I replaced my thermostat a few months ago and never had any problems till the last few days. It will overheat Almost all the way to the Hot mark then shoot right back down to the middle mark at random times. Sometimes I can drive and it will not do it at all. Well my question is when I was reading the manual it says the thermostat should "lock" into a recess on the housing by turning it a bit. On mine there was absolutely nothing to lock the thermostat into. Is it possible that it's bouncing around a bit causing my cooling system to go crazy? Has anyone else changed there thermostat and actually had it lock in? Thanks!
Might need to bleed your cooling system for possible air pockets. Make sure your coolant is proplery mixed and have your overflow bottle filled to at least the cold mark as well. It's a pain getting all the air out.
Test it in a pot of boiling water
I bought premixed coolant so I'm sure that's good. The overflow bottle is just over the cold mark. I tried getting the air out the best I could. I left it running for about 20-30 mins with the cap off. Doesn't seem like it's moving much though. It dropped down once and I added more fluid. After doing that I couldn't get anymore air to the top.
That was the first thing I did since I've had trouble with getting brand new thermostat that are bad.
Kinda off subject be does anyone know why this thread I started isn't showing up under "Find all threads started" on my profile page?
3.8,5.0? Waterpump bad? Radiator clogged?
If you look into the radiator while someone gives the gas a quick stab, what does the level do? Any swirling, gurgling, or odd stuff?
Sorry I should have posted this to start with. It's a 88 5.0. When I changed the thermostat I drained the system and ran some cleaner through it. So I wouldn't think it would be clogged. What I drained to start with was clean and even with the cleaner I didn't notice anything in the anti-freeze.
I didn't have anyone around so I pressed on the throttle with my hand while I looked at it and I didn't notice any reaction inside the radiator.
As far as if the water pump is bad, Im not sure. How can you really tell? I don't hear any noise from the pump itself and there is no fluid leaking from around it. The only two signs I know of a failing water pump besides a steam ball exploding from it, haha.
I was thinking that if your coolant was low (due to a possible air pocket) that after the engine was hot, revving the engine with the cap off might show a little drop in fluid...sure sign that your w/p is moving fluid.
Maybe a bad connection on the temp gauge sensor/sender?
Replaced Temp gauge sensor/sender (both). I'm thinking (hoping since I've never done a water pump....yet) it might just be some air pockets that are being stubborn.
If I let it run for a loooooong time with the cap off the level will drop a little, but barely noticeable and revving the engine seems to have no effect.
I even ran it had around the blocks for a bout 15-20 trying to heat it up really quick and the needle bounce upped pretty high while I that then dropped to middle. By time I got home and parked the needle was a little less than half and I was able to take the cap right off with out steam or fluid shooting off. And if I didnt just put a new cap on it I would say it's the cap, but I also eliminated that thought.
Also I took the cluster out earlier and took a reading from the R/W wire from the temp sending unit to behind the dash and only got .7 OHMS so I'm thinking the wiring is fine.
Also I was really hoping someone could answer my other question. About if the thermostat is really supposed to "lock" in the thermostat housing. Or do you just place it in there with the gasket and just bolt it on. I've read three different books for my car they all say the thermostat is supposed to be twisted into the housing. but my housing is smooth and has no groove for it lock into.
Far as I know the t-stat drops in, then the neck goes on and bolts it down tight.
My gut is either an air pocket or possibly even the w/p's impeller fins are corroded to the point there's not much if any flow. This happened to my 92 5.0 truck...the summer of '02 I noticed it gradually getting hotter. Ended up being the pump, of course, the collateral damage of twisting off a couple of the bolts sucked a fat one. I took it to the shop since I didn't have the means to get the bolts out, they dropped the pan, messed up the pan gasket, and finished it off by tossing in a new timing set.
Truck had a severe lack of maintenance when I bought it, after I fixed a lot of little piddly stuff, it was great runner. Ran the day I sped it. I will always kick myself in the ass for that.
