Author Topic: Engine squeal disappears when aircon compressor cuts in? (Read 1923 times)

jonespa65 · « **on:** July 23, 2018, 11:06:57 PM »

Hi all!
My 2009 Jazz 1.4 manual has recently started making an engine area squeal that is present when both moving or stationary. This is present when there is no aircon engaged, but is also present intermittently when air con is running. Oddly the noise seems to disappear for a few seconds when (I think) the compressor is running.
We topped up the low pressure side of the air con about three weeks ago using a Halfords kit, and all was fine, very nice and cool, but after a couple of weeks we start to get this squeal which wont go away.
It seems odd that all should be fine for say 300 miles since the topup, then we get the squeal, or maybe the two events are not related? Its also a bit odd that there's only a noise when the aircon ISNT running, but disappears when it is ?

Any ideas out there?

Jocko · « **Reply #1 on:** July 24, 2018, 06:04:52 AM »

Welcome. Check the alternator drive belt.

culzean · « **Reply #2 on:** July 24, 2018, 10:34:28 AM »

The Jazz with I-VTec engine has an automatic belt tensioner (same as the one I have just had experience of on my Civic). The i-DSi engine uses the alternator pivot and a manually adjustable screw tensioner. The automatic tensioner pushes on the small exposed pulley under the engine mount and pushes down on a loop in the belt (which is why the pulley surface is ungrooved and most of the pulley is visible from above) - the 'release mechanism' consists of a 19mm spanner fitted over the hexagon (below the pulley directly under top engine mount) and a big upward pull (you can buy a proper cranked tool for about £20 to make it easier, I used two spanners and a house brick (brick was to hold spanners in 'release ' position while you get belt back on to pulleys). It could be a bearing that is making a noise rather than the belt (which will last 150,000 plus easily). The tensioner pulley bearing is favourite, and the aircon clutch bearing. The difference in loading on the pulleys with aircon engaged may quieten the squeal down a bit. A favourite check for belt squeal is to turn all the loads on (heated screens, headlights etc) and quickly dab the accelerator, if the squeal gets louder for a short time and then quietens down it may be belt, but if the squeal is there and fairly constant with revs with or without extra loading and dependent more on engine speed it may be a pulley bearing.

jonespa65 · « **Reply #3 on:** July 25, 2018, 05:36:19 PM »

Thanks Jocko and Culzean.
I've just had an op on my nose which has laid me up for a bit, but I'll try and follow your suggestions when I feel a bit more mended.
Cheers

culzean · « **Reply #4 on:** July 25, 2018, 06:34:20 PM »

Quote from: jonespa65 on July 25, 2018, 05:36:19 PM

Thanks Jocko and Culzean.
I've just had an op on my nose which has laid me up for a bit, but I'll try and follow your suggestions when I feel a bit more mended.
Cheers

Attached is a PDF with photos showing belt tensioner pulley and its release hexagon. when you put a spanner (ring spanner end of a ring / open ended combination spanneris is best as it cannot slip off ) over the hexagon and lift the spanner it lifts the arm of the tensioner and releases tension on belt - you may have to fit another spanner (ring end) into the open end of the combination ring / open ended spanner to get more leverage - a suitable fairly solid bit of wood (I used a house brick on my Civic) can be slid under the end of the spanner to stop it springing back down. You can now spin the idler pulley of tensioner to see if it makes a noise before going to the trouble of replacing it.

The aircon clutch pulley is a PITA to get to, it is the very lowest of the 2 pulleys straight below alternator pulley, you will need a torch to see it, and to get it off need to remove under-guarding from wheel arch and maybe washer bottle and bumper - I suspect the belt tensioner pulley may be the prime suspect for making a noise though, as there are plenty of youtube videos showing how to change them on many makes of cars, not just Honda.

I would discount belt squeal as the auto tensioners fitted to modern cars makes that all but impossible, but check the belt is not cracking or frayed when you look at it, the Kevlar / polyeurethane micro-V belts fitted to cars now are amazing and should be good for 100 to 150,000 miles at least.

jonespa65 · « **Reply #5 on:** July 31, 2018, 01:54:24 PM »

Hi culzean. Ive done as suggested and the auto tensioner pulley is a bit of a dog to get to once the spanner's in the way isnt it? I can only get one finger to the pulley so cant really spin it, but it does sound a bit dry even just on a slight turn. I see that a new part is £70-100, but is it possible to lubricate the existing, or is that a nono?
Is there enough room available to remove / replace it in situ or do I need to get the engine mount etc off?
Cheers