정비/수리 노하우

RPM 연동하여 엔진룸에 발생하는 기계적 소음

Ticking Rattle Or Buzz Noise Heard The Best In The Passenger Compartment - (Mar 20, 2017)

Supersession Statement

This PI was superseded to update Recommendation/Instructions. Please discard PIP5395A.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern

A customer concern of rattle or ticking noise that is louder inside the vehicle than outside.

The noise may be picked up at the back of the left valve cover.

The noise may also sound like a lifter tick

This may also be called a fuel line buzz or ringing noise. 

Recommendation/Instructions

Listen to the fuel line connection at the left side of the engine.  

If the noise is heard best at the fuel line (this sound will be real loud with a stethoscope).

The fuel feed line between the high pressure fuel pump and chassis fuel line could be the cause allowing high pressure pulsation back to the low side of the fuel system. There is not a good way to test the check valve, the line will need to be replaced. 

On  pickups and SUVs, a vibration in the fuel line at the fuel tank may also be observed.

Reevaluate the concern.

There  are two different fuel line types  that contain this check valve and vary by model. 

The line above is the fuel feed pipe for Corvette, truck and SUV.

This line connects the chassis fuel line to the high pressure fuel pump. 

These pictures above shows the chassis fuel feed pipe for the LT4 supercharged ZL1 Camaro. 

On LT1 Camaro and LT4 CTS-V this line would have a jumper line with quick disconnects at both ends. 

One end will connect to the chassis line and the other to the high pressure pump feed line. 

Warranty Information

LABOR OPERATION	DESCRIPTION	LABOR TIME
4026830	Fuel Feed Pipe Replacement	Use Published Labor Operation Time

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

증상 : 노킹은 확실히 아니고, RPM 연동해서 특정 상황 - 토크가 좀 걸려서 엔진에 진동이 생길만한 구간.

고단에 물려 있을때 1500~3000 rpm 사이의 가속상황. 등 에서 발생하는 미세한 태핏소음? 또는 체인소음? 등으로 들리는 노이즈

확실하진 않지만 의심되는 상황..

아직 수리하진 못했습니다.

추가로, 메쉬라인이 엔진위를 가로질러, 엔진쪽으로 꼽히는 부분.  그쪽도 다른차에 비해 뭔가 유격이 있는 느낌?ㅠㅠ

손가락으로 톡톡 치면 금속성 노이즈가 미세하게 느껴지는데. 이것또한 연료라인 맥동에 의해서 진동시 "차르르르르~" 하는

소음을 유발시킬수도 있을것 같습니다.

비슷한 사례 겪으신분 혹시 계신가요~?? 

모든 가능성을 소거한다는 개념으로,  부품수급이 된다면, 일단 두개로 나눠진 연료라인을 다 교체해 보고 싶네요 ㅋㅋ