Sorry for the tangent here...lol,
See that's my issue with "dropping in the thermostat." Alot of cars I've worked on you just drop the thermostat down, but on these cars the hole is vertical and little tricky to get to so I worry it's not sitting right. I'll try to get any air out the system again tomorrow. I'm really hoping it's not the water pump, but my girlfriend loads me up with any tool you can name for Christmas so I think I can manage it. I just might freeze my but off before I'm done. But is there no real sign of a worn down water pump cept it getting hot?
No worries about the tangent, lol. I'm sure we all have some stories about our histories with our cars.
Water pumps are not that bad to replace on these cars. The thermostat, as long as the spring side goes into the intake manifold side, it should work just fine. They can be a little finicky to seal, I use the felpro paper gasket coated nicely with Permatex Indian-head shelac, then tighten the bolts.
For the water pump, you can use the Permatex shelac or rtv sealant (blue or black) lightly coated onto the pump to plate gasket and then the plate to timing cover gasket. Just be very careful when removing the water pump bolts. Some of them go into water jackets and get corroded and snap easily(like Thundersport302 said)
Make sure to get the correct pump ( the Panther chassis looks similar but rotation is different) and use the gaskets in the Felpro kit that match what was on your old waterpump. I use the Felpro over whatever gaskets may come with the waterpump.
If anything this would be a good preventive maintenence before the summer months. Good luck!
Well taking a quick look at it last night it looked like a bit more than just the water pump had to come off first to actually get to it. So it looked more time consuming than anything I guess.
Should I use an impact wrench or ratchet? Which is less likely to snap off the bolts?
Hopefully I'll get some time to look at the car in a little bit. I'll try getting anymore out of the system and go from there. I'll try to let ya'll know what the problem was in the end.
I would never recommend using an impact wrench on any fastener, which if broken or stripped would take the car out of service or would require lots of labor or special tools to remove, replace or repair. That being said, I have used an impact gun tearing DOWN an engine, removing an exhaust and removing lug nuts...
Just use a wrench or a ratchet the t stat just sits in place use a little silicone to hold it in
I would pull it out and re test it in a pot of water
How old is the water pump ? ...... Should be fine if its not that old and when they go bad they leek from the weep holes
Well just some input on this for what it is worth
First never use silicone on any gaskets . Second i have snapped many a bolt removing ford water pumps. I would never remove one with an impact. Normally the long bolts snap and once that happens the timing cover has to be removed. That is a BITCH to say the least Then the bolt has to be drilled out. As far as the T Stat i use weather strip adhesive to hold it in the manifold to ease instillation. I also drill a small hole in the stat rim to allow self bleeding. As far as i can tell you the 302 does not usually get air pockets that are difficult to remove. All i do is warm it up and top it off. Warning if you remove the water pump go easy on the long bolts that go through the timing cover. They sometimes have a nasty habit of snapping!!
If you want to talk trapped air try bleeding a PANTERA!!
The water pump is the original as far as I know. Car has 7X,XXX miles on it.
I looked over and over and can't find any leaking from the weep holes.
I tried bleeding it over and over for most of the day today. No real change in the problem. But now when I press the throttle I can actually see the fluid get sucked down a bit and come back up and before it didn't do that. It doesn't overheat while I drive, which is did a little bit at first. If I'm at a light for a long time it will slowly creep up, but never to the hot mark, just about 3/4's of the way up. Any chance of it being the fan clutch?
Well if it sucks down the coolant the core might be clogged up. Sucking down means the core is stopped up. Look down the tank and see if you can see the core flow capillaries. Rev the engine and see if coolant is flowing through the entire core. If the coolant hits the sides of the tank the core is stopped up and a new radiator is in your future. Sounds like the pump is OK. You can check the fan clutch by rotating it with the engine off. See if it has resistance. Then start the car and see if the fan spins at a good speed. If it does not it is shot!!
