Ion Posted May 31, 2009 Report Share Posted May 31, 2009 Hi again. This intermittent stalling issue is heating up again with the outside temps once again, getting into the 100's. When a/c is on the engine just cuts out, with no warning. I turn off the a/c's "auto" switch, essentially shutting off the a/c, start the engine up and it runs. As long as a/c remains off, there is not really a problem. The past couple years, I had been experiencing the same issues, identified all the error codes and replaced almost all sensors that tripped the codes. Yeah...I know I probably wasted some $ by replacing the sensors that generated the errors (MAP error, TPS error, etc), rather than trying to figure out WHY they tripped the error codes. It just never dawned on me that the a/c was running each time engine stalled in the past. Anyone have any ideas if the a/c can cause the engine to stall and more importantly...why? I think the engine stall error was 095. The car runs very well during the not-hot months and never stalls or trips error codes. Link to comment Share on other sites More sharing options...
KHE Posted May 31, 2009 Report Share Posted May 31, 2009 Does the car stall the minute the A/C is turned on or is the stall random in nature when the A/C is on? Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
Ion Posted May 31, 2009 Author Report Share Posted May 31, 2009 Randomly Link to comment Share on other sites More sharing options...
growe3 Posted May 31, 2009 Report Share Posted May 31, 2009 Does the engine die when under way, or at idle? If at idle, with the AC off does the engine idle at 650 RPM? If so then engaging the AC does it die suddenly, or slowly loses RPM and dies? -George Drive'em like you own 'em. - ....................04 DTS............................ Link to comment Share on other sites More sharing options...
Ion Posted May 31, 2009 Author Report Share Posted May 31, 2009 Does the engine die when under way, or at idle? If at idle, with the AC off does the engine idle at 650 RPM? If so then engaging the AC does it die suddenly, or slowly loses RPM and dies? -George George... Engine idles normally at about 750 - 800 rpm when ac on or off. This has remained consistent since I've owned the car (1998). While ac is running, engine will randomly shut down...instantly. No regularity re: when either. Happens while accellerating or sitting at stop sign idling. -Don Link to comment Share on other sites More sharing options...
Ion Posted June 2, 2009 Author Report Share Posted June 2, 2009 Hi again. This intermittent stalling issue is heating up again with the outside temps once again, getting into the 100's. When a/c is on the engine just cuts out, with no warning. I turn off the a/c's "auto" switch, essentially shutting off the a/c, start the engine up and it runs. As long as a/c remains off, there is not really a problem. The past couple years, I had been experiencing the same issues, identified all the error codes and replaced almost all sensors that tripped the codes. Yeah...I know I probably wasted some $ by replacing the sensors that generated the errors (MAP error, TPS error, etc), rather than trying to figure out WHY they tripped the error codes. It just never dawned on me that the a/c was running each time engine stalled in the past. Anyone have any ideas if the a/c can cause the engine to stall and more importantly...why? I think the engine stall error was 095. The car runs very well during the not-hot months and never stalls or trips error codes. Anyone? Noone has experienced this issue? Link to comment Share on other sites More sharing options...
growe3 Posted June 2, 2009 Report Share Posted June 2, 2009 Don, This is an unusual problem. I am wondering if the AC on is concidential. With the AC on you are having a larger electrical load , and the engine will be a little warmer than normal. I had a similar problem (not with the AC) with the engine suddenly shutting off. Seconds later it would start up fine. No problem for days then again it would shut off. I replaced the PCM and all was healed. Apparently it would occasionally overheat and cut out. This may or may not set a code to trace. Do you have any error codes set right now? -George Drive'em like you own 'em. - ....................04 DTS............................ Link to comment Share on other sites More sharing options...
Ion Posted June 2, 2009 Author Report Share Posted June 2, 2009 Don, This is an unusual problem. I am wondering if the AC on is concidential. With the AC on you are having a larger electrical load , and the engine will be a little warmer than normal. I had a similar problem (not with the AC) with the engine suddenly shutting off. Seconds later it would start up fine. No problem for days then again it would shut off. I replaced the PCM and all was healed. Apparently it would occasionally overheat and cut out. This may or may not set a code to trace. Do you have any error codes set right now? -George Yes..the old P095 - Engine Stall, accompanied by the old P032 - Open MAP. I replaced the MAP Sensor over a year ago. That falls in line with my initial statement on this thread, where changing out the sensor that sent an error code didn't fix what caused it to trip. I'm on my 3rd PCM. I believe it's the original one, NOT the one that was reconfigured after some sort of recall issue that mandated a fix. I have bought each of my replacements from Carquest. Are you aware of the part numbers relating to the PCM's? I have all that info buried away somewhere, but if you have it handy, that might help establish if still using the pre-recall serial number PCM is the root of my ongoing issues? Thanks... Link to comment Share on other sites More sharing options...
adallak Posted June 2, 2009 Report Share Posted June 2, 2009 What if AC draws too much current? The saddest thing in life is wasted talent Link to comment Share on other sites More sharing options...
rek Posted June 2, 2009 Report Share Posted June 2, 2009 My '96 stalled at a stop sign with the AC on. Soon after, I had to replace the AC compressor. The compressor seized. Set your DIC to display volts. Check it when it stalls, for low volts... rek Link to comment Share on other sites More sharing options...
