This is my short DIY way of dealing with hot temperatures under the hood of my Jeep TJ.
A common problem with older model Jeeps, it can lead to premature electrical and mechanical engine component failure. (I've already burned through a couple ignition coils and it's stranded me from a failed CPS during the last 2 years).
This mod cools down the engine compartment by allowing trapped heat to escape through holes cut into the hood.
Now, I'm not interested in gaping holes in the hood of my Jeep, but I also don't want to pay $$$ for expensive sheet metal louver panel kits.
*** The classic disclaimer *** This is my own experience. If you want to do this to your Jeep, have fun, but it's on your own responsibility. Don't do something your not comfortable with. I'm not responsible for your actions, or your vehicle, and I'm only responsible for my own vehicle.
That being said, let's roll....
keywords: ( Jeep Wrangler CJ TJ YJ XJ ZJ LJ hot heat engine motor hood Cherokee Comanche 4.0 overheat )
Step 1: Figure Out Where You Want to Put the Holes
I'm putting these holes just behind where the radiator is.
One set of holes will go here. Another set (in a future instructable) will go towards the rear sides of the hood.
These spots are the mapped low pressure areas in the engine compartment and yield the best results (I will leave it to you to Google it up).
Try doing an image search for Jeep louvers. You will see there are several patterns. Many patterns have a long thin louver panel that goes along the front edge of the hood.
Mine are different (obviously).
Step 2: Figure Out the Shape
I drew up a pattern for the holes and cut it out of paper so I could trace it onto my material.
This also helps to lay out the design on the hood prior to doing any cutting.
Step 3: Choose Your Material
I chose to cut the rings out of .050 aluminum sheet that I had laying around.
Trace the pattern onto the metal. Use a jig saw to cut it along the outide and inside perimeter.
The inside perimeter can be started by trilling a hole for the jig saw blade.
Step 4: Choose / Apply Netting and Insulating Material
I decided to use the plastic gutter guard material as a net (the stuff that keeps leaves out of your gutter).
You will also want to use the sponge rubber weatherstripping material to put on the bottom of the ring. It will be used to hold the net to the ring and also to keep the metal and plastic from rubbing against the hood where it will be fastened.
Cut some netting the same size of the ring. Cut lengths of the weatherstrip and stick it to the ring.
Step 5: Drill Holes in the Rings
1. Make a hole pattern around the ring.
2. Clamp the rings together.
3. Drill the holes just small enough to keep the head from popping through. You'll need to have room to move the fastener around in order to screw it down.
Step 6: Transfer Hole Pattern to Hood
Before doing this, place both rings where you want them on the hood and trace around them using a pencil. If the ring moves while drilling, you can then move it back with reasonable accuracy.
Hold each ring against where you want to, then lightly pressing the drill bit through each hole to the hood.
Step 7: Figure Out How You Will Fasten the Rings to the Hood and Drill the Holes
You can use sheet metal nutplates or machine screw nutserts. Depends on your mood. I decided to use nutserts and stainless steel 6-32 x 3/4 oval head machine screws with countersink finish washers. This keeps the screw head from tearing into the paint as it's being driven in.
The size of the drill bit corresponds to which fastener that you decide to use.
Step 8: Cut the Holes
Once you are sure of yourself, cut the holes.
This can be done with a grinder or a jig saw.
Be highly careful....the radiator, hoses, and belts are just below the surface. Raise the hood before cutting.
Make sure not to hit any of the holes....it's easier than one would expect.
Step 9: Paint the Rings and Netting
For this, I used primer, then Truck Bed Coating that you can get at Wal-Mart.
Step 10: Attach the Rings - Finished Product
Be careful at this step, if the screw is crossthreaded in the nutsert (assuming you are using nutserts), then the nutsert will have to be replaced. Also, screws this size can easily be stripped or the head popped off.
Start all screws before tightening them. Also, tighten them all the way and evenly, so the rings are not bent.