Adam -
1. :welcome:
2. Shudder at idle - usually carbon buildup around the throttle plate or around the idle plunger - check out the Northstar and Tech Tips forum for write-ups on removing and make sure you use throttle body cleaner and not carb cleaner - different chemicals. This also could be caused by a vacuum leak - perhaps a cracked plenum.
3. Hesitation - See #2 or perhaps a busted front motor mount.
4. Don't get creative performing your tune-up. Use only OEM plugs, AC Delco part 41987 - One of the vendors on the right --> or Rock Auto
5. If you do not have proof of coolant change in the last 2 years you will need to do this very soon - drain and fill - no need to flush - search this site for info on coolant sealant tabs. Use the same coolant to fill that you drain - 50/50 mix using distilled water. Change every 2 years thereafter.
6. No need for synthetic oil - 5W30 of your favorite - use the built in oil life monitor to determine interval - Go way to the top of this page and read the Cadillac Technical Archive.
7. Vibration at highways speeds - I've never had this problem - some say bad tires, bad balance, etc. Try just rotating your tires and see if that fixes / changes the problem.
8. Just about anything is available from a search of this site. Tip: I use Google to search the site as the internal search engine has some limitations. Go to a google search box and type site:cadillacforums.com XXXXX where XXXXX is your search term, e.g. site:cadillacforums.com cracked plenum
1. :welcome:
2. Shudder at idle - usually carbon buildup around the throttle plate or around the idle plunger - check out the Northstar and Tech Tips forum for write-ups on removing and make sure you use throttle body cleaner and not carb cleaner - different chemicals. This also could be caused by a vacuum leak - perhaps a cracked plenum.
3. Hesitation - See #2 or perhaps a busted front motor mount.
4. Don't get creative performing your tune-up. Use only OEM plugs, AC Delco part 41987 - One of the vendors on the right --> or Rock Auto
5. If you do not have proof of coolant change in the last 2 years you will need to do this very soon - drain and fill - no need to flush - search this site for info on coolant sealant tabs. Use the same coolant to fill that you drain - 50/50 mix using distilled water. Change every 2 years thereafter.
6. No need for synthetic oil - 5W30 of your favorite - use the built in oil life monitor to determine interval - Go way to the top of this page and read the Cadillac Technical Archive.
7. Vibration at highways speeds - I've never had this problem - some say bad tires, bad balance, etc. Try just rotating your tires and see if that fixes / changes the problem.
8. Just about anything is available from a search of this site. Tip: I use Google to search the site as the internal search engine has some limitations. Go to a google search box and type site:cadillacforums.com XXXXX where XXXXX is your search term, e.g. site:cadillacforums.com cracked plenum
but with that you can spray mostly everything with carb cleaner, it's a little less sensitive..haha
