Jump to content
SAU Community

Recommended Posts

This is driving me nuts.

Only on first start up in the morning a very loud squeal comes from the general area of the belts. It happens whether the a/c is on or off so it is not slippage there.

On start up engine idles around 1000-1100 and the noise is deafening. Its an auto, and when I shift into reverse the revs drop to 8/900 and the noise stops. If I put it back into park the revs go up and the noise starts.

Before I start pulling things to bits has anyone got a clue????

By the time the car is out on the road its all quiet

Just went and started engine six times and it did it each time. Seems to be associated with rpm. BiIk/

Edited by 66yostagea
Link to comment
https://www.sau.com.au/forums/topic/292841-squealing-belts/
Share on other sites

First thing I would look at is belt tension, as it's a 5 minute fix.

Then, if all seems well, I'd check for belt wear, as they wear, the peak of each rib in the belt can bottom out in the grooves on the pulley.

The belt relies on the wedging action of the sides of each rib in the belt, not contact with the base of the pulley groove. You then lose the wedging action of the belt; voila! Slippage with a correctly tensioned belt.

Hope this makes sense, Dale

Link to comment
https://www.sau.com.au/forums/topic/292841-squealing-belts/#findComment-4891618
Share on other sites

its friction related, or lack there of. the belts are probably cold in the morning, and once the engine warms up they warm up and grip a little more. also they would stretch or shrink (i would guess stretch) when warm.

if they look old, replace them!

Link to comment
https://www.sau.com.au/forums/topic/292841-squealing-belts/#findComment-4891646
Share on other sites

At a guess, I'd say, first thing in the morning, the belt's less grippy because it's cold, also the load from the alternator is quite high, giving a rev while the alternator is loading the belt could cause the slip.

Link to comment
https://www.sau.com.au/forums/topic/292841-squealing-belts/#findComment-4891648
Share on other sites

Dont bother with that Belt Grip sh1t - does nothing!

as mentioned just find what belt needs to be tensioned and nip up the tension on it.

Agreed, belt grip, it actually does work, just covers up an existing issue, I use it from time to time on multi vee belt set ups (up to 15 belts over 6 metres in length) at work, to get to the end of a production run. But we then change them as a matched set. Put the cash towards a new belt.

Link to comment
https://www.sau.com.au/forums/topic/292841-squealing-belts/#findComment-4891664
Share on other sites

Hi.

The best way to stop a squealing belt is chalk. Chalk powder is ideal if not get a stick of chalk rub on sandpaper sprinkle the dust on the belt and if you still have a squeal it needs tensioning correctly. You dont need expensive sprays an lubes.

Link to comment
https://www.sau.com.au/forums/topic/292841-squealing-belts/#findComment-4891690
Share on other sites

i get a cold start belt squeak most of the time!

asked my mechanic about it and he just said it was common in stageas for cold start squeakage. haha

tightening the belts should get rid of most of it!.. :)

Link to comment
https://www.sau.com.au/forums/topic/292841-squealing-belts/#findComment-4891733
Share on other sites

if tightening the belt doesn't work its time for new ones. belts usually squeak either because they aren't tight enough, or the belt or the pulley is worn to the point where the ridge of the "V" on the belt is touching the valley of the "V" on the pulley, usually its the belt thats worn. the belt shouldn't be that tight that it is so tight it feels solid or with very little play, running them this tight will cause wear on the pulleys and can even flog out the bearings on parts like the A/C compressor, Alternator etc.

Link to comment
https://www.sau.com.au/forums/topic/292841-squealing-belts/#findComment-4891806
Share on other sites

So.

I have slackened off the altenator belt a bit. It seemed tight and the pulley grooves look very shiney compared to the others. I'll check in the morning and keep you advised.

