I have what is probably an elementry question, but how can I tell if my thhermostat is going bad? The reason I ask is because my temp gauge goes way up after the car has been running for a few minutes then goes back to normal after I turn on the heater. I

still goes through the thermostat, if it is in question just change it, you looking at $10 for the thermostat and seal and about 5 minutes of you time to change it. Might be worth the investment if you are keeping the car to flush the coolant system (and yes the heater core too) not the do it your self kit but by a mechanic with the pressure machine and the cleaner. It'll be about $120 or so, but it makes a difference in the cooling, mine barely gets to halfway on the worst day, and before it was 3/4 of the way to hot. You might want to check you electric fan if you got one, since earlier ones had a clutch fan, make sure it is running. the A/C overrides it to on, so pop the hood and let it heat up with the climate control off and see what it does (the fan) and if it gets to hot turn on A/C and see if the fan comes on then. If it does then the coolant temperature switch is probably bad. (on the block usually). If the thermostat is bad you will be able to grab the upper radiator hose cause no water will be going through it.

I know this question was directed at Kit, but can I add my 2 cents?  I have a 93 XLT (171,000 miles) that had the same exact problems you describe.  I went to autozone and picked up a Robert Shaw thermostat and a temp sender unit they had in stock.  Both very reasonable priced.  After I installed both of them my temp guage stays perfectly in the middle and has been this way for over a year.  You can save yourself a lot of money by installing these parts yourself.  After you do the job yourself you will wonder why you spent all that money on labor for such an easy job.  I spent under $20 for both the thermostat, and temp sender unit.  You will need some antifreeze if you do the job yourself.    You will have to install an after market temp guage to get an accurate reading.    Does anyone on here have a factory oil guage that always shows on the low side during normal driving?    Joe

"A.C.

Any auto parts store like Napa should have them on the shelf that would work just fine. By leaking meaning through the T-stat or around it? Why 180? I've heard it was Good and Bad on a 4.6. Not sure myself about that or what comes in the car to begin with. I don't blame you for doing it the easy way, saves you from having to dispose of it afterwards. And a pressure test of the system isn't a bad idea since the sn95's have been known to leak around the Plastic tanks/center section. Mine did. Phil Jones Phillip.l.jones@...

It is leaking where the t-stat housing and the t-stat cover come together. The guy said that was a sign that the t-stat was sticking and just getting old. Why 180? Good question. I have heard both sides of the t-stat debate, too and here is my thinking. I may be wrong, and any of y'all are welcome to correct me. I believe 180* is where the computer switches over from "warm-up" mode into normal mode. I believe during warm-up, the engine runs rich. My understanding of the t-stat is that it controls when the fan kicks on. By putting the 180* in, the fan should kick on just after the engine is properly warmed-up. This will put a little extra drain on the battery, but should definately help with the Texas heat, and If I am lucky, even net me some slightly cooler, denser air. If I am correct about 180* being the cut-over point, then it is the 170* and 160* t-stats I would stay away from. Again, this is just my understanding of how it all works. To put it in perspective, I consider myself to be about a level 1 shade-tree mechanic (i.e. I only feel comfortable doing the simple stuff).

well, I am not sure of the exact temperature the computer goes into closed loop mode but with a 160 thermostat the engine will not go into closed loop mode. With a 180 it will. Closed loop is when the O2 sensors come on line and start tuning the air fuel mixture. Before that the engine is only running on set fuel maps. You want to be in closed loop for better part throttle performance, adaptive learning (when computer learns new air/fuel maps for all condidtions), and for reduced emissions. I have also heard things about with a 160 you will wear the cylinder bores more. Not sure if this is true though. So, get the 180 :-) Eric http://members.aol.com/whitelx

Matt the T-stat assuming we are talking about the one w/ a hose, not a sensor for the fan only controls flow based on water temperature. This in turn effects the water temp which will cause the fan sensor to triger the fan motor when teh WATER hits it's correct temperature. A does lead to C put there is a B (actual water temp in the mix) The fan won't come on line if it's trigger is say 190 or something higher even thought the flow t-stat si opening at 180. What Eric says about under 180 washes w/ my understanding of it. Phil Jones Phillip.l.jones@...

Clarification: What Eric says about under 180 being bad washes w/ my understanding of it on a 4.6. Don't know on the 5.0s. there was a WAR on the Corral (4.6) a while back on this and it seemed to go 50/50 so in this case my $$ goes w/ the dudes who designed the car=) Phil Jones Phillip.l.jones@...

