Screeching noise from engine

[Thesfactor]

I've read threads on here where people state that they hear screeching noises coming from their engines - mostly turns out to be a tensioner pulley problem.

Well I've been hearing this noise from my engine early in the morning for about 30 seconds and then it goes away, i'm not sure if this is normal? I've had the belts and pulleys replaced under warranty because of this noise, even after replacing everything the noise still persists, I'm not sure if I should be looking at other things that might be failing? Anyone with experience in this area - Do all your cars start the same screech (I presume its from my belt) for a couple seconds to a minute and does it then go away?

I own an '04 325i with 22,500 miles on it. 5spd if it helps. Thanks in advance!

[nicknoodles]

my civic used to do the exact same thing and it was a tensioner bearing, obviously for the tensioner puller itself.....although i assume if you had the pulley replaced then the bearing itself would be replaced too?? im not sure.....but thats what it was on my civic...hope this helps buddy...good luck

[AdamBath]

maybe its a little condensation on the belts, that goes away after that 30 seconds? thats what i've experienced on a lot of cars i've owned...

[ImportFanatic]

Belts and tensioner..change them if you havent in awhile or ever..

[pphil09]

My car makes some type of a schreeching noise at startup, along with some air blowing sound, and also a put-put-put type of nosie, coming form the right side of the car, to the right of the coils and spark plugs. It seems like it is related to a part on the car that is exposed when the hood is open, and it says something like Pierburg or something on it. It is a black cylinder, and it has a slant on about 1/2 of the cylinderical top. Is this what you are talking about?

Also, if anyone knows what this cylinder is, I would like to know. It is near the front of the car...

[Thesfactor]

Belts and tensioner..change them if you havent in awhile or ever..

I think I already mentioned this in the OP but yeah I had the belts and tensioner and pulleys and everything replaced under warranty. I'm not sure why the noise is still there. If I take it back to the dealership will they get mad at me - I don't want to be one of those customers that ends up being really nitpicky and they start ignoring all my other concerns.

[Thesfactor]

maybe its a little condensation on the belts, that goes away after that 30 seconds? thats what i've experienced on a lot of cars i've owned...

Yeah it goes away in about 30 seconds or so, it baffles me. The dealership said they replaced everything and the noise is still just there! Should I still get it checked?

[pphil09]

does your problem have anything in common to what I said earlier?

[Jager561]

Pphil... what you are asking about is the air injection system. It works at start up to help heat up the catalytic converter by injecting air into the exhaust flow. Pefectly normal to hear that puttering noise for 30 or so seconds after a cold start.

My vote on the screeching is condensation on the belt... especially if you part outside overnight. Possibly caused by a weak tensioner or stretched belt. I assume you are not hearing any valve clatter... and this is not an oil pressure issue. If not condensation or belts... possible water pump bearings telling you to get ready to replace the pump.

[Thesfactor]

Pphil... what you are asking about is the air injection system. It works at start up to help heat up the catalytic converter by injecting air into the exhaust flow. Pefectly normal to hear that puttering noise for 30 or so seconds after a cold start.

My vote on the screeching is condensation on the belt... especially if you part outside overnight. Possibly caused by a weak tensioner or stretched belt. I assume you are not hearing any valve clatter... and this is not an oil pressure issue. If not condensation or belts... possible water pump bearings telling you to get ready to replace the pump.

I think you're right Jager561, it might be condensation on the belt. I do park outside overnight unfortunately. So do you think I should have them check it again? This will be the third time for this problem (as i said before the replaced the stuff I mentioned about only last week). Is this going to hurt my car if I ignore it? Possible water pump bearings? What are the tell tale signs for this other than the 30 second screech?

Pphil09(sorry if i butchered your screen name): I don't think the problem is what you described it to be.

[Jager561]

The water pump will just tend to fail... the seal will fail and the bearings will be ejected... it is a noticeable event. There is no visual check on the pump. I really doubt it is the pump though, you usually don't have a squeal... and if you do, it won't go away. I really think it is condensation, especially if you only have the squeal in the morning and not at cold start up in the afternoon. New tensioner and new belt... look for something leaking... like the power steering reservoir... it is located above the belt and the hoses at the bottom have a habit of leaking... the crimp clamps are the weak point. I suggest you do a visual exam in the morning and see if you can pinpoint the squeal... it is annoying as hell if nothing else... feels like you are driving an old beater... my now 22 year old Fiero does the squeal thing every now and then... but I expect it there... good luck!

