95 Windstar Temp Gage Fluctuating

My 95 Windstar temperature gage is sometimes running hot when idling, and always when I turn on my heater. Otherwise, it's running at the proper temp. My Upper hose burst last week, then my heater hose... I replaced them both, and all was well, except my coolant resevior was suddenly filled with a greasy, thick, rusty sludge.

(I'm checking my oil to see if any "mud" shows up, and it's still good, clear oil)

I flushed out my coolant system completely today, mixed the proper ratio of coolant/water, and have it back to clear coolant again. It's running ok, but still, when I turn on my heater, it starts to run hot on the gage, then the heat coming through the vents dies off and becomes cool. Also, my A/C compressor comes on??!!??

I have a new thermostat, but have not installed it, because I believed that if I could clean the rusty sludge out of the system, the thermostat would work fine... I believe it is working properly, because it opens and closes as it should, and the upper radiator hose is hot when running. No point in fixing something if it's not broken...

(my cooler fans are working just fine)

I replaced the EGR valve the other day, and it's since then that the van has started doing this temp gage fluctuation. I was so happy to finally see the "check engine" light go out after the EGR replacement, but when the van overheated today, the "check engine" light came back on again.

It doesn't make sense to me at all... I'm completely puzzled over this van.

I don't know if I can help much.

I was going to mention the cooling fans since you mentioned a problem at idle. Are you certain there is not an issue here?

There are a lot of things that can be checked for running hot but since it seems okay under most conditions I will not mention them.

Are you certain the gauge or sender unit is operating correctly?

The function of the EGR is to lower cumbustion chamber temperatures by throwing in some exhaust fumes. It doesn't seem to track your particular problem but EGR and temp are related.

The other item is the water pump itself. A weak water pump could conceivably not circulate the coolant well enough at idle and when the heater is on it may have more work to do (I am unsure if the heater lines are always connected or not). Perhaps the water pump belt is slipping.


GL.

Hi DRW1000

Yup, the cooling fans are working well; no problem at all with them. The sending unit doesn't seem to be malfunctioning, I've taken a look at the pump, and there's no leakage at the weep hole, and belt is good and tight.

When I had replaced the burst upper radiator hose, then the heater hose, last week, it was running at normal temp.

The CE light had been on since I bought the van 4 months ago, and I got tired of seeing it, so decided to fix it. The code I got was "P1407 EGR No Flow Detected." I changed the PCV valve first and still got the same error code, so went ahead and changed the EGR valve. The CE light went out for about 60 miles, then came back on again. I cleared the computer with the unit from my local auto parts store yesterday, and it stayed out until the cooling system overheated today. The CE light came back on while I was filling the radiator with water. (had the engine running of course, while filling the water)

I had first thought that maybe there was still air in the cooling lines; that would cause a loss of heat coming from the heater momentarily, but I have run it for a couple of hours to get any air out of the system, so that isn't making sense to me either.

Another thing, while I was flushing out the cooling system, with my hose, the temp gage was showing perfect temp until I put the radiator cap on. I would then remove the cap, and the temp would fall back to normal again, then raise way up hot, as soon as I put the cap back on again. ????? Pretty confusing at this point.

You may have a severely blocked radiator. I'm not familiar with your model...wouldn't know how to test or repair...but with a little shopping, you can probably find a new aftermarket radiator for less than $100.

You may have a severely blocked radiator. I'm not familiar with your model...wouldn't know how to test or repair...but with a little shopping, you can probably find a new aftermarket radiator for less than $100.

If the rad was blocked, would it run hot only if I turned the heater on, or was stopped at a light? I mean, this is something that makes a lot of sense, because of the rusty sludge (like very soft, runny peanut butter LOL) the engine burped out through it when the upper hose burst. That's why I flushed it out with my garden hose set on jet. I did get a lot of rusty water backwashing out while I was flushing it, and I continued flushing for a good hour, till the water was running clear. I figured by then, that the radiator was finally cleaned out. I will search a bit to find out how to check for blockage in a radiator now, though, so thanks for that feed. I really hope it's not that. I don't have the time to wrestle with a radiator.... gotta be moved out to a new house by the end of the month, and this van issue is really holding me back from doing the move. Bad timing for this prob.

Any other ideas out there? I will check out whatever feeds I get, and I'm bound to figure this thing out, but I do need the help ideas I'm getting here. Thanks everyone. http://www.automotiveforums.com/vbulletin/images/smilies/smile.gif Oh, and it's a 3.8 engine, 95 Windstar.

Not knowing how your cooling system is configured, I'm afraid to guess how you are getting the symptoms you're getting.

Obviously, there's a good chance you've still got some gunk in the system. I would suggest you get some aggresive chemical cleaner for the cooling system and give it a try. Read the instructions on the container. You are looking for one that requires that you remove the thermostat during cleaning process. You may want to remove and save the anti-freeze/water mixture you now have installed...if you think its good.
Prestone used to make a two-part cleaner package. May be available at NAPA...or they may have their own brand. Let the cleaner stay in the system for as long as recommended...perhaps a bit longer. Then follow up with the neutralizer treatment.