Phil, that goes for ALL computer controled cars :-) Eric

Must be the OBDII, eec federal rules/standards no? Or is it more complex than that? Phil Jones Phillip.l.jones@...

http://www.corral.net/Forums/Forum21/HTML/000197.html This is one of the better thermostat debates at The Corral. I believe 'Kim' is an ex-Ford-tech. She/He (yes, there are guys named 'Kim') is the moderator of the "X-Tech" forum at least. I'm just going to run a 195 and be done with it. (Oh, and I have a better understanding of how the thermo/engine coolant/radiator coolant scenario works, now. Enough so, to realize my first post was a bit bone-headed ... well, at least I put a big 'ole disclaimer on it ;)

Great, Hope I as able to help you some. Phil Jones Phillip.l.jones@...

Any auto parts store like Napa should have them on the shelf that would work just fine. By leaking meaning through the T-stat or around it? Why 180? I've heard it was Good and Bad on a 4.6. Not sure myself about that or what comes in the car to begin with. I don't blame you for doing it the easy way, saves you from having to dispose of it afterwards. And a pressure test of the system isn't a bad idea since the sn95's have been known to leak around the Plastic tanks/center section. Mine did. Phil Jones Phillip.l.jones@...

It is leaking where the t-stat housing and the t-stat cover come together. The guy said that was a sign that the t-stat was sticking and just getting old. Why 180? Good question. I have heard both sides of the t-stat debate, too and here is my thinking. I may be wrong, and any of y'all are welcome to correct me. I believe 180* is where the computer switches over from "warm-up" mode into normal mode. I believe during warm-up, the engine runs rich. My understanding of the t-stat is that it controls when the fan kicks on. By putting the 180* in, the fan should kick on just after the engine is properly warmed-up. This will put a little extra drain on the battery, but should definately help with the Texas heat, and If I am lucky, even net me some slightly cooler, denser air. If I am correct about 180* being the cut-over point, then it is the 170* and 160* t-stats I would stay away from. Again, this is just my understanding of how it all works. To put it in perspective, I consider myself to be about a level 1 shade-tree mechanic (i.e. I only feel comfortable doing the simple stuff).

well, I am not sure of the exact temperature the computer goes into closed loop mode but with a 160 thermostat the engine will not go into closed loop mode. With a 180 it will. Closed loop is when the O2 sensors come on line and start tuning the air fuel mixture. Before that the engine is only running on set fuel maps. You want to be in closed loop for better part throttle performance, adaptive learning (when computer learns new air/fuel maps for all condidtions), and for reduced emissions. I have also heard things about with a 160 you will wear the cylinder bores more. Not sure if this is true though. So, get the 180 :-) Eric http://members.aol.com/whitelx

Matt the T-stat assuming we are talking about the one w/ a hose, not a sensor for the fan only controls flow based on water temperature. This in turn effects the water temp which will cause the fan sensor to triger the fan motor when teh WATER hits it's correct temperature. A does lead to C put there is a B (actual water temp in the mix) The fan won't come on line if it's trigger is say 190 or something higher even thought the flow t-stat si opening at 180. What Eric says about under 180 washes w/ my understanding of it. Phil Jones Phillip.l.jones@...

Clarification: What Eric says about under 180 being bad washes w/ my understanding of it on a 4.6. Don't know on the 5.0s. there was a WAR on the Corral (4.6) a while back on this and it seemed to go 50/50 so in this case my $$ goes w/ the dudes who designed the car=) Phil Jones Phillip.l.jones@...

Phil, that goes for ALL computer controled cars :-) Eric

Must be the OBDII, eec federal rules/standards no? Or is it more complex than that? Phil Jones Phillip.l.jones@...

http://www.corral.net/Forums/Forum21/HTML/000197.html This is one of the better thermostat debates at The Corral. I believe 'Kim' is an ex-Ford-tech. She/He (yes, there are guys named 'Kim') is the moderator of the "X-Tech" forum at least. I'm just going to run a 195 and be done with it. (Oh, and I have a better understanding of how the thermo/engine coolant/radiator coolant scenario works, now. Enough so, to realize my first post was a bit bone-headed ... well, at least I put a big 'ole disclaimer on it ;)