Still overheating after......

[SW SHO]

Car has been overheating to the point of boiling and coming out of the overflow bottle.

I've replaced the ECT even though the fan is working with either Max A/C or Panl/floor on.

Replaced T-Stat and worked hard at getting all air out of system.

Replaced the radiator cap.

The only relative issue is with the a/c istelf. I had a bad connector on the a/c compressor (it was just not keeping the conector in place letting the connector slip loose). Once that was fixed I realized the compressor was always on. Blowing cold, but alway on.

Well, I remembered I had adjusted the screw on the accummulator sensor and it begain to short cycle ( which I know is sign of low pressure). Replaced switch with factory screw settings.

What happens now is when the temp get to about the N of NORMAL the a/c compressor will go to always. I've raised the EATC temp to 90 panl/floor and heat is blowing, but the compressor stays on?

What's causing the overheating? I'm at a loss now.

 

[SHO_Diehard]

Motorcraft or aftermarket thermostat?

Might want to list everything you've done. I just did a search and couldn't find it.

 

[SW SHO]

T-Stat is aftermarket.

I think my first post lists what I've done.

Temps still climbing, but not boiling over now? I'll try to get an accurate water temp tomorrow.

 

[Ishodu]

Go to a OEM thermostat first, not many if any aftermarket ones work correctly for the SHO IMO.

 

[gospeedgo]

Another vote for a Motorcraft T-Stat

at the very least, look at the aftermarket one that you installed and make SURE it has a 1/8" weep hole, or better yet a small check ball like the ford one. If not, chances are the t-stat is most of the problem. We see it daily with Mustangs.

 

[Jason Bowles]

I third the Motorcraft Thermostat. Trust me I had the same problem about the time that my CPS went out. The maintenance shop that I went through put an aftermarket t-stat on and the car overheated, and the radiator blew seals (which they just replaced costing me $450). They ended up paying for another new radiator and replacing the t-stat as well as comping me new plug wires for their mistake ( i was ****** off and gave them that option - or court).

USE OEM!!!!!!!

 

[SHO_Diehard]

The other important thing the Motorcraft has is the disk that closes off the bypass.

SW, I could not find that post. Maybe you can cut and paste since you know where it is.

 

[SHOtimer]

The AC Compressor will always run unless you select the modes "off", "vent", or "floor" on the EATC.

Doug

 

[Shoman594]

Does the fan come on ? Double check.

 

[SW SHO]

Yeah, I wanted to get the Motorcraft, but it was on a Sunday and the only place open was Checker. It has the weep hole, and my fan is running for sure.

It seems to be running less hot now, but still reaches the black line just below the H. I'll seek out the motorcraft T-stat.

For the record I've replaced the ECT, T-stat, radiator cap, cleared system of air bubbles, new coolant (obviously).

I know the temp sensor could be showing the gauge off, but I know that it's getting close to high tolerance as the a/c compressor will shut off when the temp gets to the danger zone temp. The good news is the fan will cool it down after about 10 minutes with the car at idle.

I'll post back after the motorcraft t-stat goes in, but if you guys have any additional info please do.

 

[Snake2715]

Long shot here but I figured it couldnt hurt.

Someone didnt have the alternate coolant (red) in there before you obught it did they? As those are non mixable. and if you added green to red you might experience those symptoms.

Also what mix at least 50 water / 50% anitfreeze...

 

[SW SHO]

I've had the car now for 7 years (Second owner), and no it's the regular coolant proper mix of 50/50.

 

[F-22 Raptor SHO]

Let me reel this issue in for you just a bit:

Having recently done a T-stat because I just wanted to make sure my 168,000 mile t-stat wasnt the original, I experienced the same issues. There are only a couple things that will cause the conditions you are seeing: and you replaced the 2 culprits already: the rad cap and the t stat.

You say you worked hard to get the air out, but really you have alot still in there. Its tough getting it all out. The boiling over into the overflow jug is not the car overheating per say, rather it is more air working its way out of the system. Just watch your temperature when it happens. If it is moving all over the place, it is air in the system. I had my temp gauge go nearly to the O then drop down to L....then back up.

Here is how you would know:

1: After the jug fills up with fluid (boiling and bubbling)....what happens after the system cools down? Does the fluid go back into the motor?

You see what is happening is the air that is still in the system is trying to get out due to the high pressue...the water is in the way, which is then displaced into the overflow jug. The jug fills up as the air pushes out. When the jug is full, the air then starts bubbling out. When the car cools down, the water gets sucked back into the system. Sometimes this leaves the radiator low. Just make sure your system is topped off again after the car cools down. It will take a bit for the air to work out. Check this out and see if it doesnt remedy itself in a few days. Keep coolant handy and be careful with hot radiator systems.

 

[SW SHO]

Thanks Raptor, I'll keep up on this "air in system" issue. I hope it's that simple.

 

[Normster]

Just one thing do you know if the coolant is circulating ? cause I had this similar problem the coolant was staying in the block and not circulating, found out the culprit it was my heatercore had to replace it was blocked there.
something else to consider, well good luck.

 

[SW SHO]

**update w/question**

Okay, I spend about an hour getting all air out of system, and replaced my overflow bottle as I notice a small hole on the top under the bottle cap.

Here's the root of the extreme overheating and realtive question....

When the a/c is active and cycling as it should this causes the extreme overheating. Case in point.....Tonight I got the car up to temp around the M on the gauge with the a/c cycling as it should.....

Then I disconnected the switch on the accumulator to eliminate cycling of a/c and went for a drive. Kept it in third gear at around 40mph in 70 degree heat, city driving. Temp crept up to the O on the gauge and held there for about 10 more min of driving.

Pulled over and reconnected the accumulator switch and a/c started cycling. Within 5 minutes of driving the gauge with above to the hash mark under the H.

Pulled over again and disconnected the switch again and drove home with same method of speed/gear. Temp fell back to the O and I left it at idle for 10 min and no change.

I'm okay with the temp on O/R as it's within tolerance.

Now the question......Is my compressor on it's way out; by that I mean binding and putting heavier than normal load on engine when cycling? I had it pressure tested today and mechanic says it read 32 and it blows cold like it should.

What other methods/symptoms are used to diagnose a bad compressor?

Thanks for any additional input guys.

Lance

 

[spazmoid]

wow, my car's temp hardly ever gets past the L, and only gets past the A after driving at least 15-20 miles. You think my thermostat could be bad?? Maybe i should think about changin the temp sender too.

 

[SHO_Diehard]

It's hard to imagine the compressor adding that much load to the engine. Running the A/C would put more load on the radiator though since the A/C condenser is in front of the radiator.

Even air in the system should eventually line out somewhere. My '89 does not have an overflow tank right now because of the double core radiator taking up the space, so there is 1-2 inches of air space above the antifreeze. It still cools fine.

The thermostat is still an unknown. Try a Motorcraft thermostat.