The other day I was driving and then something happened, It sounded like I sprung an exhaust leak. No big deal I thought, so i kept on driving and noticed that my AFRs were way off. When I came to a stop they went really lean (17+).

When I finally got home and opened the hood I noticed that there was some fresh oil residue around the oil fill cap on the valve cover and the PCV breather hose had burst at where it was connected to the intake. I figured the oil was from the added pressure in the crankcase due to a failed pcv valve and the hose being burst open.

The hose was long enough to where I simply cut the hose and reconnected it. However my afrs are still running lean. So I went ahead and also checked the PCV valve which was ok as it still rattled, and i cleaned it for good measure. Still no fix. Currently the car is still running extremely lean and I don't have any leads. The "exhaust leak sound" was actually the engine as it was running so lean and started pinging("sounds like a **** ton of really loud bees in a tin can)

Does anyone have any suggestions or has anyone heard of something similar happening to the breather hose? I've googled it and cant find any explanation as to why there might have been a pressure build up.

 

When was the last time you replaced the fuel pump relays? Is the small FPR hose still on? Are you running stock injectors? Stock fuel pump?

 

Walbro 450, 1000cc injectors, FPR hose is still on and I've never replaced the FPRs.

 

Pull that hose off and check it in entirety. If it was brittle enough to snap/burst it may have failed in more than one spot or immediately again.

 

So uhh, I’m dumb, the turbo to manifold gasket blew and I lost a lot of my bolts holding the turbo on. This was causing an exhaust leak (hence the noise) and the lean readings. The hose must of ripped off, not burst, with how loose the turbo became due to having no bolts. That could have been really really bad, I’m lucky it wasn’t worse.

 

Glad you figured it out! Are you on a stock turbo? I can't imagine it doing that with all the PITA bracket action it has going on!

 

No I’m currently running an mhi18k at 26lbs.

 

Wow. Yea that could have been really bad.

 

Make sure you are using the OEM lock washers. Without them, this will keep happening.

 

Yeah I definitely wasn’t 😅.