Strange loud "whirring" noise on startup?

[IcantDo55]

115K 4x2 v8

When you start it motor makes a loud whirring noise for 20 seconds or so than it stops. Sounds like a electrical motor or a fan of some kind. Best guess it sounds to be coming from middle of motor like in the intake manifold. Truck runs and drives fine no CEL.

Search did not help because I don't know if i spelled "whirring" right.

Thanks

 

[IcantDo55]

115K 4x2 v8

When you start it motor makes a loud whirring noise for 20 seconds or so than it stops. Sounds like a electrical motor or a fan of some kind. Best guess it sounds to be coming from middle of motor like in the intake manifold. Truck runs and drives fine no CEL.

Search did not help because I don't know if i spelled "whirring" right.

Thanks

Follow up:

I typed this after changing oil and it was the 1st and 2nd start up while cold. I had truck idling while I posted this, went back outside turned it off and on and no noise. Just posting whit I see.

 

[awdjunkies]

This may sound stupid but, do you have XREAS on your Rig?

 

[IcantDo55]

This may sound stupid but, do you have XREAS on your Rig?

Thats the corner to corner shock thing right? I dont believe the 4x2 came with that. Why?

 

[HokieRunner]

115K 4x2 v8

When you start it motor makes a loud whirring noise for 20 seconds or so than it stops. Sounds like a electrical motor or a fan of some kind. Best guess it sounds to be coming from middle of motor like in the intake manifold. Truck runs and drives fine no CEL.

Search did not help because I don't know if i spelled "whirring" right.

Thanks

What year is your 4Runner? Sounds like it's the air pump system going bad. I had the same thing but installed a bypass module to fix the issue.

 

[awdjunkies]

Thats the corner to corner shock thing right? I dont believe the 4x2 came with that. Why?

Ah okay, because if you did, that would be something to look at(Process of elimination). I say this because sometimes I can hear this whirring noise, which happen to be the XREAS doing it's thing.

PS: Sorry, I didn't catch the 4x2 thing from the get go..

 

[awdjunkies]

What year is your 4Runner? Sounds like it's the air pump system going bad. I had the same thing but installed a bypass module to fix the issue.

Yeah, the emissions pump system.

 

[IcantDo55]

What year is your 4Runner? Sounds like it's the air pump system going bad. I had the same thing but installed a bypass module to fix the issue.

2006
I like bypasses.

Where is this pump? Can I default it on to see if its the sound and how?

 

[chmura]

This is the engine fan.

During start up you get a big whirl sound because the fan comes on and then after a few seconds stops.

My Tacoma did this too.

Completely normal.

 

[IcantDo55]

This is the engine fan.

During start up you get a big whirl sound because the fan comes on and then after a few seconds stops.

My Tacoma did this too.

Completely normal.

This is really loud. Had truck for 6 months I think I would have heard it before.

 

[HokieRunner]

2006
I like bypasses.

Where is this pump? Can I default it on to see if its the sound and how?

It's located UNDER the intake manifold, so a proper fix is expensive. There are a couple bypasses: cheap one involving a relay, resistor and some wiring, or a $200 solid state module that tricks the air injection system into thinking conditions are such that it should NOT run (keeps it in stand-by mode), and then there's the whole top engine tear down to replace a couple expensive pumps and air valves.

What it is

http://www.toyota-4runner.org/4th-gen-t4rs/116457-brief-whirring-revving-noise-startup.html

module and a good read on why/how they fail

Let me know if you have any other questions. I know another member here did the relay/resistor method which works just as well as the module. [MENTION=68704]superman3043[/MENTION]

Bottom line is that you can also just live with it, but it can/will throw codes depending on which part of it has failed and certain codes will throw the vehicle into limp mode (rarest side effect but still a possibility).

Can I default it on to see if its the sound and how?

It will only activate when the engine is cold. Which is why when you went back out and fired up the truck again it didn't activate. Not sure if you have a scantool or not but might want to do a OBDII scan or stop by a parts store that does complimentary scans. It might turn up a pending code.

