Hello everyone! I am the newest owner of a 1995 Cadillac Deville Concours. I purchased the car from a friend of the family because I needed wheels fast and payments low and infrequent. Whether or not I lucked into a good deal remains to be seen. Despite a multitude of problems, I really appreciate the engineering that has gone into this car and I'm definitly going to consider keeping this one long term or at least buying a similar model. Purchasing new might be an option, but I don't know if the newer models live up to the class that this car has.
I could use some help solving some problems at the moment. I haven't been able to purchase a set up factory manuals yet, and the off-the-shelf books available locally and in the public library are too vague and general in nature.
Question 1: I keep getting an intermittent CEL, decoding as left and right cylinder banks running too rich. The light comes on and stays on for a day or two, then goes out while driving and stays out for a day or two. The seller had just put in platinum plugs, and when I pulled them out to inspect them, six of the eight had the light black fluffy fouling on them. I pulled spark plug wires from the coils one at a time with the engine running, and I believe I have one weak coil but the rest are firing great. The engine burns a little oil, but not a significant amount... not enough to be seen in the exhaust when idleing. On to my question: I noted somewhere in the internet that the PCM has an octane selection. Without a manual I can't elaborate, just read that the octane level is either 87, 90 or 93. I'm wondering if this is selectable and if so maybe a previous owner had it 'detuned' for regular gas and since I'm putting in premium it is too rich of a mixture.
Question 2: I also get the message that the traction control is disabled, and again, it comes and goes but mostly stays on. Is the switch in the glove box supposed to be a momentary push button, or should it 'click' with a definitive on and off position? You can push on mine, but it has no effect on the message whether or not the traction control message has been displayed or not, leading me to believe that perhaps the button in the glove box is bad.
Question 3: The car surges at low or idle speeds, and this can cause quite a panic when pulling up behind someone at a stoplight and the car suddenly wants to speed up. It's as if the PCM is searching for a good idle speed or compensating for something to keep the engine from dying. The normal idle speed is adequate, probably around 700 to 800 rpm. I want to say that I suspect a bad idle control solenoid, but don't want to start throwing money into shadetree troubleshooting since money is scare at the moment. Could this be related to question #1?
Question 4: The left turn signal flashes extremely fast. All the bulbs in the circuit are functioning correctly, and I'm wondering if either one of the bulbs is of the wrong wattage rating, acting almost like a short, or if the flasher (or might it be flashers) is weak and needs replacment. As with most of the other problems I have been experiencing, this one fixed itself temporarily (for a few days) and then came back.
Question 5: When cold, the engine starts right up. When warm, it is hard to start about 3/4 of the time, taking up to 10 seconds of cranking to get going. It happend even after I cleaned all the plugs off. To date, I've changed the fuel filter and air filter, ran a couple of cans of fuel injector cleaner and gas dryer through the tank, and sprayed some carb cleaner down her throat. I gave the engine a good high pressure bath, and highly suspect that this caused a lot of my temporary problems although that was two weeks ago and some of them are still haunting me.
On the good side, according to the on board computer, I'm averaging 25 mpg when I drive carefully. Recently the engine started sputtering and even backfired a few times, and the mileage when south accordingly. I think I just got a bad tankful of gas, as it went away on its own and has been running smoothly for several days now.
So in a nutshell: Fouling plugs, hard warm starting, intermittent PCM code indicating rich fuel mixture, wandering low speed idle. Magic pill/sensor, or just needs a LOT of TLC.
BTW, if anyone has a set of factory manuals for a '95 Concours they'd wish to part with at a reasonable price, let me know. I had a set scoped out on eBay, but a sniper got them at the last possible second. I'm also in the market for a factory wheel for this car, apparently quite rare, for use as a spare tire which I do not have at the moment.
I could use some help solving some problems at the moment. I haven't been able to purchase a set up factory manuals yet, and the off-the-shelf books available locally and in the public library are too vague and general in nature.
Question 1: I keep getting an intermittent CEL, decoding as left and right cylinder banks running too rich. The light comes on and stays on for a day or two, then goes out while driving and stays out for a day or two. The seller had just put in platinum plugs, and when I pulled them out to inspect them, six of the eight had the light black fluffy fouling on them. I pulled spark plug wires from the coils one at a time with the engine running, and I believe I have one weak coil but the rest are firing great. The engine burns a little oil, but not a significant amount... not enough to be seen in the exhaust when idleing. On to my question: I noted somewhere in the internet that the PCM has an octane selection. Without a manual I can't elaborate, just read that the octane level is either 87, 90 or 93. I'm wondering if this is selectable and if so maybe a previous owner had it 'detuned' for regular gas and since I'm putting in premium it is too rich of a mixture.
Question 2: I also get the message that the traction control is disabled, and again, it comes and goes but mostly stays on. Is the switch in the glove box supposed to be a momentary push button, or should it 'click' with a definitive on and off position? You can push on mine, but it has no effect on the message whether or not the traction control message has been displayed or not, leading me to believe that perhaps the button in the glove box is bad.
Question 3: The car surges at low or idle speeds, and this can cause quite a panic when pulling up behind someone at a stoplight and the car suddenly wants to speed up. It's as if the PCM is searching for a good idle speed or compensating for something to keep the engine from dying. The normal idle speed is adequate, probably around 700 to 800 rpm. I want to say that I suspect a bad idle control solenoid, but don't want to start throwing money into shadetree troubleshooting since money is scare at the moment. Could this be related to question #1?
Question 4: The left turn signal flashes extremely fast. All the bulbs in the circuit are functioning correctly, and I'm wondering if either one of the bulbs is of the wrong wattage rating, acting almost like a short, or if the flasher (or might it be flashers) is weak and needs replacment. As with most of the other problems I have been experiencing, this one fixed itself temporarily (for a few days) and then came back.
Question 5: When cold, the engine starts right up. When warm, it is hard to start about 3/4 of the time, taking up to 10 seconds of cranking to get going. It happend even after I cleaned all the plugs off. To date, I've changed the fuel filter and air filter, ran a couple of cans of fuel injector cleaner and gas dryer through the tank, and sprayed some carb cleaner down her throat. I gave the engine a good high pressure bath, and highly suspect that this caused a lot of my temporary problems although that was two weeks ago and some of them are still haunting me.
On the good side, according to the on board computer, I'm averaging 25 mpg when I drive carefully. Recently the engine started sputtering and even backfired a few times, and the mileage when south accordingly. I think I just got a bad tankful of gas, as it went away on its own and has been running smoothly for several days now.
So in a nutshell: Fouling plugs, hard warm starting, intermittent PCM code indicating rich fuel mixture, wandering low speed idle. Magic pill/sensor, or just needs a LOT of TLC.
BTW, if anyone has a set of factory manuals for a '95 Concours they'd wish to part with at a reasonable price, let me know. I had a set scoped out on eBay, but a sniper got them at the last possible second. I'm also in the market for a factory wheel for this car, apparently quite rare, for use as a spare tire which I do not have at the moment.