Engine bay rattle

[Supermofo]

Mrs came home with the shopping yesterday in my car and there was a rattling noise coming from the passenger side of the engine bay. Sounded a bit like something loose. Popped the bonnet and couldn't put my finger on where it was coming from other than the right of the engine somewhere. I turned the AC off and the noise got slightly quieter but was still there. It was bloody hot yesterday 30c and super humid.

So this morning I've gone out and started the car and it sounds normal. Put AC on and getting a very slight rattling noise from the inside of the passenger wheel arch, can also hear it if I kneel down by the AC rad/condensor? in the front air scoop. The noise is much less than yesterday but it's much cooler so thinking AC isn't working as hard.

So my current thinking is this is probably AC related but will have to get someone to look at it. Before and as well as, anything I can check? It's a 2016 Mazda 3 and space is bloody tight and I can see jack from above and the underneath is all plastic covers. Quick google mentions belts and clutches...but equally it could be something is just loose.

I'm going on holiday in it on the 13th Aug so will need to get it checked before I go, esp in case it isn't the AC.

[KungFooBob]

Sounds like the triple overhead manifold sprocket.

[weeksy]

the AC pump unit has a bearing which certainly on Mondeos make this noise when they're knackered. It was the case on my previous one anyway.

[Le_Fromage_Grande]

Ford and Mazda often use the same engines and ancillaries, our last Mondeo had a Mazda designed engine made in Mexico

[Supermofo]

Ford and Mazda often use the same engines and ancillaries, our last Mondeo had a Mazda designed engine made in Mexico

Not in this one I don't think as mine has the Skyactive engine with super high compression ratio but they might share things like AC gubbins. Looks like I'll be taking a trip to a spanner monkey either way and praying it's not too painful.

[Yorick]

Sounds like the triple overhead manifold sprocket.

I thought it sounded more like the fluffle valve or the tweekle shaft.

[Supermofo]

Sounds like the triple overhead manifold sprocket.

I thought it sounded more like the fluffle valve or the tweekle shaft.

Bloody norfern monkeys

[KungFooBob]

[Druid]

The clutch on the a/c compressor has been known to fail on these. The parts aren't too expensive but it was a bit awkward to get to on my Mazda 6. I don't suppose it will be any more accessible on yours.

[Supermofo]

The clutch on the a/c compressor has been known to fail on these. The parts aren't too expensive but it was a bit awkward to get to on my Mazda 6. I don't suppose it will be any more accessible on yours.

Ta my quick Google last night seemed to point at the clutch.