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1997 Mustang V6 3.8 Overheating issues

23K views 30 replies 10 participants last post by  izzy1111 
#1 ·
Ok I need some help hopefully this will help. I am new to joining a forum but i have searched on here several times before I joined and found answers. I have a 1997 v6 3.8 mustang, of course a work in progress but I love my car and this is the 3rd one I've owned. Here the deal about a month ago my car overheated and I was in tacobell drive through and I freaked because I smelled antifreeze and saw the smoke from it overflowing, I have replaced my thermostat, fan motor, had a system flush, my antifreeze is actually a little past the full point in the overflow tank, I have bled the coolant system, and my car is still overheating, now the fan just doesn't kick on until it gets extremly hot on the letter L on the temperature gauge. if I run my ac 90% of the time it stays pretty cool. But I want to get this fixed ASAP because I don't have the money right now to replace an engine as much as I would like a 5.0. I have read a couple things online but I can only do as much as I can afford. Anyone have any ideas?
 
#2 ·
it could be a ccrm or a fan, or it could also be something else completly.

start the car, run the a/c, and use a test light to probe the red wire on the 2pin connector going to the fan.

if you have power, confirm that you also have ground at the black wire.
if there is 12v & ground at the connector, the fan is bad.

if you do not have power, you need to back probe your way back to the battery. a stuck open relay in the CCRM would be the likely cause for no power to the fan.

if you do not have ground, you'll need to back probe the harness to where the ground goes.
 
#3 ·
Well I know I repalced the fan motor literally 2 months ago, today I went to lunch and my car is running REALLY hot now and when I popped the hood it was EXTREMLY hot I looked behind the thermostat. and there were small bubbles, I have been told this is my intake gasket but that the heat could have caused the seal to break that it may not be the PROBLEM. :/ REALLY stressin bout this. I am trying to get this figured out and not spend hundreds to thousand of dollars because this year alone I have dumped about 2500 into it in repairs and its killin me. The fan comes on but ONLY when it gets EXTREMLY hot. I am trying to upload a picture of where I saw the leak but I can't get it too.
 
#6 ·
ok well I have been told a couple of things, check to see if my radiator cap is good and it actually does need to be replaced so I am doing that tonight, I know I don't have a clogged hose so here are a couple things I am thinking if anyone can very possibly the order I should start
~waterpump
~CCRM
~Radiator
~replays for the fan
I really want to keep my car but I get frustrated pretty easy so its hard to be patient especially since its my only mode of transportation so I am trying to get it running again.
 
#10 ·
oh heres the issue, the radiator cap did help but I have a couple issues so on the 11-15-2010 I am using my entire paycheck to do repairs i gotta pick up parts BECAUSE It still overheats and I do NOT want to risk warping a head, the heat has caused me to blow my upper and lower intake gaskets and I checked my oil today because RARELY it shows white smoke in the morning but I saw the water separating from my oil and its starting to look hazy. Mr. Red pony if you want to help I am grabbing dillon to help me, heres the list of repairs I am doing on the 15th and HOPEFULLY this will fix the overheating issues:
~spark plugs and wires
~upper and lower intake manifold gaskets
~head gaskets
~(CCRM) Constant control relay module
~thermostat
~thermostat gasket
~oil & filter
~waterpump
these are because my odometer and tripometer stopped working but EVERYTHING else on the instrument cluster works.
~odometer gears
~vehicle spead sensor

If anyone can think of anything extra to add to the list that may be causing the overheating please let me know and I'll update as soon as these repairs are done.
 
#11 ·
Are you getting head bolts? Thats is going to take a lot of time and work to put new head gaskets on.. You need new bolts for it though because they are torque to yield.

Try just replacing the thermostat first.
 
#12 ·
You might want exhaust manifold gaskets as well, because you have to take the manifolds off to get to some of the head bolts.
 
#14 ·
If you plan to replace the head gaskets, carefully check the gasket surfaces. If it's been overheating at least the heads need to be resurfaced. If you are using MLS (multilayer steel) head gaskets be sure to talk to a machinist about the required surface finish. Also
every trace of old gasket material has to be removed from the block gasket surface.
 
#15 ·
ok here was the issue, my car after I replaced the thermostat was not actually overheating the gauge was telling me it was there are two sensors about 20-40 bucks each that tell the fan to kick on my mechanic did say that my intake manifold gaskets needed to be replaced as well but it wasn't actually overheating after I replaced thermostat.
 
#16 ·
So I take it that we are assuming that when it did actually overheat it caused the CTS to go bad? And that made it look like it was still overheating.
 
#19 ·
Post resurrection....


Ive have this issue myself and its very common for our years. The real problem is (unless you truly have other cooling failures) that the resistor behind the coolant gauge is worn out, and shows a reading that its overheating. Best way to tell its not overheating is using an OBDII scanreader device to tell you the actual coolant temp, should be about 200-210, the fan usually kicks on about 210 degrees.

Thats why even if you replace cooling related parts, the gauge still reads its overheating.


But to replace the sensors just incase. They are located on coolant lines around where the big upper coolant hose goes into the engine, they are gold in color, the main one for the computer and fan control is behind and around the coilpack.

Goodluck.
 
#20 ·
ok ty its not circulating i guess because i have no thermostat and its not flowing in the radiator and im guessing the water pump is bad but idk the water pump looks new this is just really aggravting me and there is white smoke comming out the tail pipe what does that mean?
 
#23 ·
Usually waterpumps go bad when they start to leak from their seal, which they have a weep hole to tell if thats going on. But to think thats its actually seized and not turning, I doubt that, it could be that your belt tentioner has worn out and not turning all belt accessories well, including the waterpump. But you say it looks new, so i dont think its your problem, especially the white smoke out your tailpipe.

But is the white smoke always constant? Or only on start up?
 
#24 ·
how many miles does you car have on it, a bad water pump will usually seep out of the weep hole, or the bearings could be bad, but i doubt that since is turning, and how often do you see white smoke?
 
#25 ·
belt tensioner is new the white smoke goes away after its crunk up for a lil while and its not as bad as before we changed the intake gaskets its sat since september then i bought it in march the intake gaskets on each side was gone and they were the original ones it has 218,000 miles on it
 
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