Hello! I recently replaced the elbow hose that connects the check valve and the secondary air injection system to the air pump below the engine. I did this because the hose became compromised and actually opened up from some melting/burning from the extreme temperatures ( though I noticed some previous damage to this hose, it needed replacing). In the replacement, I noticed how quickly and hot the check valve and the rest of the secondary air injection system to the engine block became. I thought it was considerably hot, so I checked the same system on the driver/right side and it was considerably cooler but still warm. The hose and piping leading down under the engine the do become hot after driving it a bit ( like the hot air is backing up throught the valve against the normal operating flow). A code had been thrown but went away so I did not get to pull it. I am afraid this will happen again and that the extremey hot air is not good for the system. Can someone tell me why my left air check valve and injection system leading to the block would get so much hotter, comprimise a hose, and throw a code. I was in the middle of replacing the check valve when it dawned on me the valve and piping leading to the engine/exhaust system get hot when the car is on and disconnected from the rest of teh air system. Is there a valve where the injection system meets the block that is stuck open letting hot air from the engine bleed into the secondary injection system? Have any ideas whats going on? Thanks for any help guys!

 

The hose melted due to a bad check valve. The valve allows the secondary air from the pump to pass through the valve and in into the exhaust. It does not allow exhaust to reach the rubber hoses.

 

Thanks Captain, I suspected it was the check valve, but had an extremely difficult time getting it loose last night. It seems to be seized on there pretty well. Any recommendation for this? One other question related to your answer. Why is the check valve and piping to the block getting hot when the elbow hose is detached from the valve. Does the valve effectively keep hot air in the block and out of the metal piping the valve is connected to? Thanks for your help.

 

Penetrating oil called "PB Blaster" works well. If that doesn't do it, try heat, (propane etc).

Why is the check valve and piping to the block getting hot when the elbow hose is detached from the valve. Does the valve effectively keep hot air in the block and out of the metal piping the valve is connected to?

Exactly correct. The check valve only allows air from the pump into the exhaust, not exhaust into the elbow.