fo_runner

When I attempt to start my 3.0, it turns then makes a strange "steam engine puff" from the passenger side of the engine bay. When the engine starts, it continues making this sound constanly, but not as loud as before. When I accelerate, I can still hear it, like a high powered steam engine

What is the source to my problem?

Silver_Truck

maybe exhaust leak...check the manifolds and the crossover gasket...also check for a coolant I dunno

fo_runner

It's pretty loud when I crank the engine. Its sounds similar to an BOV (blow off valve).

It might be a vacuum leak; this problem started ever since I "attempted" to change my pcv valve. I couldn't get the hose to go on the PCV valve completely. Engine vacuum might be pushing the small valve, causing the noise.

dragon564

It seems as if you have answered your own question.......

fo_runner

I just solved my problem; the # 3 spark plug was loose and when I took it out; it was white. Must be the unburned fuel. So I wiped it down, put the spark plug back in, and started her up. No noise is coming from it now, and I have more power on tap.

kevin444

Are you trying to hide the fact you have a BOV that your not telling us ahaha kidding!

fo_runner

A BOV on my 4runner. Thats a rarity dude