View Full Version : removal of hood liner

08-18-2006, 06:55 PM
Overheating issues. New waterpump, rad, no thermostat, new filler tank, new fan clutch... temp is going down but still a little high. Can I remove the liner under the hood? Does it serve any other purpose?

08-18-2006, 07:24 PM
The liner is for noise and fire suppression. Either way, you have some other issue to deal with.

08-18-2006, 07:28 PM
put the thermostat back in , or a new one thats 160 or 180dg and try it .

08-18-2006, 08:11 PM
Did you change the cap on the tank [f]

And you can remove that luxary noise supression BS. My MJ came without it.

08-18-2006, 08:56 PM
Make sure that all the air is burped from the system and that the expansion tank is in good shape.try jacking the front end up a foot or so in the air ,it may help as it is idling til warmed up with the rad cap off.Just a trick I learned over the years with my XJ.

08-18-2006, 10:37 PM
Like Liz said, put a new thermostat back in. It will run hotter in some cases because the coolant is passing through the rad too quickly to dissapate heat.

Then get a shop to do a "block test" to see if it has a leaking head gasket/cracked head.

08-18-2006, 11:38 PM
Well I dont have any coolant in the oil or oil in the coolant... so the HG should be good. I talked to the original owner today and he said the overheating has been a on-going issue. The clutch fan install today has made a dermatic difference. I'll find out tomarrow when I hit the bush with a trailer. Between a new fan, and the aux fan on full time.. I sure hope she'll be able to handle the heat. I'f this dosnt go over well... I'll do the thermostat and look elsewhere in the system that hasnt been replaced. The filler bottle cap is a year old. Dosnt seem to be leaking...

I've read about spacing the hood... give it a 1" lift or so... good idea or not? I started to get my hardware collected today for this "mod"

08-19-2006, 12:13 AM
Spacing the hood? Sounds like something a group of hillbillies thought of just before they passed out.

08-19-2006, 12:29 AM
my jeep runs hot.. under like 80 degress while i drive but when i stop for around 5 mins or more it shoots up around 100 or more on hot days.. i got a brand new tank brand new rad brand new thermo
and the clutch fan is in good shape

08-19-2006, 07:22 AM
I got a small hood scoop off some junker and put it on my XJ, drilled some holes in the hood under the scoop so hot air can get out. Worked good. You need the thermostat. That kind of system is hard to fill, make sure it's full.

08-19-2006, 09:08 AM
A backwards facing scoop might help, but then again just some openings in the hood would do too, air rushing over the hood would create a vacuum and suck hot air out.

08-19-2006, 12:34 PM
If you know the old owner, ask if they ever had a leak that they put barsleak or something in.

When you took the rad out and stuff, was there any silica buildup? Cause that could also be built up in the block. Also wondering if you replaced the coolant hoses? You could have one collapsing once hot.

But the other suggestions are good too. Rad cap (replace it if you weren't the one that did it. usually the most overlooked compontent of the cooling system & could be the wrong one), get the air out etc. What core rad did you put in? Not sure why you're running the truck without a thermostat, but if you get a lower temp one like Lizard suggested that should help too.

08-19-2006, 01:12 PM
You will definately want to put a thermostat back in don't go lower than about 175-180 the computer for the fuel inj won't like it will try to stay in cold run mode if you go to much lower than that.

The biggest problem most people have with the 87 to 90 Cher 4.0 is getting all the air out of the cooling system ( stupid expansion tank filler junk brought over from stupid Renault ) best way to do that is to either pull off the heater hose at the thermostat housing or put a flusher T in the heater hose to the thermostat housing and leave it open when fillng the coolant and fill untill you see coolant come out of that hose then close it up and top up the system ( also you only want the expansion bottle about half full when you are done filling, the thermostat housing is the highest piont on the engine for coolant and the heater hose there bypasses the thermostat so it will let all the air out of the bock if you leave it open when filling.

You said you have a new fan clutch that is good they are a little prone to going on the XJs make sure you have the fan shroud in there as well and if you have the aux electric fan in it you can jumper the high temperature switch to make the fan run all the time. On the drivers side of the rad near the bottom there is a temperature switch ( a two wire plug ) unplug it and jumper the two wires together on the body harness part (not the piece sticking out of the rad) then when you turn the key on the electric fan should start running.

08-19-2006, 02:06 PM
Thanks. The aux fan runs full time. (turn the a/c on and it turns on, the a/c pump is dissabled) Do I need the fan shroud? I took it off... I also have a flusher T right when described. I took all the air out like described also. Parked on a hill etc. I'll give this new fan a try today... camping day!

08-19-2006, 02:26 PM
Most people would be suprised at how much a fan shroud does, the shroud makes the fan pull 90% of the air it moves through the rad not from around the sides of the fan.

08-19-2006, 02:37 PM
Well I got er' back in. Only took about 5mins. Just finishing getting canned beans and KD packed and I should be off. Now hmm... cant forget the axe and source of flamage.

08-19-2006, 02:39 PM
here's the scoop I put on, rear facing, off some junker. Just drilled some holes in the hood and put the scoop over them. No electric fan, no overheating. [cheers]


08-19-2006, 09:21 PM
here's the scoop I put on, rear facing, off some junker. Just drilled some holes in the hood and put the scoop over them. No electric fan, no overheating.

Only problem with this configuration of hood scoop is that at speed there is an area of high air pressure just in front of the windshield. This is what made the scoops on the sixties muscle cars (challengers, hemi cuda's etc.) which faced backwards work. so instead of letting air out what is actually happening is that air is going in.

