roving1
Well-known member
So a few times after long uphill climbs in 4lo I have heard a gurgle noise when I shut the engine off. I thought it was just the HVAC but recently I had the A/C off and I went poking around and realized it was coming from the upper rad hose exiting the head.
So in this case I was climbing from about 9k' to 13k' and had been running under high load and low speed for at least an hour. I had to get out of the vehicle to scout something so I shut it off to leave it in gear and with the parking brake due to the steepness of the trail. So after about 5-10 minutes of scouting I came back and noticed the gurgling. Now there was a ton of latent heat build up from how I was running and then just shutting the engine off but I'm still not sure what is going on.
So I assume it is boiling but then I can't explain this next thing. I pull the cap off the overflow and there is no coolant in the oil and a normal amount of coolant in the over flow bottle. As I pull the cap with the plastic hard line that descends into the coolant res (the line connected via hose to the cap outlet on the radiator fill at the cap) out higher the minute it goes above the coolant level there is an air sucking noise and immediately the gurgling/boiling stops in the hose. Huh? What just happened here?
I heard the noise twice more continuing the climb. Each time the indicated temp was 205 or less.
Other info. When I hook up to the truck via torque app the temp is in the 215 range with the engine off. As soon as I restart it the temp drops to 205 at idle and fast idling drops it to the 200 range. Temp needle in the truck is where it always is. No coolant in oil and vice versa. No history of oil or coolant consumption. I could here maby slight hissing from the rad cap but very very small. I don't think enough to cause low pressure. Vehicle has about 160k on it. Can hear the fan wailing away so it's not that. I checked the coolant level under the rad cap when the truck was cool overnight and there is coolant right to the top. Truck did the Morrison Jeep trail in 85 degree temps loaded to the gills which is an unrelenting probably 3 hour climb under high load in 1st gearr low. Didn't notice it then but it may have been windy enough to mask the noise.
So it doesn't seem to be overheating exactly. I am assuming the gurgling is boiling? So is it possible I just have marginal coolant? A stuck Tstat thst isn't enough to overheat totally but maybe have the coolant in the head get too hot?
What the hell is going on when I lift the line going from the coolant over flow over the coolant line and the gurgling stops right away? I am not getting this at all.
So far I have not heard it during any kind of normal city or highway driving.
Any ideas?
So in this case I was climbing from about 9k' to 13k' and had been running under high load and low speed for at least an hour. I had to get out of the vehicle to scout something so I shut it off to leave it in gear and with the parking brake due to the steepness of the trail. So after about 5-10 minutes of scouting I came back and noticed the gurgling. Now there was a ton of latent heat build up from how I was running and then just shutting the engine off but I'm still not sure what is going on.
So I assume it is boiling but then I can't explain this next thing. I pull the cap off the overflow and there is no coolant in the oil and a normal amount of coolant in the over flow bottle. As I pull the cap with the plastic hard line that descends into the coolant res (the line connected via hose to the cap outlet on the radiator fill at the cap) out higher the minute it goes above the coolant level there is an air sucking noise and immediately the gurgling/boiling stops in the hose. Huh? What just happened here?
I heard the noise twice more continuing the climb. Each time the indicated temp was 205 or less.
Other info. When I hook up to the truck via torque app the temp is in the 215 range with the engine off. As soon as I restart it the temp drops to 205 at idle and fast idling drops it to the 200 range. Temp needle in the truck is where it always is. No coolant in oil and vice versa. No history of oil or coolant consumption. I could here maby slight hissing from the rad cap but very very small. I don't think enough to cause low pressure. Vehicle has about 160k on it. Can hear the fan wailing away so it's not that. I checked the coolant level under the rad cap when the truck was cool overnight and there is coolant right to the top. Truck did the Morrison Jeep trail in 85 degree temps loaded to the gills which is an unrelenting probably 3 hour climb under high load in 1st gearr low. Didn't notice it then but it may have been windy enough to mask the noise.
So it doesn't seem to be overheating exactly. I am assuming the gurgling is boiling? So is it possible I just have marginal coolant? A stuck Tstat thst isn't enough to overheat totally but maybe have the coolant in the head get too hot?
What the hell is going on when I lift the line going from the coolant over flow over the coolant line and the gurgling stops right away? I am not getting this at all.
So far I have not heard it during any kind of normal city or highway driving.
Any ideas?
