I have a 95 3.8L Mustang that has been overheating off and on for about a year. Approx. 160,000 miles and has been good to me. Ususally all I need to do is add more fluid and bleed the air out of the system and it is fine for a few months. (There is a slight leak somewhere, we have not been able to determine the source (head gasket?).) Well, it was running fine and one day it starts overheating so I tried some stop leak in addition to what I normally do to "fix" the problem and things seem to get worse from there (though I had used it before with no problems). I resorted to replacing my thermostat thinking it might have gotten clogged. That didn't work, so I figured new thermostat was bad. Had some problems when replacing it so I went to Ford dealer and bought new thermostat and housing. Replaced it and did a radiator flush. It's still overheating, despite my efforts. Have a feeling the cleaner used for the flush isn't completely out of the system because of foam still present that I try and try to flush out. Plus, when I open the bleeder valve now, it acts like no fluid is getting past the thermostat because nothing comes out but steam. Could I have another bad thermostat? Could I have installed it incorrectly even though I have replaced it before with no problems at all. When I run the car without a thermostat there are apparently no problems. I need some help! Thanks in advance if someone can help me!!
I think my heads might be blown...I need help
- Thread starter orangej
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MustangLX-5.0
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I know this probably sounds dumb,but it does happen.Did you install the the thermostat in the right direction?It only goes one way,And if you put it the wrong way (Assuming it will fit in backwards) it will act like a plug.Also make sure you got a thermostat for the correct temperature range.Too high and you could over heat.Stock thermos usually operate at around 190 degrees °F .
You may also want to check your oil for signs of coolant.Milky colored in some areas or condensation would tell you a gasket is leaking coolant into the oil.Also check the coolant for signs of oil.Rainbow colors in the surface...black or brown thick globs within will show if there is a leak.You mentioned foam from possible residual flushing cleaner.It may not be the cleaner that foam is coming from.A head gasket leak in certain areas can cause this effect.To make sure your system is completely flushed out ..get a hose (Make sure it is filtered water)...pull the thermostat housing off.Put the hose into the coolant passage on the lower intake where the thermo housing bolts on to.Turn the hose on all the way.Starrt the car but let it idle.Don't rev it.And ALWAYS keep the hose running into the coolant port at it's highest output.Make sure your motor is cool before you attempt this as you don't want to run cold water through hot cylinder heads.You only need to do this for about a minute.
I know some people who would object to this as they may think engine damage could occur.As long as you keep the hose on at it's highest setting and...one small detail.While the hose is running,Keep changing the direction the hose is facing,from right..to left..to right...etc.There are coolant passages running both ways (2 cylinder heads..ehh).
Also,with that many miles on your engine,I wouldn't be suprised if it was due for a gasket/s.94-96 V6's are notorious for head gasket failure.
You may also want to check your oil for signs of coolant.Milky colored in some areas or condensation would tell you a gasket is leaking coolant into the oil.Also check the coolant for signs of oil.Rainbow colors in the surface...black or brown thick globs within will show if there is a leak.You mentioned foam from possible residual flushing cleaner.It may not be the cleaner that foam is coming from.A head gasket leak in certain areas can cause this effect.To make sure your system is completely flushed out ..get a hose (Make sure it is filtered water)...pull the thermostat housing off.Put the hose into the coolant passage on the lower intake where the thermo housing bolts on to.Turn the hose on all the way.Starrt the car but let it idle.Don't rev it.And ALWAYS keep the hose running into the coolant port at it's highest output.Make sure your motor is cool before you attempt this as you don't want to run cold water through hot cylinder heads.You only need to do this for about a minute.
I know some people who would object to this as they may think engine damage could occur.As long as you keep the hose on at it's highest setting and...one small detail.While the hose is running,Keep changing the direction the hose is facing,from right..to left..to right...etc.There are coolant passages running both ways (2 cylinder heads..ehh).
Also,with that many miles on your engine,I wouldn't be suprised if it was due for a gasket/s.94-96 V6's are notorious for head gasket failure.
Thank you so much for a response!! I do know about those crappy engines but was hoping that, by some chance, that it wasn't the head gaskets. My brother has a couger w/same engine and got his fixed before warranty and has had problems since, but for the most part, no overheating problems.
I'm still open if any one else might have some advice. I've heard it's not too difficult to do the head gaskets on those hopefully...because I LOVE the car and have low funds to take it somewhere. What a pain, Ford should be responsible since they knew. I've had problems w/every Ford dealership around this area. (MI). Thanks for your help and I will try what you said as a last resort MustangLX.
