digital_dreamer Posted September 20, 2005 Report Share Posted September 20, 2005 Just got back from the Midwest VCOA meet. Lots of fun!CEL came on after restarting at home. My Palm based OBDII software (Auterra Dyno-Scan on my Treo 650) shows a P0014 code, “‘B’ camshaft position - Timing over-advanced or System Performance.” eh?I know the CEL doesn’t come on unless the code is generated more than once after a restart. And, I’ve reset the CEL and it came back on with the same code, so I have a problem. Am I dealing with a crankcase position sensor problem?I have the ST ECU upgrade and have always been curious about the ignition advance. Look at the timing with no engine load and you can see it go up to 47-degrees of advance at 4.2K-rpm. Is that normal?! Seems scary high. Now, under load it will drop (low teens or lower), depending on the amount of boost and throttle position.There are NO OTHER symptoms I can detect.Need your input. regards,MAJ Link to comment Share on other sites More sharing options...
digital_dreamer Posted September 23, 2005 Author Report Share Posted September 23, 2005 Well, it wasn’t a “glitch,” as I originally thought. After two days of being off, it came back on again. Same code.Now, the pattern I notice is that it seems to come on after driving for a reasonable distance, then slowing down to park the car. Each time it happened it was as I was parked/parking at work. First time: Drove 2 hours from KC to work location - CEL on restart.Second time: Drove 45 minutes to doctor, then 45 minutes back to work location - CEL driving into lot.Now, the P0014 code is generic and may be too general to conclude anything regarding Volvo troubleshooting.Here’s the latest freeze frame, which doesn’t seem to reveal anything meaningful other than an oddly low temperature reading for a hot car (thermostat should begin to open at 190°F, and be fully open at 215-220°F). The temperature gauge in the instrument cluster is at the typical midpoint.:Car only has 56k miles. I plan on replacing timing belt next summer. Wondering if I should check the belt, crank position sensor, and/or pull the valve cover for inspection...regards,MAJ Okay, here’s me thinking out loud:Say the low temp reading is the smoking gun. Bad temp sensor.Engine just comes off a highway speed run and coasts downtown. Typcially, this is when engine is hottest, as the engine has just been working hard, there is relatively little cooling air running through radiator, and water pump isn’t pumping as fast. ECU thinks engine is warm (not hot). Engine is under little boost and load. ECU tampers with timing.Whoa. Knock sensor tells ECU to retard... more retard. Retard some more.ECU asks, “Why must I retard this much?” It’s Overadvanced!! CEL!!Tell me what’s wrong with this scenario. Is it stupid, and why? Link to comment Share on other sites More sharing options...
starfish Posted September 23, 2005 Report Share Posted September 23, 2005 I was looking to see what a P0014 code is but can't seem to locate that exact code to compare to a Volvo DTC. Looks though like your problem maybe with the camshaft reset valve though. Anyhow, contact resistance across the valve is 3.7 ohms. With the ignition on and camshaft reset valve connector disconnected the voltage on connector # 1 should be approximately battery voltage and connector # 2 be a pulse modulated signal with top voltage at approximately battery voltage and with a frequency of approximately 250 Hz . How clean in general is your motor oil? There are small passages in the reset valve that can get clogged. The valve may need cleaning before further diagnosis leads to a possible bad CVVT unit. If the valve checks out electrically remove, disassemble it and clean with some Carb spray. Link to comment Share on other sites More sharing options...
digital_dreamer Posted September 25, 2005 Author Report Share Posted September 25, 2005 I was looking to see what a P0014 code is but can't seem to locate that exact code to compare to a Volvo DTC. Looks though like your problem maybe with the camshaft reset valve though. Anyhow, contact resistance across the valve is 3.7 ohms. With the ignition on and camshaft reset valve connector disconnected the voltage on connector # 1 should be approximately battery voltage and connector # 2 be a pulse modulated signal with top voltage at approximately battery voltage and with a frequency of approximately 250 Hz . How clean in general is your motor oil? There are small passages in the reset valve that can get clogged. The valve may need cleaning before further diagnosis leads to a possible bad CVVT unit. If the valve checks out electrically remove, disassemble it and clean with some Carb spray.Thanks for the reply! Got me looking in a different direction.I don't believe my 99 has the CVVT, but it does have the camshaft position sensor (on the exhaust side) and solenoid. I did a Google search and found another fellow with the same code who replaced both sensor and solenoid.There's very little information on this mechanism. I know the camshaft sensor is to indicate which stroke the piston(s) is/are in (it is a 4-stroke engine, after all). The crank position sensor only indicates crank position, but no clue is provided regarding whether the piston is on the power stroke or intake stroke, for example. That's where the camshaft sensor comes in.But, I have NO idea what the solenoid is for. Reset valve, you say? Can you provide me some information on what it does or how it works?I got it last year with 43K miles. Changed the oil twice since then with Mobil 1 Synthetic.I have to admit I've never been to comfortable with the way this engine sounds. It's noisy. Sounds like mostly valve train noise. But, then, I've never had one before and don't have one to compare it with. It's puzzling, because my 760 Turbo with 265K miles was really quiet — could hardly tell it was running with the hood down.regards,MAJ Link to comment Share on other sites More sharing options...