 

[IcantDo55]

It's located UNDER the intake manifold, so a proper fix is expensive. There are a couple bypasses: cheap one involving a relay, resistor and some wiring, or a $200 solid state module that tricks the air injection system into thinking conditions are such that it should NOT run (keeps it in stand-by mode), and then there's the whole top engine tear down to replace a couple expensive pumps and air valves.

What it is

http://www.toyota-4runner.org/4th-gen-t4rs/116457-brief-whirring-revving-noise-startup.html

module and a good read on why/how they fail

Let me know if you have any other questions. I know another member here did the relay/resistor method which works just as well as the module. [MENTION=68704]superman3043[/MENTION]

Bottom line is that you can also just live with it, but it can/will throw codes depending on which part of it has failed and certain codes will throw the vehicle into limp mode (rarest side effect but still a possibility).



It will only activate when the engine is cold. Which is why when you went back out and fired up the truck again it didn't activate. Not sure if you have a scantool or not but might want to do a OBDII scan or stop by a parts store that does complimentary scans. It might turn up a pending code.

Excellent post sir. Will report back after fix

 

[IcantDo55]

Found it:

http://www.toyota-4runner.org/1398043-post356.html

 

[earthrealm]

This is the engine fan.

During start up you get a big whirl sound because the fan comes on and then after a few seconds stops.

My Tacoma did this too.

Completely normal.

mine does this too...........guess its normal..opened the hood to confirm, its the fan alright

 

[IcantDo55]

I read in one of the many searches I did that you could unplug the pump. Where is the plug?

 

[HokieRunner]

I read in one of the many searches I did that you could unplug the pump. Where is the plug?

I'm honestly not sure where the plug is. If you can find the plug and undo it you might throw some codes. Not 100% sure on that but just a possibility.

 

[slyfox75]

Yeah....I don't think its as easy as disconnecting the pump.
I've done the AIP bypass mod and it's not too bad for a DIY type person.
As the weather gets colder.....you rproblem(if its the AIP pump) will go away.
If air temp is below 41F it won't turn the AIP pump on(you've most likely read this already on other posts). That's the poor mans way of testing Hope for a cold night and go test the cold engine and less than 41F outside. See if it whines. If not....BINGO. Mine would throw codes from time to time until I did the mod....been running fine now for 8 months or so.
Good Luck.

 

[IcantDo55]

Yeah....I don't think its as easy as disconnecting the pump.
I've done the AIP bypass mod and it's not too bad for a DIY type person.
As the weather gets colder.....you rproblem(if its the AIP pump) will go away.
If air temp is below 41F it won't turn the AIP pump on(you've most likely read this already on other posts). That's the poor mans way of testing Hope for a cold night and go test the cold engine and less than 41F outside. See if it whines. If not....BINGO. Mine would throw codes from time to time until I did the mod....been running fine now for 8 months or so.
Good Luck.

In my searching I have found that people have done this but not any real details on how. I hear we need a relay and a resister. You have any details on the mod?

Thanks

 

[IcantDo55]

Yeah....I don't think its as easy as disconnecting the pump.
I've done the AIP bypass mod and it's not too bad for a DIY type person.
As the weather gets colder.....you rproblem(if its the AIP pump) will go away.
If air temp is below 41F it won't turn the AIP pump on(you've most likely read this already on other posts). That's the poor mans way of testing Hope for a cold night and go test the cold engine and less than 41F outside. See if it whines. If not....BINGO. Mine would throw codes from time to time until I did the mod....been running fine now for 8 months or so.
Good Luck.

Looks like you are the go to guy for these "kits".

http://www.toyota-4runner.org/4th-gen-t4rs/140490-secondary-air-injection-help.html#post1362509

Still selling parts or offering the details on what parts to get and where to wire them up?

 

[slyfox75]

yeah I can help and/or supply parts.
Email me at [email protected] and let me know what you need or what questions you might have.

Thanks