dingels75
Well-known member
Overheating under load - leaking head gasket?
2002 Jetta TDI, 365K miles, blown head gasket?
The car overheated in June for the first time ever in 365K miles (original owner) on a long uphill. EGR bypass at 100K. It had started to lose coolant very slowly and I could see leakage and crud coming from the water pump so I assumed that was the issue and parked the car until a few weeks ago. I did TB install #4 including the water pump with metal impeller and the hard coolant pipe o-ring and the coolant temp sensor were replaced. It still overheats under load (up long hills), the car had no or intermittent heat blowing out the vents and the water in the overflow boiled out. I flushed the heater core and the radiator, both clean and clear which leads me to suspect a blown head gasket. A leak-down test found no outright culprit that I had expected to find? Both fans test good, the new thermostat is opening and the metal impellers of the new WP do not spin on the shaft. I'm convinced that it's the head gasket and I'm ready to pull the head. What has me confused is the seemingly okay leak-down test but I found a thread in this forum that stated that it is possible for the leak-down test to not show an outright issue. There's no antifreeze in the oil. Also, There's no coolant flow into the overflow tank like it should have but none of the hoses are blocked. I assume that head gasket exhaust leaking into the coolant system could stop coolant flow because of the higher pressure from the exhaust? I have had a lot of white smoke only at start up for the past year or so. I think that I have covered everything. Am I missing anything before I pull the head???
2002 Jetta TDI, 365K miles, blown head gasket?
The car overheated in June for the first time ever in 365K miles (original owner) on a long uphill. EGR bypass at 100K. It had started to lose coolant very slowly and I could see leakage and crud coming from the water pump so I assumed that was the issue and parked the car until a few weeks ago. I did TB install #4 including the water pump with metal impeller and the hard coolant pipe o-ring and the coolant temp sensor were replaced. It still overheats under load (up long hills), the car had no or intermittent heat blowing out the vents and the water in the overflow boiled out. I flushed the heater core and the radiator, both clean and clear which leads me to suspect a blown head gasket. A leak-down test found no outright culprit that I had expected to find? Both fans test good, the new thermostat is opening and the metal impellers of the new WP do not spin on the shaft. I'm convinced that it's the head gasket and I'm ready to pull the head. What has me confused is the seemingly okay leak-down test but I found a thread in this forum that stated that it is possible for the leak-down test to not show an outright issue. There's no antifreeze in the oil. Also, There's no coolant flow into the overflow tank like it should have but none of the hoses are blocked. I assume that head gasket exhaust leaking into the coolant system could stop coolant flow because of the higher pressure from the exhaust? I have had a lot of white smoke only at start up for the past year or so. I think that I have covered everything. Am I missing anything before I pull the head???
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