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Hello,

I get in my car this lovely sunny summer morning, and start it up only to be greeted with a very strange noise coming from the engine. It sounds like a rattle, almost (but not quite) like a diesel sound on a cold winter morning. Think Clarkson's sub-10k "supercar" tappety rattle but nowhere near that loud. This rattle increases with engine speed and doesn't seem to matter if it's under load as it does it when coasting downhill in gear. In addition to that, there's a whistling noise when the rpm needle is between 1000 and 2000rpm. Again, it doesn't matter if the engine is under load as it does it in neutral or coasting downhill. I can hear both more clearly inside the car rather than under the bonnet, but it definitely sounds odd.

When first starting the car, the rattle isn't there but then appears after around 2 seconds of idling. Before you say, it's air conditioning - it's not, as it appears before the familiar "click" to engage air con. Also, does it with air con completely off.

Otherwise, there's no loss in power, no smoke and no alarm displays on the dash.

Any ideas? I do 90 miles a day driving (mainly motorway), so don't want the engine to blow up enroute. Could it be something simple, like an aux belt slip? Not sure why it would generate a rattle though...

Oh, it's on an original cam belt by the way at 70K now, but HDi service says replacement is due every 96k...

Sounds like the Bottom Pulley to me.

Whistle wise have a quick look/feel under the bottom intercooler hose as this can rub on the radiator bracket and make a hole in it (I had this but it developed quickly into an 'air blaster' in 2/3 days flat).

Similarly the bottom pulley (if it is that) deteriorates on the rapid (2/3 days) turns into a really nasty noise like you don't feel like driving it.

Have a looky for a brown 'dust' around the cambelt end of the engine and possibly some shiney metal filings too.

Ooo, and mostly, funny noises will dissapear when you fit a nice new aux belt (I have experienced this on mine).

Is it worth taking of the aux belt and run the engine to see if the sound/whistling goes away? Both noises appeared at the same time, so I am assuming it's coming from the same source.

Captain Jack wrote:Is it worth taking of the aux belt and run the engine to see if the sound/whistling goes away? Both noises appeared at the same time, so I am assuming it's coming from the same source.

It will certainly help you narrow down where the noise is but shouldn't we be carefull removing and replacing the belt without changing for new parts? .....just thinking of mbell666 who changed/messed with his aux belt only for the cambelt to snap within 2 weeks when the aux bely through a wobbly

Just been out to listen to it again and the whistling is coming from the left hand side of the engine around the aux/cam belt area. It's fairly faint but definitely there. I still can't pin point where the excessive rattle is coming from as the diesel is fairly rattly anyway but I can only assume it's coming from the same source.

I'd definitely take off the aux belt & see if the noise disappears CJ.
You've got the bottom pulley or the alternator which may be squealing.

Yeah, may as well do this at the weekend - the car is booked in to the garage for next Wednesday, so let's hope it lasts around 600 miles or so before then!

Coincidentally, when it cambelt change due on HDI 110's? HBoL says 72k, officials says 96k....

Take a photo of it before you remove it, If it's anything like the tubby the routing is a nightmare!

Ive heard from vaious sources 72k, 96k, 100k.
If it were mine & I knew I was going to do it once in the time I will have the car, I'd do it soon as & get it over with.
Do the cam belt kit, water pump, aux drive belt kit for certain. Swap the bottom pulley too if there's any doubt over it. Expensive, but so long as you only do it all once and avoid a bigger problem it'll be cheapest in the long run.

Timing belt replacement interval is 96,000 miles under normal conditions, 80,000 for adverse conditions.....I would class regular motorway use as adverse conditions.

I replaced my belt kit at 60,000 and my fleet customer insists on 50,000.

Before you venture into taking off the belt, spray WD40 all over the belt, including the ribs, if the noise goes away, then remove the belt and check everything that the belt runs on.Replace it as a matter of course.

Photgraph the belt run as teamster says, or draw a picture of the pulleys and belt run.

jasper5 wrote:I would class regular motorway use as adverse conditions.

Whatwhat? You can't get an easier drive for a car than a motorway cruise, unless you're on about the M25 at rush hour or driving at the red line! One motorway mile is about as hard on a car as 100 yards inner-city, if that!

mjb wrote:

jasper5 wrote:I would class regular motorway use as adverse conditions.

Whatwhat? You can't get an easier drive for a car than a motorway cruise, unless you're on about the M25 at rush hour or driving at the red line! One motorway mile is about as hard on a car as 100 yards inner-city, if that!

I was thinking the same thing I normally drive between 80 and 90mph with rpm needle sat at around 2800rpm.

Captain Jack wrote:I normally drive between 80 and 90mph with rpm needle sat at around 2800rpm.

That's a whole lotta belt-revolutions though

I think motorway use (and the mileage it brings) clocks up many many hours of use and would degrade the belt quicker than the odd 20 minute run into town?

'Arduous' use in terms of Peugeot servicing refers manily to the oil quality and the Filters I think which would get hammered in-town whereas on the motorway these things fair better. Not sure which is worse for a cambelt but I'd go for the 'hours of use' myself.

Welton wrote:

Captain Jack wrote:I normally drive between 80 and 90mph with rpm needle sat at around 2800rpm.

That's a whole lotta belt-revolutions though

100 miles in 5th is a hell of a lot less revolutions than 100 miles in 1st-3rd, and it's usually many times less time too. The biggie is that it's a lot less changes in speed and temperature, so the belt doesn't have to expand and contract as much to keep the sprockets in sync.