Bay13 Posted September 25, 2005 Report Share Posted September 25, 2005 I don't believe my 99 has the CVVT,No time like the present to change your beliefs. All Volvos 1999 to present have CVVT on at least one of the cam shafts, some have 2 and some have VVT on both cams.Your CVVT has a valve that is electro/hydraulic to varry the cam timing. The hydraulic part is engine oil and there is a solenoid that is electrical. The engine oil is used to rotate the VVT and is regulated by the solenoid that is controlled by the ECM. Like already mentioned they get clogged or they fail.to take the valve off and clean it you will need a new gasket, Volvo part number is 30731212. To find the valve that is on the top of the head, on the timing belt end, remove the plastic covers that cover the spark plugs. You can take off just the piece thats on the passenger side and you should be able to get to everything. Link to comment Share on other sites More sharing options...
starfish Posted September 25, 2005 Report Share Posted September 25, 2005 I got it last year with 43K miles. Changed the oil twice since then with Mobil 1 Synthetic.I have to admit I've never been to comfortable with the way this engine sounds. It's noisy. Sounds like mostly valve train noise. But, then, I've never had one before and don't have one to compare it with. It's puzzling, because my 760 Turbo with 265K miles was really quiet — could hardly tell it was running with the hood down.regards,MAJMost likely this is a problem that is related to the CVVT reset valve solenoid causing the check engine light. A failed CVVT reset valve can create some rattling or knocking. If the valvetrain was noisy way prior to the CEL coming on you may need oil pan o-rings. In regards to your comments about some other guy with the same code changing a crank sensor to fix this code, it is not in the realm of possibility. This is a CVVT code only. Were you able to do the electrical test of the solenoid and wiring?The reset valve is very susceptible to varnish build up from lack of regular oil changes. Try removing the reset valve by unbolting it from the top of the cam cover. Test it by seeing if there is flow between the middle round hole in the aluminum plate and the hole closest to the solenoid. Try adding a hot and ground to the solenoid connector. The plunger should move and you should have flow between the middle hole and the hole furthest from the solenoid. You can take the snap ring off and remove the solenoid, washer, spring and plunger. Clean these all out along with the housing plate by spraying with the solvent. Do not attempt to sand these parts. Wipe them dry and apply some clean engine oil and reassemble them. Clear the codes and retest. If the reset valve is clean and now working properly but the code is back, your CVVT unit may have failed. Link to comment Share on other sites More sharing options...
digital_dreamer Posted September 26, 2005 Author Report Share Posted September 26, 2005 No time like the present to change your beliefs. <snip>Well, Volvospeed changed my beliefs. So, it does have CVVT! (on the exhaust) starfish,Yes, I've checked the solenoid. The solenoid checks out electrically at 4.9 ohms and I certainly get a 250Hz signal from the plug. However, I didn't check to see if the solenoid is mechanically sound. It looks VERY clean, with no buildup whatsoever. (Running Mobil 1 Synth). Plus, there was plenty of oil in the channels, except for where it seems to enter the camshaft channel.I didn't check it with power, because I didn't know what voltage drives it. 12v power at 4.9 ohms sounds about right (2.5A), but the 250Hz input made me wonder about its continuous duty capability if I were to hook up 12v to it.I noticed the center channel with a hole in the plunger, and it appeared it could move either way, as there's a channel on both sides. I tried to see if I could move the plunger in (toward the solenoid; most move in), but it wouldn't budge. Now, after reading your post, I realize it can only move out/away (on power).I’ll check this out again to see if it can move under power. If it does, would that point to a oil circulation problem? I’m assuming the oil in the CVVT has to be under pressure to operate, and so receives the oil first before being sprayed on the rest of the valve train.Thanks for your help, guys.regards,MAJ Link to comment Share on other sites More sharing options...
digital_dreamer Posted October 1, 2005 Author Report Share Posted October 1, 2005 Okay, I've been able to check out the solenoid mechanically.When off, oil flows from middle hole to hole closest to solenoid. No problem there.When on, oil mainly flows from middle hole to large open area outside plunger, but also to the next hole furthest away from solenoid.What does that tell you? Is it normal?So, the pressurized oil rotates the cam and then escapes to the valve assembly. The amount of oil pressure applied to the CVVT unit is regulated by the oscillating solenoid via PWM, much like the fuel injectors except the CVVT solenoid pulses at a constant rate. Reminds me of the old Lambda oxygen sensor on the '78 264 that regulated emissions via Pulse-Width-Modulated fuel pressure regulator.Let me know what is my next step. Replace solenoid?Hopefully, I don't have any deeper underlining issues with the CVVT or rest of the valve assembly. regards,MAJ Link to comment Share on other sites More sharing options...
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