I bought my 4Runner (3.4L) back in August and absolutely love it...well until the past month or so when I started having some problems. I'm not much of a mechanic and would appreciate any advice on my problem.
About a month ago, it started running "rough." The very next day my Ultra Gauge showed error code P0303. Look this up and said misfiring cylinder. No problem because I had already purchased NGK plugs and wires but hadn't gotten around to replacing them. Installed them and noticed that the plug in cylinder 3 had a burnt streak on the porcelain. I also moved the ignition coil from cylinder 3 to cylinder 1 in case it happened again. All seemed well afterwards.
A couple of days later though I get another error, P0301. Must be the ignition coil since it moved cylinders. Bought a new Denso ignition coil and a new plug. I figured I might as well change out cylinder 1's plug again. Maybe not necessary but for a few dollars why not.
After all of this, the 4Runner was running great except that my gas mileage dropped. I was getting around 22mpg on the highway and now I was getting about 17mpg. I ran some fuel injector cleaner, put in a couple tanks of premium Shell gasoline, and reset EFI fuse. It then jumped back up to 19mpg so I thought it would get better over a few tanks but it was actually gotten worse.
Fast forward to earlier today. I drove it to my mailbox while it was dark and noticed a faint amount of smoke around my passenger side headlight and a burning smell. I popped the hood and saw smoke coming from my headers from an oily residue on it. This is where my engine skills stop and I need advice. This oily residue is all around the engine where the intake manifold connects to the engine. It is on all sides of the engine. I noticed this before but I wasn't having issues so I just discounted it. I took a picture with my cell phone a few minutes ago.
https://www.dropbox.com/s/jbuquew4b3hol5m/2013-01-11 20.13.37.jpg
What would be causing this oily residue on the engine? A leaky gasket??? Would this cause my gas mileage to drop? My oil dipstick shows it is full, and the oil looks new.
I know this is a long write-up but I really do not want to put my 4Runner in the shop if I don't have to. Any ideas?
About a month ago, it started running "rough." The very next day my Ultra Gauge showed error code P0303. Look this up and said misfiring cylinder. No problem because I had already purchased NGK plugs and wires but hadn't gotten around to replacing them. Installed them and noticed that the plug in cylinder 3 had a burnt streak on the porcelain. I also moved the ignition coil from cylinder 3 to cylinder 1 in case it happened again. All seemed well afterwards.
A couple of days later though I get another error, P0301. Must be the ignition coil since it moved cylinders. Bought a new Denso ignition coil and a new plug. I figured I might as well change out cylinder 1's plug again. Maybe not necessary but for a few dollars why not.
After all of this, the 4Runner was running great except that my gas mileage dropped. I was getting around 22mpg on the highway and now I was getting about 17mpg. I ran some fuel injector cleaner, put in a couple tanks of premium Shell gasoline, and reset EFI fuse. It then jumped back up to 19mpg so I thought it would get better over a few tanks but it was actually gotten worse.
Fast forward to earlier today. I drove it to my mailbox while it was dark and noticed a faint amount of smoke around my passenger side headlight and a burning smell. I popped the hood and saw smoke coming from my headers from an oily residue on it. This is where my engine skills stop and I need advice. This oily residue is all around the engine where the intake manifold connects to the engine. It is on all sides of the engine. I noticed this before but I wasn't having issues so I just discounted it. I took a picture with my cell phone a few minutes ago.
https://www.dropbox.com/s/jbuquew4b3hol5m/2013-01-11 20.13.37.jpg
What would be causing this oily residue on the engine? A leaky gasket??? Would this cause my gas mileage to drop? My oil dipstick shows it is full, and the oil looks new.
I know this is a long write-up but I really do not want to put my 4Runner in the shop if I don't have to. Any ideas?
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