Saving motor from failure- detonation
Saving motor from failure- detonation I have done a ton of research so far, and decided Id post up my own thread and get some input.
2000 Transam M6, 145,000 miles
4.10 gears
longtubes, ORY, catback
SLP lid, 85mm maf and smooth bellows
ported TB, TB coolant bypass, FRA mod
Tune by frost
Car hauls ***. Feels great, I have the temperature hanging around 200 degrees warm with the fan engagement modified by frost.
I originally got the tune in the first place because the car pinged badly at WOT past 5000+ rpm. Got the computer back and it was still there, just not as bad.
Installed some TR6 plugs gapped at .045, also installed a seperator inline with the pcv valve. Detonation seems to be unaudible at this point, and KR is inconsistent. Most runs I see a maximum of <1 degree, but on one run I saw around 2 degrees of KR. This is after my plugs and PCV mod.
Trying to eliminate this issue, because I dont like my car detonating or pinging, at all. Let me know what route would be best guys. Thanks!
PS- Valve seals I believe are going south, car smokes a little when dropping RPMS, such as free revving in neutral. May be the cause, but looking for other assistance as well.
2000 Transam M6, 145,000 miles
4.10 gears
longtubes, ORY, catback
SLP lid, 85mm maf and smooth bellows
ported TB, TB coolant bypass, FRA mod
Tune by frost
Car hauls ***. Feels great, I have the temperature hanging around 200 degrees warm with the fan engagement modified by frost.
I originally got the tune in the first place because the car pinged badly at WOT past 5000+ rpm. Got the computer back and it was still there, just not as bad.
Installed some TR6 plugs gapped at .045, also installed a seperator inline with the pcv valve. Detonation seems to be unaudible at this point, and KR is inconsistent. Most runs I see a maximum of <1 degree, but on one run I saw around 2 degrees of KR. This is after my plugs and PCV mod.
Trying to eliminate this issue, because I dont like my car detonating or pinging, at all. Let me know what route would be best guys. Thanks!
PS- Valve seals I believe are going south, car smokes a little when dropping RPMS, such as free revving in neutral. May be the cause, but looking for other assistance as well.
TECH Addict
Joined: Mar 2013
Posts: 2,628
Likes: 30
What is your fuel pressure at WOT? Have you tried changing the fuel filter? The engine computer has no way of monitoring the fuel pressure, so if its a bit low it will ping at WOT if the fuel p is just a bit low. I had the same situation.
Lots of miles and bad valve seals.....
I think you need to remove your heads and clean your pistons. They are probably caked up with burnt oil. That cake, when it gets hot, causes little hot spots all over the pistons surface and that causes pre-ignition of the fuel air mixture. It won't happen when the engine is cold, it gets bad when it gets all the way up to operating temp and its hot outside....
I had this issue and all my pistons were completely covered with a layer of caked on burnt oil. I took my heads off and had them re-done....cleaned the pistons.....and problem 100% solved.
A top end foam cleaning might get it off if there's just a little bit......but most likely won't do it all.
.
I think you need to remove your heads and clean your pistons. They are probably caked up with burnt oil. That cake, when it gets hot, causes little hot spots all over the pistons surface and that causes pre-ignition of the fuel air mixture. It won't happen when the engine is cold, it gets bad when it gets all the way up to operating temp and its hot outside....
I had this issue and all my pistons were completely covered with a layer of caked on burnt oil. I took my heads off and had them re-done....cleaned the pistons.....and problem 100% solved.
A top end foam cleaning might get it off if there's just a little bit......but most likely won't do it all.
.
Update- Did some runs yesterday, and some logging.
Unfortanutely I didnt log the 02s, but I did log Spark advance, rpm, KR, coolant temp, IATS, etc.
I hooked up a fuel pressure gauge. 57 at idle, drops to 52 at WOT. I saw at maximum <1 degree yesterday. I still want to be on the safe side, and do not want to hurt the motor. I have an extra hotwire kit from my Turbobuick I might be able to fab up to my stock pump to see if I can raise the fuel pressure a bit. I am assuming this will be beneficial for me?
One more thing- the reason I may not be detonating now is because the IAT have been in the low to mid 60s when Im doing runs, I bet it would start to ping again when the IATS reach 80+.
Also, the car is burning some oil. My friend said once I floor the car, a oil cloud exits the exhaust. Hopefully PCV system? Might be valve seals.
I bet it is probably hot spots on the pistons, which totally sucks.
Unfortanutely I didnt log the 02s, but I did log Spark advance, rpm, KR, coolant temp, IATS, etc.
I hooked up a fuel pressure gauge. 57 at idle, drops to 52 at WOT. I saw at maximum <1 degree yesterday. I still want to be on the safe side, and do not want to hurt the motor. I have an extra hotwire kit from my Turbobuick I might be able to fab up to my stock pump to see if I can raise the fuel pressure a bit. I am assuming this will be beneficial for me?
One more thing- the reason I may not be detonating now is because the IAT have been in the low to mid 60s when Im doing runs, I bet it would start to ping again when the IATS reach 80+.
Also, the car is burning some oil. My friend said once I floor the car, a oil cloud exits the exhaust. Hopefully PCV system? Might be valve seals.
I bet it is probably hot spots on the pistons, which totally sucks.
