ltmark
Member
2003 Expy, 5.4L 186K
Sporatically overheating. Sometimes temp gauge spikes and then returns to normal, but often spues coolant out of Degas bottle when it does.
Idles poorly
changed all plugs and checked injectors and coils - all ok or replaced! Ran good for a while. Still runs pretty good!
Flushed system
new water pump
new fan clutch
new degas bottle
new cap
no leaks!!
new thermostat (185)
Was worried about head gasket because looses 1/4 to 1/2 gallon of coolant every few days. NO SMOKE from tailpipe!
Got Block test kit. Says that if blue test fluid turns from blue to yellow, then head gasket leak! It went "Clear" after a few minutes, but not yellow. Testing at tailpipe turned immediately yellow, as expected.
Radiator reading (ifrared heat gun) 175 at top inlet ( pointing at the fins), but goes down to 120/130 at same top level as I move toward other side, still at the top of radiator. Sporatic readings along the radiator as I move downward from right to left.
IF the radiator is blocked in various loactions, would coolant spue from cap (degas bottle) when stat opens but full volume is then blocked by faulty radiator. If it went to hot and stayed, I could understand, but it will peak and then go back to normal after it spues.
No clear evidense of blown head gasket! No clear forceful bubbling in degas bottle.
However, when it starts to overheat, I see foamy coolant coming back up to the degas bottle from the via the hose (the main fill hose at the degas bottle bottom) going to the bottom of the engine.
I have NOT checked cylinder compression
If it was head gasket, I was going to try some Blue Devil because I just want it to make it 1 more year! Then it goes to Make a wish!
Any thoughts!
Sporatically overheating. Sometimes temp gauge spikes and then returns to normal, but often spues coolant out of Degas bottle when it does.
Idles poorly
changed all plugs and checked injectors and coils - all ok or replaced! Ran good for a while. Still runs pretty good!
Flushed system
new water pump
new fan clutch
new degas bottle
new cap
no leaks!!
new thermostat (185)
Was worried about head gasket because looses 1/4 to 1/2 gallon of coolant every few days. NO SMOKE from tailpipe!
Got Block test kit. Says that if blue test fluid turns from blue to yellow, then head gasket leak! It went "Clear" after a few minutes, but not yellow. Testing at tailpipe turned immediately yellow, as expected.
Radiator reading (ifrared heat gun) 175 at top inlet ( pointing at the fins), but goes down to 120/130 at same top level as I move toward other side, still at the top of radiator. Sporatic readings along the radiator as I move downward from right to left.
IF the radiator is blocked in various loactions, would coolant spue from cap (degas bottle) when stat opens but full volume is then blocked by faulty radiator. If it went to hot and stayed, I could understand, but it will peak and then go back to normal after it spues.
No clear evidense of blown head gasket! No clear forceful bubbling in degas bottle.
However, when it starts to overheat, I see foamy coolant coming back up to the degas bottle from the via the hose (the main fill hose at the degas bottle bottom) going to the bottom of the engine.
I have NOT checked cylinder compression
If it was head gasket, I was going to try some Blue Devil because I just want it to make it 1 more year! Then it goes to Make a wish!
Any thoughts!