Under Bonnet insulation

dazza85 · Post by **dazza85** » Fri Oct 26, 2007 8:04 pm

On the underside of the bonnet on my Isuzu (and the Surf) there is a layer of insulation which is molded so that it sits clear of the under under-side of the bonnet execpt at the edges and the central brace.

I have removed it to cut the hole for the inter-cooler scoop.

The question is why is it there ??

To keep the the engine cool ??

To keep it warm ??

To reduce the noise ??

Do I bother putting it back in ??

Jezza · Post by **Jezza** » Fri Oct 26, 2007 8:39 pm

I took it off when I did my scoop, but then I put it back on as it was just taking up space in my shed, then it fell of while up the poulter after it had absorbed what felt like 10litres of water...... any way

, It made no difference at all

tallsam66 · Post by **tallsam66** » Fri Oct 26, 2007 9:32 pm

Yep..its for sounds insultation.
Often they put similar stuff over the driveshaft tunnel of on the floor of the boot to redude transmission & road noise.
If it was designed to reduce or reflect heat it would have a silver alloy foil stuck to it to reflect heat.