So I think my truck realized I was trying to sell it, and is giving me one last surprise. I pulled into my school parking lot tonight and noticed a loud noise coming from under the hood accompanied with a partial loss of pedal power. I took a video with my phone I will try to upload now, but if I can't I will get it up later on tonight. The noise is coming from the left side.of the engine around the top to middle half. It doesn't sound like a click or knock, but more like an air leak every half second or so...make a sshh sshh sshh sshh sshh sound...; and when I shut the engine off it almost sounds like it decompresses for a moment. I know that's a pretty bad description, but its all I can think of to describe it. Oil and coolant levels are fine.and.its not overheating. Im leaving it here overnight and will dig into the problem more in the daylight. Any ideas so I can have some sort of piece of mind and know maybe where to start? Thanks ahead of time

Joseph

 

Maybe a loose spark plug, but it sounds more like you popped a head gasket on the valley pan (inner side) of the head. Take the oil filler cap off while it's running, if you feel a lot of pressure pulsing out of the valve cover it's time for a compression test.

 

Thanks for the reply. I've tried uploading the video I took earlier tonight, but the site does not recognize the file. Boson, I'll try out your advice tomorrow when I can get back to the truck. A buddy and I will more than likely be hauling the truck to my mechanic...where it literally just came from last week...to have him look it over. What an awesome birthday present LR has handed me today! I'll keep everyone posted on what the problem is, as well as costs, etc. Thanks again for the help

 

Blown head gasket will make that noise by venting exhaust out the side oif the block, so will a stuck valve.