murphysf

Loud Sharp Screeching Sound

First a bit of background:

2000 RX300 285k miles

5 days ago when I started the vehicle in the morning, upon startup I heard what seemed to be some engine rattling sound that lasted about 5-10 seconds. It went away and I never heard that sound again. I thought the sound might have been valve train noise or could have been something different. I check the oil level and it was about 1.25 quarts low. That evening when I got home from work I changed the oil.

The following day (4 days ago) I drove the car 5 hours nonstop on the freeway and no issues. I drove the car the last few days without an issue.

Yesterday evening on the way home, after another 5 hours of non stop highway driving I was 5 miles from home and doing about 60mph on the freeway and heard a loud sharp screeching sound. I eased off on the gas pedal and slowed down to about 45 and the sound went away. I slowly gave it a little more gas and the screeching returned. Eased off and it went away. This happened a total of 3-4 times within the period of a minute or so. Then went away. The loud sharp screeching sound seemed to come from behind the dash or the center dash console area where the shifter is. I could be off on the location of the sound as the duration of the sound did not last long

I just woke up and started the vehicle let it warm up and drove it for 5 miles and everything seems fine.

Any idea what might be going on.

I am hoping this is not signs of lack of lubrication, oil starvation due to the sludge characteristics this engine is know for. Are there any tests or checks that can be performed to rule this out?

The oil pressure light on the dash never came on

Any ideas or input is greatly appreciated.

Thanks!

murphysf

I forgot to add that the 1.25 quarts low was not a surprise based on the last time I changed the oil, and the minor oil leak, and slight oil burning consumption.

fastnoypi

were you running a/c? a worn ac clutch can exhibit similar sounds when engaging/disengaging

murphysf

no, not running the AC

ukrkoz

Well, AC starts without telling you so if your vents are pointed on windshield. But it appears to be speed related more than AC related.
I say it's related to low oil level.
Rattle in the morning is likely tensioner/belt rattle till it built up oil pressure.

PS. Speed or RPM related. Put it into neutral and run through range of RPMS.

murphysf

thanks for the reply.

what did you mean by AC starts without telling you? The AC was off, however I believe I might have had the heat on a lower fan speed.

The sharp screeching I heard yesterday after a long 5 hours of freeway driving went away as I backed my foot off the pedal. I was originally doing around 60 mph and when I heard the noise backed off on the gas pedal and it went away, was driving around 45mph, then gave it a bit more gas to get my speed up and the sound came back. This happened 2-3 times. The vehicle was not under load just cruising on a flat freeway.

Didn't get a chance to check if it speed or rpm related, as it all happened so fast, next time I will shift into Neutral.

Ended up driving a different vehicle to work today but plan to drive it alot this week on short local trips (less than 25 miles each way).

You mentioned that the loud screeching might be related to low oil level. I'll check it later today but I just changed it 4 days ago.

Thanks

salimshah

screetch typically comes from belt slip. There are two belts on the outside ... A/C-alternator-main_pulley and main_pulley-steering_pump. The slip typically happens and the belt quickly heats up and then it no longer slips.

Salim

murphysf

I'm going to drive it as much as I can on short non-critical trips to see if the sound comes back.

It could have been belt noise, I've experienced belt noise a few times in the past with my VW and Toyota but think this might be something different.

Is there a topic or thread where people discuss the symptoms when they start having engine or valvetrain failure due to the sludge issue?

I'll keep the group posted as to what I find.

simplecar

salimshah

Not a good idea. The belt needs to be dry .. it is ok to spray wet it with water but definitely not oiled.
Belt should be examined every 36K miles and should be replaced at around 42k miles.

Belt tension should be checked every service.

If you sprayed the alternator bearing and the noise went away, then you must have the alternator examined.

WD40 is a great product but it dislodges the lubricant of the bearing.

Salim

salimshah

If that thread exists, it would be going all over the place. What you did (and others do) is post and let it go where it takes. It is recommended that the thread starter does a search for key word before posting. You can search on "oil gel" or just "gel" or "sludge". Just take the valve cover off and you should be able to see the sludge if any. Rear valve cover or the oil sump can give you better information but that is more work. Do not confuse oil get with thin golden brown (I refer that at patina) baked on layer due to oil vapors.

Salim

Nad1370

If the OP can provide a sound clip of the "screeching" noise, we might be able to narrow it down.

murphysf

What did you fix? This has nothing to do with the original post and seems like a misleading entry, unless I am missing something?

murphysf

good point if I can reproduce it I will try and capture a sound clip.

I drove it today for 30 minutes to work and then another 30 minutes back and no noise.

simplecar