Power Loss - Boost doesn't go higher than 0.4
12-15-2012, 02:09 AM
#17
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Whoa! Easy, people! I am past the stage of psychological and otherwise development to derive pleasure from telling people about having problems with a car that does not exist. Yes, i am from Europe and there are tons of Cayennes of this production year. On a side note - if i made somebody smiling then good for you, people. Smiling is a good thing and i am glad i helped 
As for the problems with the car - still limping. It seems like this problem is not due to improper starter replacement. They found a leak in a tubing that connects the throttle with the intercooler. The leak is now fixed, the car runs even faster now and is a total beast. But still goes into the limp mode. Faulty codes that are present are these - p1080 and -1094 (iirc). Both have to do with air mass.
Now, since there are no leaks to be fixed, mechanic says that MAS sensor is the next and probably last suspect. The difference between two MAFs on idle is about 2-3 digits, which, he says, a sign of improper function. A probable cause of a faulty MAF is leak in the tubing and unfiltered air which could damage the MAF. So now i have to wait until Monday and see if the new sensor does the trick... ON MY CAYENNE 2007))
As for the problems with the car - still limping. It seems like this problem is not due to improper starter replacement. They found a leak in a tubing that connects the throttle with the intercooler. The leak is now fixed, the car runs even faster now and is a total beast. But still goes into the limp mode. Faulty codes that are present are these - p1080 and -1094 (iirc). Both have to do with air mass.
Now, since there are no leaks to be fixed, mechanic says that MAS sensor is the next and probably last suspect. The difference between two MAFs on idle is about 2-3 digits, which, he says, a sign of improper function. A probable cause of a faulty MAF is leak in the tubing and unfiltered air which could damage the MAF. So now i have to wait until Monday and see if the new sensor does the trick... ON MY CAYENNE 2007
))
12-15-2012, 07:33 AM
#18
It could also be as simple as cleaning the sensor. Check here. It could be as simple as removing the sensor (housing), spray clean, replace housing. That said, if let get too dirty too long, damage can result. In that case, no amount of spraying can help. But at least try the less expensive (and simple) route first.
//greg//
//greg//
12-16-2012, 04:31 AM
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Yeah, the first thing i am gonna try is to clean the MAF. Thanks for the tip anyway.
The original MAF Sensor for this car is damn too pricey! I've heard that it is possible to replace the sensor element located inside the sensor with an OEM version, although one has to know the model s/n to know what to replace it with. I will to find those s/n while cleaning it.
The original MAF Sensor for this car is damn too pricey! I've heard that it is possible to replace the sensor element located inside the sensor with an OEM version, although one has to know the model s/n to know what to replace it with. I will to find those s/n while cleaning it.
12-17-2012, 11:41 AM
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Ok, replaced the MAF and the problem still persists... It's getting really annoying now.
The difference in readings between two MAFs is about 2-3 points. Sensor 1 is showing about 12 kilos and Sensor2 about 9. Is it normal? What can be causing this difference?
The difference in readings between two MAFs is about 2-3 points. Sensor 1 is showing about 12 kilos and Sensor2 about 9. Is it normal? What can be causing this difference?
12-17-2012, 12:38 PM
#22
Drifting
What are the voltage readings of your MAF sensors with the key on and engine off?
I have not seen camshaft adjustment faults cause limp mode, but that's not to say it couldn't happen. If you are getting faults, I would definitely try to get it fixed. It could just be a simple camshaft adjustment solenoid failure.
Have you checked your air filters?
I have not seen camshaft adjustment faults cause limp mode, but that's not to say it couldn't happen. If you are getting faults, I would definitely try to get it fixed. It could just be a simple camshaft adjustment solenoid failure.
Have you checked your air filters?
12-17-2012, 01:47 PM
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I dont remember the voltage readings, but the weight readings with the key/engine off were zero. I think voltage were zero too but will have to double check.
Will look deeper into adjusting camshafts. Is it always necessary to open up the engine?
Air filters are in an OK shape. Not new, but not too dusty/oily.
Since readins on both MAFs are so different, is it possible that oily intercooler is preventing the flow of an intake air so much that the readins are THAT different and it puts the car into the limp mode? Tubings and MAF were oily when we replaced it.
And i still can't get the thought that it is all because they did something wrong when they were replacing the starter out of my mind....
Will look deeper into adjusting camshafts. Is it always necessary to open up the engine?
Air filters are in an OK shape. Not new, but not too dusty/oily.
Since readins on both MAFs are so different, is it possible that oily intercooler is preventing the flow of an intake air so much that the readins are THAT different and it puts the car into the limp mode? Tubings and MAF were oily when we replaced it.
And i still can't get the thought that it is all because they did something wrong when they were replacing the starter out of my mind....
12-17-2012, 03:44 PM
#24
Drifting
You should see voltage at both MAFs with the key on and engine off (0.8-1.1 volts if I remember right), but the weight reading should be zero with the engine off.
If your camshaft adjustment problem is just a solenoid, it's not a big deal - very easy to replace. If it's an actual failed cam adjuster, it is a much bigger job requiring special tools (though it can all be done without removing the engine).