BTW, I did install the thermostat the right way, I'm just afraid it fell out of place or something dumb like that.
I'm still open if any one else might have some advice. I've heard it's not too difficult to do the head gaskets on those hopefully...because I LOVE the car and have low funds to take it somewhere. What a pain, Ford should be responsible since they knew. I've had problems w/every Ford dealership around this area. (MI). Thanks for your help and I will try what you said as a last resort MustangLX.
BTW, I did install the thermostat the right way, I'm just afraid it fell out of place or something dumb like that.
Crai-zy horse
New Member
Like LX said, check for wite film or condensation in the oil. That would mean it's almost definitely the heads or at least the head gaskets. There was a recall on those for the '94, but not for the '95s (odd in my opinion scince they're basically the same). My head's are going in my '95, but I haven't had any overheating problems. I would check all your hoses and the like for cracks or crimps. Check the entire cooling system for anything out of the ordinary. Sorry if that's not a whole lot of help but its about all I got.
Thanks for all your help. I'm in the process of working on it right now. No signs of coolant in the oil or oil in the coolant. Without starting the car I took the thermostat off and all that came out was pure foam (from that cleaner I used in flush?). Gonna try a couple more things cause me and some of us working on it don't think it looks like the heads. We can't get thermostat to open. I think there is a leak in the radiator...we are messing with it now. I'll take your advice. I let you know what we find out cause hopefully this can help someone else. Thanks!
The heads and the block are made of different metal and they heat expanded at different rates causing the head gasket to leak. I thought Ford fixed it in 96 as I have a 96 with 115K miles on it and never replaced the gasket.
I saw here, they make a special head gasket you can use to solve the problem, I'd ask my Ford dealer what kind. I think it was a metal gasket.
They make a head gasket checkers and this is the best I could come up with on Google. http://www.forparts.com/hon2.htm The one I saw was nothing but a radiator cap with a clear tube attached, put it on and make sure the cooling system and tube are full of water, run the engine until it is warm and if you have a gasket leak you'll see bubbles coming up the tube through the water.
Try going to a radiator repair shop or ask around at garages and I'm sure you'll find one.
Is your thermostat bad? Easy test, put it in a pot of water along with a thermometer that goes up to 250. Turn the stove on and watch to see when it *starts* to open, 200 degree stat should start to open at 200, not be fully open, and as it exceeds 200 open more and more and should be fully open at about 212F.
In the old days a friend had a radiator repair shop and I pulled a few wrenches for him. Before he put a new stat in he always checked it using the above method.
Needless to say, the cooling system is one of the most important components of an engine but is the most neglected.
I think there is a leak in the radiator.. Finding a leak with just water in the radiator is hard because the heat evaporates the water. Put 25% anti freeze in it and run it, make sure your pressure cap is good so you get 15 lbs or so of pressure. The antifreeze will come ouf the hole and not evaporate like water and you will see what appears to be a wet spot where it's leaking.
Most of the time they leak around the flues/tubes on the top or bottom plate, and in that case best to recore it, if it can be recored. If it's been leaking a long time you may see a white crusty build up around the hole(s). Now adays they use high tech composite material that is crimped and they're throw aways.
Radiator caps: Look at the seal and if there is an appreciable groove in it, replace it. Stant makes good caps and the spring-center valve design provides extra system sealing protection over that of the drop-center model; it is less vulnerable to contaminants interfering with the seal. In order for the cap to do it's job, which is cusing pressure on the water, the seal must be good. Take an old cap holding 5 lbs of pressure on a car that requires a 15 lb cap, yup, it'll overheat. The water filler neck where the seal rests, keep it clean.
One more tip, don't dog it until the temp comes up because while it's warming up things are going on expanding and the oil is warming up and just not good to dog an engine until it comes up to operating temp. Hope all this helped, good luck. Huney.
I saw here, they make a special head gasket you can use to solve the problem, I'd ask my Ford dealer what kind. I think it was a metal gasket.
They make a head gasket checkers and this is the best I could come up with on Google. http://www.forparts.com/hon2.htm The one I saw was nothing but a radiator cap with a clear tube attached, put it on and make sure the cooling system and tube are full of water, run the engine until it is warm and if you have a gasket leak you'll see bubbles coming up the tube through the water.
