So, I installed the plenum kit from Hughes on my 5.2 . it doesn't use any oil anymore but it still pings pretty bad under acceleration. not nearly as bad as before the new plenum, but still, the ping. on top of that it reeks of antifreeze but I cant find a leak or a drip anywhere is this a valve problem? carbon build up or something else?

 

I say two things

use a higher grade of fuel

or try an old trick I cant vouch for this so if your engine blows up if you know what I mean

Well the trick is was to spray H2O/water down the throttle body and rev up the engine at the same time

what does this do

it breaks up any carbon build up in your cylinders and on the valves

as I said use at your own caution

but my Dad did it all the time in the old days

 

I've done the water thing. Remember just use VERY LITTLE water at a time. I've also use trans fluid the same way. Same thing applies just use VERY LITTLE at a time.

But you may not have to use water seems there is water in the gas every where these days.

 

Pressure test the cooling system and let the tester sit for some time. The most common leak is between the transmission bell housing and the back of the engine block. As far as the pinging, you can try using a scanner and retard the sync timing on the dist. Or you can also check the dealer for any flash updates on the PCM.

 

When did you last replace plugs, rotor, cap and wires? My cap points were all corroded when I got the truck and rotor was worn down. Likely none of those items had been replaced from when the truck was new.

There is also a TSB on a change for the routing of the plug wires to eliminate parallel interference between the wires. I did all of this on my 5.2 and it eliminated the ping completely. Here is a link to the TSB:

http://dodgeram.info/tsb/1998/18-48-98/18-48-98-v8.htm

The part numbers for the plastic risers to run the wires through are included, just take that to your local dealer. It is a pretty common repair, my dealer had all the parts available.

One other thing you might do is induce some Seafoam into the intake through the vacuum hose attached to the brake booster. Remove the vac line and slowly pour in the Seafoam, use about 1/3 of the can. You will know if you pour too fast because it will stall the motor. Reattach the line and shut the truck off for 5 minutes. Then go take it for a drive and watch all the blue smoke pour out of the exhaust. If you did the plenum repair you likely will have quite a bit of carbon buildup. Did you replace your upstream O2 sensor after the plenum replacement?

Where do you smell the antifreeze? In the cab or under the hood? My truck weeps a bit from the line coming out of the water pump. Never had any cooling issues and the loss in coolant is negligible. Check the passenger side floorboard, could be a heater core leak or blow back from the drain in the airbox. Another flaw on these trucks, put a 90 degree elbow on the drain from the airbox to direct any flow downward.