Hey everybody,

Has anyone ever had this noise before? or know what it could be? please help! I notice the noise gets louder as the RPMs are going up while I'm driving.. it isn't affected when I turn the a/c on/off..

Thanks in advance for viewing and any input!

 

Wild guess....sounds like a cam chain slapping against the plastic cover. Have you had the start-up rattle TSB performed?

 

Could be a really really bad water pump bearing...

 

@lexIS007 - I don't think I've had that done yet.. I tried to get it done before my warranty was up but they couldn't replicate the sound since that only happens to me when it is below 40 degrees..

@RTIS250 - if that is the case.. is it ok to drive it to the dealer? and would that affect anything else if i keep driving it?

thanks for the responses!

 

Correction: I meant metal cover not plastic cover.

 

You should be able to reach down there, with the engine off of course, and see if the pulley for the water pump wiggles at all. Ive heard noises this bad before, and water pumps are fairly common. The noise is pretty loud, i wouldnt drive it regardless. Start by checking the pulley for play... if it moves, get it towed in, dont chance having the pump let go while driving and overheating the engine.

I kinda doubt its a cam gear noise... those go away after a few seconds. Sounds more like a bearing issue...

 

I'll check on the pulley in the morning and see what I can do about getting it to the dealer.. I pulled on the belts around the pulley and didn't notice any play on the pulley but I didn't actually pull on the pulley itself..

thanks again for the input lexis007 and rtis250! I really do appreciate it!

 

Yeah, if you're still on the OE water pump...$20 on the water pump bearing is toast. Check to see if you can see any pink coolant residue down the side of the block below the pump.

GL!

 

^my only concern with the water pump possibility is that, your right about when the bearing begins to even show slight signs of wear, there would be pink fluid on or around the water pump area....this doesn't seem to be the case here.

 

Leave the car with the dealer overnight (get a loaner while it's there) so they can start it up cold. That noise sounds like a tensioner bearing or possibly water pump/AC/alternator bearing. . It's usually the tensioner bearings that make noise when they are cold that goes away when hot.

 

Update:

I took it to the dealer and they said that it is the water pump. I haven't gotten the full details but I will be sure to get the details when I pick up my car and update you guys.

Another issue - my "Check VSC" and related dash lights randomly come on while I'm driving and always go away after I turn my car off and back on. The dealer said that I need to replace a "Stop Lamp Switch". Is this something that is an actual problem? or is this just a switch that malfunctions and is incorrectly throwing the "Check VSC"? I'm asking because it's about $220 to fix this..

Also, my airbag light has been on for a few months and they say that the "AIR BAG LF KNEE CONNECTION" needs to be replaced and that costs $187.50. Is there a cheaper alternative to this? Maybe it's a harness that I can just purchase and replace myself?

 

When it comes to Lexus wiring harnesses or switches, there are no cheap alternatives. Sorry. But I was on the money on that water pump huh!?! LOL!

 

Haha unfortunately you are right about there being no cheap alternatives. I guess I'll go ahead and take the hit and have Lexus fix these things. And yes you were right on the money! haha So was RTIS250.. Thanks again for the help, guys!

 

The stop lamp switch basically has 2 switches inside of it... its a built in failsafe if one switch fails, the other is good. They can cause codes when they start to go out. Best to get it replaced before it gets worse. Glad to hear i was right about the water pump (well, its cheaper than engine work, haha). Wheres my long distance diagnostic fee?

 

Hahah RTIS250.. What do you charge?