I've noticed recently a kinda tapping from the engine when I put the engine under a pretty good load. For example, have it in 4th going up a hill when going about 35 and floor it. When just puttering up the hill, no tapping, but if I floor it to try to accelerate, then I hear it. Is this knocking? Something need to be checked out?

It drives fine otherwise.

 

It really sounds like spark knock to me. One way to test this is run your gas tank down low, then fill up with premium. See if that gets rid of the noise, if so you have spark knock!

 

that and our engines knock like crazy anyway...

 

unless I wasn't paying attention, this is somewhat new.

I read a bit on spark knock and one thing was carbon buildup. I put about 1/2-2/3 can of seafoam down the brake booster and holy crap did that thing smoke! After that, I heard it in 2nd and 3rd gear. I wonder if my plugs got fouled, tomorrow I'm going to take some out and check.

 

Two things got rid of my knock, a 180F thermostat and Autolite 103 plugs. There is supposedly only a 12 degree difference between the 180 and the factory thermostat, but even the temperature dummy gauge showed a massive difference. Heat can be a huge contributing factor to predetonation.

The Autolite 103s are one step colder plugs, don't waste your money on platinum or iridium or any multi-prong plug. They are colder, so they won't self-clean as well and copper plugs aren't meant to be run for more than 15,000 miles at best.

 

would fuel injector noise increase as load increased? maybe what I'm hearing is injector ticking.

the tapping/ticking isn't all that loud, it is just slightly louder than my normal engine gurgling.

 

Hmmm, guess my post didn't go through.

Prevent pinging by using any of these (according to BOSS at RPS):

180 thermo
Hot Water Bypass mod
High Octane
Copper based plugs (single prong)

 

No, BOSS said use the CORRECT octane, which is 87. You only use high octane in the determining process to see if you have spark knock or not.

 

from what i read, if you put 1/2 to 2/3 a can of seafoam in you should replace the spark plugs anyways. its only supposed to be 1/3 thru the booster line, 1/3 into the gas and a 1/3 into the oil.

 

website says 1/3 to 1/2 goes down the intake. i'm going to give it another go this weekend. I just put plugs in last year, I'll be cleaning them afterwards.

the tstat, bypass, and different plugs sound like bandaids to an underlying problem. It shouldn't have done this out of the factory.

 

I took the spark plugs out today since it was so nice. I put a set of Autolite 764 double platinum plugs in last year. They looked pretty good. Just a dusting of carbon in the "trough", none on the prong or insulator. There were the tiniest of flecks of white things on the prongs, which I'm guessing are from the seafoam knocking loose pieces of gunk. since it has been warmer, not as much knocking...I guess it is temp related. I'm going to wait until later in my oil change interval to give it another seafoam treatment.

 

How about an exhaust leak? My 94 has a slight leek at the EGR tube on the driver side manifold. I just replaced the gasket and it's quiet again. I only heard it during moderate to heavy throttle.