AKexplorer21
New Member
- Joined
- November 26, 2013
- Messages
- 8
- Reaction score
- 0
- City, State
- Anchorage, Alaska
- Year, Model & Trim Level
- 1996 Ford Explorer
Last summer I purchased a 1996 4.0 L V6 Ford Explorer with a manual transmission and 135,000. Aside from a small oil leak from the valve covers I had repaired, I had no problems until the alaskan winter set in.
After the temps dipped down into the single digits, I noticed startup become a lot more difficult, often taking at least a minute to get it running. Even plugging in my engine block heater didn't seem to help. Eventually the check engine light came on too.
Once it does start up, the engine will briefly rev up to around 2000 RPM before falling back under 1000 RPM, repeating this cycle for a few minutes. After the car warms up, the engine idles very rough and unevenly. It'll swing between 500 and 1000 RPM, often times sounding like it's going to stall out but it rarely does. This also causes the battery voltage to swing, so the interior lights and headlights flicker.
There's also problems when the car is in motion, although the engine sounds like it's running smoothly. When I shift into neutral the engine will rev up to as high as 3500 RPM and stick there, anywhere from 5 to 30 seconds before rapidly dropping to a normal level. When in gear, there's a similar "sticking" effect, which causes the car to accelerate for a few seconds even when my foot is completely off the gas. In lower gear, the acceleration can also be really jumpy. When the car's in 3rd gear and higher all of these issues aren't even noticable.
When I borrowed a friend's scanner, I found out the car was throwing the p0171 and p0174 codes for a lean engine condition in banks 1 and 2. I also got the p0305 and p0306 codes for a cylinder misfire in 5 and 6. I'm planning on having the plugs and wires replaced to start, which might not be the whole problem but could stand to be replaced anyway. I talked to one mechanic who suggested it could be the IAC valve. However, I recently noticed a loud hissing noise coming from the top of the engine, loud enough to be heard inside the car. I've heard this generation of Explorers has problems with the upper intake manifold gaskets developing leaks, but would a simple vacuum leak be enough to cause all the problems I described?
After the temps dipped down into the single digits, I noticed startup become a lot more difficult, often taking at least a minute to get it running. Even plugging in my engine block heater didn't seem to help. Eventually the check engine light came on too.
Once it does start up, the engine will briefly rev up to around 2000 RPM before falling back under 1000 RPM, repeating this cycle for a few minutes. After the car warms up, the engine idles very rough and unevenly. It'll swing between 500 and 1000 RPM, often times sounding like it's going to stall out but it rarely does. This also causes the battery voltage to swing, so the interior lights and headlights flicker.
There's also problems when the car is in motion, although the engine sounds like it's running smoothly. When I shift into neutral the engine will rev up to as high as 3500 RPM and stick there, anywhere from 5 to 30 seconds before rapidly dropping to a normal level. When in gear, there's a similar "sticking" effect, which causes the car to accelerate for a few seconds even when my foot is completely off the gas. In lower gear, the acceleration can also be really jumpy. When the car's in 3rd gear and higher all of these issues aren't even noticable.
When I borrowed a friend's scanner, I found out the car was throwing the p0171 and p0174 codes for a lean engine condition in banks 1 and 2. I also got the p0305 and p0306 codes for a cylinder misfire in 5 and 6. I'm planning on having the plugs and wires replaced to start, which might not be the whole problem but could stand to be replaced anyway. I talked to one mechanic who suggested it could be the IAC valve. However, I recently noticed a loud hissing noise coming from the top of the engine, loud enough to be heard inside the car. I've heard this generation of Explorers has problems with the upper intake manifold gaskets developing leaks, but would a simple vacuum leak be enough to cause all the problems I described?
