95SevilleSLS Posted March 7, 2007 Author Report Share Posted March 7, 2007 Thanks for the info! Another thing I forgot to add is that the spark plug was EXTREMLY tight. I thought they weren't supposed be very tight due to possibly ruining the heads. -Dusty- - 02 Seville STS, white diamond - 93 Sixty Special, Tan with vinyl top - 79 Coupe DeVille, Tan with Tan top - 06 GMC Sierra Z71, Black - 92 Silverado C1500, black and grey - 83 Chevy K10 Silverado, Black and Grey Link to comment Share on other sites More sharing options...
OynxSTS Posted March 8, 2007 Report Share Posted March 8, 2007 Another thought... My 02 was getting terrible performance and lousy mileage too... Are there any codes? 2002 was not a good year at GM for catalytic converters... Mine failed at 60,000 miles. Does the car haul? try driving it hard... The performance should be in the category of "fun" If it is ho-hum... take a close look at the Cat. Easin' down the highway in a new Cadillac, I had a fine fox in front, I had three more in the back ZZTOP, I'm Bad I'm Nationwide Greg Link to comment Share on other sites More sharing options...
BodybyFisher Posted March 8, 2007 Report Share Posted March 8, 2007 Good point Greg, as you know my wife's 2002 Monte Carlo had a bad CAT, they had a run of bad CATs in 2002... One thing about the AC DELCO plugs, you say your Denso plugs were really tight. This was once posted by 'the guru' he was a GM powertrain engineer for the Northstar: "The OEM AC DELCO spark plugs for the Northstar have nickel plated threads on the shell to minimize the chances of "galvanic corrosion" between the dissimilar metals causing a problem. Plugs rarely give a problem quite honestly. Most problems experienced in removing plugs occur due to overtorqueing the plugs at the last installation". Here is more info on spark plugs: The following information was originally sent to all General Motors dealers as a DCS message on October 14, 1999: It has come to our attention that some GM dealers sell a customer service to remove Platinum tipped spark plugs and clean the threads at regular intervals to prevent the seizure of the spark plugs in the cylinder heads at high mileage. Platinum tipped spark plugs are designed to operate under normal vehicle operating conditions for up to 100,000 miles (160,000 kms) without periodic maintenance. When no engine performance concerns are present, platinum tipped spark plugs should not be removed for periodic inspection and cleaning of threads, doing so would compromise the spark plugs ability to withstand their corrosive environment. The threaded area, although not sealed, serves as a protective environment against most harmful elements. Removing and cleaning spark plugs will introduce metallic debris and brush scrapings into the thread area which may further the corrosion process. Chromate coated spark plugs should not be wire brushed or handled in any way once they are put in service. Chromium topcoats form a protective oxide on spark plugs that is not effective if scratched. Both coated and uncoated spark plugs will have the best chance of surviving a corrosive environment if they are left in position. Attempts to maintain spark plugs by removing them and cleaning the threads can actually create the corrosive condition that the procedure was intended to prevent. © Copyright General Motors Corporation. All Rights Reserved 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...
95SevilleSLS Posted March 8, 2007 Author Report Share Posted March 8, 2007 I think it's peforming well. I haven't driven another STS my year, so I don't have anything to compare it to. It will set your head back in the chair, I know that. There was one code, but it was something about the navigation didn't have a disc...not sure what that was about. How else can I check out my cat? I figured those were too tight. I'm going to probably replace them tomorrow. Do you have to do anything special to get to the back plugs? Can I get to them without any special equipment or have to roll the engine forward? -Dusty- - 02 Seville STS, white diamond - 93 Sixty Special, Tan with vinyl top - 79 Coupe DeVille, Tan with Tan top - 06 GMC Sierra Z71, Black - 92 Silverado C1500, black and grey - 83 Chevy K10 Silverado, Black and Grey Link to comment Share on other sites More sharing options...
OynxSTS Posted March 8, 2007 Report Share Posted March 8, 2007 If it goes well it isn't the Cat... a Plug Cat will result in really awful performance... Easin' down the highway in a new Cadillac, I had a fine fox in front, I had three more in the back ZZTOP, I'm Bad I'm Nationwide Greg Link to comment Share on other sites More sharing options...
95SevilleSLS Posted March 8, 2007 Author Report Share Posted March 8, 2007 Do you know of any other signs? Didn't GM extend some warranty for 6 years 100,000 miles or something on the cats? How would I go about replacing them or having it checked without getting charged up the A-hole. -Dusty- - 02 Seville STS, white diamond - 93 Sixty Special, Tan with vinyl top - 79 Coupe DeVille, Tan with Tan top - 06 GMC Sierra Z71, Black - 92 Silverado C1500, black and grey - 83 Chevy K10 Silverado, Black and Grey Link to comment Share on other sites More sharing options...
BodybyFisher Posted March 8, 2007 Report Share Posted March 8, 2007 I believe its 80K miles/5 years See this link: http://caddyinfo.ipbhost.com/index.php?sho...2521&hl=CAT 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...
