2.4E engine, strange "bing" at idle
04-15-2008, 05:31 PM
#1
5th Gear
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2.4E engine, strange "bing" at idle
have strange unfamiliar “ping” or “bing” sound occurring in my 2.4E engine from 1972.
The 'bings' escalate in cadence as the engine gets to operating temperature, after starting up, and after driving for a while.
The engine revs seems to dip just slightly after each ping –but not enough to show on the rev. counter. As though as if there’s an occasional non-detonation..
When driving the 'bings' doesn’t seem to occur…
The engine pulls very solid and strong during quick acceleration, but more roughly at cruising below 3000 rpm, or accelerating slowly.
Any ideas what causes this?
Thanks in advance
Peter
The 'bings' escalate in cadence as the engine gets to operating temperature, after starting up, and after driving for a while.
The engine revs seems to dip just slightly after each ping –but not enough to show on the rev. counter. As though as if there’s an occasional non-detonation..
When driving the 'bings' doesn’t seem to occur…
The engine pulls very solid and strong during quick acceleration, but more roughly at cruising below 3000 rpm, or accelerating slowly.
Any ideas what causes this?
Thanks in advance
Peter
Last edited by Peter 911-69; 04-16-2008 at 05:05 PM.
04-16-2008, 05:47 PM
#4
Rennlist Member
Usually your "ping" aka "bing" is caused by a lean condition that 2.4 liter MFI cars can have. The idle CO% is relatively lean to begin with, and add to that a little wear in the throttle bodies (butterflies/shafts) and you've got a little too much air entering the engine. This makes the engine unhappy, and it spits back through the intake, causing your noise. If your idle CO is set at about 2.5 - 3%, richen it up to about 3.5 - 4%, that will help. Of course, that adjustment will speed up the idle a little, which can be compensated for. You need to have someone do this that really knows MFI, you can't do it with guesswork...
04-17-2008, 07:42 PM
#6
Rennlist Member
Well, now that's a tough question! It is never a good idea to ignore a problem or symptom that has the possibility of causing great harm to the car. A lean mixture is one of those problems, and if you don't know what the mixture is set at the car should be looked at. There is a possibility that the car's only problem is worn throttle bodies, or a minor glitch in the MFI system, but there is a greater chance that the car needs attention. Find a competent technician, and get the car looked at...
