chicofuentes0224 Posted May 28, 2008 Share Posted May 28, 2008 The days here have been getting warmer. So has the MJ. My truck's getting really hot now but not overheating yet. Here's my first question. With the temperature hot, the top of the radiator fins are warm , but the bottom is cool. Is this normal or does it mean my radiator is blocked? The truck has new: thermostat, fan switch (electric fan does work but does not bring the temp down) fluid, pressure bottle and cap. I guess the water pump works because fluid shoots into the bottle and I just replaced the fan clutch and bled the closed system by removing the sensor on the back of the head (which blew all over the place when I took it off) Question number two: If it's normal for the radiator fins to be cool at the bottom what should I check next? Link to comment Share on other sites More sharing options...
Pete M Posted May 28, 2008 Share Posted May 28, 2008 I'd say they are blocked. Time for a new one. Be sure to get a later model one with the radiator cap. They are a direct replacement and it makes filling up much easier. How hot is it getting? Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted May 28, 2008 Author Share Posted May 28, 2008 I'd say they are blocked. Time for a new one. Be sure to get a later model one with the radiator cap. They are a direct replacement and it makes filling up much easier. How hot is it getting? If I get one with a radiator cap don't I have to change evrything else over to the newer style though? At the begining of the week the gauge would read a bit over the 210 mark I used a laser thermometer to point at the sensor on the head. It said anywhere from 215 to 225. Tonight the gauge is almost in the red and the same spot/laser thermometer is reading 230 to 245. :eek: However nothing is leaking/system is under pressure and the big reason I think it's blocked is because the fan isn't turning on until it gets really really hot (wasn't like that before). The temp at the fan switch is perfectly normal (160-180). Link to comment Share on other sites More sharing options...
Pete M Posted May 28, 2008 Share Posted May 28, 2008 220 is normal for a 4.0, but "in the red" is, well, in the red. And that's not good. :D No you don't have to change to an open system. I swapped the rad into my 88 but kept the rest of the pressure system. I love the addition of the radiator cap. I think it actually saved my pressure bottle on the dunes when the cap popped after the engine overheated (needle was pegged all the way over). Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted May 28, 2008 Author Share Posted May 28, 2008 So Pete, what should I ask for at NAPA tommorow? A 91 or newer radiator for a 4.0 automatic. Link to comment Share on other sites More sharing options...
Pete M Posted May 28, 2008 Share Posted May 28, 2008 Yup. That's what I got. :thumbsup: Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted May 28, 2008 Author Share Posted May 28, 2008 So, called NAPA today. 1988 radiator=$145 1992 radiator=$158 These are both aluminum with plastic ends. He then told me the 1992 also had a copper one w/brass ends for $210. He can't get it though. I take it the copper one is better? Anybody have any opinions? Later on, I called a friend who's a VW mech. He said don't spend the money on the radiator because he thinks the head gasket is blown. Told me to get a kit that hooks up to the coolont bottle and somehow changes color if there's a loss of compresion due to a head gasket leak. Anybody have any experience with this? Link to comment Share on other sites More sharing options...
Geonovast Posted May 28, 2008 Share Posted May 28, 2008 There are a couple other things you could try. Pull your oil dipstick. If there's any redness to it, there's a chance coolant is getting in your oil, which would be if blew your head gasket. Do a regular compression test. Link to comment Share on other sites More sharing options...
LEAD_NOT_FOLLOW Posted May 28, 2008 Share Posted May 28, 2008 If you replace your rad. get an all metal 3-core one. They cool better, last forever (lifetime warranty with a CSF), and are not that much more expensive. I run the CSF's in all my rigs and swear by them. Motion has them for $205 w/free shipping. http://motionoffroad.com/catalog/index. ... rers_id=43 Link to comment Share on other sites More sharing options...
Pete M Posted May 28, 2008 Share Posted May 28, 2008 I'd go all-metal for sure. Link to comment Share on other sites More sharing options...