Ion Posted June 3, 2009 Author Report Share Posted June 3, 2009 An alleged online cadillac service guy suggested the crank position sensor has remedied stalling in other northstar caddies. But, on the other hand, a friend who had his replaced said it remedied an issue that prevented the car from starting after it had come to rest. His car never suddenly stalled while running. Is this sensor better known to address non-starting issues, opposed to intermittent stalling issues, such as the issues I have been experiencing for the last few years? Link to comment Share on other sites More sharing options...
Ion Posted March 2, 2010 Author Report Share Posted March 2, 2010 UPDATE: After donating another $1200.00 to a local shop to locate the source of this irritating, ongoing, intermittent stalling, Open MAP error message issue and like all others, failing to do the job, I once again replaced the MAP sensor on my own, with an AC Delco MAP, opposed to another "OEM" MAP. This is another subject for another post. All problems disappeared...for the time being. THEORY: As I removed the old one, I noticed the MAP's nozzle in which barometric pressure is sensed, had oil in and around it. The source of this oil? The age-old Northstar leaking case half. My unqualified theory about the source of the ongoing intermittent stalling, surging, revving, "Open MAP" error message etc, is...oil from the friggin leaking case half is getting up into the intake manifold, ultimately, through time, entering the MAP sensor's nozzle, altering the sensor's ability to perform to spec. IRONY: after all the money I have donated to local alleged Northstar "experts" through the years, I could have easily afforded to have the leaky case-half repaired, two times over. Estimates for this were all around $2000.00. So now when the symptoms return, and until the leaky case half is fixed, I totally expect them to return, I now know that I can replace the oil-fouled MAP for around $75.00 and 40 minutes of my time. Link to comment Share on other sites More sharing options...
BodybyFisher Posted March 2, 2010 Report Share Posted March 2, 2010 Your theory that a case half leak is causing your MAP to get oil on it is wrong. A bad case half seal leaks externally to the ground it does not leak up into the manifold as you say It looks like you may have solved your problem, try to stay positive here. You seem to be having problems with mechaincs, post your problems here we should be able to help or at least lead you in the correct direction. We have many owners with the 94 that can help The idea posted above regarding your stalling was a good one (AC hub bearing). Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
KHE Posted March 2, 2010 Report Share Posted March 2, 2010 Nice that you fixed it but I don't see how a leaking case half would get oil up into the manifold? Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
BodybyFisher Posted March 2, 2010 Report Share Posted March 2, 2010 One more thing, you have an ISC motor on that engine, if properly adjusted it should prevent stalling. What has been done with the ISC motor? Did you replace it?, adjust it?, clean it? Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
Ion Posted March 2, 2010 Author Report Share Posted March 2, 2010 Perhaps someone can explain how oil residue ended up on the MAP's nozzle? Anyone? Link to comment Share on other sites More sharing options...
BodybyFisher Posted March 2, 2010 Report Share Posted March 2, 2010 Perhaps someone can explain how oil residue ended up on the MAP's nozzle? Anyone? Maybe its me, but I don't like the attitude you are conveying in your writing, maybe its your style or maybe I am being sensitive. PERHAPS SOMEONE/ANYONE? to me is condescending for a member that is obviously having problems fixing a problem for years while looking for help Oil /carbon residue or condensate gets into the intake from the EGR system, its normal and looks like hell. It is from EGR gases and when the car cools it condenses and settles. Have you ever cleaned the phenolic spacers and mouse holes? Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
CarlaValentine Posted March 2, 2010 Report Share Posted March 2, 2010 On the 94 Northstar, it is perfectly normal for oil to get under the manifold cover. There's really no point in trying to clean it all up because it will just come back. Why it happens, I don't know for certain, but I have been reassured that it's nothing to worry about. In my case with MAP sensor issues, it was a matter of fixing a bare wire, and replacing the sensor. When the sensor was replaced however, I noticed that the rubber seal inside the electrical connector on the sensor had deteriorated and stuck it self to the sensor, allowing oil to get into the connector. I cleaned the connector and replaced the seal when I changed the sensor and have had no problems since. If you start having problems again, check that rubber seal to be sure it is keeping oil out of the connector as it is supposed to. From what I have read and heard the oil can cause a problem with the current in the connection and lead to the MAP not working properly. It is also important to torque the manifold cover bolts to the proper spec. Too loose will cause a vacuum leak. Too tight could strip the threads. The torque spec for that is 8-11 Nm. Link to comment Share on other sites More sharing options...
Ion Posted March 2, 2010 Author Report Share Posted March 2, 2010 Perhaps someone can explain to me how oil residue ended up on the MAP nozzle? If they can, maybe the answer can once and for all, solve this endless drama... Link to comment Share on other sites More sharing options...
