I just bought a 98 Blazer with about 70K miles. It runs good execpt
for a bad ping problem. I am living at an altitude of just over 9000
ft and I am running hi-octane fuel.


I assume the problem is either with the EGR system or the knock sensor.
Can anyone tell me how to check these systems?


I would go down to a local auto parts store and buy a manuel, but since
I live in Quito Ecuador, manuals are a bit hard to find.


DRW

Try Ebay for the manual. Sorry though I'm no help with your ping.

Have you ever done a tune-up? What plugs are you using? What gap?

If you've never done a tuneup, do the tuneup and if it doesn't solve your problem, at 70k miles, you really haven't wasted any money - it needed done anyways.

An engine shouldn't ping at 70k - I'd probably start with plugs (search the forum for the correct gap), cap, and rotor first.




I just bought a 98 Blazer with about 70K miles. It runs good execpt
for a bad ping problem. I am living at an altitude of just over 9000
ft and I am running hi-octane fuel.


I assume the problem is either with the EGR system or the knock sensor.
Can anyone tell me how to check these systems?


I would go down to a local auto parts store and buy a manuel, but since
I live in Quito Ecuador, manuals are a bit hard to find.


DRW

Higher than normal coolant temperatures = Replace rad cap with something not AC Delco.

Carbon in the cylinders = use 16 oz of Marvel Mystery oil per full tank fill up to decarbonize the cylinders.

Poor fuel flow = change the fuel filter

Since I just purchased this Blazer, I didn't have any hitory to know how it was supposed to run. When I test drove it I remembered a little ping, but not much. The first tank of gas I put in regular just to see how it ran. Not surprising, it pinged badly. The second tank was Premium and it ran about the same.

Most people I talked to seemed to think it was fuel, so for the thrird tank I filled up with premium at a different station (Texico) and it runs like a different vehicle!

So it appaears that the problems was bad gas after all.

One "home remedy" that I was told by a local mechanic here to raise the octane of gas is to put "moth balls" in the gas tank, (1 per gallonof gas). He says that will eliminate most pings.

I am not about to try it in my car, but anybody know what moth balls are made of?

DRW

Napthalene.

Higher than normal coolant temperatures = Replace rad cap with something not AC Delco.

Carbon in the cylinders = use 16 oz of Marvel Mystery oil per full tank fill up to decarbonize the cylinders.

Poor fuel flow = change the fuel filter

Read this post would ya.

There's quite a bit of info here. The last 2 paragraphs talk about moth balls in the tank:

http://www.faqs.org/faqs/autos/gasoline-faq/part3/preamble.html