Pre-Detonation?
#21
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My brain's fried from a long day at work, but if you still have the AIR system in the car, is there a possibility that the check valves are going bad? I know that can be an issue with cars running headers and using the AIR system, but I can't remember if it's only at idle/low rpms, or through the whole rpm band.
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From factory, these cars are set up with fat mixture and
low timing. To have ping roll on at 5000RPM is not too
likely as-stock.
There was a tendency to lose rocker needle bearings,
which end up in the oil pan and make some serious clatter.
Find anythying like that?
If you run an oiled type air filter then you could clean
the MAF. If you pull the TB and wipe your finger around
in the intake, and come up with a bunch of oil from the
PCV you could give it a SeaFoam treatment.
low timing. To have ping roll on at 5000RPM is not too
likely as-stock.
There was a tendency to lose rocker needle bearings,
which end up in the oil pan and make some serious clatter.
Find anythying like that?
If you run an oiled type air filter then you could clean
the MAF. If you pull the TB and wipe your finger around
in the intake, and come up with a bunch of oil from the
PCV you could give it a SeaFoam treatment.
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I agree with jimmy on those points.
MAF is a big one that I forgot to mention. If the car has had a K&N or other oiled type filter for a period of time, I'm sure it could use a cleaning. I've seen dirty MAFs cause all types of issues in the past.
MAF is a big one that I forgot to mention. If the car has had a K&N or other oiled type filter for a period of time, I'm sure it could use a cleaning. I've seen dirty MAFs cause all types of issues in the past.
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Never ever had a oiled type air filter.
I'm trying to get the car hooked up on HP tuners to see what's going on here. I will be VERY surprised if it was an enternal mechanical issue. The car has had a spoiled life from the time it rolled off the assembly life till present day. I can't see it.
I'm trying to get the car hooked up on HP tuners to see what's going on here. I will be VERY surprised if it was an enternal mechanical issue. The car has had a spoiled life from the time it rolled off the assembly life till present day. I can't see it.
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If you can get access to the scanner, let us know what you find. In addition to any knock retard at WOT, also check some other things like:
- LTFTs & STFTs (B1 & B2) at idle, cruise, and WOT
- Overall timing at WOT
- B1S1 & B2S1 O2 readings at WOT
- Misfires (cylinder specific, if you can view that)
- Scan for any stored/pending DTCs
There are other things you can look at, but hard to know what direction to really worry about until you get those basics. But before going any deeper I would check out that exhaust leak, and also verify that the plugs are all tight.
- LTFTs & STFTs (B1 & B2) at idle, cruise, and WOT
- Overall timing at WOT
- B1S1 & B2S1 O2 readings at WOT
- Misfires (cylinder specific, if you can view that)
- Scan for any stored/pending DTCs
There are other things you can look at, but hard to know what direction to really worry about until you get those basics. But before going any deeper I would check out that exhaust leak, and also verify that the plugs are all tight.
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not to hi-jack, but im having similar problems it sounds like from my car, except my car being an a4, it only does it at 2-3 shift when im going up a hill at wot where it has to remain in the red a lil longer than it would on flat ground, it doesnt seem to do it on flat ground it just shifts before it does it i guess.![Barf](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_barf.gif)
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also ive hooked mine to tech 2 before and if i remember correctly my car had dtcs showing for o2 sensors, i done this at school, and now that im out of school i have no access to a scanner to check it again. maybe the trim is negative, making it run lean on both of the cars?
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also ive hooked mine to tech 2 before and if i remember correctly my car had dtcs showing for o2 sensors, i done this at school, and now that im out of school i have no access to a scanner to check it again. maybe the trim is negative, making it run lean on both of the cars?
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Negative fuel trims indicate the PCM's attempt to correct a rich condition as observed by the front O2 sensors.
However, LTFTs will never be negative at WOT (if they are averaging negative at cruise, they will defualt to 0% at WOT).
However, LTFTs will never be negative at WOT (if they are averaging negative at cruise, they will defualt to 0% at WOT).
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Bringing this one back because I'm having the same issue, hit 5k and up and hear alot of knock. Weird thing is I see very little if any KR, max I've seen is about 3 degrees, most of the time it's around 1-2. Car is mostly stock, low miles (37k). Only mods are:
- SLP lid
- CAI duct
- TB coolant bypass
- Bassani true duals
Car has always had this knock. BTW fuel trims are fine, O2s read fat at WOT, stock fuel pump was replaced with walbro, fuel pressure holds 56 at all times. Always run 91 octane too, cats looked good when I did the exhaust.
I'm going to be changing plugs this weekend (don't trust those tiny irridium electrodes).
I suspect that, or possibly oil consumption (isn't that bad though). I should note this one has a decent amount of piston slap, sounds like a rod knock when cold, goes away to a slight tap when hot. Kind of suspect that for oil consumption...
- SLP lid
- CAI duct
- TB coolant bypass
- Bassani true duals
Car has always had this knock. BTW fuel trims are fine, O2s read fat at WOT, stock fuel pump was replaced with walbro, fuel pressure holds 56 at all times. Always run 91 octane too, cats looked good when I did the exhaust.
I'm going to be changing plugs this weekend (don't trust those tiny irridium electrodes).
I suspect that, or possibly oil consumption (isn't that bad though). I should note this one has a decent amount of piston slap, sounds like a rod knock when cold, goes away to a slight tap when hot. Kind of suspect that for oil consumption...