Yeah I rarely go fast enough for 5th gear as all the roads are 35-45 mph roads..how would a 180º stat make the temp higher I think the oem is 192 right? So shiuldnt it runa little cooler on the gauge...I hhaven't done anything when the sending unit yet os it a possibility that's the prob...and also I notice that whenever I use any power accessories like light wipers blinkers anything that draws power from the battery the gauge will slightly move...example when my foot is on the brake at a light or something it will make it hotter and when I take foot off it bounces back down not a hugh bounce but I can notice it on the gauge...could that mean its a bad groundbor something of rhat nature?
Yes, okay, two things. Yes, the factory thermostat is a 192. A 180 can actually make the coolant temp hotter because it opens before the coolant in the radiator has had the proper amount of time for its heat to be dissipated by the fan, incoming airflow, and radiator itself. Thus, the coolant which is in the rad, which is too warm, goes into the already hot block, and the hot coolant that was in the block replaces it in the rad only to continue the cycle. In many cases a 180 is not good for the car.
Furthermore, the Ford engineers and software programmers spent millions of dollars and countless hours designing the cooling system to work, well, as a system. For example the cooling fans come on at about 190 degrees. The ECM also relies on a certain engine temp for open/closed loop operation. Throwing a 180 stat in changes those variables. Also, even with under drive pullies your car should not need a 180 stat if all other cooling system components are working properly. If it does need it, then you are most likely band aiding another issue that will eventually catch up to you.
You outta think about a Motorcraft 192 stat. Trust me, no Mr Gasket, no aftermarket, a Motorcraft stat. Also get a Motorcraft radiator cap and your two sensors from Motorcraft. This way you KNOW you are not getting dud or cheapo products out of the box. Somethings need to be OEM and those items are the somethings.
Secondly, check your grounds. If they are bad you cannot trust your gauges. However, your coolant bubbling over while idling is a separate issue from the possible ground issue.
My suggested fix is this:
1) pressure test the radiator. If it holds pressure, then make sure its flushed. If its old or has had rusty or tap water buy a factory replacement from autozone or pep boys for about $90 and fill it with premixed 50/50. Also get a catch container in case you need to dump your new antifreeze for further repairs (see step 6). Consider getting Motorcraft upper and lower hoses if getting a new rad. The Motorcraft lower will have the correct spring in it to prevent collapse.
2) install a Ford OEM 192 thermostat. You can get one on Amazon for $10.
3) toss your aftermarket rad cap and get a Motorcraft one from Amazon for $12.
4) make certain that the car can idle without overflowing out of the uncapped radiator while the car is parked nose inclined, vent on, a/c dial on full heat, and blower motor on high. If it cannot, check for signs of head gasket leaks (I.e., water in oil, oil in rad, compression bubbles in rad). If head gaskets are fine...
5) make sure that HEAT is coming out of the vents. If there is none and your heater isn't leaking then you still have an air bubble in the system. You need to properly bleed it out. These cars are notorious for trapping air and being hard to bleed. If you need to do this I will gladly walk you through it on the phone. If you have had the lower rad hose off this process can take hours. If all is well here...
6) check your water pump. Is it leaking? Is it making a whistling noise? If it is, replace it with a Motorcraft unit. Again, Amazon has it, even LMS has it, but get Motorcraft. If it is not leaking, nor making noise then by now the issue will be fixed.
I really suspect a failing stat, or a bad rad, or improper bleeding of the system, but not so much a water pump. After you have addressed the overheating you need to check out the 6 or 7 grounds on the car so that you get correct readings even when using power accessories. Sorry for the length of the reply. I'm willing to walk you through this if you need help.
about this cooling system my jeep and camaro were easy to rid of air matter of minuetes...and this mustang can take hours? I'm beggining to get nervous hahaha
