chicofuentes0224 Posted October 13, 2008 Share Posted October 13, 2008 Is it possible that a thermostat can open when it hits operating temp but not open comepletely causing the engine to run a bit hotter? The reason I ask is because I'm still fiddling with the engine temp, I've changed the thermostat but with all the faulty parts I've recieved lately I'm wondering if maybe this one opens up, but not comepletely. Opinions? Link to comment Share on other sites More sharing options...
DirtyComanche Posted October 13, 2008 Share Posted October 13, 2008 I'm sure it could. Pop it out and throw it in a pot of boilling water and inspect it. Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted October 13, 2008 Author Share Posted October 13, 2008 I'm on it sometime this week. Thanks eh :cheers: Link to comment Share on other sites More sharing options...
Akula69 Posted October 13, 2008 Share Posted October 13, 2008 Is it possible that a thermostat can open when it hits operating temp but not open comepletely causing the engine to run a bit hotter?The reason I ask is because I'm still fiddling with the engine temp, I've changed the thermostat but with all the faulty parts I've recieved lately I'm wondering if maybe this one opens up, but not comepletely. Opinions? That's exactly what the 'stat was doing in my daughter's XJ. When I dropped it in the coffee cup (of heated water) it opened about 1/8 inch and stopped. Of course, I didn't figure this out till it blew out the side of the radiator :headpop: Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted October 13, 2008 Author Share Posted October 13, 2008 Here's my new 180* thermo. Where am I supposed to drill the two holes? I see a dimple that let's the coolant thru in the second photo so if that is 12 o clock the opposite at 6 is blocked by an arm on the other side. Should I go thru that and what size drill bit would you guys use? Link to comment Share on other sites More sharing options...
reson46 Posted October 14, 2008 Share Posted October 14, 2008 Throw that in the trash and get the proper 195 degree thermostat. Willy Link to comment Share on other sites More sharing options...
BLHTAZ Posted October 14, 2008 Share Posted October 14, 2008 Throw that in the trash and get the proper 195 degree thermostat. Willy X2 The proper t-stat for the engine will be 195 and come with a hole in it that goes at the 12:00 position with a little check ball in a copper sleeve to allow flow only in one direction. :cheers: Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted October 15, 2008 Author Share Posted October 15, 2008 Throw that in the trash and get the proper 195 degree thermostat. Willy X2 The proper t-stat for the engine will be 195 and come with a hole in it that goes at the 12:00 position with a little check ball in a copper sleeve to allow flow only in one direction. :cheers: Not that it matters much anymore because I ordered a dealer one from Brent but Willy I'd like to know why you suggested throwing the 180* one away? I have no idea if you've read all of my previous posts on my cooling problem but I'll re-cap it real quick. New: 195* thermostat upper/lower radiator hoses waterpump heater control valve and hoses running to and from the heater core 3-core all metal radiator fan clutch metal tank expansion tank (to replace the plastic one) second overflow bottle to convert it to an open system I've put the second electric aux fan on a relayed switch. I've had the whole system flushed by Valvoline on their machine twice I've bled the system thru the temp sender a dozen times There is no head gasket leak. (No oil in coolant/vice versa and I've used a block tester to confirm) Compression test is fine When I replaced the waterpump I even went as far as sticking a dentist's little mirror inside the engine as far as I could to see if I could find any buildup. (Almost none) Alas the only way to keep my temp around 210* at the gauge (201* at the thermostat housing) is to run the aux fan on full time and my HVAC system on full blast (hot or cold it doesn't matter) If I don't use both I run up about 10-20*. OK, remembering that I didn't even know what my temp was until I put in a full gauge cluster I started to rethink my situation. When I first put in the full cluster it always showed 210*. I started having problems last winter because the engine would never heat up. This is when I found out that the OP had removed the thermostat and never replaced it. I put one in and that's when I started running warm. So after changing EVERYTHING in the cooling system I've decided to start at the begining again. Maybe I just put in a faulty thermostat from the start. Now I know CW always says these engines run warmer (220*) but I've found out if I can keep the engine at 210* I get 1-2 better MPG. It doesn't seem like much but going from 10 MPG to 14 MPG is a definite improvement. After all this I figured if the thermo I put in last winter isn't faulty maybe putting in the 180* one will help me get that couple degrees I need lower. Now I'll try the dealer one. Maybe it will make a differnce, maybe it will be like every other part I've replaced that's been perfectly fine to start with. I was just wondering why you said "Throw it in the trash." Link to comment Share on other sites More sharing options...
reson46 Posted October 15, 2008 Share Posted October 15, 2008 Using a cooler thermostat will cause the computer to think it constantly needs to run rich to warm the engine IF the cooling system is actually able to keep it that cool. These engines are designed to use a 195 degree thermostat. This just results in poor mileage and increased wear from constantly running rich. Using cooler thermostats does nothing to address the cause of a cooling issue. If the cooling system is not able to cool the engine to 180 degrees, it will continue to overheat and that cooler thermostat is doing nothing for you. Once the thermostat is open, it no longer does anything to help cool. Whatever is causing the cooling issue will continue to drive the temperature up. Willy Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted October 15, 2008 Author Share Posted October 15, 2008 Wow :eek: That was a fast reply. Thanks for the explanation Willy :cheers: By any chance ,you don't happen to have any other ideas on the cooling issue do you :brows: Link to comment Share on other sites More sharing options...
mvusse Posted October 15, 2008 Share Posted October 15, 2008 I hate to point out the obvious, but you have a 20 or so year old truck. Have you ever had the radiator flow tested? Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted October 16, 2008 Author Share Posted October 16, 2008 I hate to point out the obvious, but you have a 20 or so year old truck. Have you ever had the radiator flow tested? I put in a brand new one from MO. It made absolutely no differnce in temp. Link to comment Share on other sites More sharing options...
