19redbird90
Member
- Joined
- March 13, 2010
- Messages
- 13
- Reaction score
- 0
- City, State
- Madison WI
- Year, Model & Trim Level
- 99 Eddie Bauer/01 Ranger
Very strange behavior I can’t figure out on my 99 Explorer 5.0. Last week (100-degrees for four days straight), my temp gauge started going crazy. Once it reaches normal running temp, it skyrockets past the “H”. When I accelerate it goes back to normal. When I brake, it goes back to normal (weird). Going down the highway, it jumps all over the place, almost like a sloshing effect. I changed the temp sending unit…no luck. Replaced the t-stat…no luck. No noise from the pump and no water from the weep hole. No coolant loss at all.
Here’s the kicker–I realized a few days ago that this does not happen after dark when the ambient (outside) temp is below 80-degrees or so. That would seem to rule out a gasket or head problem (also have no oil in coolant, no coolant in oil and no white smoke). Car runs and sounds fine. My most recent theory was I might have air trapped in the system. I did have the car flushed last winter when the heat wasn’t as warm as it should’ve been. I thought maybe the tech let air in…so I tried to burp it today. With the front elevated, defrost on high, radiator cap off and engine running (from cold start), I could not see any air come out of the filler neck. However, I didn’t see much of anything happening. I thought once the t-stat opened, the water level would drop as it flowed. Not only did it not drop, it just continually overflowed coolant (very slowly) out of the filler neck long after the stat opened and the upper hose was hot.
Important note: Last week it was just the gauge going nuts in hot weather. This week, the message center will also occasionally tell me “check engine temp”. When it does, I accelerate quickly, the gauge goes down and the message goes away.
What am I missing??
Here’s the kicker–I realized a few days ago that this does not happen after dark when the ambient (outside) temp is below 80-degrees or so. That would seem to rule out a gasket or head problem (also have no oil in coolant, no coolant in oil and no white smoke). Car runs and sounds fine. My most recent theory was I might have air trapped in the system. I did have the car flushed last winter when the heat wasn’t as warm as it should’ve been. I thought maybe the tech let air in…so I tried to burp it today. With the front elevated, defrost on high, radiator cap off and engine running (from cold start), I could not see any air come out of the filler neck. However, I didn’t see much of anything happening. I thought once the t-stat opened, the water level would drop as it flowed. Not only did it not drop, it just continually overflowed coolant (very slowly) out of the filler neck long after the stat opened and the upper hose was hot.
Important note: Last week it was just the gauge going nuts in hot weather. This week, the message center will also occasionally tell me “check engine temp”. When it does, I accelerate quickly, the gauge goes down and the message goes away.
What am I missing??