Engine on my LS4 hours of work and nothing, seafoam = crap, new ngk plugs

Well i just got the tps screws off, somehow i just put my bodyweight into the screw and both of them turned, i put the better one on top and left the mangled one off. The car now idles at 700 perfectly, the pinging still present though. maf has already been cleaned, that was my first guess. car does feel alot strong at mid range now, just that ping is haunting hah

on my LS4 hours of work and nothing, seafoam = crap, new ngk plugs

Ok over the past week i have replaced the tranny fluid, full case of type 4, power steering fluid and diff fluid. The car runs great except the tps is adjusted too low and the screws are mangled, and i have a low speed 1200 rpm light throttle pinging.



so going cheap route first i picked up a can of seafoam from napa to see if the pinging was carbon buildup over 150k miles. I used 1/3 the can slowly let the pcv hose suck it up. The car stalled after a bit waited the 5 minutes cranked it and it ran like crap for a few minutes, cleared up. one thing that really caught my attention was that the seafoam smoke was comming out behind the manifold from down low, maybe i have a crack in my exhuast somewhere. the smoke cleared up and i put some of the sea foam in the crank and in the tank. the car ran like crap, so i went and filled it up with premium it took 9 gallons. After a few miles the car ran better EXCEPT the low rpm 1200-1500 ping was now mega loud and 1000-2800 rpm. I though about it and the seafoam probably killed the plugs.



So i went and bought a set of NGK plugs. Put them in. Reset the ecu.



Drove for a few miles and the car was mega torqy had gobs of power. as i got home and had cars and walls for the motor noise to bounce off of the low rpm ping is there. Its not even as bad or loud as it was before the seafoam and its harder to replicate but its still there.



So i put it in P and reved the motor a few times, after about the 4th time reving it to 3500 and let go of the throttle it almost stalled out.



Im not sure what to think now. The car is running with more power definitely. Do you guys think since my idle is low from the tps not being adjusted correctly thats why reving the motor and letting off in neutral it dips down to 3-400 rpm and idles back up to 500-550. I know this is too low an idle but i am stil trying to get those screws off. Tomarrow i'll goto the hardware store and pick them up. Or do you think the ping and low idle are related.Im not sure what to make of this. Other than that the car is very strong.

i'll do the oil change asap

Update : went to home depot on my lunch with the screw in hand. I looked at the chart and the dummy holes, the stock screw is a 4.7mm size. Unfortunetly they didnt have the correct size i got the closest in standard size and tryed it , didnt fit. So i'm out $1.08, I'll hit the ace hardware on the way home. I know my tps is working fine but i cant tighten it down enough to not go out of adjustment. I was idling at 1300 when i got back from my home depot excursion.

I think that you have the same problem that myself and the other guy that had noisey exhaust when wet problem. A small exhaust leak... not pinging causing the noise. It was downpouring rain this morning and when the car hit heavy water on the road and water when up under the car, it sounded like the muffler fell off... after a few thousand feet the noise went away and the car we back to normal. I gotta get under there and check it out... whether it is a cracked pipe or loose bolt I am not sure but its most likely not an O2 sensor.

And "seafoam = crap" because.....?

You just said the car was "mega torqy" (sic) and had gobs of power.... and the ping was not as bad or loud as it was before you used seafoam, but "seafoam = crap"?

I'm with you on that one-- my roommate's V6 Mustang has a &quot;tick&quot; that's obviously an exhaust leak, probably a crack in one of the manifolds because it seems to be just one cylinder... My '65 Dart (when it still had a Slant Six) had the same kind of tick-- the exhaust manifold was missing some studs holding it to the head.<br />
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That he saw the seafoam smoke coming out there proves there's a leak there-- he should take it to a competent shop to have it checked out. One that won't charge $600 to tighten a bracket.

reread it it internet nazi, that after i changed the plugs, sea foam fouled my plugs, caused hesitation and make my pinging incredibly bad

And so changing the plugs fixed that.

That's to be expected-- if an engine is heavily carboned up a treatment like that can foul the plugs. Common knowledge-- or so I thought it was but I guess not everybody knows that after all.

I'm that other guy. It was the donut gasket between the manifold and the downpipe. When it gets bad enough you can duplicate it by putting it in drive, stand on the brake and hit the gas. When the engine torques hard it'll open up a half inch gap where that donut is and you'll hear it. I bought a new gasket for 5 bucks and had it installed for 10, although its easier said than done, there's like 5 heat shields in the way. That part is fixed, but now my car bogs hard when cold. I think its a carbon problem, I cleaned the MAF sensor and that helped massively, but it still didn't completely go away.

F'in Awesome!!! Thanks for the update!!!

go thru a vacuum line, PVC valve or brake booster

Do you happen to know how to use that sea foam stuff in a 2000 Prizm? Can you get to the throttle body easy enough to pour it in like your supposed to, or do I have to go through some vaccuum line or something crazy

Get the DEEP CREEP and spray it directly into the intake.

Phillip - I was going to suggest to check for an exhaust leak, but you already found it. How the hell did you have so much carbon in it to foul the plugs? What kind of plugs and how many miles? What kind of gas are you putting in it?

Something doesn't sound right.


At first I thought Seafoam = crap because first of all I couldn't find it anywhere. The trick is to put the liquid in the tank and DEEP CREEP in through the intake and some through the PCV or CCV hose if necessary. I still haven't put any into the crankcase of any car - just don't see the need unless you are running Pennzoil or some other parrafin-based crap. I've had nothing but good results and I haven't had any fouled plugs, even on this old beater POS that my old boss had me work on.