Link to comment
https://www.sau.com.au/forums/topic/292841-squealing-belts/#findComment-4892811
Share on other sites

lol yea when i bought mine i had the same issue. on my first service i gave it a tweek up about 6 months ago and still havnt heard a thing. i work with belts all the time and like everyone's sayin its ether not tentioned right or its worn out.

btw try not to take the cheat option with chalk or similar do it right and save future issues.

Edited by fat_stag
Link to comment
https://www.sau.com.au/forums/topic/292841-squealing-belts/#findComment-4892981
Share on other sites

Fingers crossed. I think it is fixed.

I would have thought the altenator belt was too TIGHT, so I slackened it off a bit: that made it worse! So as Luke suggested I tweaked it up a bit and, voila!, she is OK.

Thanks to all for your input.

Link to comment
https://www.sau.com.au/forums/topic/292841-squealing-belts/#findComment-4893589
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I neglected to respond to this previously. Get it up to 100 psi, and then you'll be OK.
    • I agree with everything else, except (and I'm rethinking this as it wasn't setup how my brain first though) if the sensor is at the end of a hose which is how it has been recommended to isolate it from vibrations, then if that line had a small hole in, I could foresee potentially (not a fluid dynamic specialist) the ability for it to see a lower pressure at the sensor. But thinking through, said sensor was in the actual block, HOWEVER it was also the sensor itself that broke, so oil pressure may not have been fully reaching the sensor still. So I'm still in my same theory.   However, I 100% would be saying COOL THE OIL DOWN if it's at 125c. That would be an epic concern of mine.   Im now thinking as you did Brad that the knock detection is likely due to the bearings giving a bit more noise as pressure dropped away. Kinkstah, drop your oil, and get a sample of it (as you're draining it) and send it off for analysis.
    • I myself AM TOTALLY UNPREPARED TO BELIEVE that the load is higher on the track than on the dyno. If it is not happening on the dyno, I cannot see it happening on the track. The difference you are seeing is because it is hot on the track, and I am pretty sure your tuner is not belting the crap out of it on teh dyno when it starts to get hot. The only way that being hot on the track can lead to real ping, that I can think of, is if you are getting more oil (from mist in the inlet tract, or going up past the oil control rings) reducing the effective octane rating of the fuel and causing ping that way. Yeah, nah. Look at this graph which I will helpfully show you zoomed back in. As an engineer, I look at the difference in viscocity at (in your case, 125°C) and say "they're all the same number". Even though those lines are not completely collapsed down onto each other, the oil grades you are talking about (40, 50 and 60) are teh top three lines (150, 220 and 320) and as far as I am concerned, there is not enough difference between them at that temperature to be meaningful. The viscosity of 60 at 125°C is teh same as 40 at 100°C. You should not operate it under high load at high temperature. That is purely because the only way they can achieve their emissions numbers is with thin-arse oil in it, so they have to tell you to put thin oil in it for the street. They know that no-one can drive the car & engine hard enough on the street to reach the operating regime that demands the actual correct oil that the engine needs on the track. And so they tell you to put that oil in for the track. Find a way to get more air into it, or, more likely, out of it. Or add a water spray for when it's hot. Or something.   As to the leak --- a small leak that cannot cause near catastrophic volume loss in a few seconds cannot cause a low pressure condition in the engine. If the leak is large enough to drop oil pressure, then you will only get one or two shots at it before the sump is drained.
    • So..... it's going to be a heater hose or other coolant hose at the rear of the head/plenum. Or it's going to be one of the welch plugs on the back of the motor, which is a motor out thing to fix.
    • The oil pressure sensor for logging, does it happen to be the one that was slowly breaking out of the oil block? If it is,I would be ignoring your logs. You had a leak at the sensor which would mean it can't read accurately. It's a small hole at the sensor, and you had a small hole just before it, meaning you could have lost significant pressure reading.   As for brakes, if it's just fluid getting old, you won't necessarily end up with air sitting in the line. Bleed a shit tonne of fluid through so you effectively replace it and go again. Oh and, pay close attention to the pressure gauge while on track!
×
×
  • Create New...