CLUE

Yeah I tried giving the sensor a wipe, since I've done everything else now (drain rad, new thermostat, use prestone flush with water, drain rad again, fill again w/water, drain rad again, fill with 50/50). I'll see if I can top it up anymore right now, maybe it went down a bit after I got home and parked last night. If that doesn't do it, guess I'm off to buy a new rad cap, then if that doesn't do it, I'll try replacing the sensor, I'll see how much it costs, if its cheap like the rad cap then maybe ill just get both, I want to have it working as I didnt put a new therm stat housing seal in, because everywhere was closed or didnt have in stock, so if that starts leaking i want the sensor working so I can replace it. Thanks for the input, think it's probably a bum sensor now, might as well replace the rad cap as well.

CLUE

Where is the coolant temperature sensor located on my car? (91 GT 5.0) for those who haven't read the older posts. I looked around online, but I got fed up trying to find any info on it's location on my car. Can I see it around the thermostat housing, do I have to take anything off to get at it? It's dark out right now so I'll have to wait until morning, but I got the new sensor. I put on the new radiator cap at my friends house after letting it cool down, then on the way home the low coolant light came back on, so I'm going to try replacing the coolant sensor. Please let me know where it's located, so I can easily change it in the morning. I also see from one video I watched that I should put liquid pipe thread sealant on the sensor threads? Thanks

mattdel

Lower intake manifold for the temp sensors. One on the passenger side near the heater hoses is the 2 wire sensor, for the computer. On the drivers side near the #1 injector, is a single wire sensor, thats for the gauge.

CLUE

Ok, I will just post pics of what I have, I hope I got the right one, I didn't know there was multiple sensors! Think this will be my fix for the low coolant light coming on still after I've done just about everything else?

The_Dude

No, that won't fix it. You have to replace the sensor inside the recovery bottle. Unfortunately, it ain't cheap. That's why I haven't done it.
http://foxresto.com/products/view/13...w_Level_Sensor

CLUE

That's the one I thought I was getting, I just asked for a coolant temperature sensor, thinking that's what I'd get. I haven't installed the one I got yet, so I should be able to bring it back for a refund, or atleast exchange for that one. I was kind of wtf when I opened it up, because I thought maybe it was just the end piece of that one (the receptacle or plug looking end piece), I didn't know there was multiple sensors. I need to buy a manual, that'd probably help me out for alot of minor things. That one's cheaper than the one I got anyways, so I can just exchange it for that one and hopefully LORDCO will have it, or I'll look around, I'll probably even get a few bucks back out of it. Thanks again, this will save me money and time, as well as fix the problem i hope.

fl1a

The one you are holding in the picture is also known as the ECT sensor. it is the sensor that provides feedback to the computer. The other thermostatic sensor is also called the sender. That one has a single threaded post on top and is used with the gauge. A Haynes repair manual for your car can give a lot of help identifying the various parts you are going to want to know.

CLUE

Ok, I just got back from returning that part (sensor) and on the way home I started getting more issues, can someone help me diagnose what's wrong? The low coolant sensor light came on, which it had been doing before, but followed by the check engine light this time, so I parked and shut the engine off for a bit and checked the coolant levels, it has plenty of new coolant. I grabbed the top rad hose and the bottom rad hose, the top one was pretty hot, while the bottom one seemed warm-hot, but not hot like the top one. The temperature gauge on the dash goes up to the middle of the normal range and doesn't seem to go up high, but I don't fully trust it, because I think somethings going on, I think it was getting a bit hot for a 10-15 minute drive in stop and go traffic. The top hose seems to get hotter even quicker after I did the flush and changed the coolant/thermostat/rad cap, could just be because it is cleaner after the flush? After checking it, letting it cool down a little, I continued home, the low coolant light came on again shortly followed by the check engine again right before I got home. The check engine light did come on a month ago, but I changed the oil (synthetic) and put a new oil filter in and it went away til now, nothing seems to be leaking anywhere and all fluid levels are fine, so I think the check engine light is related to heating up, or coolant circulation this time. The other day, I put in a new thermostat and did a radiator flush with prestone rad flush then flushed with water and drained it twice, put new 50/50 coolant in and yesterday I got a new radiator cap and put that on as well. Is it possible the new thermostat I put in isn't functioning properly, I didn't put it in backwards... could it be that the pin needle hole on the thermostat is not in the right spot? I'm asking this because I didn't notice the location of the old one and when I felt in the housing I couldn't feel anything that would indicate a certain spot for that. It seemed to sit snugly when I put it in and turned to the right a bit, like thats the position it wanted to be in, how important is the position of the pin needle hole position on the thermostat? I also had to re-use the old thermostat housing seal, but it is not leaking. The new radiator cap I got from Lordco, said 15 psi and the old one I had was 16psi, but I told them the year and make of my car of course when purchasing, is this ok? Could it be something as simple as air in the system, I'll probably try to bleed it again. This is turning into a little bit of a headache, what could the main issue be? I am hesitant to go on a long drive anywhere for fear of overheating and doing damage. I hope you can understand how I detailed everything, sorry for the long post, but I wanted to explain exactly what I have done to it and what's happening. Lordco didnt have the other sensor I wanted and ford said they don't sell that part anymore, so I'll have to order it off that site, I will do that... thanks the dude. It appears my work is not done, what do I do next?

CLUE

I think I'm going to just try a bunch of stuff again tomorrow morning (since I have spare time on my side), starting with (1) checking the coolant level of course... duh! (2) Start it and turn the AC on full and run the car for a bit, to see if the cooling fans are working then let it cool down. (3) Remove rad cap, start car again and run for 10-15 minutes, last 5 min with heat on high and fan off to hopefully let the coolant go through a few cycles and the upper hose starts heating up, so I know that the thermostat is going from closed to open. (4) I will check the coolant level again and take it around the block a few times to see if I get the same outcome. (5) I will go pick up the gasket sealer and thermostat housing gasket and drain some coolant, and install a brand new gasket properly, can someone tell me if the pin needle hole on the thermostat should be on the top half or bottom half of the thermostat when going in (example: 12 o-clock, or 6-oclock), I didn't see how it was last time, but it seemed to only fit snugly in one spot, with the pin needle hole on the top 1 o-clock position I think. (5) I will bleed and top up again as necessary. Is there a bleed hole on the thermostat housing, or is it ok to just bleed it by removing rad cap? Please let me know if there's anything else I should do, or if there's a better way to do any of the things I'm going to try, or maybe I'm forgetting to do something? I might have to take it in to my mechanic, but I'm strapped for cash until I get working for a bit and kind of need my car running good for getting to work, so that's my last alternative, hopefully it's not the rad itself, or a headgasket, the car still has very low mileage, only 49,600miles on it. Please see my last post for all the details on what I've done already (what's been going on and what's going on with it right now). Thanks to everyone who's posted so far, I'm learning a lot in the process, appreciate it!

fl1a

Your thermostat should go in with the pin at top and the broader portion down. When you go to get the gasket, i would once again suggest getting a Haynes repair manual for your car. It will help a great deal. Your low coolant light should be a indicator of your reservoir level, not the level of coolant in your engine. If you are getting a check engine light, see if the auto parts place you are using will loan or rent or even read your stored codes in your engine management system. It is the only way you will know what caused the check engine light. The Haynes manual has a list of the code numbers and their respective causes. Replace your gasket, refill your cooling system, fill your reservoir, and keep it filled to the full line and check it each time the engine sits overnight. With no leaks in your system, the engine coolant will properly top off from the reservoir after a few overnight cooling periods. Your radiator should get hot water from the top and cool it to return at the bottom.