2000 4cyl - blown head gasket or no?

[Lazy John]

A week ago Sunday, my "check engine" light came on. My vehicle now idles a bit rough and has lost a few miles per gallon in gas mileage, and it seems to have more power than it did before the "check engine" light came on. Friends who have driven it seem to think it's an oxygen sensor. The local dealership is trying to tell me it might be a blown head gasket (which they charge thousands to fix), but I've done some research and my vehicle is not exhibiting even one of the classic blown head gasket symptoms. The oil dipstick is not bubbly. There is no white exhaust coming from the engine. There is no liquid coming out of the tailpipe. The vehicle is not running hot.

Any answers?

L J

[fourwd1]

Have the codes read to find out why the Check Engine Light is on, and you'll probably have your answer. And it doesn't sound like a blown HG, but a pressure check of your cooling system and/or an engine compression check would tell you for sure.

[Lazy John]

My AC has not worked for a year (probably a leak in the line), so I doubt that's a factor. I will have my mobile mechanic check the engine compression, though. Thanks!

L J

[4Wheel]

Pull the code FIRST!
Are there bubbles coming from the radiator overflow tube in the OF tank? This is another sure sign of head gasket problems (once at operating temp)
He was referring to a coolant system "leak down" test this will tell if there is a compromised cooling system. (head gasket leaking).
This is around 14lbs pressure compared to around 100lbs compression test so if the head gasket has only a slight leak it wont show up on the compression check.

[Lazy John]

My mechanic will pull the code first. I have none of the classic blown head gasket symptoms, including the one you mentioned. Thanks for the clarification.

L J

[4Wheel]

Post back with what the code was and resolution. Im interested to see what it was. Good luck

[Lazy John]

It was an 02 sensor, just as I thought.

[byerjv]

Originally Posted by Lazy John

A week ago Sunday, my "check engine" light came on. My vehicle now idles a bit rough and has lost a few miles per gallon in gas mileage, and it seems to have more power than it did before the "check engine" light came on. Friends who have driven it seem to think it's an oxygen sensor. The local dealership is trying to tell me it might be a blown head gasket (which they charge thousands to fix), but I've done some research and my vehicle is not exhibiting even one of the classic blown head gasket symptoms. The oil dipstick is not bubbly. There is no white exhaust coming from the engine. There is no liquid coming out of the tailpipe. The vehicle is not running hot.

Any answers?

L J

From what I've heard - Stay away from the Toyota Service Centers. Ask your friends for a trusted mechanic and get a second opinion. It does not sound like a blown head gasket. A small hand held computer shoud reveal the problem. Is the gas cap on tight?