revolcallidac Posted February 27, 2006 Report Share Posted February 27, 2006 I did a search and can't find anything, so here goes... my son's 97 Deville has 106,000 miles on it, and has been doing well...until today. He said while he was driving, he heard a clunk, then felt like the car was losing power, no warning lights or anything showed up, then under acceleration, it felt like the engine was shuddering. He made it home, mpg's didn't change, says it only does it under hard acceleration. Motor mount? I'm not that savvy on diagnosing, so I posted here for him. Ever run into this anywhere else? Says it feels like the engine is about to fall out, but as far as "running" says it runs fine. Link to comment Share on other sites More sharing options...
chazglenn3 Posted February 27, 2006 Report Share Posted February 27, 2006 Sounds like a motor mount to me...maybe one of the "dog bones" at the top front of the engine? Charles Charles Link to comment Share on other sites More sharing options...
revolcallidac Posted February 27, 2006 Author Report Share Posted February 27, 2006 I hope that's all it is. Up to now, he hasn't had any symptoms or problems. Doesn't even leak oil. Link to comment Share on other sites More sharing options...
KHE Posted February 27, 2006 Report Share Posted February 27, 2006 I would verify the fuel pressure under acceleration. If that is OK, then pull the spark plugs and inspect them to make sure the platinum pads on the ground electrodes are not missing. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
WarrenJ Posted February 27, 2006 Report Share Posted February 27, 2006 Seat yourself comfortably in the driver's seat and read the diagnostic trouble codes stored in the car's computer. This site will help you if a trouble code is stored: http://myweb.accessus.net/~090/toc.html#cad Regards, Warren P.S. Post back here with any questions. You'll find lots of help. P.P.S. Oh yeah, WELCOME! There is no means of avoiding the final collapse of a boom brought about by credit expansion. The alternative is only whether the crisis should come sooner as the result of a voluntary abandonment of further credit expansion, or later as a final and total catastrophe of the currency system involved. - Ludwig von Mises Link to comment Share on other sites More sharing options...
revolcallidac Posted February 28, 2006 Author Report Share Posted February 28, 2006 He had the codes read today and there were none. After reading Jason Adcock's experience with spark plugs we are thinking that is probably the culprit. We're going to check them out in the next day or so. Trans fluid is nice and pink, that was checked out today by Mr. Transmission, said it wasn't the problem. I've done spark plugs before on other cars, anything major to watch out for if we have to change these? I know NOT to put anti-seize on them...use AC plugs and wires, torque to 11ft/lbs and retorque a couple days later (read that on here). thanks Link to comment Share on other sites More sharing options...
WarrenJ Posted February 28, 2006 Report Share Posted February 28, 2006 Don't forget to let us know how this turns out. Afterall, that's how this community learns. Regards, Warren There is no means of avoiding the final collapse of a boom brought about by credit expansion. The alternative is only whether the crisis should come sooner as the result of a voluntary abandonment of further credit expansion, or later as a final and total catastrophe of the currency system involved. - Ludwig von Mises Link to comment Share on other sites More sharing options...
revolcallidac Posted March 1, 2006 Author Report Share Posted March 1, 2006 update....today, he called me while driving up a hill....spitting, sputtering, finally SES light came on. We'll read it tomorrow...I really believe it's the plugs or wires, just like JasonA's. Link to comment Share on other sites More sharing options...
revolcallidac Posted March 2, 2006 Author Report Share Posted March 2, 2006 Codes are P063 and P0300 ride control...don't know why that's set. and Misfire...according to this site. This is such a good resource to turn to. Link to comment Share on other sites More sharing options...
revolcallidac Posted March 3, 2006 Author Report Share Posted March 3, 2006 The link someone gave me above was great info on how to access the self diagnostics...however, it does not tell how to clear them. Link to comment Share on other sites More sharing options...
jhall Posted March 3, 2006 Report Share Posted March 3, 2006 Check the wire condition at night to see if any arcing is occuring off the wires. Some "glow" around the wires is OK, but strong arcs are a definate problem. Goose the throttle to see if anything shows up. If no trouble with the wires, pull the plugs. Check to see that the electrodes are OK and look for signs of flashover on the ceramic insulator that is covered by the spark plug boot. Flashover leaves black residue that appears to be a thin sooty deposit on the spark plug ceramic insulator, but black cracks can also appear in the ceramic - an obvious failure. If this shows up, change the wires and the plugs (wires can be a bit pricey > $100). Once this is checked out, clear the codes and drive it. If the ride control issue is real, it will pop back up again. Good luck! Link to comment Share on other sites More sharing options...