BodybyFisher Posted March 2, 2010 Report Share Posted March 2, 2010 Nice that you fixed it but I don't see how a leaking case half would get oil up into the manifold? Perhaps someone can explain to me how oil residue ended up on the MAP nozzle? If they can, maybe the answer can once and for all, solve this endless drama... TRY READING MY POST #17 ABOVE, I ANSWERED YOUR QUESTION Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
Ion Posted March 2, 2010 Author Report Share Posted March 2, 2010 On the 94 Northstar, it is perfectly normal for oil to get under the manifold cover. There's really no point in trying to clean it all up because it will just come back. Why it happens, I don't know for certain, but I have been reassured that it's nothing to worry about. In my case with MAP sensor issues, it was a matter of fixing a bare wire, and replacing the sensor. When the sensor was replaced however, I noticed that the rubber seal inside the electrical connector on the sensor had deteriorated and stuck it self to the sensor, allowing oil to get into the connector. I cleaned the connector and replaced the seal when I changed the sensor and have had no problems since. If you start having problems again, check that rubber seal to be sure it is keeping oil out of the connector as it is supposed to. From what I have read and heard the oil can cause a problem with the current in the connection and lead to the MAP not working properly. It is also important to torque the manifold cover bolts to the proper spec. Too loose will cause a vacuum leak. Too tight could strip the threads. The torque spec for that is 8-11 Nm. Hi Carla... You had mentioned this in a previous note, but thanks again for your reply! I did check the rubber around the connector and it was wet with oil, but did clean it up and make sure no oil was in physical contact with the connection. Link to comment Share on other sites More sharing options...
Ion Posted March 2, 2010 Author Report Share Posted March 2, 2010 Nice that you fixed it but I don't see how a leaking case half would get oil up into the manifold? Perhaps someone can explain to me how oil residue ended up on the MAP nozzle? If they can, maybe the answer can once and for all, solve this endless drama... TRY READING MY POST #17 ABOVE, I ANSWERED YOUR QUESTION My bad...thanks for the explanation. BTW...My condescention is not directed at you or anyone else on the boards as I directly referenced local "experts", meaning in my town...not anyone here. Good day... Link to comment Share on other sites More sharing options...
BodybyFisher Posted March 2, 2010 Report Share Posted March 2, 2010 No problem, we are here to help, bounce stuff off of us BEFORE running to those experts. Keep in mind that we are only as good as you. This is a give and take. We are diagnosing the problem based on YOUR input and YOUR experiences with the car. The better our interaction the more likely we can help you. You didnt answer my question, were the EGR Phenolic spacers and mouse holes cleaned? Was any work done on the ISC motor (Idle Speed Control)? Responding to questions helps us help you Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
CarlaValentine Posted March 2, 2010 Report Share Posted March 2, 2010 On the 94 Northstar, it is perfectly normal for oil to get under the manifold cover. There's really no point in trying to clean it all up because it will just come back. Why it happens, I don't know for certain, but I have been reassured that it's nothing to worry about. In my case with MAP sensor issues, it was a matter of fixing a bare wire, and replacing the sensor. When the sensor was replaced however, I noticed that the rubber seal inside the electrical connector on the sensor had deteriorated and stuck it self to the sensor, allowing oil to get into the connector. I cleaned the connector and replaced the seal when I changed the sensor and have had no problems since. If you start having problems again, check that rubber seal to be sure it is keeping oil out of the connector as it is supposed to. From what I have read and heard the oil can cause a problem with the current in the connection and lead to the MAP not working properly. It is also important to torque the manifold cover bolts to the proper spec. Too loose will cause a vacuum leak. Too tight could strip the threads. The torque spec for that is 8-11 Nm. Hi Carla... You had mentioned this in a previous note, but thanks again for your reply! I did check the rubber around the connector and it was wet with oil, but did clean it up and make sure no oil was in physical contact with the connection. I hope you have cured your problem. I know how frustrating it was for me when I couldn't figure out why my car was stalling. It happened at a stop, accelerating, and sometimes would be fine for days before it started acting up again. There was never a pattern to it, or a common factor in play every time it happened. I spent about 250$ in parts and 30 hours or so under the hood of my car in the freezing cold before I finally got the problem solved. My biggest issue was that the computer never set a code for the MAP sensor until about a month after it started happening, so I had no idea that was the problem at first. I noticed in a prior post that you mentioned your RPM's at an idle are 850-900. That's a bit high. I agree with BodyByFisher that you should have your ISC (Idle Speed Control) motor checked out. That would be a typical idle speed at a cold start, but it should drop to around 500-600 rpm's once the engine warms up. I also had a high idle problem, right before my MAP sensor failed. (not saying they were related, but it's possible). My idle was much higher than that though, averaging 2,000 rpm's at rest. It got to a point where my car would actually drive itself, and stopping was a struggle. I took my ISC motor apart, cleaned the contacts, re-greased the gears, and it solved the high idle problem entirely. Link to comment Share on other sites More sharing options...
Ion Posted March 2, 2010 Author Report Share Posted March 2, 2010 I have not touched the ISC...is it on or around the throttle body? Link to comment Share on other sites More sharing options...
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