Looking for some insights into recent engine problems.

2000 Ranger, 4.0 OHV, Automatic, 2wd

A couple of weeks ago, I started to notice a squeaking/chirping noise from my engine compartment. Noise is intermittent from rear of engine compartment and I think I narrowed it down to the camshaft synchronizer.



A few days ago, I went for a drive and put the pedal down while driving up a 2 mile 8% grade hill. I continued to cruise some forest roads before returning home (about an hour drive total). About halfway through the drive, I turned on the heat and noticed it was blowing cold air. I checked the temp gauge, which was normal. Later the air warmed up for a couple of seconds, once or twice, but got cold again immediately. Then I noticed the truck was lacking power and the headlights seemed to be flickering ever-so-slightly. I drove up and over another hill (nice and easy) and at the bottom, when I turned onto a flat road, the truck stalled when I hit the gas. It started right back up and I babied it home, but failed to pay attention to the temp gauge. About a half mile from home, I noticed the temp was high (around the ‘H’ mark), I put it in neutral and coasted most of the rest of the way home. I touched the gas to get to my parking spot and temp gauge shot up into the red. I immediately parked and shut the engine off.



I checked the oil to find that it was milky white. Oil was changed just 10 days ago and the truck was barely driven in between, so this likely happened on this drive. The engine (while off) was making a gurgling noise, mostly from the passenger side. There was a trace of smoke under the hood. Still had a couple inches of coolant in the reservoir, but not sure how much was in there before.



I let the truck sit for about 48 hours, and today I started it up. It was cold outside (35 F) and the truck started right up and idled fine. I checked the exhaust and it was billowing white, but that went away after a few minutes and then appeared normal. I let the truck idle for about 5 minutes then drove nice and easy down to the corner gas station (< 1 mile). Truck ran fine, exhaust looked normal for a cold day. Went inside to buy something, when I came out the truck did not start on the first crank, but I waited 5-10 min and then it did start right up. Drove home, parked, once again saw smoke under the hood, just a trace and smelled like burnt oil – definitely coming from the passenger side of engine. During the < 2 miles of driving the engine temp increased to normal (halfway between L and H) but did so in fits and start. I looked down a couple of times and the temp gauge shot up like 1/8 of the way in a second or two. Still, the engine temp stayed normal as it idled back at the house.



So… it definitely seems like a head gasket issue. I’m wondering, though, if the failing cam synchronizer could have caused a misfire at high RPMs going up that first hill, which blew the head gasket. It just seems like too much of a coincidence that the cam sync started acting up, then this happened. The truck otherwise runs fine (only 75K on engine).



Otherwise, overheating would have to have cause the gasket failure and I’m not sure why the truck would have been overheating.



If you guys have any thoughts, that would be great. Thanks!

 

Nope.. just bad luck on your part.

 

A few comments:

As noted, a cam sensor problem won't cause a head gasket failure.

It does indeed sound like an overheat situation, which can be caused by something as simple as a thermostat stuck closed, or a slipping or broken accessory belt negatively affecting the cooling fan.

It's possible that the computer put the motor into "limp mode" when it overheated which might explain some of the motor's erratic behavior during that time. Try and reset the computer by taking the cable off the negative battery post for 10 minutes.

The milky white oil is not a good sign and could very well mean a blown head gasket and/or lower intake gasket, and/or even a warped or cracked head.