Adrian Bridge Posted April 29, 2018 Share Posted April 29, 2018 HiThis may sound an awfully dumb question but advice please. New to this. 1996 1.6 K series. Cam belt (routine change) about 500 miles ago. Last 100 miles squeeking sound that can be heard above the exhaust noise about 1 squeek / second but increases with revs.I've taken the nose cone off and had a look ? from alternator belt or alternator. Everything looks OK to me - nothing rubbing. Electrics and starting fine (apart from turn in indicators not working - separate topic).Any ideas? Is this a common problem and do I need to get it fixed ?Adrian Link to comment Share on other sites More sharing options...
Area Representative Paul Richards Posted April 29, 2018 Area Representative Share Posted April 29, 2018 Difficult to diagnose without actually hearing it, but it doesn't seem like alternator belt if it is a regular squeak. Slipping alternator belt is normally a screech that will often go worse if you put more load on the battery i.e. turn on headlights, heated screen etc.Could be alternator bearing or similar. Link to comment Share on other sites More sharing options...
thompster Posted April 29, 2018 Share Posted April 29, 2018 Alternator belt would tend to squeal more on engine acceleration and reduce as the alternator catches up with the engine speed. Cambelts can squeak if too tight but usually a sort or chirrup/humming sound that can come on as things warm up and the belt gets tighter on hot pulleys. It could also be the cambelt tensioner or possibly water pump but hard to say without hearing it.Best thing is to have a listen with then engine running and bonnet / nose off, try and work out which area its coming from and take it from there. Link to comment Share on other sites More sharing options...
John Vine Posted April 30, 2018 Share Posted April 30, 2018 Does the sound occur when the engine is idling and the car is at rest, or when the car's moving? When you say it increases with revs, is this also as road speed increases, or merely when you speed up the engine with the car stationary? Can you record the sound and post it up here?JV Link to comment Share on other sites More sharing options...
John Vine Posted April 30, 2018 Share Posted April 30, 2018 Thinking more about this, could the squeak be caused by the cambelt itself?Assuming your idle speed is 900 rpm, the camshafts are turning over at 450 rpm (= 7.5 /sec). The camshaft sprockets have 48 teeth and the cambelt has either 143 or 145 teeth (depending on engine variant). So, a given point on the belt passes by every 2+ seconds -- not far off the squeak frequency you observe.Just a thought.JV Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted April 30, 2018 Leadership Team Share Posted April 30, 2018 Adrian, if it's the alternator belt and you get a complete failure it's not going to be serious, if however as John may have alluded to, it's the cam belt and it fails it's going to be terminal. I would therefore investigate the cam belt as soon as possible.Remove the belt cover upper section and check if anything is rubbing or if you can locate the squeak more accurately, it might be that something has moved slightly since the belt change.Stu. Link to comment Share on other sites More sharing options...
revilla Posted April 30, 2018 Share Posted April 30, 2018 @JV: I was just doing exactly the same mental maths as you but noticed you'd beaten me to it!@bridge984: Just a few thoughts on the cam belt.1) Not sure if this affects the 1.6 as the pulleys are a different design but on the 1.8VVC the back piece of the cam belt cover tends not to sit very flat against the head and the exhaust side cam pulley tends to rub the plastic. Most of the engines I've stripped have had a rubbed worn ring where the pulley has touched the plastic. This can make funny rubbing noises but I think at a higher frequency than you are experiencing.2) The cam belt is self-centering on the pulleys, which are carefully shaped to stop the belt walking off the sides of the pulley; it always walks in towards the centre. If there was anything wrong with this, and I'm thinking worn pulleys, damaged belt, wrong tension etc. the belt could start to wander, specifically if could start to oscillate, wandering either side of of the centre line in a regular pattern. This could give a squeak at a frequency fairly unrelated to the frequency at which the belt goes round if it runs at one extreme or the other of its walk. If you run the engine with the front cover off and look down on the top part of the belt you may be able to see it wandering.3) Once (when rebuilding a friends engine by torchlight at about 2am, don't ask!) I actually fired it up without having tensioned the cam belt. The belt tensioner was just loose. Luckily we got away with it and realised quite quickly what the funny noise was... it was a sort of chirping squeak about once a second, mainly from the tensioner flapping around. This was on a manual tensioner engine - not sure would the 1.6 be auto-tensioner or manual? I've also seen an auto-tensioner misinstalled with the little spring hooked up wrongly and not doing a lot, so even if auto it's worth a look at the tensioner. Link to comment Share on other sites More sharing options...
revilla Posted April 30, 2018 Share Posted April 30, 2018 Just one more random thought. Wet sump or dry sump? I'm guessing you would have mentioned the scavenge pump belt if dry sump, but if it is dry, there's the whole scavenge pump side of things that could squeak, and then there's the infamous clucking chicken noise it makes when it is working properly! Link to comment Share on other sites More sharing options...
Dave_P Posted April 30, 2018 Share Posted April 30, 2018 Spray or drip a little water onto each belt, or pulley (if you can get at them) in turn. Squeak will momentarily disappear when you get the right belt. Not foolproof but has usually worked for me.( if it is a belt). Water quickly dries and causes no issues later Link to comment Share on other sites More sharing options...
John Vine Posted April 30, 2018 Share Posted April 30, 2018 ...not sure would the 1.6 be auto-tensioner or manual?My guess would be manual. Could the OP please confirm?JV Link to comment Share on other sites More sharing options...
Adrian Bridge Posted April 30, 2018 Author Share Posted April 30, 2018 Thanks for all the advice and contributions.Cam belt changed about 500 miles ago in February. Dry sump.Armed with your advice I will have a more careful look and listen to see if I can locate more clearly the source of the squeek and let you know how I get on.Many thanksAdrian Link to comment Share on other sites More sharing options...
revilla Posted April 30, 2018 Share Posted April 30, 2018 There is a sound from the dry sump system, usually described as a "clucking", which has fooled a few new owners into thinking something is wrong. The scavenge pump should be capable of drawing oil away from the sump faster than it returns to the sump, and therefore ends up gulping air making a rhythmic clucking sound. I wonder if that could be what you are hearing? If it does turn out to be that, it's all normal. In fact if it stops you need to worry and probably service your scavenge pump! Link to comment Share on other sites More sharing options...
John Vine Posted May 1, 2018 Share Posted May 1, 2018 I was just doing exactly the same mental maths as you...Of course, my introducing the cam sprocket bit was unnecessary, given that the crank sprocket has 24 teeth. My excuse is that I was trying to record the steps my brain (or what passes for one) had taken. Btw, the water pump sprocket also has 24 teeth. Is that a design feature or simply coincidental? Do they derive from the same casting?JV Link to comment Share on other sites More sharing options...
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