94vertluvr Posted February 7, 2011 Report Share Posted February 7, 2011 Hey guys I replaced my thermostat in the 94 3.4L with a 195 degree thermostat because i was having trouble with it generating heat in the cabin. Now the temperature gauge goes over 200 and just into the orange zone and the check engine light comes on but it doesn't go above the orange line and then it will go down below 200 and back n forth. Is this right? Cause for concern? Please let me know what you all think. Thanks! Quote Link to comment Share on other sites More sharing options...
AL Posted February 7, 2011 Report Share Posted February 7, 2011 Did you properly bleed the coolant after installing the thermostat? Quote Link to comment Share on other sites More sharing options...
95 vert Posted February 7, 2011 Report Share Posted February 7, 2011 Did you properly bleed the coolant after installing the thermostat? Air pocket. That's what I'm thinkin Quote Link to comment Share on other sites More sharing options...
Galaxie500XL Posted February 7, 2011 Report Share Posted February 7, 2011 Been there, got the t-shirt. Also, the water pump could possibly be an issue. My 3.4 had a crummy one when I bought the car, and I never could eliminate the air pocket and attending temp fluctuations until the water pump was replaced. Quote Link to comment Share on other sites More sharing options...
734_jackson Posted February 12, 2011 Report Share Posted February 12, 2011 there is a air pocket, there is a coolant line from the thermostat housing to the top of the water pump housing. if this line is there you want to loosen it at the thermostat housing after it is hot, loosen it an wait for coolant to come out steady. then tighten. i had this problem about a month ago. good luck Rob:thumbsup: Quote Link to comment Share on other sites More sharing options...
94vertluvr Posted February 14, 2011 Author Report Share Posted February 14, 2011 Ok this is all news to me. I've never heard about this happening before! Some mechanic I am! lol I'm not but I need to be for my cars' sake! I parked the car until I could get around to it again, will look at this again this week and see if I see that line line your talking about Rob. Is this air pocket situation particular to this model/engine or is it a common thing when you change the coolant that you can get an air pocket in there?? Thanks for the help again guys!!! Quote Link to comment Share on other sites More sharing options...
virtuetovice Posted February 14, 2011 Report Share Posted February 14, 2011 Air pockets can happen in any closed coolant system. It's happened to all of us...numerous times. Quote Link to comment Share on other sites More sharing options...
nitehawkjcb Posted February 25, 2011 Report Share Posted February 25, 2011 Did bleeding the system solve your issue? Quote Link to comment Share on other sites More sharing options...
94vertluvr Posted February 26, 2011 Author Report Share Posted February 26, 2011 Did bleeding the system solve your issue? Hey - I did open up the 2 air bleed valves to where they both were putting out a steady stream of coolant; did this several times and drove the car in between just to see what effect. I'm not really sure if I fixed it or not; the temp gauge goes back and forth from what looks like 160 just above the 2nd heavy white line to up to what looks like just over 200; between the last white line and the first orange line. Also, the low coolant light is coming on intermittently for a minute or 2 at a time then off; I get out and pop the hood and the level is just above the HOT level so I'm not sure what is happening with this. This crap is so dang aggravating!!! Nice to have a paid off car but shit what you have to go thru to put headaches to bed!!! Any ideas? Quote Link to comment Share on other sites More sharing options...
BXX Posted February 26, 2011 Report Share Posted February 26, 2011 I gotta ask this, but did you put the new thermostat in the correct way? Quote Link to comment Share on other sites More sharing options...
94vertluvr Posted February 27, 2011 Author Report Share Posted February 27, 2011 I gotta ask this, but did you put the new thermostat in the correct way? Good question but yes! Have changed several. Quote Link to comment Share on other sites More sharing options...
BXX Posted February 27, 2011 Report Share Posted February 27, 2011 Good question but yes! Have changed several. Ok:lol: Cause as a technician, ive had many people replace their own thermostats and bring it in for us to figure out why it overheats or has other issues, and ive seens soooo many thermostats put in backwards. They dont work that well backwards:lol: Quote Link to comment Share on other sites More sharing options...
