2003 overheating?

[Martynka]

Sounds exactly like what I experience with a bad head gasket. If this occurs on first startup, what I found was that the coolant would leak into the cylinder when the engine cooled down overnight.

One week ago I changed all spark plug. I did it because I was doing borescopy of the cylinders, it was dry everywhere. Engine runs smooth at start, stable on idle. I drove with computer connected to the ECU. No missfire. I checked exhaust, both pipe without smell of coolant, without humidity and cloud of steam.

Good luck, but I am betting on a cylinder head gasket

I afraid of this, it is reason why I checked exhaust gas in coolant. It is not a problem for me to remove cylinder head and change gasket with alignated head. I have Romero, maybe alu engine block started to play but I want to wait for warmer day.

Last time I changed cylinder gasket in V8 in two parts. One day after work left side because I need car to work, next day second side but it was old Range Rover

EDIT: Expy has clean oil and no butter inside valve cover oil cap.

 

[Drae]

My 03 5.4 Expedition would overheat that way from time to time before I changed the cylinder head temperature sensor. It's located under the intake so you'll have to remove it. I haven't had that issue in 3 years since replacing it. I know it seems crazy a sensor can make the vehicle overheat but it sure as hell did. I can't explain it but it hasn't intermittently overheated like that again.

 

[Martynka]

It's located under the intake so you'll have to remove it.

This one :



??

hmmmm... 3 years ago I removed intake because had some false air, if I know....

EDIT: I remeber that I had one or two times fault from this sensor on OBD tester. I thought sensor fault was because of overheating not overheating because of sensor fault.

 

[Drae]

It's on the driver side head at the front. If you look just under the intake manifold, you can see it and put your hands on it. I tried removing it with the intake on but it wasn't happening with my large hands.

 

[Martynka]

It's on the driver side head at the front. If you look just under the intake manifold, you can see it and put your hands on it.

Ok, I found photo from my changing intake manifold gasket.



Is it sensor at front right side near inlet to fifth cylinder ??

 

[Drae]

Yes by cylinder #5

 

[Martynka]

One reason more why in my opinion it is not a head gasket. Today was warmer, about 55 F. I started and completely cooled down engine few times. All time without overheating. The engine temperature gauge showed 3/4 and after few second dropped to half. Now is much colder and after start engine overheating.

My problem started with first cold days last year. In summer I drove all South Europe without problems.

I checked spark plugs removed 3 weeks ago. All nice burned, no sympthoms of coolant.

 

[Hamfisted]

Marty do you have a infra-red temperature gun. So you can shoot it at the motor and see if it's actually over heating ? Or does your scan tool show live data, where you can see what the PCM is seeing for engine temp ? You should have full vacuum at the hot water control valve when a cold temperature is selected, and the valve control arm should be retracted toward the vacuum chamber. As you select a warmer cabin temperature the vacuum gradually decreases and allows the valve's actuation arm to gradually move out and open the valve for hot water to flow. If you're not getting a good vacuum when cold is selected you need to track down the vacuum leak, or replace the control solenoid there under the dash.


Thermal IR Gun on Amazon

Ford 5.4 CHT Sender on Amazon












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[Martynka]

Hi here

Marty do you have a infra-red temperature gun. So you can shoot it at the motor and see if it's actually over heating ?

Yes, I have Fluke and can check it.

Or does your scan tool show live data, where you can see what the PCM is seeing for engine temp ?

Yes, as you remember I have in car Superchips F5 Flashpaq with gauges but have few more and FordSys too. Live data shows something like this : the same like gauge on dashboard

ovi

www.youtube.com

I started record just before overheating, after rise RPM temp drop to about 190F and is stable. I can drive 100 mph on highway 20 minutes without problem.

If you're not getting a good vacuum when cold is selected you need to track down the vacuum leak, or replace the control solenoid there under the dash.

I afraid of this, it is not enought place to put my fingers. I only checked by eyes that both plugs are on places.

I replaced old one to new one:



nothing change.

You should have full vacuum at the hot water control valve when a cold temperature is selected, and the valve control arm should be retracted toward the vacuum chamber.

No reaction. Is my theory is possible ?? Valve still open at start and engine has no time to cool down 5 gal. of coolant after open thermostat ??

I'm sure that last year I have cold air from blower till engine warm up. Now I have warm from start ( few minutes after start ). It looks like before issue valve was closed on cold start.

 

[Hamfisted]

Try a new CHT sending unit.
If you need to, you can zip tie the hot water valve closed until you get the vacuum issue straightened out.