Try going to a radiator repair shop or ask around at garages and I'm sure you'll find one.
Is your thermostat bad? Easy test, put it in a pot of water along with a thermometer that goes up to 250. Turn the stove on and watch to see when it *starts* to open, 200 degree stat should start to open at 200, not be fully open, and as it exceeds 200 open more and more and should be fully open at about 212F.
In the old days a friend had a radiator repair shop and I pulled a few wrenches for him. Before he put a new stat in he always checked it using the above method.
Needless to say, the cooling system is one of the most important components of an engine but is the most neglected.
I think there is a leak in the radiator.. Finding a leak with just water in the radiator is hard because the heat evaporates the water. Put 25% anti freeze in it and run it, make sure your pressure cap is good so you get 15 lbs or so of pressure. The antifreeze will come ouf the hole and not evaporate like water and you will see what appears to be a wet spot where it's leaking.
Most of the time they leak around the flues/tubes on the top or bottom plate, and in that case best to recore it, if it can be recored. If it's been leaking a long time you may see a white crusty build up around the hole(s). Now adays they use high tech composite material that is crimped and they're throw aways.
Radiator caps: Look at the seal and if there is an appreciable groove in it, replace it. Stant makes good caps and the spring-center valve design provides extra system sealing protection over that of the drop-center model; it is less vulnerable to contaminants interfering with the seal. In order for the cap to do it's job, which is cusing pressure on the water, the seal must be good. Take an old cap holding 5 lbs of pressure on a car that requires a 15 lb cap, yup, it'll overheat. The water filler neck where the seal rests, keep it clean.
One more tip, don't dog it until the temp comes up because while it's warming up things are going on expanding and the oil is warming up and just not good to dog an engine until it comes up to operating temp. Hope all this helped, good luck. Huney.
Forgot to tell you. They make a special machine to flush cooling systems and if you ask around you should be able to find a shop that has one. They take the stat out and hook the machine up to the engine and radiator and use a cleaning agent and run it through one way then reverse the flow and does a heck of a good cleaning job.
Well, thanks. Most of the stuff you suggested my Dad has told me to try but I haven't had much time and I'm tired of messin with it. I had done the boil water test on all three thermostats and none of them opened. So, I bought a failsafe set at 160 degrees (instead of 190). As long as I put fluid into the bleeder valve every couple days, it doesn't overheat, I wonder why. The water pump seems to be workin fine when I check it. I know about the poor workmanship and ideas put into the building of those engines. The cap is one of the first things I replaced. Thanks for the help, I'll keep working at it.
I had the same problem with my wifes 94 vert. I ended up being the passenger side rear freeze plug. It finally gave way on her. I replaced the freeze plug and took the precaution of rebuilding the heads. I haven't had the problem since. That was 2 years ago and about 30K miles. The leak from the freeze plug didn't show, since it is under the AC unit at the firewall.
Ok, I've been driving it around w/no problems so long as I fill the bleeder valve w/antifreeze every couple days. Then today, out of the blue, it overheats slightly so I let it cool and add some fluid. Get back on the road, overheating no more but the check engine light comes on. I've owned it for 7 years and the check engine light has only come on once 3 yrs ago and it was a sensor. Why did that light come on now? Any ideas? I have a scan tool that I'm gonna use to try and figure this one out. Just wondered if anyone has any ideas?? Thanks!!
cjones
Founding Member
98CobraClone
New Member
Removal of intake is about the hardest part, keeping all of the parts sorted out.
Once you get to removal of the heads, you will definitely want to have NEW head bolts and gaskets in hand. You have to use new head bolts because the old bolts have stretched in the engine, and will not have the holding power required for long life.
Depending on the gasket material, there may be a graphite coating that will need to be cleaned. I used a gasket scraper, then a razor blade along with wiping it down with sandpaper and a wipe down with an industrial cleaner. Clean both the head and the engine block.
Can't remember all of the rest of the steps, but once you get it down to that point, you'll be rolling
Once you get to removal of the heads, you will definitely want to have NEW head bolts and gaskets in hand. You have to use new head bolts because the old bolts have stretched in the engine, and will not have the holding power required for long life.
Depending on the gasket material, there may be a graphite coating that will need to be cleaned. I used a gasket scraper, then a razor blade along with wiping it down with sandpaper and a wipe down with an industrial cleaner. Clean both the head and the engine block.
Can't remember all of the rest of the steps, but once you get it down to that point, you'll be rolling
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