pingpong Posted May 28, 2008 Share Posted May 28, 2008 There are a few ways to test for blown head gaskets. Here are some symptoms to look for. Loss of water :brows: if you are not losing water more then likely no blown head gasket. Unexplained missing :brows: Water don't burn :brows: water coming out the tail pipe(not as common as other tell tail signs, especially with the length of the exhaust). Also if you pull your plugs and they look "steam" cleaned. Then there is also a pressure tester to test your whole cooling sytem, but be warned.. doing this often finds the weak spot in your cooling system and pushes fluid out. Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted May 28, 2008 Author Share Posted May 28, 2008 There are a couple other things you could try. Pull your oil dipstick. If there's any redness to it, there's a chance coolant is getting in your oil, which would be if blew your head gasket. Do a regular compression test. There's no redness to the dipstick. Compression test was done with engine cold from overnight wait. Cylinders 2-6 were all 150-160. Cylinder #1 was 135. The oil on the dipstick does smell like gasoline a little :dunno: Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted May 28, 2008 Author Share Posted May 28, 2008 If you replace your rad. get an all metal 3-core one. They cool better, last forever (lifetime warranty with a CSF), and are not that much more expensive. I run the CSF's in all my rigs and swear by them. Motion has them for $205 w/free shipping. http://motionoffroad.com/catalog/index. ... rers_id=43 Yeah I'm buying that one next week. Story in a couple posts. Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted May 28, 2008 Author Share Posted May 28, 2008 There are a few ways to test for blown head gaskets. Here are some symptoms to look for. Loss of water :brows: if you are not losing water more then likely no blown head gasket. Unexplained missing :brows: Water don't burn :brows: water coming out the tail pipe(not as common as other tell tail signs, especially with the length of the exhaust). Also if you pull your plugs and they look "steam" cleaned. Then there is also a pressure tester to test your whole cooling sytem, but be warned.. doing this often finds the weak spot in your cooling system and pushes fluid out. Well the level of coolant in the bottle is not going down. However water does come out of the tailpipe at start up with a little bit of smoke. It goes away after warm up. I'm reasoning it's because the engine has 220,000 miles on it and I don't believe the PO's treated it well. "unexplained missing" maybe, truck never idles over 500 rpm but I figured it was because the inside of the valve cover is nasty with build-up and won't let the engine breath properly. When I unplug the vac line from the VC to the intake mani it idles great. (getting around to cleaning it :oops: ) What did you mean by"water don't burn"? I'm gonna borrow the pressure tester from autozone for the coolant sometime this week. The rad is getting changed anyway to the three row one. As soon as I send the money Taz is sending me a new shroud. (sorry TAZ, forgot to go to the bank today) Bought a "block test kit" at NAPA today. Looks like a big glass crayon. I skimmed the directions quickly it said to place over coolant bottle, pour some blue fluid in, turn on the engine, and start sucking air out of the bottle. If the fluid turns yellow or green then there are combustion gasses in the coolant and I guess that means the head gasket is crap. We'll see tomorrow when I do it. Back to the original "getting hot". I said the gauge was showing the engine getting real hot. Not in the red but close. Hit it with a laser thermometer from harbor freight and at it's hottest would read 230-245. Well today after chasing down a couple friends w/laser thermometers and rechecking with theirs I found out that not only is the truck gauge reading incorrectly (which we knew) but now my laser thermometer is off by about 20-25 degrees, which means my engine is really running at 210-225 Which means after all this crap it's actually pretty normal :wall: I'd still like to bring the temp down a bit. Hopefully the full shroud and new rad will help. Thanks for all the help guys. I'll update with the tests when I get em done :cheers: Link to comment Share on other sites More sharing options...
Silver88 Posted May 28, 2008 Share Posted May 28, 2008 If you replace your rad. get an all metal 3-core one. They cool better, last forever (lifetime warranty with a CSF), and are not that much more expensive. I run the CSF's in all my rigs and swear by them. Motion has them for $205 w/free shipping. Pardon me for asking, CSF? http://motionoffroad.com/catalog/index. ... rers_id=43 Link to comment Share on other sites More sharing options...
HOrnbrod Posted May 28, 2008 Share Posted May 28, 2008 If you replace your rad. get an all metal 3-core one. They cool better, last forever (lifetime warranty with a CSF), and are not that much more expensive. I run the CSF's in all my rigs and swear by them. Motion has them for $205 w/free shipping. http://motionoffroad.com/catalog/index. ... rers_id=43 I put a CSF 3-core in my MJ about 2-1/2 years ago when I installed my stroker. The engine ran hot (220* - 225*) all the time w. the 195* factory stat. I called Hesco, they recommended pulling the CSF rad and putting in one of these single core aluminum rads: http://www.alumrad.com/dblpass.html The running temp immediately dropped immediately 10*-15* and stayed there. When I pulled the hoses to drain the CSF, big globs of solder came out. I shook out about a pound of solder balls out of it later. I send it back (my dime) and they refunded my $$ after I screamed, so no more CSF products for me. Maybe I just got a bad one and they've improved their QC now. I also remember a bunch of guys on NAXJA had similar problems at the time. Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted May 29, 2008 Author Share Posted May 29, 2008 If you replace your rad. get an all metal 3-core one. They cool better, last forever (lifetime warranty with a CSF), and are not that much more expensive. I run the CSF's in all my rigs and swear by them. Motion has them for $205 w/free shipping. http://motionoffroad.com/catalog/index. ... rers_id=43 I put a CSF 3-core in my MJ about 2-1/2 years ago when I installed my stroker. The engine ran hot (220* - 225*) all the time w. the 195* factory stat. I called Hesco, they recommended pulling the CSF rad and putting in one of these single core aluminum rads: http://www.alumrad.com/dblpass.html The running temp immediately dropped immediately 10*-15* and stayed there. When I pulled the hoses to drain the CSF, big globs of solder came out. I shook out about a pound of solder balls out of it later. I send it back (my dime) and they refunded my $$ after I screamed, so no more CSF products for me. Maybe I just got a bad one and they've improved their QC now. I also remember a bunch of guys on NAXJA had similar problems at the time. The crowd now watches silently :popcorn: Anybody else? Link to comment Share on other sites More sharing options...
