Hi,

I saw different x type's over here in our country (Jordan) that some of them have originally installed an engine plastic cover and others ( like mine ) they don't ! but was thinking is it better to leave it without the plastic cover as for better air circulation leads to low the coolant engine temperature or doesn't make sense !

 

the cover is to reduce noise level. No effect on coolant temp.

 

I think some years have it, and some years don't.

My '03 has a plastic cover bolted to the top of the engine. I was recently looking at an '06, and noticed that it didn't have the same cover. I initially assumed someone had removed it. Then I looked at a bunch of other '06's online where they had pix of the engine bay, and none of those had the same cover mine did. So somewhere along the way, it looks like they dropped it.

All of them do have the insulation blanket attached to the underside of the hood (bonnet), which I imagine is there to control the noise/heat.

(and Holy Carp Mikey!%$@!!! 11,002 posts?!?!?! - You got one more thanks from me just for sheer participation!)

 

My 2005 did not have a cover; ten minute job to move the one from my '02 over to it.

 

Zip on my '06

 

My UK spec Diesel has a substantial snap on cover and the cylinder head has a jell pack silencing thingy which fits around the injectors.

 

Jordan, as for the cover affecting engine temp, it has no affect on it as the thermostat is there to maintain the engine temp at a constant value. With that being said, you may find that some of the components under the cover may run a little hotter as they would not get as much air flow at highway speeds and therefore run the risk of failing quicker.

If you are truely worried about the under hood temps, you can simply remove the seal on the back side of the hood. That will allow some air to flow across the engine and then up and over the windshield. The only "negative" would be if you start driving at say 100+ MPH (160 KPH), you may find that the air flowing through that gap may start the hood fluttering. The faster you go, the more likely this sort of thing is to happen. This is where the hood vents provide a function in that they allow the air to move through the radiator and then vent out the hood so they are not trapped under the car, causing lift at high speeds.

 

Thank you Thermo and others, That was what i need to know.