight to the engine without all the fancy stuff you guys talked about. I think I made a mistake. :Flush: Is this actually a viscous fan rather than a hydraulic fan? I've taken some pictures to show you guys what I'm talking about.

Anyway, with the car off the fan is tight when I try to turn it. I even nearly got cut man, never knew the plastic fan was that sharp.

Wierd thing is that it would seem Lexus never offered this type of fan, or so I was told by the shop technicians, could it actually be modified from another car and installed?

Oh, and another thing, I read the other Flex fan and I think it'll be great but the problem is I'm actually in Malaysia, the latent humidity here is always above 90% which makes heat exchange a bit poorer and besides, I can't get those type of electric fans here which is a shame.

Was just thinking, would there normally liquid in the hubs of these type of fans, maybe I can drain some out to make it spin slower? Do these type of fans still use ECUs or does it work purely based on the surrounding temperature?

Thanks guys!

 

[Peewee]

You have a viscous clutch fan, not a hydraulic fan.
The UZS131 Crown had this from factory on the 1UZ, its the only one that did.

The clutch has locked, its quite a common thing as they get older.
You can replace the whole clutch itself (shiny silver metal bit with fins), or try and replace the fluid inside it.

Replacing the clutch is expensive, and replacing the fluid doesn't always work.
So its your call as to what you want to do.

 

[Nick M]

Well it sounds like your hydraulic pump cylinoid, heat sensor and or ECU (reads) are faulty.....

Solenoid, not cylinoid... (sole-eh-noid)

 

[jibbby]

Thanks Nick M....I suck at spelling, but I can comprehend with the best of them...Everyones got a hang up, spelling is mine....... I should have paid more attention in English classes growing up rather then day dreaming of girls and a monster engine build in my then owned Chevy SS Nova ....:sleeping:

Solenoid it is (Sill-y-noid):alcoholic:

rparker - You should consider an electric fan swap as those viscous fan systems take more engine power to run in comparison to the hydraulic fan systems...You could gain as much as 10hp or more at high rpm's with an electric fan swap...Something to consider....

 

[Vdog]

So are you guys saying the dual fans I have on the outside of the radiator just behind the grille are aftermarket and not stock?
Mine fans turn on when the car starts, and turn off when the car gets warm. Im thinking I have a bad switch. Any ideas?