ND Ford
New Member
- Joined
- June 24, 2019
- Messages
- 7
- Reaction score
- 1
- Location
- Argusville, North Dakota
- City, State
- Argusville, North Dakota
- Year, Model & Trim Level
- 2000 Explorer Limited
- Callsign
- KB0BRY
Have done some reading about the 4.0 pushrod engine leaking coolant here and there. I have that problem with the 4.0 in my 98 Ranger. Coolant disappearing, oil was milky plus white exhaust at initial startup/warm up. So I removed the plenum, lower intake, front engine cover and found several places where the coolant was getting into the engine oil. Reassembled with new Felpro gaskets. No more coolant in the oil. BUT....I still had coolant disappearing, white exhaust on start up/warm up. So I parked the truck and next day when the engine was cooled down, pulled all the plugs and looked for any signs of coolant on them, None found. Used a bore scope, looked at each cylinder, nothing unusual, no coolant in any cylinders. All the plugs looked nice and clean. So I rented a coolant tester, the kind what detects exhaust in the coolant. Did that test on two separate occasions, no exhaust in the coolant either time. Then I did a coolant system pressure test at 15 pounds and started finding some slow leaks on hose connections, lower radiator core...so quit that before I blew out the radiator. Never find any coolant on the floor under the truck so gave up on the coolant pressure test. Still loosing coolant and white exhaust on start up/warm up. Disappears after the engine is warmed up. I had done a compression test earlier with inconclusive results but decided to do a cylinder leak down test. Pulled all the plugs, tested each cylinder at top dead center with 80 pounds of air. Watched for bubbles in the radiator. Every cylinder tested 80/80! So no blown head gasket or combustion chamber problem which explains why all the spark plugs looked good and no coolant in the cylinders. So...now I am thinking possibly a crack in a cylinder head between the intake manifold and intake valve somewhere and am planning on pulling the plenum and pressurizing each intake passage. Any ideas or does anyone see anything I might be missing here?