[Thesfactor]

The water pump will just tend to fail... the seal will fail and the bearings will be ejected... it is a noticeable event. There is no visual check on the pump. I really doubt it is the pump though, you usually don't have a squeal... and if you do, it won't go away. I really think it is condensation, especially if you only have the squeal in the morning and not at cold start up in the afternoon. New tensioner and new belt... look for something leaking... like the power steering reservoir... it is located above the belt and the hoses at the bottom have a habit of leaking... the crimp clamps are the weak point. I suggest you do a visual exam in the morning and see if you can pinpoint the squeal... it is annoying as hell if nothing else... feels like you are driving an old beater... my now 22 year old Fiero does the squeal thing every now and then... but I expect it there... good luck!

I'm really new to cars (this is my first car and I'm quite embarrassed to admit that). Do you happen to have any pictures so I can use them as reference when I check for the power sterring reservoir leak?
The squeal happens when I reverse out of my carport and let my clutch out a little (right when the car moves backwards) and then when I set it on first gear I hear the squeal for a couple seconds and then I never hear it again all day.

[Critter7r]

The secondary air pump mentioned earlier tends to get squealy when it fails sometimes too. The pump runs for about 30 seconds and then shuts off, so this too, could be your squeal. Best way to diagnose it is to have the hood open and start the car so you can trace the noise. Tensioners, secondary air pump and the waterpump are probably the most common issues. Also, just because the tensioner has been replaced doesn't mean it stops squealing. If the tensioner wasn't replaced with a hydraulic unit, the spring unit can make noise the day after it's installed, mine did. (Actually, if the tensioner spring fails, it's more of a chattering squeak, and if the pulley bearings fail, that's when you get the squeal).

Short version: you have to get in there and find the noise! Use a stethescope or a screwdriver (with your ear to the handle end of it) to locate the noise.

[hfritz]

hello!
sorry for the necro-post, but i found a search and could not find anythign else related.

my wife's 05 M3 is making a horrible loud pitched humming noise. it does do it first thing when starting, especially after a cool/cold night. i think it is the air injection pump - if you are sitting in the drivers seat it is the cylindrical object in the front right corner of the engine compartment. it does last about 45 seconds every time, but does not always make the noise (so therefore i do not think it runs on every cold start - depends upon environmental conditions).

it is actully quite loud and annoying. got BMW to replace it once, still does it. they now say it is normal.

can anyone comment? is it normal to be very loud, even inside the car?

[G. P. Burdell]

my wife's 05 M3 is making a horrible loud pitched humming noise. it does do it first thing when starting, especially after a cool/cold night. i think it is the air injection pump - if you are sitting in the drivers seat it is the cylindrical object in the front right corner of the engine compartment. it does last about 45 seconds every time, but does not always make the noise (so therefore i do not think it runs on every cold start - depends upon environmental conditions).

it is actully quite loud and annoying. got BMW to replace it once, still does it. they now say it is normal.

Did the dealer techs replace the non-return valve (the valve that's attached to the exhaust headers) at the same time they replaced the air pump? If they didn't, and if the valve is stuck open, then it's just going to kill your new pump by allowing moisture-laden exhaust gases back into the pump casing.

The pump makes a soft, vacuum-cleaner-like sound when it's new.

[hfritz]

i am not sure if they replaced the non-return valve, i can ask and look at the repair order. if that was not replaced will it make the noise very loud?

it does NOT sound like a soft vaccum cleaner, it is very loud and annoying.

[330CIAF]

What i found helped was getting a mechanics stethoscope and poking around when i first start the car on. You can get them for about 15 bucks at sears, like 2 bucks at harbor freight. Could very well help you find the source of your screeching. At least yours didnt screech for 2 days then magically disappear like mine did. now i dont know what to replace.

[hfritz]

if i used a stethoscope i would go deaf! or at least bleed from my ears for a while. that is how loud it is.

[nathancarter]

A mechanic's stethoscope isn't like a normal stethoscope. It doesn't simply amplify sound; it helps you isolate the source of noises. If used properly, it won't blow out your eardrums.

[wilreyca]

I have the same issue with the noise. I read a post, I think in the X3 forum, about that issue and how it was a bearing in one of the fans. I kind if believe that because the noise is comming from the front the engine, and my belts and pullies where recently change. And the water pump was change when It had the warranty...

[G. P. Burdell]

i am not sure if they replaced the non-return valve, i can ask and look at the repair order. if that was not replaced will it make the noise very loud?

As I said before, if the non-return valve was not replaced and if it is stuck open, then it will shorten the lifespan of your brand new air pump. How long ago was the air pump replaced? How did it sound immediately after the new pump was installed?

[hfritz]

yes, the sound reoccurred immediately after it was replaced.