Most Likely Cause for Overheating With no Leaks & Good Fan and Belt?

[Swifty Morgan]

I put dye in the coolant. I don't see any leaks with a UV light yet. I haven't found any coolant on the floor. I hoped to find leaking coolant on a hose, but no luck yet.

The coolant is low, and the oil looks normal. Added coolant the other day, and the level is still below the two marks. It has to be going somewhere.

I am hoping to get this thing to a shop on Monday morning.

I can't believe Ford thought it was intelligent to design a car with a short-lived oil pump that, when it fails, pumps coolant into the oil pan in order to destroy the engine.

I've read that the timing chain is also a weak point, so if the pump has to be worked on, I have to decide whether I want to keep the old chain or replace it when its expected 100,000-mile life is up.

Hoping for the best, but looking at used Hondas and Toyotas.

 

[Turdle]

All of em suck in one way or another. Try eating a highlander thermostat change

 

[Swifty Morgan]

Filled the reservoir up again. Marked the level with a Sharpie. Took the car out and drove it maybe 20 miles in 90+ degrees and blazing sun.

Nothing happened. The level did not go down in the reservoir. There is no sign of leakage, although I just realized I haven't crawled under the car and looked up. From the top, I checked every place where I saw dye before, and everything was clean, so I think I was looking at dye I spilled while adding it to the coolant.

When all this business was going on, I saw that the level was low. I filled it. I drove it once, and it was low again. Filled it again. This time it didn't drink the coolant. I don't know what's happening.

Maybe the coolant was low for a long time, and it just reached a point where it messed with the sensor. Is that possible? I had the thermostat replaced a while back, and I can't say I checked to see how much coolant they put in the car. For all I know, they didn't top it off.

I don't understand how a car can lose a lot of coolant one week, in one day, and not lose it the next. It's like the car sucked the first dose of added coolant down while I was running it. As if it could not get into the system until the car ran.

Now I don't know if I should bother taking it in.

It is definitely true that all or at least most vehicles have some stupid engineering. I checked out a video of a guy replacing a Highlander thermostat, though, and it looked like a walk in the park compared to a Ford water pump.

 

[Turdle]

I'd send an oil sample to Blackstone for testing. If coolant is present they'll find it.

 

[Mbrooks420]

You bought a car for someone going senile……. Sounds like the problems started even before the purchase.

I’d just trade it in. You clearly have disdain for the vehicle, and it’s certain to cost you more and more money, as they tend to do.

 

[GerryEX]

That's very mysterious and as mentioned, it could be a money pit. I'd trade it as well

 

[peterk9]

I put dye in the coolant. I don't see any leaks with a UV light yet. I haven't found any coolant on the floor. I hoped to find leaking coolant on a hose, but no luck yet.

The coolant is low, and the oil looks normal. Added coolant the other day, and the level is still below the two marks. It has to be going somewhere.

I am hoping to get this thing to a shop on Monday morning.

I can't believe Ford thought it was intelligent to design a car with a short-lived oil pump that, when it fails, pumps coolant into the oil pan in order to destroy the engine.

I've read that the timing chain is also a weak point, so if the pump has to be worked on, I have to decide whether I want to keep the old chain or replace it when its expected 100,000-mile life is up.

Hoping for the best, but looking at used Hondas and Toyotas.

The reason the water pump is internal is because the transverse mounted engine left no room for an externally mounted one. Not a great design as it turned out.

Peter

 

[FordFlintrock]

The reason the water pump is internal is because the transverse mounted engine left no room for an externally mounted one. Not a great design as it turned out.

Peter

I really do not have a problem with a chain driven pump so long as it would last 150-200k miles. But when they drop like flies at 60-80k miles it is poor engineering and/or quality control which I have been seeing more of from Ford and other manufacturers in the last few years.
When I started working at Ford Dealerships in 1982 it was not like this. Engineers from Ford would come to the Dealership spending nights at the local hotel working with the hourly paid shop foreman to inspect and help diagnose running problems on early production runs and there would be a TSB with corrections ASAP. Nowadays it is often numerous TSB's for the same problem guessing at a fix showing a lack of competence and experience by those involved to get it done correctly the first time. Certainly no shortage of mediocrity.
Quality is Job 1, remember that slogan? Today it is CAD and if it looks good on the monitor they run with it having no roll up your sleeves hands on old school folks that can anticipate a shortcoming.

I truly believe some of these electronic problems cannot be repaired at the Dealer level. If up to me I would tell the Head of the Group who designed it to pack a bag and your tool kit (if they have one) you are going to XYZ Dealer to repair a troublesome vehicle in the field and hold them accountable.
Rant over