After the cleaning/neutralizing/flushing, make sure you refill with coolant that includes the proper amount of anti-freeze or some anti-rust chemical.

Good luck.

I just took it out for a 40 mile run, and the heater worked ok, but it still overheated a bit when I came to a stop or slowed down. When I got back home, as I slowed to drive into our community, it got too hot again; heater was not on then. I let it idle in my driveway, and got out to check if the fan's were running. They were running full force, but it was still too hot. I then got back in, and revved the motor. The moment I got it to a good rev, the temperature dropped like a brick, to it's normal running temp.

The coolant in the system is still nice and clear now.

During the drive, the temp fluctuated from normal to quite a bit lower than normal. I'm going to swipe the thermostat out in the morning, and see if that makes any difference.

Oh, and when the transmission (automatic) did it's hard clunk, as it often does, when changing from 1st to 2nd, the check engine light came back on to stay on for the duration of the drive. Getting pretty tired of that light... Also, the Overdrive "off" light on the shift arm started blinking at me. It did that till I got to a red light, and restarted the van. It's done that to me a couple of times now, in the past week.

I once saw a water pump that had been removed because of ineffectiveness...the steel pump "blades" had rusted away mostly on the outer edges, leaving snubby little blade wannabees. The pump was somewhat effective, but only at high rpm.

????

I once saw a water pump that had been removed because of ineffectiveness...the steel pump "blades" had rusted away mostly on the outer edges, leaving snubby little blade wannabees. The pump was somewhat effective, but only at high rpm.

????

ok, now that just makes a LOT of sense to me, 12Ounce. Great input! Thanks so much.

Before I went to sleep last night, I did more surfing on this with the symptoms from my late drive. Most of what turned up from my symptoms was a large pocket of air in the cooling system.

This is what I found to do... jack my front end up, so the reservoir is the highest point, take the rad cap off, then work on squeezing the upper hose, then the lower hose.

If I get a large bubble coming through, I'll do it a few more times, and then also get a new rad cap, because these symptoms also say the loss of pressure from a faulty cap will cause overheating while stopped, until engine is revved.

If these don't work, then I'll replace the thermostat, and if it's still doing this, then I'm going to inspect the pump blades.

As I do each thing here, from easiest and cheapest, to harder and more expensive, LOL, I'll put the step by step results here for anyone else to follow, in case they're having an overheating issue similar to mine.

I would still recommend first removing the thermostat and doing the caustic cleaning process ... unless you've already done it.

Thinking here....... I'm also thinking that because I'm having the EGR bad flow code issue from the CE light, even though I now have a new EGR in there, the system could be plugged with carbon; can contribute to overheating...Also, the tranny is really acting up a lot, and that can also contribute to overheating of the cooling system, I'm going to do a complete fluid change after I do the step by step thing with the cooling system.... I had put Slick50 into the tranny just before my hoses burst... hmmmmm... I was told by my buddy at AdvanceAP that Slick50 should not be used, (after I already did it) because once you start using it in the tranny, you HAVE to keep using it. He said just to change the fluid as soon as I can to get it out of there, and I should be ok, because I only put it in there once. Another thing too, is that I had put that "water wetter" into my rad (one pint) just before my hoses burst, and all the sludge was f#rted through my system to my rad and reservoir.another hmmmmm... I hope these thoughts can help anyone else troubleshoot CE light and tranny issues in their Windstar... I love this van, and the 3.8L engine is a darned good engine, but the 95 Windstars have the CE light issue. and intake manifold issues so much. Darn Ford for cutting all the corners when they made this great van. I am definately beginning to understand the "F fix O or R replace D daily" jargon, because if I don't, this van will be "F found O off R road D dead" pretty soon. LOLOL kind of like owning a Harley... I think my next vehicle will be a Toyota. *smile*Looks like I'm going to actually have to bring it in to a shop and pay someone to clear the carbon issue with the EGR code, and hopefully that will fix the CE light issue I'm having.... DARN! It's so hard on women when we have to bring our vehicles to a shop for repair work. They see us coming a mile away LOLOL Oh well, what can I say...I will open a new thread for the CE light issue and report my steps in that one when I address the EGR issue, and another thread for the tranny issue, so others can find help with searches here.In the meantime, I will continue with my steps and results for the cooling issue here. This board is the best one I've found.... Thanks all! http://www.automotiveforums.com/vbulletin/images/smilies/smile.gif

I would still recommend first removing the thermostat and doing the caustic cleaning process ... unless you've already done it.

ok 12Ounce, I will do that right now, then will report back about my results later. I have to get out to the new place, after I do the caustic cleaning, to finish cleaning so I can start moving my things in. Definately not a good time to have to be going through all the vehicle issues... LOL

Oh, and one more question, just before I head out the door to do the cleaning... I do have some super radiator flush. Should I use that when I do this caustic cleaning, or should I just use my tap water? I'll wait here till I get your reply... Thanks sooooo much. http://www.automotiveforums.com/vbulletin/images/smilies/smile.gif

No, the flush material should be forgotten just now. Buy a container (usually a 2-compartment can...caustic cleaner on one end, neutralizer in the other) of the cleaner. You won't find this stuff at AutoZone or the like... only at NAPA or some radiator shop.

