New Fan is Very Noisy

[chrislloydie]

As some of you may be aware, a couple of weeks ago I had my cooling fan and motor replaced under AA warranty.

It seems to now be a 2 speed fan system in place. However it is very noisy. I have done the following tests and these are the results. Can anyone comment on if this seems right please.

Car idling with no aircon on, monitored coolant temp via IPK diagnostics, when temp reached 99 degrees, the fan kicked in on slower speed as it should. After about 30 seconds the fan went off and the IPK showed coolant temp as 94 degrees.

I then sat with car idling and temperature reading 95degrees and then switched the Auto Aircon on, set at lowest setting. Immediately the fan came on at its faster speed, I'm not sure that this is correct? Also the noise seemed excessively loud! Almost same as standing watching an aircraft preparing to take off. In fact it was rather embarrassingly loud and I quickly turned the aircon off and fan slowed to a stop.

So, can anyone confirm that the 2 speed fan fitted to the zt should be this noisy? It cant be heard from inside the cab with windiws closed, or when driving with windows down. Or is it just cos my fan has never worked since I got the car that it seems really noisy now its working.

As always, comments and advice is appreciated.

[Matt brighton]

Hi

Not sure if this helps... but I replaced the fan on my 2001 Diesel Conn se 2.0 CDT Automatic last year with one from SMC.

When its on I can hear it at tickover sitting in the car - but not whilst driving along

Its the 3 speed with no external resistor at 2pm. Spliced the wiring into the old control box as per instructions on the comprehensive fan thread.

The fan (to my knowledge) has never operated under normal use of the car all the time I have owned it - but only when the air con is switched on.

Only ever heard it operate at one speed - which isnt intrusive and as the a/c works and car hasn't overheated - I guess is ok ?. I would be interested to hear if this sounds normal from other drivers

Im assuming the diesel runs so cool it just isnt required......

(I still "worry" about it but cant bear to contemplate installing another)

[chrislloydie]

Hi Matt,

My fan doesn't come on at all when I'm driving normally, only when aircon is on. Its not intrusive when I'm sitting in the car but is very noisy when I stand next to the bonnet.

It only came on at slow speed as I left car in the sun, idling for about 20 minutes as I wanted to test the fan came on.

[Matt brighton]

Hi Chris,
sounds just like mine...... except I have never tested the car to the point where slow speed comes on.

Temp guage always at rock solid mid point - regardless of traffic jams or ambient temp - tho I know they have a wide margin befor it registers hotter than that.

Regards

Matt

[T-Cut]

I think it's probably the difference between the 'slow' speed of the 2-speed system and the 'low' speed of the original 3-speed system that's worrying you. The 2-speed motor runs a lot faster on its slow setting. Why worry how loud it sounds outside the car? Personally, I think a good meaty fan beats a whimpy sounding one any day.

I'm unsure about the high speed event you described. The fan control system will trip whatever speed is required according to a priority decided by the ECU. Engine cooling takes priority over A/C, so if the coolant is hot enough the high speed fan will run whether the A/C is on or not. If you're sure it was running at high speed, I can only suggest that the coolant was hotter than you thought.

TC

[StevenWilliams]

Sounds normal to me.

I don't have a working low speed on my 3 speed fan and the medium setting (Your low speed) is quite loud.

When the aircon is on it is very loud.



I did a temp test and at 99 degrees my medium speed comes on and switches off at 95.


Normally my temp is at between 85 when driving and 92 when idling. I forced it to 99 by keeping the revs at 3k while standstill. It still was about 3-5 mins before the temp hit 99.

[JohnDotCom]

If the inside temperature of car is quite above what you have it set on the Air Con control panel (CC)
when switched on to Auto will switch to high speed to try and reduce the temperature.
Well thats the idea if it doesn't blow your head off first!

[chrislloydie]

Thanks for the comments guys. It would seem that my fan is okay then. I had the Aircon set to LO and the outside temperature ws showiing as 27degrees so maybe thats why the fan came on high speed.

I guess I should stop being paranoid about the car going wrong and just start enjoying her!

[Jules]

Hi Chris

From your temp readings, your fan should only be coming on LOW SPEED initially for AC.

2 possible causes:

either too much gas in the AC system. (this will trigger the Trinary HP switch instructing the ECU to output HIGH SPEED)
Try disconnecting the Trinary multi plug & see if fan behaves the same (compressor will be disabled during this test


The PCB in the fan control box could be faulty. (had a few of these to date)

Fan coming on HIGH SPEED initially is not normal & will burn out your HIGH speed relay very soon as they were not designed to take a 50 AMP initial surge

Hope this helps.
Jules

[T-Cut]

Just added my quick search term = #CFO# (Cooling Fan Operation).

TC

[Jules]

Thanks T-Cut !
The other method is to Bookmark useful threads you want to keep (in alphabetical order)

Belt & braces method is to Cut & Paste a particular post & email to yourself or save as a document. You will always find stuff then ;)

[T-Cut]

Thanks T-Cut !
The other method is to Bookmark useful threads you want to keep (in alphabetical order)

My bookmark list is already too big and cumbersome, but it's a good way.

Belt & braces method is to Cut & Paste a particular post & email to yourself or save as a document. You will always find stuff then ;)

I have a similar system apart from my quick search markers. I just copy/paste stuff onto a Notepad page and store it is a suitable folder. An important issue with this can be copyright. I always mark any images and text as Copyright of the poster. For any really useful images, I ask permission to reproduce elsewhere. Most people are pleased to agree. I think it's important though copyright theft is damned annoying.

TC

[chrislloydie]

Hi Chris

From your temp readings, your fan should only be coming on LOW SPEED initially for AC.

2 possible causes:

either too much gas in the AC system. (this will trigger the Trinary HP switch instructing the ECU to output HIGH SPEED)
Try disconnecting the Trinary multi plug & see if fan behaves the same (compressor will be disabled during this test


The PCB in the fan control box could be faulty. (had a few of these to date)

Fan coming on HIGH SPEED initially is not normal & will burn out your HIGH speed relay very soon as they were not designed to take a 50 AMP initial surge

Hope this helps.
Jules

Hey Jules,

I unplugged the trinary switch at the rear of the engine drivers side with the aircon set to 16degrees and the fan immediately switched from fast speed back down to low speed. When I reconnected the plug, after a few seconds it sped up again. I cant beleive it should be doing this as its almost impossible to hear what SWMBO was saying to me when we were stood next to car!

Any advice please mate?