geosnooker2000
Well-Known Member
- Joined
- March 29, 2007
- Messages
- 286
- Reaction score
- 4
- City, State
- Somerville TN
- Year, Model & Trim Level
- '10 Eddie Bauer V8 4x4
Stats:
1996 EB 4.0 OHV 4X4 automatic tranny
My truck sat for two years until I had enough money to get the tranny rebuilt. Been driving it for 6 months with no problems, but no drive times over 45 minutes. A few weeks ago, I had the occasion to drive to my father's house and back about once a week to work on his house. This is a 1 1/2 hour trip one way. I noticed that my heat gauge bobs, but only from about 1/4 to 1/2. It does NOT overheat.
The first thing I did was replace the thermostat. No change.
Next, got a new radiator cap. It's a "cool looking" blue aluminum one my buddy who works at a radiator shop gave me for free. At that time I also got a new radiator.
It does have over 300k miles on it, so I thought maybe a new water pump and a good flush. I also replaced the fan clutch.
All this was done this past weekend, and I see no difference. Maybe even a little worse.
Odd thing about it, I get NO overflow into the overflow tank. there is exactly the same amount of coolant in there whether the engine is warmed up or cooled down. I did check the overflow line by disconnecting it and blowing into it. I blew air bubbles easily into the overflow tank, and re-attached it to the rad. cap throat.
Does this mean possibly that the pressure required for the coolant to escape through a possible failure in the head gasket or crack in the head is less than 8lbs? (or what ever the cap is rated at). I am not certain I am actually loosing coolant. It's been too soon in the burping process to tell if I am actually pushing as little as a pint of coolant into the overflow (that little I wouldn't be able to tell by looking at the level) because when I returned home after doing the repairs at my dads, I was down about a quart in the new radiator after the engine had cooled all the way, yet had plenty in the overflow tank (right at the cold fill line) it didn't suck back in....... which points to a radiator cap spring being too strong, right? Did I get a crap cap?
I had a set of heads develop cracks in my '93 4.0 that I repaired last summer, but it acted differently. The crack in the heads would allow compression to pressurize the coolant system, and would blow the top off the coolant overflow tank, push a LOT of coolant out of the system, and then overheat the engine.
This '96 doesn't even push excess coolant into the overflow tank, not that I can tell. I would have thought it would have at least pushed enough coolant into it to get to the "warmed up" line.
Could there be a leak in the head gasket that lets pressure off every time it builds up, so the coolant isn't forced into the overflow, then on cool-down, it draws air into the system through the failure, instead of coolant back from the overflow?
Thoughts?
EDIT: One more thought. About a month ago I was getting really crappy power, and about 14 mpg. turned out it was a really corroded coil pack. I replaced it and am now getting 23mpg on the hwy. The BEST I've ever gotten. Is it possible to get that good of gas mileage while sending coolant out the tail pipe? Seems like that would hinder the combustion process.
1996 EB 4.0 OHV 4X4 automatic tranny
My truck sat for two years until I had enough money to get the tranny rebuilt. Been driving it for 6 months with no problems, but no drive times over 45 minutes. A few weeks ago, I had the occasion to drive to my father's house and back about once a week to work on his house. This is a 1 1/2 hour trip one way. I noticed that my heat gauge bobs, but only from about 1/4 to 1/2. It does NOT overheat.
The first thing I did was replace the thermostat. No change.
Next, got a new radiator cap. It's a "cool looking" blue aluminum one my buddy who works at a radiator shop gave me for free. At that time I also got a new radiator.
It does have over 300k miles on it, so I thought maybe a new water pump and a good flush. I also replaced the fan clutch.
All this was done this past weekend, and I see no difference. Maybe even a little worse.
Odd thing about it, I get NO overflow into the overflow tank. there is exactly the same amount of coolant in there whether the engine is warmed up or cooled down. I did check the overflow line by disconnecting it and blowing into it. I blew air bubbles easily into the overflow tank, and re-attached it to the rad. cap throat.
Does this mean possibly that the pressure required for the coolant to escape through a possible failure in the head gasket or crack in the head is less than 8lbs? (or what ever the cap is rated at). I am not certain I am actually loosing coolant. It's been too soon in the burping process to tell if I am actually pushing as little as a pint of coolant into the overflow (that little I wouldn't be able to tell by looking at the level) because when I returned home after doing the repairs at my dads, I was down about a quart in the new radiator after the engine had cooled all the way, yet had plenty in the overflow tank (right at the cold fill line) it didn't suck back in....... which points to a radiator cap spring being too strong, right? Did I get a crap cap?
I had a set of heads develop cracks in my '93 4.0 that I repaired last summer, but it acted differently. The crack in the heads would allow compression to pressurize the coolant system, and would blow the top off the coolant overflow tank, push a LOT of coolant out of the system, and then overheat the engine.
This '96 doesn't even push excess coolant into the overflow tank, not that I can tell. I would have thought it would have at least pushed enough coolant into it to get to the "warmed up" line.
Could there be a leak in the head gasket that lets pressure off every time it builds up, so the coolant isn't forced into the overflow, then on cool-down, it draws air into the system through the failure, instead of coolant back from the overflow?
Thoughts?
EDIT: One more thought. About a month ago I was getting really crappy power, and about 14 mpg. turned out it was a really corroded coil pack. I replaced it and am now getting 23mpg on the hwy. The BEST I've ever gotten. Is it possible to get that good of gas mileage while sending coolant out the tail pipe? Seems like that would hinder the combustion process.