I Know, sounds like a stupid question, but I'm scheptical of using chemicals now, since the water wetter, and the slick50... please bear with me on this fear. LOLOL

ok, kewl, and thanks. I will buy it, and the container from Napa on my way to the new place, and do it before I head back here. I'll let you know what happens this evening.... I have LOADS of cleaning to do at the new place, so it'll take all day... Thanks again :)

The cooling system on the WIndstar is a closed-loop, pressurized system. Your radiator cap should hold the pressure in the system to 16psi or so, if you run without a cap on, then you won't have enough coolant. So your first priority is to make sure you have no air bubbles... do your little procedure there, then fill the radiator all the way up, and fill the overflow bucket to the line.

Take the van out for a short drive, at least long enoughfor the thermostat to open up, then wait for the engine to cool and check the overflow reservoir, fioll as necessary.

The heater is an integral part of the cooling system, so there is always engine coolant running through there. The environmental controls determine how much air will pass through the heater coils on their way into the cabin for heating/cooling.

IF you still have problems after all the bubbles are gone, then perhaps you do have a pump issue.

Update on the windstar... Well, I'm not worrying about the temp gage at this point. The whole exhaust system from the rear of the motor to the muffler fell out while I was driving down the highway. I'm just soooo glad I had the mind to be a AAA member. Towed it back to the car lot where I bought it, and they will have to work on it now, just to make it driveable. LOLOL All I can say right now is that I'm glad I have a good sense of ha ha.

Not in response to the cooling problems, but the EGR code. I had a '95 Windstar. The EGR code on mine was due to the flow sensor going bad, not the EGR valve. The sensor was $40'ish at AutoZone. There is a small orifice in the EGR line. The sensor measures the pressure drop across this orifice. More flow, more pressure. Hoses bring the pressure signal to the sensor, mounted on the driver's side of the manifold. The computer adjusts the EGR valve to get a certain amount of EGR flow. Label the hoses before removing them. If the hoses are on backwards, it will look like no EGR flow.

A quick test for EGR is to put a vaccum signal on the EGR valve with the engine at idle. If the engine stumbles, or nearly dies, with vacuum going to the EGR valve, then the valve is opening and allowing exhaust gas to flow.

Hope you work out the cooling issues.

I had a similar problem with a 3.0L ford ranger. It turned out to be a leaking head gasket between the intake and coolant ports of one of the cylinder heads. This let exaust gas into to the cooling system (air pockets) and some oil mixed with the exaust gas caused the coolant to turn brown and oily. My temperature gauge would run hot when idle just like yours and the heat would suddenly run cold at times (because of the air pockets in the cooling system). Also the exaust gases in the cooling system greatly increases pressure of the cooling system which is why your hoses burst and why when you leave the radiator cap off the system runs cool because the excess pressure is allowed to excape. Have your cooling system pressure checked to check for a head gasket leak now. If you wait too late, you might risk cracking the cylinder head.

Not in response to the cooling problems, but the EGR code. I had a '95 Windstar. The EGR code on mine was due to the flow sensor going bad, not the EGR valve. The sensor was $40'ish at AutoZone. There is a small orifice in the EGR line. The sensor measures the pressure drop across this orifice. More flow, more pressure. Hoses bring the pressure signal to the sensor, mounted on the driver's side of the manifold. The computer adjusts the EGR valve to get a certain amount of EGR flow. Label the hoses before removing them. If the hoses are on backwards, it will look like no EGR flow.

A quick test for EGR is to put a vaccum signal on the EGR valve with the engine at idle. If the engine stumbles, or nearly dies, with vacuum going to the EGR valve, then the valve is opening and allowing exhaust gas to flow.

Hope you work out the cooling issues.

Bingo! This is great info, and now that the van is at the shop with the exhaust system dragging on the floor, I will give this info to the mechanic. Thank you, thank you, thank you.

I had a similar problem with a 3.0L ford ranger. It turned out to be a leaking head gasket between the intake and coolant ports of one of the cylinder heads. This let exaust gas into to the cooling system (air pockets) and some oil mixed with the exaust gas caused the coolant to turn brown and oily. My temperature gauge would run hot when idle just like yours and the heat would suddenly run cold at times (because of the air pockets in the cooling system). Also the exaust gases in the cooling system greatly increases pressure of the cooling system which is why your hoses burst and why when you leave the radiator cap off the system runs cool because the excess pressure is allowed to excape. Have your cooling system pressure checked to check for a head gasket leak now. If you wait too late, you might risk cracking the cylinder head.

Bingo Again! This is also great info, and again, now that the van is at the shop with the exhaust system dragging on the floor, I will give this info to the mechanic too. Thank you, thank you, thank you.

Everyone is great here! Thanks so much all!