FxRacing282 Posted October 16, 2008 Share Posted October 16, 2008 do you have one of those cool valves that block the water from entering the cab when the heater is off? if so was it factory? because if you have it and its not a factory option that may be why you are running hot. but 210 is a good OP. 240 is when you turn the engine off. 230 is hot. now if you put a 180 in and its operating at 195-210 then leave it in. have you checked the temp with another temp guage? its possibly the one you have is faulty or innacurate Link to comment Share on other sites More sharing options...
HOrnbrod Posted October 16, 2008 Share Posted October 16, 2008 Chico, this is a long thread and refresh my memory. Have you ever actually boiled over? Like after 30 minutes in traffic or on a long climb up a long grade? Or are the overheating problemos strictly based on temp gauge (and external laser sensor) readings? I forget.............. Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted October 16, 2008 Author Share Posted October 16, 2008 Chico, this is a long thread and refresh my memory. Have you ever actually boiled over? Like after 30 minutes in traffic or on a long climb up a long grade? Or are the overheating problemos strictly based on temp gauge (and external laser sensor) readings? I forget.............. Never boiled over. I've never been in the red zone. I did have two brand new caps fail on new plastic tanks and let coolant out but it's no longer a problem with my metal expansion tank and normal radiator cap. I've let the car sit and idle in my driveway for 3 hours before (when I was running Prestone's cleaner thru the cooling system) and it never overheated. My temp gauge was close to the red zone and laser thermometers on the outside of the thermostat housing would read 215*-225* until I kicked on the fan and HVAC. Like I said, running the electric fan and HVAC on fulltime keep my gauge at 210* or a little above and laser temps on the thermo housing 200*-205*. Everything on the cooling system is new. The only thing I can think of is the thermostat is opening but not completely. It's funny you mention climbs. If I go up a hill the temp goes up slightly, but on the way down the temp drops back down to perfect temp. Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted October 16, 2008 Author Share Posted October 16, 2008 do you have one of those cool valves that block the water from entering the cab when the heater is off? if so was it factory? because if you have it and its not a factory option that may be why you are running hot. but 210 is a good OP. 240 is when you turn the engine off. 230 is hot. now if you put a 180 in and its operating at 195-210 then leave it in. have you checked the temp with another temp guage? its possibly the one you have is faulty or innacurate I have no idea what your talking about with the cool valve. The 180* thermo was never put in. It has a 195* in right now that I believe might be the problem. Temps have been verified with plenty of laser thermometers. Temp sender in the back of the head has been changed out 3 times. 2 differnt gauges have been used (Hornbrod even calibrated one.) Clusters have been switched twice. Everything works as it should. I'm shooting for the dealer thermostat from BLHTAZ to permenantly fix this, but if anybody has any other suggestions let me know. I'm all ears. Link to comment Share on other sites More sharing options...
jtdesigns Posted October 16, 2008 Share Posted October 16, 2008 Take your truck and have it sniffed for emissions. See if its something like an O2 sensor or a rich A/F ratio. I'm just trying to help you out Homes.. Couldnt hurt I guess.. Link to comment Share on other sites More sharing options...
FxRacing282 Posted October 16, 2008 Share Posted October 16, 2008 well Chico, 210 is normal operating temp. you may already know this but a 195 t-stat will start to open at 195 and be fully open around 208-210. 215 is nothing to worry about. and when the t-stat is fully open the fan should be on. so to me, everything sounds fine. but I'm probabally missing something? Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted November 3, 2008 Author Share Posted November 3, 2008 I'm still futzing with this. New dealer thermostat was put in. No change in the situation. I've been reading a lot of posts since I've been gone. How do you presure test the cooling system? Link to comment Share on other sites More sharing options...
FxRacing282 Posted November 4, 2008 Share Posted November 4, 2008 with a coolant system pressure checker. believe it or not. it connects to the radiator or wherever you want and then it pressures to about 15lbs or so and then you looks for leaks. at the garage i work at we have this light and a pair of glasses and whatever has coolant on it will glow. Link to comment Share on other sites More sharing options...
maddzz1 Posted November 4, 2008 Share Posted November 4, 2008 From the reading I have done chico, a thermostat is actually there to keep the engine hot, not cool. Ive also read that our engines like to run hot. If it isnt overheating and your new tank has fixed the problem with the cap on the expansion tank then I say forget about it. only because it seems like there is nothing left to check. Link to comment Share on other sites More sharing options...
Oizarod115 Posted November 4, 2008 Share Posted November 4, 2008 i don't know if it was your thread or not... but i just told another person to put in a new temp-sender. the little one at the back of the head that has a wire that just pushes on it. chances are its bad/causing faulty readings... and it's far cheaper than hoses/radiators/waterpumps. Link to comment Share on other sites More sharing options...
maddzz1 Posted November 4, 2008 Share Posted November 4, 2008 i don't know if it was your thread or not... but i just told another person to put in a new temp-sender. the little one at the back of the head that has a wire that just pushes on it. chances are its bad/causing faulty readings... and it's far cheaper than hoses/radiators/waterpumps. He already changed it 3 times Link to comment Share on other sites More sharing options...
Oizarod115 Posted November 4, 2008 Share Posted November 4, 2008 i don't know if it was your thread or not... but i just told another person to put in a new temp-sender. the little one at the back of the head that has a wire that just pushes on it. chances are its bad/causing faulty readings... and it's far cheaper than hoses/radiators/waterpumps. He already changed it 3 times musta skimmed that post. thought i read it good my bad. :oops: change the thermostat and ride buddy! Link to comment Share on other sites More sharing options...
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