Oil in the intercooler pipes should not cause an issue, however that oil should not be making it to the MAF.
If your camshaft adjustment problem is just a solenoid, it's not a big deal - very easy to replace. If it's an actual failed cam adjuster, it is a much bigger job requiring special tools (though it can all be done without removing the engine).
Oil in the intercooler pipes should not cause an issue, however that oil should not be making it to the MAF.
12-17-2012, 10:49 PM
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Will double check the readings on MAFs. A correction to the last post - it was -47 on both when i turned both MAFs off, and zero with the engine off.
The lower reading (9 kg VS 12 ks) on average is on the left side. On the graph, the right side is kinda stable and the left one constantly fluctuates. I was thinking that it had to do with the crankcase gases and the valve that may be causing the intake air to be leaking. Disconnected the blow-by pipe and tried to look at those readings without it (with the pipes sealed) - same deal.
An interesting thing to note - the difference becomes more pronounced after about 5-7 minutes while at idle, and right after the start of the engine it is less so (1 kg vs about 3). And faulty codes (p1080 and p1094 i believe) are usually registered at about 1200-1500 RPM, below the turbo kick-in threshold.
Could it be happening because of some misplaced tubings/pipes under the intake manifold? Some vacuum pipes? It must be somehow linked to the starter replacement procedure!
The lower reading (9 kg VS 12 ks) on average is on the left side. On the graph, the right side is kinda stable and the left one constantly fluctuates. I was thinking that it had to do with the crankcase gases and the valve that may be causing the intake air to be leaking. Disconnected the blow-by pipe and tried to look at those readings without it (with the pipes sealed) - same deal.
An interesting thing to note - the difference becomes more pronounced after about 5-7 minutes while at idle, and right after the start of the engine it is less so (1 kg vs about 3). And faulty codes (p1080 and p1094 i believe) are usually registered at about 1200-1500 RPM, below the turbo kick-in threshold.
Could it be happening because of some misplaced tubings/pipes under the intake manifold? Some vacuum pipes? It must be somehow linked to the starter replacement procedure!
12-19-2012, 12:51 PM
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Thing is, the situation with the car gets more interesting each day.
During the replacement of starter, they found one vacuum line that was "sucking air", as they said, meaning that it was damaged. So they decided to fix it - they simply cut off the part with holes in it and replaced it with a good one (just a piece of about 15-20cm long). And indeed, when i got my car from the workshop i noticed that blow-off sound became much more pronounced than before and, as i said in the beginning of the message, it now had an IMMENSE power - something i didn't feel it behave like long ago. Since i knew that it was probably the only thing what was done aside from changing a broken starter, i decided to undo it: i simply took that fixed tubing out of that vacuum line, so it is now broken again.
And what do you think? It is not as powerful as before, but it doesn't go into the limp mode. Yes, boost is about 0.8 - 0.9 max and for some strange reason, when i approach 0.4 bar mark i can hear th air being blown off by the diverter valve. What the hell? AFAIK, the tubing that i made broken again is the one that opens up the valve to shutt excess air off, so since it doesn't have this vacuum line connected to it, the valve should be CLOSED all the time and shouldn't shut the air off, so i should experience even more boost and thus more power.
Here is the pic of that line (sorry for the quality, it is dark outside):
Images are clickable and can be zoomed in.
So... Now i am having the hard time guessing what is happeing with this car and why it behaves like that...
What those line are there for? Are they for activating shut-off valves or do they do anything else?
---
A little more food for thought:
My DVs are OEM Boschs valves, but they shut the air into the atmosphere as opposed to the original installation in which air is diverted back into the intake. So, what i am thinking is this - i bought the car with a remap (not sure which one exactly) and it had those valves installed and it all worked perfectly well. After sometime they stopped swooshing and i definitely noticed that, but i didn't do anything - just didn't have time to fix that problem and the power it provided, although less than originally, kinda sufficed. Now, it is clear that swooshing sound disappeared because the vacuum line was broken and when they fixed that the car started to shut-off the excess air and had more power. But it also started to behave strangely: faulty codes having to do with incorrect air mass between MAF and throttle body (code p1080, p1094), mixture too rich and limp mode almost instantly. My speculation is this - could i somehow lost my remap and now the car doesn't "like" the fact that DVs are not blowing the air back into the intake?
Just think about - the ECU kinda knows that this exact amount of air is going to be given back, so the air/fuel mixture is adjusted and they diverted air, although being blown back past the MAF, still is being considered and the mixture is calculated accordingly. But i actually shut this air off and it never comes back. What we have as a result? Rich mixture and incorrect calculated air mass, since that mass is calculated with diverted air taken into consideration, which is simply not there.
Two main questions are:
- Could this be causing limp mode?
- How the hell it was possible to run flawlessly with this kind of set-up before? Loss of remap?
Ugh...