Shadow96SE Posted February 27, 2011 Report Share Posted February 27, 2011 Hey - I did open up the 2 air bleed valves to where they both were putting out a steady stream of coolant; did this several times and drove the car in between just to see what effect. How long did you spend bleeding it? Did you wait long enough for the thermostat to open? Could be some air stuck in the engine still, but not being bled if ya don't wait long enough.. I read it can take 20-30 minutes to get it fully bled with the car running. If there is a pocket, it could be what is kicking on the low coolant once the thermo kicks open. Quote Link to comment Share on other sites More sharing options...
94vertluvr Posted February 28, 2011 Author Report Share Posted February 28, 2011 How long did you spend bleeding it? Did you wait long enough for the thermostat to open? Could be some air stuck in the engine still, but not being bled if ya don't wait long enough.. I read it can take 20-30 minutes to get it fully bled with the car running. If there is a pocket, it could be what is kicking on the low coolant once the thermo kicks open. I bled it for probably a minute or 2 at a time; meaning i let it flow from the bleed valves for that long. Did this probably 4 or 5 times total; each time it was coming out good when I shut the valve. I was just afraid to let it run out for longer. And yes I know the thermo was open it took probably 20 minutes for the valve connected to the top hose to start putting out antifreeze. Did I do it for long enough or should I have just let the valves open for 20 minutes or so? Seems like when I'm accelerating that this is generally when the temp reading goes down and when I'm slowing is when it starts to rise. Today on the 25 mile way to work the check gauges light came on 2 or 3 times because the temp reading hit that first orange/red line and didn't go off until it dropped below 195. Quote Link to comment Share on other sites More sharing options...
94vertluvr Posted February 28, 2011 Author Report Share Posted February 28, 2011 Ok:lol: Cause as a technician, ive had many people replace their own thermostats and bring it in for us to figure out why it overheats or has other issues, and ive seens soooo many thermostats put in backwards. They dont work that well backwards:lol: LOl that's kind of amazing since most thermostats have an arrow as to which way it should go in! Quote Link to comment Share on other sites More sharing options...
mhildebrand Posted February 28, 2011 Report Share Posted February 28, 2011 I would try opening the bleeder valves while raising th RPM's to circulate more coolant through. You said its while driving that the temp fluctuates, so doing this may get the air pocket to move a bit more... Quote Link to comment Share on other sites More sharing options...
94vertluvr Posted February 28, 2011 Author Report Share Posted February 28, 2011 I would try opening the bleeder valves while raising th RPM's to circulate more coolant through. You said its while driving that the temp fluctuates, so doing this may get the air pocket to move a bit more... How long should I expect to leave the valves open for? Is there anything I need to be concerned with around all that antifreeze on the engine; and how do you make sure you don't run too low on it? Seems I get the low coolant light on it even when the tank shows full. Quote Link to comment Share on other sites More sharing options...
Jssuper Posted February 28, 2011 Report Share Posted February 28, 2011 Just curious about this, but when you drive to work and back is the level of coolant in your recovery bottle high and then after sitting over night or cooling back down the level stays high? IE: the coolant never sucks back into the radiator, thereby the level in the radiator is frequently low..... I have seen this before and I was seeing the same weird fluctuations you are having. Quote Link to comment Share on other sites More sharing options...
chrisflstf Posted February 28, 2011 Report Share Posted February 28, 2011 You still have air in the system. This worked for me: After the car is up to temp, with the heater control to max heat, hold the rpm at about 2000 for 10 secs, then let it snap back to idle. Watch for bubbles in the reservoir. Repeat until the bubbles stop. Also, make sure the rubber hose from the radiator neck to the reservoir is tight. Mine had a small air leak. A tywrap works good Quote Link to comment Share on other sites More sharing options...
