Excessive engine noise.....from engine cooling fan?

wtc88c · 06-25-09, 07:56 AM

Having bought my 06 GX 470 only a few months ago, we're encountering 90-degree-plus days for the first time. There is an unusually loud noise from the engine that I'm almost sure is cooling fan noise. It occurs after running in the heat of the day. It's not mechanical noise, but a loud roar like that of a large truck engine.
Is this typical for these models in the heat?
Does anyone know of a fix for this? a quieter fan, etc?
Thanx,
Bill

habeeb89 · 06-25-09, 08:38 AM

I am pretty sure that it is the cooling fan constantly turning on, you have to remember that the GX is no small SUV. That V8 will heat up and quick. On my GS430, the fans always roar on every few minutes and that is a smaller V8 than yours...

As long as the coolant is fresh and the temp. gauge on the instrument cluster is in the middle, you are fine.

Linko · 06-25-09, 08:54 AM

It is the cooling fan, and yours sounds very typical for summertime in the South. My GX does the same thing, but I usually don't hear it unless I am outside the vehicle or at a standstill. There is no fix - the engine needs a big fan with a lot of air circulation power to keep cool.

The G Man · 06-25-09, 11:32 AM

Thats normal, the GX has a cast iron block, it needs a lot of cooling.

snhrph · 06-25-09, 01:41 PM

You can turn off the AC to reduce the fan noise.

gsobol · 06-25-09, 02:49 PM

It's a mechanical fan, ie it's always spinning. The only thing that controls the speed is a thermal slip clutch. If it's hot outside the clutch will engage sooner and stronger (less slipage) and it will allow the fan to spin along with engine RPMs producing more air movement and noise. It will also rob more of your engine HP in doing so.

I6turbo · 06-25-09, 08:46 PM

If it really seems abnormally loud compared to other vehicles, you should check (or have someone check) the fan clutch. I live in Florida and I've never heard mine making an unusually loud roaring sound. Typically the "large truck like roar" is caused by the fan clutch being fully engaged and causing the fan to spin a a much higher speed than it normally would for a given engine RPM. I've had other vehicles with a failed fan clutch (locking up too much) and they roared in a manner that I'd describe as you have here.

wtc88c · 06-26-09, 07:25 AM

Thanks for your feedback.

mann777 · 06-28-09, 02:10 AM

My LS 94 came with a dual fan, later models came with Single Fan, There is lot of place where you can have a dual fan fitted on the GX. This improves the cooling efficiency by at least 5-8%. All you need is Additional Fan, Relay switch and a heater fuse

btle29 · 07-14-09, 05:29 PM

I have the same problem on my gx470. I contact the dealer and they told me that cause by a bad fan clutch, it's very common on the gx. The part is about $225. it's very easy to fix it yourself.