Overheating but not???

[jerbear19]

My 2000 LS is acting weird the temp is going up the fan in running super fast but the coolant is not hot. When this happens I can take the coolant cap off and hold my hand over it and its not hot. There is no coolant leaking. Just kinda confused. Lincoln dealership said it was water pump but I ran a few test on it and it tested fine. Degas bottle is fine, fan is running, and thermostat is good. I need some help here guys what's my next step?

 

[M4rk]

Degas bottle is fine, fan is running, and thermostat is good. I need some help here guys what's my next step?

How do you know that? The bottle needs to come out for a proper inspection. Even then the cracks can be very small.

 

[jerbear19]

How do you know that? The bottle needs to come out for a proper inspection. Even then the cracks can be very small.

Its new, about 6 months ago the engine, hydrolic fan, and degas bottle were replaced by lincoln. I'm going to have to pull it and see cause I think this dealership is ripping people off. About a month ago they were trying to tell me my coils on my 04 weren't on recall. And I put a new thermostat in it and its still "overheating" Where is the best place to get a degas bottle and how much r they??

 

[BlackLS06]

What about the thermostat housing?

The radiator and hoses? DCCV and cooling tree??

This is a complicated cooling system.

 

[jerbear19]

What about the thermostat housing?

The radiator and hoses? DCCV and cooling tree??

This is a complicated cooling system.

Radiator and all hoses are pretty new.
Honestly don't no what the DCCV and cooling tree even are. :shifty:

 

[tireman]

emergency

if the coolant gets too hot, then turn on your heat and fan to full blast settings to pull the temp down. you should see the temp gauge go lower, if not something else wrong. first thing to try is to rebleed the coolant system to make sure no air has gotten in. I still have original water pump in my 01 with 138k miles. I had the same problem as you. Leaks were found at water pipe seams near thermostat housing, bad plastic. So I got air in system, once corrected overheating went away. if you have the v8 then you have an auxillary pump that helps move the coolant, these do go bad. your new fan pump or fan motor may be defective also, I'm on my 5th pump and 4th fan motor, real pieces of crap, if they are not installed correctly, they also will not work correctly, did the overheating start after the fan fixes?

 

[joegr]

Let's back up a little here.

How do you know the water pump's good?

Have you done a pressure test on the cooling system?

I think that you have one or more leaks somewhere that are letting air in. If you correctly bleed the system, does the overheat problem go away for a short period of time?

 

[tireman]

yes

Joegr could the thermostat be sticking closed or put in backwards? I have read very little about bad waterpumps on these cars, maybe you have more experience with them.

 

[joegr]

Joegr could the thermostat be sticking closed or put in backwards? I have read very little about bad waterpumps on these cars, maybe you have more experience with them.

No, I doubt that it is the water pump, but I am curious as to the test that was used.

The thermostats are a multi-part assembly and certainly it can be assembled wrong. Also, the plastic thermostat housing (on gen II anyway) has features to hold the thermostat. If those features crack off, then the thermostat won't work correctly.

 

[oddball]

The Gen 1 cooling tree (aka thermostat housing) is far less complex than the Gen 2 and is unlikely to cause problems like the Gen 2 thermostat mounting problems. The Gen 1 is a more typical thermostat mount - standard thermostat sits on a ridge and the cap holds it down.

I'd still suspect a leak and an air bubble somewhere. Keep in mind that the degas bottle is a reservoir hanging on the end of the cooling cycle. Coolant does not circulate through the bottle. So the temp reading in the head does not necessarily correlate to the temp in the degas bottle. If there's an air bubble somewhere impacting coolant flow, then that will cause the coolant to boil in the heads. What can also happen is a bubble gets caught on the temp sensors.

The cap on the coolant tree is a common weak spot. They get hairline cracks in the hex hole and around the top of the tree.

 

[oddball]

Oh, just to be explicit, the Gen 1 thermostat is *not* a multi-part assembly like the Gen 2. Gen 1 is just like the same thermostats from the 60's. Disk, spring, wax cylinder and crimped cap.

 

[dk2]

Mine did the same thing a couple months ago. Temp guage spiked, decreased power, I thought it was really bad. It was low on coolant. I filled it and the problem hasnt returned or is it low.

 

[drag214]

Sounds like you have a leak and the coolant system hasn’t been purged. Just because the technicians working on your car have certifications, doesn’t mean they can't make mistakes. But it does mean that Ford Motor Company guarantees their work. Take it back to the dealer. Explain the problem. An engine replacement is very extensive and requires the technician to handle just about every part of the coolant system. Purging the coolant system, identifying defective components is part of the quality control. You shouldn’t be paying for anything.

FYI, I had a bad water pump a few years back, but it was obvious. Water pumps never go quietly. It was squeaking, screaming and pissin coolant everywhere. It was so embarrassing.

P.S.
Never remove the cap of a coolant system on a car that has been running. If you have air trapped in the coolant system, it is difficult to know the temperature of the coolant.

 

[pektel]

I had an issue where my temp guage would spike after mere minutes of it running. The coolant could not get to an overheating state in that short amount of time. I had a faulty Cylinder Head Temp Sensor.

 

[oddball]

I had an issue where my temp guage would spike after mere minutes of it running. The coolant could not get to an overheating state in that short amount of time. I had a faulty Cylinder Head Temp Sensor.

This is the other way the problem can go, but is much (much (MUCH)) less common than cracks/air/fill problems.

Best case would be to read the actual temp the computer is seeing with a OBD II reader and use a temp gun to get the true temp of the heads. If there's a huge spread, then the sensor is bad (unless it's sitting in an air bubble, in which case all bets are off).

 

[jerbear19]

Thanks guys figured out it was the water pump after all. Replaced that and while test driving it one of my ball joints broke!! Just my luck. Also bent up the fender too! Will be replace that tomorrow. I hope after that nothing will go wrong for a while. Good thing that its my back up LS!!