My engine pings or sounds like marbles when accelerating or most often when driving under load such as going up a hill.Slight hesitation or miss around 1500-2000 rpms as well. Whats strange is that it will not do this all the time.I can drive it to the store and have this happen,but when its time to go home it will run entirely better. It will not matter whether the engine is cold or fully warmed up. Different brands of gas from different stations and it still happens. Was wondering if seafoam would help and where to put it in at. The gas tank,oil,or take off the vortec plastic cover and pour it down there. Also heard abt pouring it through a booster line. Where is this booster line and how is it done. Any other ideas to rid myself of this would be appreciated. What causes this pinging sound anyway and what should i be looking at from the most obvious to the least obvious. Plugs,wires,cap,rotor,map,maf,ckp,fuel pump and new spider unit all replaced within the last six months.Thanks guys...
96 blazer LT with 180k miles from Levittown,Pa

 

Please read the rules of the forum and also all board descriptions before posting. Your post has nothing to do with this board and belongs in a tech specific tech forum... you must have missed the sticky at the top of this forum is big huge letters stating "post all tech related problems in general tech".
Anywho...this board is only for welcoming new members, not tech problems. Please read the board descriptions in the future. Thanks

 

very sorry,realized my mistake but is was too late. will correct for future posts. is there a way to transfer this post to the correct forum or must i unsubscribe this thread and start over...

 

Already done.

 

Are you getting a Check Engine Light?
Sounds like your knock sensors aren't doing their job or pretty cheap gas.
You can Seafoam it and see if it helps, Sure can't hurt. The booster line you've heard about is the big vacuum line coming from your brake booster. Disconnect it and pour 1/3 can if Seafoam dirctly into it. Do not let it kill the engine. Some guys stall the engine with thee past bit of seafoam. Wait about 20 minutes and then start it up. You may foul the plugs but this doesn't happen often where you have to pull them. You might want to later though. Make sure the neighbors know what you're doing because there will be so much smoke they'll probably call the fire department. Follow the instructions on the can.

 

Negative on the check engine light. Like you have mentioned,seafoaming cant hurt so i will give the truck a good cleaning with it. As far as the knock sensor goes,is this a pain in the *** sensor to get at and change or can it be done easily.

 

Not too bad in my opinion but then again I don't think any of the spark plugs are hard. It's all relative I suppose. Not sure about a 96 but on my 94 there are two of them. They sit in the back engine on each side. There will be a Dark Blue wire in a loom running to each of them. They are wired together in the circuit. You can disconnect the connector on both and measure the voltage. You should get 5 volts on both of them with the key in the run position. If you have both at 5 volts then measure the resistance between the knock sensor terminal and ground. Should be 8200 ohms (ideally). The range is 2100 - 8200 ohms. Below 2100 ohms or open circuit replace knock sensor. If they are not within range you either have a faulty sensor or a faulty installation. If they are within range you either have a faulty connection or faulty PCM.
If you don't have 5 volts at both you have one of 2 scenarios.
Both at 0 volts means you have an open or grounded circuir between the splice and PCM (computer) or you have a faulty PCM.
Scenario #2 is one at 5 volts and one at 0 volts means you have an open or ground in the 0 volt circuit between sensor connector and splice.
These are really easy checks to do. Usually you run these checks if you get a code. You may not want to check them if you don't have any codes. Your engine shouldn't ping though.

 

Thanks for the advice,will try to check all this weekend. Also,wouldn't a lean running engine cause it to ping as well. Any tell-tale signs of a lean running engine. It's annoying as hell as on some daily runs the truck is fine and than 10 minutes later or on the return trip home she pings.Something not quite right,but the help you get around this forum i am sure it will be just a matter of time before all is well. Also noticed today that there seems to be a delay in the overdrive kicking in,which is killing my gas mileage.Again thanks to all...

 

Ok,seafoamed the truck and still getting the pinging when accelerating. Seems to disappear around 2500-3000 rpm's. Does anyone have any info on changing the knock sensor on my 96 blazer. Also ,how many are required and should i go ac/delco or the local auto zone. What would be the easiest way to access and replace. thanks for the help
96 blazer LT 4.3

 

Have you tried running higher octane fuel? Here is a link to info on the knock sensor
http://ddizzle.webs.com/1996s10blazertech.htm. As far as the ac/delco question, I always go with AC/DELCO unless I know the other brand is better.