2002 996 C4: Bore Score, Valves or?
#46
Former Vendor
The only way an intake could make this occur is if the MAF sensor is placed outside the air inlet path enough to reduce the sensor reading. If this happens fuel trim can be added, making for a rich engine, and that causes smoke and oil consumption.
Check short and long term fuel trim with the engine at 180F coolant temp, and 200F oil temp, at idle, with the AC off. Report the readings.
Check short and long term fuel trim with the engine at 180F coolant temp, and 200F oil temp, at idle, with the AC off. Report the readings.
#47
Drifting
He mention aftermarket CAI.
I wonder if part of the intake after the MAf is slightly disconnected ?It isvery difficult to visually check this -hence my enthusiasm for the smoke test.
I wonder if part of the intake after the MAf is slightly disconnected ?It isvery difficult to visually check this -hence my enthusiasm for the smoke test.
#49
#50
FYI here's a shot of my engine bay so you can see the intake. Not positive it's Fabspeed as I don't have records of that from the previous owner and there are so many lookalikes. Not sure if this is helpful in answering the MAF sensor question, and I'm planning to discuss with the mechanic tomorrow.
#51
Rennlist Member
That's a stock airbox with the "orange cap" mod... basically stock, sans the airbox resonator chamber...
#52
Race Director
(and thus the MAF is where it should be re: the airstream from the airbox)
If you decide to get rid of the aftermarket parts, I know a guy who might buy the CF cap.
If you decide to get rid of the aftermarket parts, I know a guy who might buy the CF cap.
#53
Rennlist Member
Fabspeed indeed calls that a "Cold Air Upgrade Kit" for the low low price of $245 (plus shipping).
http://www.fabspeed.com/996-carrera-...r-upgrade-kit/
A cold air intake would look like this:
http://www.fabspeed.com/996-carrera-...r-upgrade-kit/
A cold air intake would look like this:
#55
Thanks everyone. I relayed all your comments about the MAF etc..; mechanic still suggested I replace it with the stock airbox intake boot (part # 99611022157) as it's cheap and may improve the problem. I'm ordering one today and will keep you posted.
Schnell, the existing "upgrade kit" intake is in great condition and I'm happy to sell it; email me at bbens at hotmail for more details.
Schnell, the existing "upgrade kit" intake is in great condition and I'm happy to sell it; email me at bbens at hotmail for more details.
#56
Update 5.5 months later: finally brought the car to Cape Auto in Orange County CA (generally well-regarded here) for an oil change and to help diagnose the frequent but brief left-exhaust cold-start white smoke. They first said that these flat 6 engines by their nature often smoke a bit on cold start, as many have said.
After service and road test/inspection, Cape said the car appears to be in excellent shape, runs well with everything within spec. They found no particles on the cut-open oil filter nor on the magnetic drain plug, RKAT measured 0.6 (perfect .00) VRA measured 1.03 (perfect 1.0). Car still burns a quart of oil every 2-3K miles (within spec I understand), otherwise no issues. The PPI/compression test/leakdown tests 5K miles ago all had excellent results.
I spent a bit more on this car to find a good one ($27K 5/2016 on this well-optioned C4 Cab with 40K miles and excellent service records) and this is the only real flaw I've been able to find. Of course bore scoring is still a possibility, but absent other symptoms both I and the tech at Cape Auto wonder if it's worth pursuing. This is the 3rd shop who has looked at it and I'm now of the mind to stop worrying and enjoy this beast. Thoughts?
After service and road test/inspection, Cape said the car appears to be in excellent shape, runs well with everything within spec. They found no particles on the cut-open oil filter nor on the magnetic drain plug, RKAT measured 0.6 (perfect .00) VRA measured 1.03 (perfect 1.0). Car still burns a quart of oil every 2-3K miles (within spec I understand), otherwise no issues. The PPI/compression test/leakdown tests 5K miles ago all had excellent results.
I spent a bit more on this car to find a good one ($27K 5/2016 on this well-optioned C4 Cab with 40K miles and excellent service records) and this is the only real flaw I've been able to find. Of course bore scoring is still a possibility, but absent other symptoms both I and the tech at Cape Auto wonder if it's worth pursuing. This is the 3rd shop who has looked at it and I'm now of the mind to stop worrying and enjoy this beast. Thoughts?
#57
yes a quart of oil every 2/3 k is within spec.................for now .....but if you are driving it normal it is too much and it will only get worse ,i bet the first owner beat it up some how
#58
Rennlist Member
#59
Drifting
Imho - drive it,enjoy it, keep the preventative maintenance up to your current high standard with an Indie you have evidence is trustworthy and competent. Use the correct oil for a slightly worn engine and do replace oil+filter frequently. Ask your Indie about the spin-on filter upgrade? UOA every 10,000 miles to track any deterioration. Not expensive and useful data.Watch for differences developing between Bank 1&2 in the leakdown tests you do over time.
Update 5.5 months later: finally brought the car to Cape Auto in Orange County CA (generally well-regarded here) for an oil change and to help diagnose the frequent but brief left-exhaust cold-start white smoke. They first said that these flat 6 engines by their nature often smoke a bit on cold start, as many have said.
After service and road test/inspection, Cape said the car appears to be in excellent shape, runs well with everything within spec. They found no particles on the cut-open oil filter nor on the magnetic drain plug, RKAT measured 0.6 (perfect .00) VRA measured 1.03 (perfect 1.0). Car still burns a quart of oil every 2-3K miles (within spec I understand), otherwise no issues. The PPI/compression test/leakdown tests 5K miles ago all had excellent results.
I spent a bit more on this car to find a good one ($27K 5/2016 on this well-optioned C4 Cab with 40K miles and excellent service records) and this is the only real flaw I've been able to find. Of course bore scoring is still a possibility, but absent other symptoms both I and the tech at Cape Auto wonder if it's worth pursuing. This is the 3rd shop who has looked at it and I'm now of the mind to stop worrying and enjoy this beast. Thoughts?
After service and road test/inspection, Cape said the car appears to be in excellent shape, runs well with everything within spec. They found no particles on the cut-open oil filter nor on the magnetic drain plug, RKAT measured 0.6 (perfect .00) VRA measured 1.03 (perfect 1.0). Car still burns a quart of oil every 2-3K miles (within spec I understand), otherwise no issues. The PPI/compression test/leakdown tests 5K miles ago all had excellent results.
I spent a bit more on this car to find a good one ($27K 5/2016 on this well-optioned C4 Cab with 40K miles and excellent service records) and this is the only real flaw I've been able to find. Of course bore scoring is still a possibility, but absent other symptoms both I and the tech at Cape Auto wonder if it's worth pursuing. This is the 3rd shop who has looked at it and I'm now of the mind to stop worrying and enjoy this beast. Thoughts?
#60
Race Car
If the MAF is indeed at fault/in question as Jake mentioned maybe its the removal of the resonator box as this makes mention that it does more than just reduce intake noise:
This is also why i've been sceptical regarding the orange cap mod/removing the Helmholtz resonator.
Also as DT has mentioned OP has the fabspeed "CAI" the other image with the two pods is their "competition" intake. I'm not a fan of either for various reasons.
This is also why i've been sceptical regarding the orange cap mod/removing the Helmholtz resonator.
Also as DT has mentioned OP has the fabspeed "CAI" the other image with the two pods is their "competition" intake. I'm not a fan of either for various reasons.