Ranger Posted March 3, 2006 Report Share Posted March 3, 2006 See JimD's post in this link. http://caddyinfo.ipbhost.com/index.php?showtopic=5515&hl= Link to comment Share on other sites More sharing options...
revolcallidac Posted March 3, 2006 Author Report Share Posted March 3, 2006 Check the wire condition at night to see if any arcing is occuring off the wires. Some "glow" around the wires is OK, but strong arcs are a definate problem. Goose the throttle to see if anything shows up. If no trouble with the wires, pull the plugs. Check to see that the electrodes are OK and look for signs of flashover on the ceramic insulator that is covered by the spark plug boot. Flashover leaves black residue that appears to be a thin sooty deposit on the spark plug ceramic insulator, but black cracks can also appear in the ceramic - an obvious failure. If this shows up, change the wires and the plugs (wires can be a bit pricey > $100). Once this is checked out, clear the codes and drive it. If the ride control issue is real, it will pop back up again. Good luck! WELL....I can't see down in the plug holes, however, there is arcing...especially at the #8 cylinder wire...I can hear it and see it...some more at #7...where they exit from under the engine cover. I really don't want to have to tackle this job. I'm not that savvy on doing this stuff, but I'm better at it than my son is. If he touches it, it will explode I just might have to spot him the money to have it done somewhere else besides my garage. His gas mileage has gone down now with the SES light on...he said it flashed at him a couple times....I know that can be detrimental to the catalytic converter if he drives it much more without having it fixed. On a different note, it looks as though the plugs on this car are pretty easy to reach from above. I've had to change on previous cars where I had to get underneath and reach up to get the back bank. Link to comment Share on other sites More sharing options...
Ranger Posted March 3, 2006 Report Share Posted March 3, 2006 Plugs are very easy to get at. Just remove the strut cross brace, then the ICM and set it aside after you pull the plug wires. Be advised when you do, there are 2 hidden bolts on the back side that you have to use the braile method to remove. Don't drop them. After that, the rear plugs are a straight shot. Link to comment Share on other sites More sharing options...
jhall Posted March 3, 2006 Report Share Posted March 3, 2006 As ranger said, changing the plugs and wires is pretty simple. The plugs on the firewall side of the engine require you to lean over the fender a bit and look at the spark plug location, but otherwise they are easy to reach with an extension on the ratchet. As Ranger indicated, removing the ignition module from its mount is a big help in getting to the plugs and removing / installing each wire. I've done this work without removing the cross brace, but it is easy to remove if you really want it out of the way. When changing the wires, replace one at a time so nothing gets crossed up and you get the correct lengths. Keep us posted! Link to comment Share on other sites More sharing options...
revolcallidac Posted March 3, 2006 Author Report Share Posted March 3, 2006 Cadillac wants $550 to do this! I guess I'll be doing it for him.... Do we need to disconnect the battery for any of this? Just want to do it right. Thanks for all the help so far. Link to comment Share on other sites More sharing options...
Ranger Posted March 3, 2006 Report Share Posted March 3, 2006 No need to disconnect the battery. Don't do it FOR him. Show him how. Next time he'll be able to do it himself and someday you'll need him to do yours for you. Now there's a scary thought, right. "Give a man a fish and you feed him for a day. Teach him to fish and you feed him for life. " Link to comment Share on other sites More sharing options...
revolcallidac Posted March 4, 2006 Author Report Share Posted March 4, 2006 You are so right! Link to comment Share on other sites More sharing options...
revolcallidac Posted March 5, 2006 Author Report Share Posted March 5, 2006 WELL.....everything's changed out. Old plugs looked bad. Runs ok, going out for a test drive in a minute. No fireworks under the hood anymore. But....I know how to pull up the codes...but how do you clear them? PCM codes still in the computer. My manual doesn't tell how either. thanks for all the help so far...I hope this takes care of tehe problem Link to comment Share on other sites More sharing options...
Ranger Posted March 5, 2006 Report Share Posted March 5, 2006 But....I know how to pull up the codes...but how do you clear them? After the codes are displayed you should see "PCM?". That is asking if you want to enter the PCM mode. Answer no (HI FAN = yes, LOW FAN = no) to the prompts til you see CLEAR PCM CODES? or CLEAR ALL CODES (I forget which), then answer yes. Link to comment Share on other sites More sharing options...
revolcallidac Posted March 5, 2006 Author Report Share Posted March 5, 2006 I was tinkering with it after I wrote that last note and I managed to clear them. I wasn't sure how I did it, but they went away and the SES light went off. I gunned it down the bypass......next thing I knew, that front end jumped up in my face and before I knew it we were going 85! No lights flickering at all. Checked the codes again when I got home, nothing. So far, So good! Thanks a lot!!!!!!!!!!!!!!!!! Link to comment Share on other sites More sharing options...
revolcallidac Posted March 5, 2006 Author Report Share Posted March 5, 2006 by the way, I was able to get the rear bank without removing the coil pack. Wasn't easy, but being tall, I was able to lean way in and see everything. My boy got a good lesson in auto repair and maintenance. Hopefully he will use it sometime. Boy, my back sure does ache! But, this was a lot easier than my 4.9 Deville I had 10 years ago. As little as I drive now, my new DTS will probably be traded before I have to do the plugs on it. Link to comment Share on other sites More sharing options...
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