LexusFan2

I have a 2007 ES350 with 85k miles. I’ve noticed that whenever the AC is turned on, there is an audible grinding/groaning type noise coming from the engine bay. If I turn the AC off, the noise immediately stops and returns as soon as I turn it back on.

I’ve also noticed that the noise only occurs when the car is in drive or reverse. If I switch to park or neutral, the noise immediately stops.

I had the serpentine belt as well as two idler pulleys replaced in hopes of solving the problem but the noise is still present. Any suggestions or other troubleshooting I can perform to narrow down the problem?

CQRT

I was gonna guess 'compressor' but I'd also imagined whoever replaced your pullys and belts would have looked at that ?

jcat_350

I'm gonna go counter intuitive and say the bearings on your alternator may have gone. With the car in drive or reverse, you're placing additional load on the engine. By engaging the AC compressor, you're adding yet more load to the engine. If it isn't the alternator, and the car is running fine, the AC compressor would be my next guess. Either the bearings in it or the clutch.

I would suggest taking it to a different mechanic. A few minutes poking around with a mechanic's stethoscope is all it'll take to find the noise. It may transmit up the belt to another part, but having eliminated the belt and idler pulleys, you'll know those are GTG.

LexusFan2

I've noticed there is also a loud squeaking/chirping noise from the engine when the car is idling. It sounds like a slipping belt, though that's just a guess.

If I rev the car above 1k rpm, the noise goes away. Perhaps this is connected in some way to my first post?

As far as the AC compressor bearings or clutch being bad, it still blows very cold air even with all the chirping/grinding/groaning noises. Is this expected?

It was suggested that perhaps the idle tensioner pulley may be bad, since the noises seem to occur while idling and goes away once revved.

schmikey

I remember changing in my 2010 the cabin filter I installed incorrectly ,created a buzzing sound which sounded like it was coming from the engine area.....

MadMark

One way to test if it's your alternator would be to load up the electrical system (throw the heat on full blast (not AC), press on the breaks, roll down the windows all at the same time) If you hear the grinding noise then, that would tell you it wasn't the bearing on the AC compressor. My guess is that it's the AC compressor bearing, which hopefully is a replaceable part... seeing as how an AC compressor would be quite expensive. Again, I doubt it's your alternator. Your AC is still running fine because the AC compressor is still spinning. Even when you're not running the AC, the belt is still spinning the Compressor pulley, the only difference is the clutch isn't engaged. That squeaking could be from the bad bearing, or the belt slipping over the damaged AC pulley.

miraluna

iTrader: (2)

sorry to revive this old thread.... so what was the problem? Belt tensioner pulley assembly? Bearings?

sktn77a

iTrader: (2)

I've had the tensioners/pulleys replace on my RX300 several times and they continue to chirp/grind. No idea why they can't get pulleys that work!

Gjd511

I have a Lexus ES350 2007 with the exact problem. My car makes a loud grinding noise on reverse and drive. If I put it on park or neutral the noise goes away. My problem started yesterday. I am going to look for some answers. If I find the answers, I will post them.

01LEXPL

iTrader: (10)

It's the clutch in the AC compressor.

The OEM variants are in the 200-300$ range [ACDelco] from rock auto.

I've replaced two, in my old '01ES300, and once in an '04 RX...

The noise as described, exactly what happened in my case, each time. As you can see I have over 1k in compressors between two cars lol

Priceguy

Several posts have mentioned a groaning noise from the engine compartment.
My 2008 ES350 has the same groaning or low roar when AC is on and trans is either in drive or reverse with car sitting still. AC is working perfectly. Noise seems to come from passenger side of engine compartment. We replaced the tensioning idler and both stationary idlers. No change. I began to wonder if the trans was the noise source as the noise could only be heard with trans in either drive or reverse. My theory now is that placing the trans in gear reduces the engine idling rpm by something approaching a 200 rpm reduction. At this lower rpm the noise seems to achieve a natural resonance and get louder. Thus when the engine speed is increased, the noise disappears, then reappears at idle. Noise also disappears when AC is turned off. AC is functioning perfectly.
Has anyone experienced this same problem and fixed same with a new AC compressor? I just blew something like $700 on labor and replacement idlers I didn't need. I don't want to waste more $ on an AC compressor guess. Has anyone had first hand experience in fixing this problem with a new compressor? Thanks for reviewing my problem.

nevernu

i posted this a few years backk about a growl at idle, maybe your problem is water pump as well?

""I've joined the new water pump gang. My 2007 es350 was in for its 60k mile/100k km servicing and I mentioned that there was a growl when the car was idling in gear at a stop light etc. They discovered a noisy water pump seal and low coolant levels. Replaced the water pump assy and bled the coolant system.

Tech time 2.5hrs charged !!!

I mentioned to him that many here have reported 5-10hrs labor for this procedure. He said that the Lexus book estimate was 5 hrs, and many independent mechanics around here charged up to 12 hrs. Why so much I asked? Service manager said because they don't know how to do it quickly and lift engine rather than just loosing some bolts.

And why was mine only 2.5 hours??? Because the repair was done under my extended warranty and the 2.5 hours was the actual time it took!!!

I've gotten a lot of use out of my Lexus Extended Warranty!!! (Trunk paint, camshaft, rain sensor w new windshield, water pump to mention a few biggies!!!)""

nevernu

sorry no info about how they replaced water pump

oldgrump

Listen chaps.......unless you have some mechanical ability/experience I would not suggest that you consider replacing the coolant pump yourself. Even verifying that the coolant pump is in fact toast takes time and knowledge. And there are "tricks of the trade" apparently, going by the variation in the quoted labor hours (some shops remove the engine per the Service Manual as you can see, and others do not) to do the job as seen on this forum. But.......the basic removal and installation of the coolant pump is here: http://www.doc88.com/p-316746265729.html Scroll down to pages CO-8 to CO-11.

mlacomb

Webpage not available for me