Steve777
New Member
- Joined
- Dec 23, 2017
- Messages
- 16
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- 0
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- 1
- Location
- Colorado
- Vehicle Year
- 1994
- Make / Model
- mazda
- Engine Size
- 4.0l
- Transmission
- Manual
So I am a little embarrassed to be posting this since this repair is pretty basic, but I am scratching my head as to what might have gone wrong.
94 B4000 4.0l V6 truck is in great shape and engine and drive train were runny well. I noticed the coolant was low after a trip a few weeks ago, so did some investigating. Cleaned the front of the engine and ran it for a few mins then looked for leaks. It was leaking antifreeze from both the water pump and from the thermostat housing. Just to be cautious I did one of those tests for exhaust in the antifreeze (185K miles) and it came out clean.
So I took out the old parts and put in the new ones. Not a big deal or so I thought. The old WP had coolant stains from the weep port, and the thermostat looked like the oring had been crushed or perhaps it got pushed out at the bottom??? Oh one other thing the old thermo was a 180 deg one and the new replacement was a 190, supposedly the correct stock temp.
Anyway filled it back up with new coolant and distilled water and went thru the burping process. It seemed to "burp" quite a bit from the open rad cap, and the upper hose did not seem to be getting warm as I would have expected. Temp gauge settled at 1/2 way idling in my driveway (which I figured was the 190 vs 180 thermo). Stopped, filled up the rad and overflow and took it for a test drive. (Previously the truck ran at about 1/3 on the temp gauge most of the time)
Well under the load of driving, the temp gauge kept going up. I only went about 1/3 mile then turned around and went back home. Engine was warm to hot, but did not smell overheated. Temp gauge never got over 7/8 but when I got back I could hear air (steam) burping into the overflow tank.
So I am trying to figure out what happened here. I put back in almost 2gal of diluted coolant. I captured maybe 1.5g when I drained it, so I think plenty of coolant was in the engine. I suppose the new thermostat may not be opening all the way, and that is causing overheating. Or I suppose the new WP is defective and the impeller is not really turning and moving water (I checked and it turned freely after torquing the WP bolts).
The only thing which seems to have gone right is there no longer are any leaks from the thermo housing or WP, so I suppose that is good.
Seems like from the burping when under load, might be some areas of the engine that did not have sufficient coolant, but there should have been enough in there.
Anyone have any thoughts as to what is going on here, and what to check first?
94 B4000 4.0l V6 truck is in great shape and engine and drive train were runny well. I noticed the coolant was low after a trip a few weeks ago, so did some investigating. Cleaned the front of the engine and ran it for a few mins then looked for leaks. It was leaking antifreeze from both the water pump and from the thermostat housing. Just to be cautious I did one of those tests for exhaust in the antifreeze (185K miles) and it came out clean.
So I took out the old parts and put in the new ones. Not a big deal or so I thought. The old WP had coolant stains from the weep port, and the thermostat looked like the oring had been crushed or perhaps it got pushed out at the bottom??? Oh one other thing the old thermo was a 180 deg one and the new replacement was a 190, supposedly the correct stock temp.
Anyway filled it back up with new coolant and distilled water and went thru the burping process. It seemed to "burp" quite a bit from the open rad cap, and the upper hose did not seem to be getting warm as I would have expected. Temp gauge settled at 1/2 way idling in my driveway (which I figured was the 190 vs 180 thermo). Stopped, filled up the rad and overflow and took it for a test drive. (Previously the truck ran at about 1/3 on the temp gauge most of the time)
Well under the load of driving, the temp gauge kept going up. I only went about 1/3 mile then turned around and went back home. Engine was warm to hot, but did not smell overheated. Temp gauge never got over 7/8 but when I got back I could hear air (steam) burping into the overflow tank.
So I am trying to figure out what happened here. I put back in almost 2gal of diluted coolant. I captured maybe 1.5g when I drained it, so I think plenty of coolant was in the engine. I suppose the new thermostat may not be opening all the way, and that is causing overheating. Or I suppose the new WP is defective and the impeller is not really turning and moving water (I checked and it turned freely after torquing the WP bolts).
The only thing which seems to have gone right is there no longer are any leaks from the thermo housing or WP, so I suppose that is good.
Seems like from the burping when under load, might be some areas of the engine that did not have sufficient coolant, but there should have been enough in there.
Anyone have any thoughts as to what is going on here, and what to check first?