Clicking Noise on Heavy Acceleration - Any Ideas?

Bilko · Post by **Bilko** » Thu May 07, 15 6:18 pm

Starting to push my car now it's been checked over and noticed I get a loud 'clicking' noise on heavy acceleration. At first I thought it was pinking, but it seems to loud and 'mechanical' sounding to be that. If I accelerate firmly it doesn't do it, but as soon as I stamp the throttle it happens. Sounds like poking a stick into a spinning bike wheel (if that makes sense). I'm wondering if the fan could be touching the shroud as there is very little clearance between the two, but also wondering what else it could be?
There's quite a bit of end play on the power steering pump pulley, could it be this? What else changes under heavy acceleration?

latil · Post by **latil** » Thu May 07, 15 6:35 pm

A worn or dry UJ?

Charger · Post by **Charger** » Thu May 07, 15 6:36 pm

leaking header gasket??

Gareth · Post by **Gareth** » Thu May 07, 15 8:31 pm

Is it worth a quick blast without the fan shroud fitted ?

Bilko · Post by **Bilko** » Thu May 07, 15 9:17 pm

Gareth wrote:Is it worth a quick blast without the fan shroud fitted ?

I thought of trying that, but the shroud is a complete closed circle and won't come off with the fan in place.

Bilko · Post by **Bilko** » Thu May 07, 15 9:19 pm

latil wrote:A worn or dry UJ?

Sound is definitely coming from the engine bay.

Post by **MattH** » Thu May 07, 15 9:39 pm

Flex plate!! See my woes recently.

Pete · Post by **Pete** » Thu May 07, 15 9:51 pm

Charger wrote:leaking header gasket??

That would be my starting point, nice and easy and cheap!!!

Bilko · Post by **Bilko** » Thu May 07, 15 9:53 pm

MattH wrote:Flex plate!! See my woes recently.

I was thinking the same thing Matt, but I don't get it on idle or revving the engine in neutral. I can accelerate strongly on at lest 1/2 throttle with no problems but the minute I floor it the sound comes in. If I back off the sound disappears. My money was on detonation, but 2 'second opinions' on a drive-along say it's too loud to be pinking. Plugs are also a nice brown colour.

Blue · Post by **Blue** » Fri May 08, 15 8:41 am

Sounds like detonation to me too, my 511 was a bugger for it. Fine until you really stuck your foot in it then it rattled like crazy. I confirmed it for sure by filling it up with high octane race fuel, It loved that and no rattling whatsoever.

Bilko · Post by **Bilko** » Fri May 08, 15 9:50 am

Blue wrote:Sounds like detonation to me too, my 511 was a bugger for it. Fine until you really stuck your foot in it then it rattled like crazy. I confirmed it for sure by filling it up with high octane race fuel, It loved that and no rattling whatsoever.

That was my first try Blue. I filled it with 99 octane fuel and chucked in an octane booster too. Made no difference.

Blue · Post by **Blue** » Fri May 08, 15 10:36 am

I tried that first still not be enough octane, 110 race fuel was though.

John · Post by **John** » Fri May 08, 15 12:11 pm

Try retarding your timing and taking it for a blast.

Dave81 · Post by **Dave81** » Fri May 08, 15 12:50 pm

Charger wrote:leaking header gasket??

I've only ever had leaking gaskets that are audible throughout the rev range (even at idle).

If you can't hear the noise at idle then I'd be surprised if it was!

Even so, with the hood up, get a hose and do the old stethoscope route........

MilesnMiles · Post by **MilesnMiles** » Fri May 08, 15 1:08 pm

I'm with Latil regarding retarding the timing a bit and testing.
If you jump on the throttle you are getting the noise when the engine is under load but not at peak revs. Most likely to get detonation then.
If it's safe to hit full throttle with the car parked, does it still make the same noise ie when it's not under load? If not it would indicate pinking.

Unless it's the fan