Silverado 2007 has low pressure when first start up and knocking sound

SOURCE: really bad gas milage

The 93-94-95 all have this problem ..the fuel line that come into the back do split and leak ..other problem is with vaccum lines coming off the back of intake and vacuum lines come apart from a 3 way fitting.located fire wall .when these are off will cause gas smell and bad millage .... hopes this helps...

SOURCE: ticking noise and low oil pressure

DOES IT HAVE A LOT OF MILES ON IT OR MAY BE THE OIL PUMP IS IS GOING OUT? THERE IS A SPRING IN THE PUMP THAT IS A BYPASS FOR HOW HIGH PSI IT MAY HAVE BROKE THAT WILL GIVE YOU LOW PSI.

SOURCE: I have a '93 chevy silverado 1/2 ton with oil pressure problems

Sounds like the engine bearings (crankshaft) are worn. Try using a heavyer grade of oil, unless you want to rebuild the engine.

SOURCE: low oil pressure after engine warms up in 94 blazer with 4.3

I have a 99 blazer and ever since I have owned it, it reads lower in pressure when idling, but will go up too 40 while driving. This is normal for the vehicle. If the pressure gets real low, and stays low, it means its time for an oil change.

As long as the pressure goes up when you give it gas, it is fine.

Testimonial: "But why has it started reading low, especialy after the new oil pump was put on. It read a constant 40 even when idling before."

gord storey

• 477 Answers
• Posted on Dec 15, 2010

SOURCE: 2007 Chevy Silverado oil pressure

If you are lucky , replacing the oil pressure sender unit will solve the problem. Your truck might have perfectly good oil pressure , but a bad sensor. OR you might actually have low oil pressure , which is not good , and will be expensive to fix. Good luck.