With the car off and cold, try spinning the fan blade with your hand. If it spins freely with very little resistance, clutch is probably shot. If you see alot of grease and grime around the clutch hub it probably has worn bearing seal
When it comes to water pumps and thermostat gaskets I learned from experience that they can leak without a little sealant on the gasket. I had to take a water pump back off of my 302, just after topping it off with antifreeze and getting ready to drive it, noticing it leaking from the plate to pump gasket. This was installed with dry gaskets. so now my own personal preference is those gaskets get a light glaze of rtv or shelac.
Good call Tom on the radiator.
Would another sign of a clogged radiator be that when I have my cap open on the radiator trying to bleed out the air the overflow seems to fill up and the level of the radiator itself goes down just a little bit?
Fan clutch appears to be good then. With the engine off and could I can only get about a 1/4 to 1/2 turn on the fan when i try to spin it.
If you look down in the radiator with the cap off, do the end of the tubes have a bunch of corrosion on them? If these are like this on the ends, they are probably not flowing well throughout the core of the radiator.
What does your oil look like? Have you changed the plugs lately? If so did any of them appear wet/glazed with a green tint? I am not narrowing out a leaking head gasket or cracked head.
The radiator looks new inside. I'm not sure how old it is since I've haven't had the car for a year yet.
I've had the oil changed about 1000 miles ago and it looks good still.
Plugs and wires were changed about 8 Months ago. When I did change them they looked pretty good. Not wet at all, just a bit of carbon build up on them.
Wouldnt a leaking head gasket or cracked head cause it to overheat quickly? and all the way? It takes a long time before it will even get 3/4s of the way up.
If there was no pressure in it at operating temperature, I'd say the cap was not holding pressure. Probably venting to the overflow tank.
I would agree with you normally if I hadn't bought the cap about a month ago. There are chances of the new part being faulty though I guess.
I've had new caps that stuck closed and caused hoses to burst.
Ouch...Don't want that happening with my face over it.
Haha, it hapened to me with my face over it. Once on my maxima, I I had to remove the cap roadside due to overheating. I carefully removed the cap and was surprised to find no pressure. When I went to look inside the radiator, the bottom part of the cap dislodged from the filler neck and the coolant evacuated directly into my face. Luckily I was not seriously burned. It was an aftermarket cheesy cap.
Now you know what a lobster feels like! LoL. But glad you weren't seriously hurt though.
I got the Stant cap from Advanced. The only kind they had. I think it was made in like Mexico, but seemed to be pretty much the same design as my original.
Yeah, I was pretty red. Lol. The cap that broke was from China, but it also happened to my girlfriends cap on her Buick.
Hmmm are you also the one that happen to install the one on her Buick? I'm starting to see a pattern here. Haha just playing
Haha, no. I was oem as far as I know.
Here is what to do to see if the cap is a cold vent type or a cold sealed type. Remove the cap and hold it with the spring down. If the sealing valve comes off the rubber sealing gasket(not spring loaded) it is a cold non pressure cap. If the flapper is spring loaded it is a cold sealed cap. Most cars of this vintage used a non spring loaded flapper. They were very common back then. They only made pressure when the coolant slammed them shut. Normally when the engine was up to Temp. Check this and if it is not spring loaded you might want to replace it with a sealed cap. Normally i use a 7 LB cap on early cars with a 180* stat. Radiator caps are all different. most people dont investigate them and most dont know how they work Just saying. Normally when you can see the flow in a radiator capillaries shoot coolant in a hard stream across to the side of the tank they are clogged. Have it flow checked if it is suspicious. Coolant should just spill over in the tank like a water fall. You just may have a blown head gasket. You can check this with BLOCK CHECK. Or use a stant pressure pump and monitor the system pessure for exhaust pressure. I check for blown gaskets with the emission machine.
Sorry for the delay in the replies. I've been pretty sick for a few days so I haven't been working on the car. I will be changing the radiator tomorrow because I'm thinking that might be the problem even though the radiator "looks new" from what I can see. And I'll go from there and let ya'll know what happens. I do have to say that I change my fan clutch the other day and it really improved my car idle. It no longer surges. Didn't fix the overheating, but it did help something else so it was a bad try, haha.