94vertluvr Posted March 1, 2011 Author Report Share Posted March 1, 2011 Just curious about this, but when you drive to work and back is the level of coolant in your recovery bottle high and then after sitting over night or cooling back down the level stays high? IE: the coolant never sucks back into the radiator, thereby the level in the radiator is frequently low..... I have seen this before and I was seeing the same weird fluctuations you are having. YES!!! That is exactly the case!!! Is this from air still being in the system?? Thanks again to the contributors who help with this level of problem solving on this site!! Quote Link to comment Share on other sites More sharing options...
Jssuper Posted March 1, 2011 Report Share Posted March 1, 2011 YES!!! That is exactly the case!!! Is this from air still being in the system?? Thanks again to the contributors who help with this level of problem solving on this site!! Yes to a degree... After it has sat and cooled down and you remove the radiator cap you will hear a "pshh" sound as pressure is released from the radiator. Also the coolant level in the recovery bottle is probably near full to full or even over flowing at times correct? I am assuming this is the case as excess pressure in the radiator is the only thing that can keep coolant from flowing back into the radiator from the recovery bottle. Also it is excess pressure in the cooling system that is pushing coolant into the overflow bottle and causing random air pockets in the cooling system causing erratic temp behavior you describe. I have been through this once. I was beating my head against the wall on this one literally. If my descriptions and symptoms are correct, I am afraid I have some bad news... You have had a headgasket failure. Quote Link to comment Share on other sites More sharing options...
94vertluvr Posted March 1, 2011 Author Report Share Posted March 1, 2011 Yes to a degree... After it has sat and cooled down and you remove the radiator cap you will hear a "pshh" sound as pressure is released from the radiator. Also the coolant level in the recovery bottle is probably near full to full or even over flowing at times correct? I am assuming this is the case as excess pressure in the radiator is the only thing that can keep coolant from flowing back into the radiator from the recovery bottle. Also it is excess pressure in the cooling system that is pushing coolant into the overflow bottle and causing random air pockets in the cooling system causing erratic temp behavior you describe. I have been through this once. I was beating my head against the wall on this one literally. If my descriptions and symptoms are correct, I am afraid I have some bad news... You have had a headgasket failure. Actually Jssuper that is not the case with mine. I don't hear the pshh at all after it cools down and no the tank is not overflowing ever that I've noticed - it's pretty much been the same level. I had new head gaskets put on it last year so I kind of doubt they'd be bad since I've probably not put 500 miles on it since! I think I'm taking it to a mechanic this week...at some point you get tired of banging that head against the wall! lol Quote Link to comment Share on other sites More sharing options...
94vertluvr Posted March 1, 2011 Author Report Share Posted March 1, 2011 You still have air in the system. This worked for me: After the car is up to temp, with the heater control to max heat, hold the rpm at about 2000 for 10 secs, then let it snap back to idle. Watch for bubbles in the reservoir. Repeat until the bubbles stop. Also, make sure the rubber hose from the radiator neck to the reservoir is tight. Mine had a small air leak. A tywrap works good Willing to try anything at this point!!! Thanks! Quote Link to comment Share on other sites More sharing options...
Jssuper Posted March 1, 2011 Report Share Posted March 1, 2011 Oh, well good then.. it sounds like you simply still have some trapped air in the system somewhere. You can imagine how long it took me to determine I had a bad head gasket on my issue. This would have been the 3rd time I have seen it happen, but you ruined it for me. Have you run it with the heater on..? Does it blow heat constant? Quote Link to comment Share on other sites More sharing options...
94vertluvr Posted March 1, 2011 Author Report Share Posted March 1, 2011 Oh, well good then.. it sounds like you simply still have some trapped air in the system somewhere. You can imagine how long it took me to determine I had a bad head gasket on my issue. This would have been the 3rd time I have seen it happen, but you ruined it for me. Have you run it with the heater on..? Does it blow heat constant? LOL! I'm HAPPY to ruin your record on blown head gaskets!!! But you know at this point...nothing would surprise me! I've actually not driven it much so haven't tested the heater on it other than after I replaced the thermostat I ran it to check it got hot an it did. One thing that does puzzle me along those lines is even when the heater is turned OFF I get heat coming out of the lower foot vents so I'm not sure what that is all about. Quote Link to comment Share on other sites More sharing options...
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