Bursting sound on turbo system

ERNANGEL

MEMBER
1995 NISSAN SERENA
4 CYL
2WD
AUTOMATIC
190,000 MILES

Nissan serena 2.0 dsl cd20t engine auto trans why
while speeding at 90+rpm and the turbo rpm 2900 bursting sound exist in turbo system and engine and turbo rpm drop right away. Same time bursting sound stop after I step off the accelarator. It always happened when I travel long distance.

1 Reply

MMPRINCE4000

MECHANIC
8,548 POSTS

Turbo cars are equipped with a compressor bypass valve, also called a blow off valve.

This protects the compressor wheel from damage when under boost and you suddenly let off gas. The compressed air on compressor side is vented to atmosphere or back to compressor side.

If you did not have this the compressor wheel would be damaged.

Sounds like the valve is venting somewhere other than what it is supposed to.

Check tubing and connections to bypass for leaks or missing/loose clamps.