Okay So I changed the radiator today. I don't consider myself the best of mechanics, but I know how to do simple things and this radiator was a pain! It was the Ready-Rad Radiator 433556. The directions said to supposedly just clip the rubber inside of the mounting brackets on the driver side and it will fit right in. There is no way this radiator will fit to the stock brackets. The bottom driver side of the radiator is way bigger than the bracket itself even with out the rubber. And the top bracket would be big enough to fit over the top, but it isn't long enough to reach the radiator to hold onto it. Has anyone installed this before? Am I just completely messing this up somehow? I have it installed and it sits safe enough for now, but I will work up a custom bracket to fit it better soon. Also with the kit came transmission line adapters? It seemed like the old lines fit right into the radiator. I kept them in case I am supposed to be using them. Am I supposed to a union between the original lines fittings and the "adapters"?
I need to go buy more anti-freeze tomorrow to top it off, so I'll let ya'll know if they cooling issue is fixed or not.
I would double check that you have the correct radiator. Can you post pictures of the radiator and maybe we can help you determine just by looks if its the right one? If you can, show how where and how its not fitting correctly.
I checked the part number on the box and checked online and it says it is the correct one. I will try to take pictures later today when I get back home. Everything fits fine except on the driver side where the radiator meets the brackets.
I am late to the party, but for future reference.
The thermostat is supposed to have a weep hole to allow air to pass when it is closed. If an air pocket is trapped in the housing the stat won't open.
Look closely at the valve disc in the stat. You will see a tiny nick in the edge.
I didn't get to take pictures yet today since it was raining for most the day and I didnt want to be out there since I'm already sick so I'll try again tomorrow.
I did notice this thermostat looked a little different than the one I pulled out. It was extremely flat compared to any thermostat I have seen before. You know how there is usually like a rim or ripple. Sorry if that sounds weird. It's the best I can explain what I'm talking about without a pic, lol.
Also my original did have something close to a small rivet through a hole that jiggled back and forth that looked as if it could be the weep hole you are talking about.
If the one I have in now does not have the weep hole that could be causing the overheating problem?
Yes that is the weep hole. Some of them just have a small notch in the edge of the valve instead of the hole. The quality control on the notch is poor on some of them and it's too small or no hole at all.
If an air pocket is trapped in the thermostat housing the thermostat will not open.
Sorry it's been so long since I've added my status to this post, but a few things came up and the the cougar was on hold for a bit. I usually like to finish a post so that anyone else searching the forums can get any help they need by just reading previous postings. So...I drained and flushed the system again. Put a new thermostat (like the 4th or 5th one). This time is was a Valucraft 192 degree from Autozone. This is the only one I could find with a weep hole that actually locked into place like the original manuals say they should. I also took off the water pump and replaced it even though when I took off the original it still looked brand new. I thought I'd throw the new one on there since I already had it all apart. And too anyone is the future who wants to remove the water pump, it is not as hard as it looks. Took me about 2 hours at most. Just make sure you keep the bolts in the right order since all of them are different sizes.And use a torque wrench at 16-18lbs. So with the new thermostat, water pump, radiator cap, radiator, temp sending units and fan clutch. It now heats up a bit below the half way mark even though it takes a good time before it reaches it that. I'll just say that is due to the outside temperatures and say it is good for now. I'm not sure what fixed the problem to be honest since the last thing I changed the was the water pump(even though the other looked brand new) and another thermostat at the same time. But I can recommended the Valucraft for when you have to change your thermostat since it's the only one that seem to lock in place for me.
It's good you fixed it. If the water pump was original it may have been your problem. The water pump is stupid easy to do. The only thing you really have to worry about is breaking the two lower bolts on each side of the pump that go through the timing cover. They have a tendency to snap off as they pass through a water jacket and can get crusty.
Yea some of the bolts were a bit aged, but not as bad as I had as I thought they would be. Does anyone know where I can get some new bolts for it? I really wanted to put new ones in it this time around, but I couldnt find any. Autozone had some that would fit, but did not have a complete set. If it every comes down to it i could always make my own, but I dont mind taking the easy route sometimes and spending the few extra bucks.