I went to the mountains the other day to return my buddies 6x12 trailer. Its a 1000 lbs maximum, probably less. When I got to my destination I shut my truck off as normal. I was watching my temp on a scan gauge and it was at 203 most of the time but went to 211 at the last small climb. No big deal.
After the truck sat for a few minutes I noticed a coolant smell and the overflow tank was bubbling over. I turned the truck back on and the scan gauge showed 225 for a second but went to 218 and then back down to 200 and finally settled to 183 or so. I felt the radiator hose and it had no pressure. I shut it off and it sucked the coolant back into the system from the overflow tank. I opened the cap and the radiator was full. I added 12 oz of water to the overflow tank to make up what was blown out.
I drove the truck after monitoring the levels and the rest of the day it was at 178-198. Depending on the grade I was driving. I checked several times to make sure the level was full and I was not reading air or steam temperature.
Tests performed:
Pressure tested the cooling system to 17 psi and it did drop about 3 psi over about 5 minutes, no leak noticed but it was dark outside. Paid extra close attention to the PHH and rear heater / hoses. none found.
Some condensate was coming from the exhaust but no abnormal smells and its colder outside about 56 deg F. Plus my truck sits alot 10k miles in about 6 years. So condensate does not shock me.
Replaced radiator rap with OEM
Put truck on ramp and a sloped driveway to try and burp the system. Loosened heater hose with heater valve open and engine off, straight coolant. Ran truck for 45 mins at 1500 rpms with a coolant funnel and saw no air. / no bubbles indicating exhaust pressure. max temperature reached was 183 even with blocking half the ac condenser off to limit airflow. both heaters on and running, then heaters off but left heater valve open.
Verified heater valve operating
Tested radiator cap with coolant pressure tester.
Fan clutch was locking up as needed.
Oil looks good no milkshake
No bubbles in coolant while revving the engine
Past Work Done-
Head gasket was replaced by a shop in durango before I bought the truck. All OEM parts, hoses, machine work etc. 229k miles / 2012
Changed old radiator due to turning brown because of age. Used Toyota new upper / lower hoses and red coolant, verified I had a good 50/50 mix with distilled water OCT 2019
New OEM radiator cap - 258,300 miles - today May 2020
Installed used transmission 258k April 2020
Thoughts / Questions:
I don't believe a stuck thermostat can cause low pressure unless the temp stays very low. Correct?
Water pump seems to be working but maybe the impeller is worn and causing a lack in flow. However, I would expect to see higher temperatures if that was the case.
It obviously boiled over because it was not pressurizing. That does not concern me very much.
Thought maybe the system has air because of the radiator replacement. I didn't drive the truck much before the transmission failed.
Wheres my pressure?
Say head gasket, and I'm going to the V8 swap thread.
After the truck sat for a few minutes I noticed a coolant smell and the overflow tank was bubbling over. I turned the truck back on and the scan gauge showed 225 for a second but went to 218 and then back down to 200 and finally settled to 183 or so. I felt the radiator hose and it had no pressure. I shut it off and it sucked the coolant back into the system from the overflow tank. I opened the cap and the radiator was full. I added 12 oz of water to the overflow tank to make up what was blown out.
I drove the truck after monitoring the levels and the rest of the day it was at 178-198. Depending on the grade I was driving. I checked several times to make sure the level was full and I was not reading air or steam temperature.
Tests performed:
Pressure tested the cooling system to 17 psi and it did drop about 3 psi over about 5 minutes, no leak noticed but it was dark outside. Paid extra close attention to the PHH and rear heater / hoses. none found.
Some condensate was coming from the exhaust but no abnormal smells and its colder outside about 56 deg F. Plus my truck sits alot 10k miles in about 6 years. So condensate does not shock me.
Replaced radiator rap with OEM
Put truck on ramp and a sloped driveway to try and burp the system. Loosened heater hose with heater valve open and engine off, straight coolant. Ran truck for 45 mins at 1500 rpms with a coolant funnel and saw no air. / no bubbles indicating exhaust pressure. max temperature reached was 183 even with blocking half the ac condenser off to limit airflow. both heaters on and running, then heaters off but left heater valve open.
Verified heater valve operating
Tested radiator cap with coolant pressure tester.
Fan clutch was locking up as needed.
Oil looks good no milkshake
No bubbles in coolant while revving the engine
Past Work Done-
Head gasket was replaced by a shop in durango before I bought the truck. All OEM parts, hoses, machine work etc. 229k miles / 2012
Changed old radiator due to turning brown because of age. Used Toyota new upper / lower hoses and red coolant, verified I had a good 50/50 mix with distilled water OCT 2019
New OEM radiator cap - 258,300 miles - today May 2020
Installed used transmission 258k April 2020
Thoughts / Questions:
I don't believe a stuck thermostat can cause low pressure unless the temp stays very low. Correct?
Water pump seems to be working but maybe the impeller is worn and causing a lack in flow. However, I would expect to see higher temperatures if that was the case.
It obviously boiled over because it was not pressurizing. That does not concern me very much.
Thought maybe the system has air because of the radiator replacement. I didn't drive the truck much before the transmission failed.
Wheres my pressure?
Say head gasket, and I'm going to the V8 swap thread.
