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07 Lexus IS250 RWD,153K, and as of Thursday, been hearing like a squeal/whining coming from the engine. Can be heard from inside the cabin. Gets a little louder when pressing on the gas. Next few days, there has been a electrical burning smell as well. So my first thought is the alternator and after doing some digging around, and finding a video on YouTube with same noise, I came to conclusion that alternator finally going out but what if it’s just the serpentine belt? My AC worked fine, my headlights did not seem to get dim, engine is not overheating. And never lost power steering.. no warning lights on (vsc and trac control on for different reason)
what are are your thoughts?
Unsure of what to replace... alt or belt or both..
In the past, I had my car die twice on me in the winter. (Bought a new battery from local shop both times) Both times I was told it was alternator(from different shops) causing issue because it was only at 12.8V charge instead of 14V but then local shop admitted their batteries have had multiple complaints of not being able to start in cold conditions so they refunded me and I bought a better battery from advance auto instead. Ever since then car has ran like new & no issues since with car starting since then.
ALSO, because I jumped to conclusions and assumed it was alternator & did not want to get stranded on side of the road with more snow coming in as soon as tomorrow and only spare time I have was yesterday & today... I have already taken my alternator and the belt out... took me 6 hours yesterday and plan on finishing today but I need to know if alternator needs to be replaced for sure... will post pics later of belt and link to YouTube video of noise
What I've seen on my car cold start up. Is 14.2 volts then stabalizes at 13.5-7V always. My car is 8 years old now, and owned it for 3 the numbers never change.
The proper way would have been if you went to an auto store and had your alternator checked. If the test revealed it is the alternator, then you have to replace it. And yes if the charging voltage is less than ~ 13.6 Volts, then most likely it is the alternator.
Do you have a new battery? Batteries last a few years if the alternator is doing its job.
@MikeFig82 Appreciate the feedback ! Every post I've looked at, your responses are always educating & helpful. uploading pictures here in a sec of belt.
@mandyfig Yes, as stated, I have had the alternator tested multiple times in the past. But because I was worried about the alternator dying suddenly while on my commute to work for the next week with snow coming, I made the bone head move of just jumping in and yanking the alternator out; but Recently, it was probably 5 months ago. Car died as soon as got back from a long trip, would not start immediately after I parked car at my place. Everyone said it was alternator, went with my gut again & bought a brand new battery from advance auto & no problems since with any electronics on the dash or from the A/C or anything. Then just recently, on thursday, car made the whining/squealing-ish noise... (posting video soon) thanks for the feedback.
Judging by your photos it seems you have problems with the idler pulleys. The back side should always be smooth on the belt. Inspect for any misalignment on the pulleys, built up debris on the pulley grooves.
^^ I think it is just the original belt showing high mileage.
OP, is the burning smell that prompted this change out reflective of your old alternator? If so, it may have burned up the diodes or regulator. Sniff test it and smell for that burned smell if you still have it.
Also, grab volt meter so you can monitor your battery when need be. As you can see 12v batteries usually sit at 12.95v when fully charged and require >13vdc but less than 14.1v to maintain their charge. Sustained alternator output above 14.3v can damage a lead acid battery.
MikeFig82 is right on the visual observation on the pulley belt. If your idler pulleys were worn out, you will hear squeals and some grinding noises, do you hear them?
@MikeFig82 So I'm pretty confident now that it is not the alternator. After reading the link you posted, maybe it seems that I have some minor build up in the belt (shining particles) or as you stated the idle tensioner. So what I am going to do, after talking my dads friend who is a mechanic, I am going to go test my alternator his auto parts store & test my belt as well to see if we receive the same noise I am hearing. If we are, I'll replace the Alternator + Belt, if not ill focus on the tensioner/ pulleys & go from there. Thank you again for all the advice.
@mandyfig I do not hear any noise of any kind, they all flow freely except for the biggest pulley of all the other ones which I think its connected to the tensioner? or maybe its the camshaft? Here are some pictures: They don't look clogged with debris or worn or seem to have any issues. Thank you for your help as well! much appreciated!
Pulley next to the alternator that I pulled out to make it easier, seems in excellent condition & did not make noise when we were pulling it out. Shiny Particles ^ Some scratches? on this pulley The big pulley that doesn't move, think its connected to camshaft or tensioner kinda dirty?
Yes my concern was what is making the belt groove. Your pulley picture just confirmed. Check with your mechanic first. I would think eventually it will fray your new belt in the long term. Does the idler pulley have a deep groove? You can see slight pitting too. Look at your belt it seems to be just tapering. As the marking is not consistent all the way around the belt itself.
Can we circle the wagon and ask how many miles on the belt in the picture?
Also it is worthy to note that the grooved side of the belt does 90% of the work while idlers and tensioners use the backside. That said if the belt lasted 150k miles you got your moneys worth and throwing money at new pulleys will not make a whine go away.
JM2C but the tiny grooves in the belt are nothing and chances are the bearings in those idlers fail before it ever takes the life of the belt. Sure you could replace them but its not going to gain you anything when another belt will last 100,000 miles.
I do suggest you get a hand held volt meter with the ability to test diodes and you can diagnose part of your alternator problem yourself.
Update:
The alternator passed the "Bench Test" & the short answer is: The problem ended up being the belt.. After testing the old belt again (which was "cleaned" by the guys at the shop), it still squeaked but after replacing it with a new one, the noise seemed to go away.. But. not sure if I am being paranoid, I feel like I can still hear some sort of low squeaking or whistling (like the car is tuned up) when using the A/C or Heat.
@MikeFig82 We were right to say that the issue was not the alternator & because of the remaining noise coming from engine when I use the heater, I think I'll have a mechanic check them to see if all is well & that I did not miss anything. @2013FSport Thank you for the advice, also enjoy seeing your comments on posts, which are always extremely helpful! I apologize for not including that information. I put a new belt on at 89K when I purchased the vehicle. So got about 65K out of the belt, which is why I was concerned with the sudden noise. seeing that is did not make it very close to 100K And again the belt looked fine upon inspecting it.
01-21-19, 09:25 AM
Bad alternator or bad serpentine/drive belt?