mvusse Posted May 29, 2008 Share Posted May 29, 2008 Radiator with plastic tanks cannot be repaired. All metal radiators are repairable. You pay more up front, but if it ever needs fixed it could be cheaper. Of course if there's excess solder inside the radiator, that's just piss poor quality. I usually check stores to see who carries a lifetime warranty radiator. Don;t care if they have plastics tanks, cause if it ever fails I just pull it, plop it onto the store counter and tell them I need a new one. Around $150 is not bad for a radiator. Even $210 isn't all that bad. Sure , my Geo's radiator was $100, but it was about the size of a heater core. The radiator in my Suburban is $499. But that sucker is 2' high, 3' wide and 3" thick. Link to comment Share on other sites More sharing options...
HOrnbrod Posted May 29, 2008 Share Posted May 29, 2008 I'm not trying to start an argument, really, just stating what happened to me. CSF radiators at the time were made in China and Mexico, among other places. The China-made rads were junk; the ones from Mexico were supposed to be okay. Found this out after that fact, and guess which one I got. I'm sure CSF has straightened this out long ago, but I'm stickin' with my aluminum rad. :cheers: Link to comment Share on other sites More sharing options...
BLHTAZ Posted May 29, 2008 Share Posted May 29, 2008 When I did my conversion...I bought one from these guys... Radiator Express Nice radiator, cools very well and never goes over about 200...even in 90+ degree temps with the AC on. Link to comment Share on other sites More sharing options...
LEAD_NOT_FOLLOW Posted May 29, 2008 Share Posted May 29, 2008 Dunno hornbrod.... I've now ran 4 CSF's without issues. We have them in all our rigs and I've never had an issue with any of them. Actually I've been quite happy with the quality and performance of them. Maybe you just got a bad one, or maybe I've just been lucky and gotten 4 good ones. I'd guess the prior though... ;) Link to comment Share on other sites More sharing options...
HOrnbrod Posted May 29, 2008 Share Posted May 29, 2008 Yeah, I'm sure I got a bad one. During that time everyone was asking the parts houses to pull the rad out of the box to check the "Made in ??" label. I've read also that some of them from China came w. plastic tanks but were advertised as all metal. I ordered mine online and had no control over what they sent me. :oops: Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted June 2, 2008 Author Share Posted June 2, 2008 So, I used the Block Tester from Napa to test and see if there were any exhaust gasses in my coolant. Good news is that there is not, so head gasket is good. Went ahead and changed out the temp sender on the back of the head to see if that was bad and my gauge would read normal. Brand new sensor. Gauge still reads the same. I'm getting a "new" gauge and see if it will read normal then. I used two more differnt laser thermometers on the sensor and the thermostat housing and the temperature still reads normal on them (190-215*). We'll see....... On a side note. Does anyone know if the CSF radiator from Motion Offroad has the hole to screw in the temp switch for the Aux fan on it or am I going to have to look for something else? Side note #2. I've read Eagle's and BLHtaz's post about using the Moroso surge tank instead of the plastic pressure bottle. Besides more coolant capacity and the fact that it won't crack like plastic, what are the advantages of using it? Link to comment Share on other sites More sharing options...
Motion Offroad Posted June 3, 2008 Share Posted June 3, 2008 On a side note. Does anyone know if the CSF radiator from Motion Offroad has the hole to screw in the temp switch for the Aux fan on it or am I going to have to look for something else? The 88-90 (renix) one does, but does not have a filler tube. The 91-97 one does not have the hole for the temp switch but does have a filler tube. Call, Email, or PM us if you have any other questions. :cheers: Link to comment Share on other sites More sharing options...
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