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Hi, noob here. I got small leak on my 2008 Cayenne Base with 130k. I bought an ebay version smoke machine, but has no idea where to plug it in. Anybody used it before? Thank you so much.
A smoke machine will help you find a vacuum leak, so I'm assuming that's what you're trying g to locate. You need to hook it up to the air intake so on the downstream side of the airbox (anything prior to the MAF won't have any effect on anything since the air is metered by the MAF). Find your air filter and plug the hose going out of the airbox with the smoke machine accessories and introduce the smoke there then pool to see where it comes out.
Hi, thank you all for the reply. I run a scan and have 6 codes.
1. P0507: idle control system rpm higher than expected value
2. P0440: Above upper limit value, Evaporation Emission System
3. P2187: Above upper limit. System too lean at idle bank 1
4. P2189: Above upper limit. System too lean at idle bank 2
5. P2187: No communication with bank 1
6. P2189: No communication with bank 2
I am not sure about 5, 6, assume it is not an issue?
My scanner(IcanScan) can collect data, freeze frame or something, but I don't know what data I need. Anybody has any thoughts? Thank you so much!
P0440 and P0507 indicate some leak.
Thank you, Petza914, MAF (Mass Flow Sensor) can cause codes on banks, also can cause P0440 code?
Yes, it can cause codes on both banks. The air gets metered by the MAF, then the DME takes that creates the baseline fuel trims for the 2 banks, then the O2 sensors analyze the mixture coming past them and reports that info back to the DME and the DME adjusts the fueling for each bank based on the info from the O2 sensors. The fact that you're getting Out of Range messages on both banks points to a problem with a part that is common to both banks. For example if you had a crack in the Bank 1 intake manifold, it's likely you would only get out of range messages on that 1 Bank since the unmetered air would be introduced after the MAF and the O2 sensor for that bank would see something that doesn't jive with what it's expecting to see.
The 0440 code does point to something emissions related though and I'm not familiar with all the components that make up that system. Does the car run rough as well? If so you can also do a test where you just unplug the connector at the MAF putting the car into Limp mode, which means it will default to middle-of the road values for the fuel trim and stop metering and analyzing so much. If the car runs better with the MAF disconnected, that might be your problem.
Are you or was a PO running the stock airbox or a cold air intake with an oiled filter. Over oiling these types of filters is a common cause of MAF failure as the oil gets on the platinum sensor wire and contaminates the readings.
Thank you, Petza914, MAF (Mass Flow Sensor) can cause codes on banks, also can cause P0440 code?
P0440 could be a gas cap that is not sealing. If its setting a check engine light replace the cap.
If no check engine light it could be a weak vacuum pump, not necessarily a leak.
On the 2008 the vacuum pump is a cam driven unit mounted at the back of the engine on the passenger side. Its a PITA to replace so you should be sure its faulty.
I would skip the smoke machine for now and invest in a vacuum gauge. A good vacuum pump should pull about 20"hg.
Yes, it can cause codes on both banks. The air gets metered by the MAF, then the DME takes that creates the baseline fuel trims for the 2 banks, then the O2 sensors analyze the mixture coming past them and reports that info back to the DME and the DME adjusts the fueling for each bank based on the info from the O2 sensors.
Not to question the accuracy of your statement - but how does the ECU adjust the mixture for each bank when on the V8 at least - the intake throttle body is one body for both banks, fed by a Y shaped fitting that mixes air from both airboxes (or turbos)? Anyone know how they do this? It seems as if that would have to be done almost on a cylinder to cylinder basis, which implies a very fast O2 sensor and a very fast ECU...
You definitely have a vacuum leak. My guess would be failed oil separator, its becoming more and more common on the v6s. There is also a plastic brake booster line at the back of the engine that is prone to cracking and leaking. You may have 2 separate issues but I bet thats your "system too lean" faults. I would attempt to address those before the p0440 tank vent fault.
Not to question the accuracy of your statement - but how does the ECU adjust the mixture for each bank when on the V8 at least - the intake throttle body is one body for both banks, fed by a Y shaped fitting that mixes air from both airboxes (or turbos)? Anyone know how they do this? It seems as if that would have to be done almost on a cylinder to cylinder basis, which implies a very fast O2 sensor and a very fast ECU...
Although the air mixes from a starting common point, the fuel that combines with that air is directly injected into each cylinder on the DFI engines, and controlled for each bank, so the pre cat and post cat O2 sensors for each bank analyze what they're seeing and adjust the fueling for each bank independently. The 997 works the same way even though it's a flat 6 with a single MAF and 1 throttle body splitting to both sides. If you track live values via a Durametric or similar you can monitor the fuel trim values for each bank and see that they're usually slightly different. Also, if you reset the fuel trims you'll notice that the engine stumbles first a few seconds until the DME reduced the analysis and adjusts them, then the idle smooths back out again.
Hi, guys, I finished testing the air intake part and looks like it is OK.
I remove the air filter box and manage to introduce the air there, and did not find any leak. Also it seems the smoke cannot get into the other part, because throttle is closed? Here is the picture.
Introduce smoke at the arrow
I try to locate the break booster hose but it is hidden behind everything, in order to pull it out, it seems that I need to remove wipers, covers, etc.
So I follow all the hoses I think related to air (all of them looks fine, no crack). but I don't know where I can insert the smoke for testing.
On the back between engine and the wall, I think this is the Purge Valve.
Looks like this is the purge valve. The red arrow point to a hose running to the left front of the engine.
Here is the hose I want to lose and use for the smoke test, but I am afraid I will break something.
The hose is what the red arrow point at the picture above. I want to lose the metal clamp for smoke test.
Is it a good spot to insert smoke?
I cannot recognize the parts at all. All the connector are different from US cars. I think I need to find a workshop manual or service manual before I do something bad and stupid.
I found "PORSCHE CAYENNE 2003 - 2010 SERVICE REPAIR MANUAL" only $9.90 on ebay and "PORSCHE CAYENNE 2003 - 2008 SERVICE REPAIR FACTORY WORKSHOP MANUAL - AS USED AT PORSCHE DEALERSHIP GARAGE - RARE CHANCE TO OWN THE MANUAL - PDF DOWNLOAD" at tradebit for $14.95. Do you guys think it is legit and useful? It is indeed a very good deal if it is what it states is true.
07-02-2018, 11:24 AM
How to hunt small leak 2008 cayenne?
