Contour Enthusiasts Group Archives Forums Modifications Duratec Performance rattling/popping at end of gear acceleration

I put in a new air intake about a week ago and just recently I started noticing a sort of rattling/popping noise when I first start my engine, when I give a small burst of acceleration (in low gear), and at the end of gears one and two when accelerating. Any one know what's going on?

mine does the same thing at startup and at the end of a gear. the rattle at startup is the timing chain rattling(inevitable) but im not sure what the other rattle is.

Actually, after doing the intake mod a week ago, I reset the computer and drove it around to let the computer relearn, but when I drove around, I accelerated really fast because I was so excited about my intake. Two days ago, I reset it again and when I drove it around I accelerated slowly to let the computer relearn at a more normal opperation level, and the rattling seamed to start to pickup after that.

Sounds like it's pinging (sound like marbles rattling in a can?), that's not good. Did you install everything correctly? Any Check Engine Lights coming on. What your describing is detonation from running lean. If you ghetto-rigged something with your intake, you may have caused it to run lean and ping like that. It's a great way to destroy your engine.

could this pinging be stopped by running a higher octane gas?

You Should Definitely Run 91 Octane Or Higher If At All Possible....Yeah Its Expensive But So Are The Effects Of Running Your Motor Too Rich Or Lean....

Why has it just recently started doing this? I have always used 87 octane fuel with no problems before. Plus, the car manual suggests the use of 87 octane fuel.

... but if it's pinging you will want to use more than 87 regardless of what the manual says. Added octane will help somewhat with the pinging (if that's what the problem is)

You say this started after installing an intake? Check all your connections for leaks, which could let un-metered air in and throw off timing.

my intake is as follows: filter--MAF--steel pipe--engine. Could the problem be that since the steel pipe that gets hot is after the MAF and the MAF deoesn't recognize the hot air that is going into the engine? I do plan on putting several coats of heat resistant paint on the steel. Here is a picture of the intake setup:

No, that's no a problem. but if you didn't connect all the hoses from the valve cover breathers and idle air control valve properly, you'll mess up the a/f ratio.

All I see is a big fat red X so I can't see what you've done to confirm anything.
But like what others have said. Run at least 91 (a full tank) and see if the pinging stops or decreases. IF it does, then I suspect you are running lean and the increased octane is fighting the pinging off.