I am having a problem wih my car. The engine knocks and it backfires. When i listen to the engine with the hood open it sounds like a loud winding noise. I was thinking there is a leak somewhere in my intake but im not sure. Maybe a bad gasget? any suggestions at where i should start would be great. Thanks

 

Start by inspecting all the vacuum hoses for splits, cuts, nd burns. Don't forget the power brake booster and cruise/HVAC vacuum lines. What is the idle RPM? What is the idle vacuum reading?

 

put a mechanic vacuum guage on it

the carb makes a loud and constant sucking noise it is really hard to hear any vacuum leak over the noise

like already said check all hoses for cracks and such

make sure all vacuum sources in carb and manifold are plugged to a hoseor plugged off

try some starting fluid or something similar around the intake and carb gaskets while its running see if it speeds up

backfiring and such would not be a vacuum leak problem but rather an ignition timing or cam timing incorrect or valvetrain issue, messed up valve, a rocker nut tightened too much, a sloppy timing chain commonly causes backfiring also

how long has it been like this and if it didnt do it until something was worked on on the engine then what was it ?

what kind of knocking are we talking here ?

spark knock?

or top end knock or bottom end knock ?

low rpm or high rpm or ?


good luck