Use Cowl for Heat Extraction / Vent

My XJ was overheating and having P0303 after sitting for a while. I replaced the fan clutch and the needle doesn't go over 210 any more, but it does heat soak and boil the fuel.

I've seen some people using the cowl for air intake. I don't want to drill into my hood to do hood louvers.

The next logical thing is to drill into the cowl/firewall area and use that for heat extraction. I"m assuming between the mechanical fan (that now works!) and the AC fan (which I'll rig up to a switch) I should be able to get most of the heat out that way.

Has anyone done this? Tips/Tricks?

Assuming you could get it to work you'd probably just channel the engine heat into the cab via the cabin air intake in the cowl. Maybe look at drilling port holes through the inner fender instead (this is where the cowl drains too, so it's just a different line to the same destination).

Your idea will work fine ..... untill you drive at speeds over 20mph and the downward air pressure in front of the windscreen slows/stops the venting action.

Its why the cabin vent intake is there

Too much air entering the rear of the engine bay can even affect the radiator air intake. So work out your openings dimensions to suit or be able to block them off for highway running speeds/when fans are inactive.

FWIW ... 1/2" or 3/4" spacers on the hood hinges with some door seal rubber along the firewall so that the bonnet is still sealed between the hinges is as good a fix as any.

..... as air will vent / be fanforced out the rear corner areas at all vehicle speeds.

Only downside is its not as pretty as some vents .... So if you find some decent looking vents you can mount close to the rear corners & side of the hood... you almost get as good a vent system - with prettiness ....

Googling some vehicle airflow/windtunnel images will help you come up with something to suit your needs.


:cheers:

Please list your entire heat soak or hot soak fixes
6-24-10, 82 posting of info http://www.naxja.org/forum/showthread.php?t=1031365

Interesting, I never would have thought that it would affect cooling at higher speeds. I really would only use it at slow speeds or when off road ... I've never had it do the boiling fuel thing p0303 other than when wheeling with it. That is about the only time I've got it hot enough to do it.

I really don't feel comfortable drilling and cutting my hood ... with my luck I'd have a goofy looking Jeep with odd looking hood vents! haha.