08-20-2006, 05:15 AM
I never had any problems with overheating going fast and either way air is flowing thru the engine compartment. It works, thats the main thing. [cheers]

08-20-2006, 09:45 AM
Those scoops aren't very effective for that unless they're very close to the windshield, I doubt his is sucking air in. Still, I would have put it a little further forward. Honestly, heat bleed holes in the hood are one of the most effective ways to deal with underhood heat.

08-20-2006, 12:16 PM
[quote=girlcrazy_4]Well I dont have any coolant in the oil or oil in the coolant... so the HG should be good. I talked to the original owner today and he said the overheating has been a on-going issue. quote]

An engine overheating from a bad headgasket/cracked head won't necessarily leak oil into the coolant, or other way around. It pushes exhaust gases into the cooling system, overheating the coolant and over pressurizing the system.

Just one of many things I would check. Doesn't take long, make sure the Jeep is warm, or hot if possible. Take rad cap off, take out some coolant so the block test doesnt' suck it up! Then put block test bottle in place of cap and watch for the fluid to change colour. If it does, you have a problem! A shop shouldn't charge more then an hours labour for the test, hopefully less considering it only takes a short time.

08-20-2006, 07:02 PM
Good news... the new clutch for the fan has worked out pretty good. Towing a trailer up a steep long bush hill in 4x4, 3 people, all food, beer, large thing of water etc... running the engine around 2200rpm... the temperature went 3/4 of the way up, just as red when I hade to "give er" to get up the final descent. (hill takes 20mins) so I think she's doing pretty damn good.

On a bad note... a reaf leaf decided to pack it in along with the front diff. She's starting to moan pretty heavily... along with all my turn signals... they dont work anymore. Probably a flasher issue since the fuses were all good.

But once again on a good note, I found a parts jeep. Has a 6.5" lift kit in it... Going to buy the jeep and rape it of all the parts. May as well switch front diffs while I'm at it... Anyone have a picture of a 6" lift? I think it may be a "little big"

08-21-2006, 09:53 AM
My 90 Xj with auto was running hotter than I liked, but never actually overheated. I was planning on a trip to the coast via duffie lake rd, pulling a tent trailer and I know about the hills on that road, esp out of pemberton on the way home. So I prepped:

Rad is a fairly new Modine unit (installed before I bought the jeep), new pressure tank and cap, good coolant mix.
I got some hood vents from a turbo new yorker at kelowna pick a part. installed. Noticeable difference in underhood temps but still getting hot up hills.
I made an oval loop out of 1/4" flexible copper that goes in front of the rad, behind the grill, and is plumbed to a water reservoir and generic windshield washer pump under the hood. There are 4 holes at each end of the copper oval that are angled towards the rad. When I activate my aux windshield washer pump ,the water shoots out in front of the rad and gets sucked over it by the fan. Works like a champ. Pulling up the hill out of Lillooet (sp?) I let the gauge get just into the red, then turned on my (patent pending) water cooler and the temp actually started dropping while I was still pulling up the hill. It uses a lot of water in a short time but I only need and use it for severely steep hills.
Coming back the other way, out of pemberton was not an issue because part way up the hill we ran into the great granddaddy of all rainstorms and the whole vehicle was getting hosed down on the way up.

Now, coming down into Pemberton was another issue -----burning brakes, anyone?

08-21-2006, 09:55 AM
oh, yeah, next step is to install the Ford taurus electric fan that I picked up at Kelowna pick a part. the air movement specs on those units are awesome. has to be better than the mechanical 'propeller' that's on the jeep now...

08-21-2006, 11:41 AM
The water-cooler idea sounds doable. I was going to do a simular idea to the intercooler on my other car. I have a spare isuzu impulse hood scoop... that'll look pimp on the jeep hood.

08-21-2006, 11:46 AM
LOL! that is so funny - my original motivation for developing this water cooled thing was for the intercooler on my turbo Audi. haven't got around to that yet as I've been driving the jeep.

What is your other car?

08-21-2006, 12:33 PM
AWD Isuzu Impulse Turbo 5sp... pretty rare car. Head has been shaved, walbro 255lph fuel pump, dsm 450cfm injectors, full custom stainless intake/intercooler setup, slammed to the ground... was a 'sick' car last year but she's been up to the bush a few too many times. Since it has a limited slip rear diff, and the viscous coupling in the transfercase splits about 60% of the power to the rear, she's a fun car to drive. This years winter project I think I'm going to lift it, put some aggresive winter tires on and have a trail car... sad for the rarity but the body's beat.

pics are here. http://www.funinbc.com/forum/showthread.php?t=66829&highlight=isuzu+impulse

08-21-2006, 12:44 PM
Sweet - mine's an AWD Audi 5000 Turbo Quattro wagon in brilliant "arrest me red" - turbocharged, intercooled inline 5 cyl - yes 5, not 6. 5 spd with manually lockable center and rear diffs (vacuum dash switch) Been a bit neglected since I got the cherokee but I've been thinking of cleaning her up a bit and attracting some speeding tickets....:) I have a complete spare motor than I am going to build up and drop in, chip the ecu but nothing too radical. My engine has 2 valves per cyl but there are some rare ones out there with the 4 valve/cyl crossflow heads that I would love to get my hands on....

08-22-2006, 12:59 AM
wash out the rad most likely mud in there thats what my problem was

08-22-2006, 03:13 PM
the ac condensor is full of bent fins/rocks etc. I was going to take it out but it looks as if I've gotta remove the whole bumper. I dont have the patience for that.