During the replacement of starter, they found one vacuum line that was "sucking air", as they said, meaning that it was damaged. So they decided to fix it - they simply cut off the part with holes in it and replaced it with a good one (just a piece of about 15-20cm long). And indeed, when i got my car from the workshop i noticed that blow-off sound became much more pronounced than before and, as i said in the beginning of the message, it now had an IMMENSE power - something i didn't feel it behave like long ago. Since i knew that it was probably the only thing what was done aside from changing a broken starter, i decided to undo it: i simply took that fixed tubing out of that vacuum line, so it is now broken again.
And what do you think? It is not as powerful as before, but it doesn't go into the limp mode. Yes, boost is about 0.8 - 0.9 max and for some strange reason, when i approach 0.4 bar mark i can hear th air being blown off by the diverter valve. What the hell? AFAIK, the tubing that i made broken again is the one that opens up the valve to shutt excess air off, so since it doesn't have this vacuum line connected to it, the valve should be CLOSED all the time and shouldn't shut the air off, so i should experience even more boost and thus more power.
Here is the pic of that line (sorry for the quality, it is dark outside):
Images are clickable and can be zoomed in.
So... Now i am having the hard time guessing what is happeing with this car and why it behaves like that...
What those line are there for? Are they for activating shut-off valves or do they do anything else?
---
A little more food for thought:
My DVs are OEM Boschs valves, but they shut the air into the atmosphere as opposed to the original installation in which air is diverted back into the intake. So, what i am thinking is this - i bought the car with a remap (not sure which one exactly) and it had those valves installed and it all worked perfectly well. After sometime they stopped swooshing and i definitely noticed that, but i didn't do anything - just didn't have time to fix that problem and the power it provided, although less than originally, kinda sufficed. Now, it is clear that swooshing sound disappeared because the vacuum line was broken and when they fixed that the car started to shut-off the excess air and had more power. But it also started to behave strangely: faulty codes having to do with incorrect air mass between MAF and throttle body (code p1080, p1094), mixture too rich and limp mode almost instantly. My speculation is this - could i somehow lost my remap and now the car doesn't "like" the fact that DVs are not blowing the air back into the intake?
Just think about - the ECU kinda knows that this exact amount of air is going to be given back, so the air/fuel mixture is adjusted and they diverted air, although being blown back past the MAF, still is being considered and the mixture is calculated accordingly. But i actually shut this air off and it never comes back. What we have as a result? Rich mixture and incorrect calculated air mass, since that mass is calculated with diverted air taken into consideration, which is simply not there.
Two main questions are:
- Could this be causing limp mode?
- How the hell it was possible to run flawlessly with this kind of set-up before? Loss of remap?
Ugh...
Last edited by StabMe; 12-19-2012 at 03:10 PM.
12-19-2012, 04:19 PM
#27
Drifting
You're getting rich faults and limp mode because the air is diverted to the atmosphere when that vacuum line is connected. This is air that the MAFs have already accounted for (and the DME has provided fuel for), and instead of going back into the intake, it's going to the atmosphere, so your car is getting less air than it is fueling for. Essentially, it is acting like a boost leak when your diverter valves open, and this can cause limp mode. With the leak at the vacuum line, the diverter valves would not open, so no boost leak.
How was it running with this setup before? I don't know. If it was tuned for atmospheric diverter valves it might have worked.
How was it running with this setup before? I don't know. If it was tuned for atmospheric diverter valves it might have worked.
12-20-2012, 04:53 AM
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Well, this very logical and exactly what i thought when i disconnected the vacuum line.
More interesting question is this - why the car acts SLOWER with the vacuum line disconnected?
When they repaired the vacuum line, i immediately felt an increase in power. OTOH, when i "unfixed" that vacuum line the car became much more sluggish. Although the vacuum line is disconnected, i still can hear them blowing off the air. They blow constantly as soon as RPMs hit about 3-4.000 mark. When the vacuum line was in place, there wasn't any sound of constantly blown off air, only swooshes while shifting.
And it was a vast difference in power and overall dynamics of the car. Faster downshifting, turbos engage at lower RPMs, higher boost (apporx 1.2-1.3 VS 0.8), etc...
Going to fix those hoses so the blow the air back and see what difference it makes.
More interesting question is this - why the car acts SLOWER with the vacuum line disconnected?
When they repaired the vacuum line, i immediately felt an increase in power. OTOH, when i "unfixed" that vacuum line the car became much more sluggish. Although the vacuum line is disconnected, i still can hear them blowing off the air. They blow constantly as soon as RPMs hit about 3-4.000 mark. When the vacuum line was in place, there wasn't any sound of constantly blown off air, only swooshes while shifting.
And it was a vast difference in power and overall dynamics of the car. Faster downshifting, turbos engage at lower RPMs, higher boost (apporx 1.2-1.3 VS 0.8), etc...
Going to fix those hoses so the blow the air back and see what difference it makes.
12-21-2012, 02:12 AM
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Went to the workshop yesterday and insisted on connecting BOVs fittings with intake pipes. They didn't think it would help, but did it anyway upon my request. I reconnected the vacuum hose as well.
Car runs nicely - lots of power, no limp mode. Problem solved. Yes baby!
Car runs nicely - lots of power, no limp mode. Problem solved. Yes baby!