95SevilleSLS Posted March 8, 2007 Author Report Share Posted March 8, 2007 Well that's not nice...mine just went over that. -Dusty- - 02 Seville STS, white diamond - 93 Sixty Special, Tan with vinyl top - 79 Coupe DeVille, Tan with Tan top - 06 GMC Sierra Z71, Black - 92 Silverado C1500, black and grey - 83 Chevy K10 Silverado, Black and Grey Link to comment Share on other sites More sharing options...
JasonA Posted March 8, 2007 Report Share Posted March 8, 2007 I replaced the spark plugs on my '97 without too much trouble. I didn't have to physically move the engine or anything. I used an electric impact gun to remove the spark plugs. This was recommended by the guru, and I was scared to death to do it, but man it worked like a champ. They all came out nice and clean. I installed the new plugs with with a torque wrench obviously. I haven't touched them yet on my '01. Don't plan to until 100,000 miles or close to it, unless a problem makes me look at them sooner. Your car has one catalytic converter. There's a test they can do that involves installing a backpressure monitor in your exhaust stream (usually into one of the O2 sensor bungs) and run the car. That will tell them if the converter is plugged or providing too much of a restriction. If your converter is bad, replacement isn't that expensive. You can get an aftermarket high-flow cat for less than $200 and have it welded in for not much money. I'm sure GM wants $700-1000 for the converter if you bought one new through a dealership parts department. Jason(2001 STS, White Diamond) "When you turn your car on...does it return the favor?" Link to comment Share on other sites More sharing options...
95SevilleSLS Posted March 8, 2007 Author Report Share Posted March 8, 2007 What are you supposed to torque the spark plugs to? -Dusty- - 02 Seville STS, white diamond - 93 Sixty Special, Tan with vinyl top - 79 Coupe DeVille, Tan with Tan top - 06 GMC Sierra Z71, Black - 92 Silverado C1500, black and grey - 83 Chevy K10 Silverado, Black and Grey Link to comment Share on other sites More sharing options...
BodybyFisher Posted March 8, 2007 Report Share Posted March 8, 2007 What are you supposed to torque the spark plugs to? '98 specifies 11 Lb ft. The '04 specifies 13 - 17 Lb ft. Different plugs (41-987) and coil-on-plug setup I will be back shortly with the '02 spec 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...
95SevilleSLS Posted March 8, 2007 Author Report Share Posted March 8, 2007 I'm guessing it is the 13-17 because I have the coil on plug set up. Just guessing. When did they switch to the coil on plug? That was the coolest thing they have done! -Dusty- - 02 Seville STS, white diamond - 93 Sixty Special, Tan with vinyl top - 79 Coupe DeVille, Tan with Tan top - 06 GMC Sierra Z71, Black - 92 Silverado C1500, black and grey - 83 Chevy K10 Silverado, Black and Grey Link to comment Share on other sites More sharing options...
BodybyFisher Posted March 8, 2007 Report Share Posted March 8, 2007 I just looked in the SI manual and it states: Spark Plug 15 N·m 11 lb ft According to this link that I have been following COP began 2000 another reason why I want a 2000 http://www.cadillacforums.com/forums/north...tar-2000-a.html OK hold the phone! I just checked and there was a bulletin (Document ID# 703556), here is the revised spark plug torque: Tighten the spark plugs between 17-23 N·m (13-17 lb ft). 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...
95SevilleSLS Posted March 8, 2007 Author Report Share Posted March 8, 2007 Thanks! -Dusty- - 02 Seville STS, white diamond - 93 Sixty Special, Tan with vinyl top - 79 Coupe DeVille, Tan with Tan top - 06 GMC Sierra Z71, Black - 92 Silverado C1500, black and grey - 83 Chevy K10 Silverado, Black and Grey Link to comment Share on other sites More sharing options...
clarkz71 Posted March 9, 2007 Report Share Posted March 9, 2007 I doubt if you will find a PCV valve on your engine. Not only does his engine have a PCV valve, but so does both of your cars. Same valve GM has used since the 70's. CV769C. This valve is used on GM cars from the early 70's to 2004 according to AC Delco's website. 2004 CADILLAC DEVILLE DTS V8 4.6L 281cid GAS FI N Engine VIN = 9 Qty Req Qty ACDelco Part# Description EMISSION / PCV VALVE AR CV769C VALVE,PCV STRAIGHT FITTING HIGH FLOW 5.2 CFM 01 CV769C VALVE,PCV Link to comment Share on other sites More sharing options...
JasonA Posted March 9, 2007 Report Share Posted March 9, 2007 That's funny -- my 1984 Olds Cutlass with the Olds V8 took that exact same valve. Jason(2001 STS, White Diamond) "When you turn your car on...does it return the favor?" Link to comment Share on other sites More sharing options...
clarkz71 Posted March 9, 2007 Report Share Posted March 9, 2007 Yeah, I couldn't believe it when I looked at the vehicle list. It was 25 pages long, and said there are 973 cars/engines that take that valve. Link to comment Share on other sites More sharing options...
JimD Posted March 9, 2007 Report Share Posted March 9, 2007 I doubt if you will find a PCV valve on your engine. Not only does his engine have a PCV valve, but so does both of your cars. Same valve GM has used since the 70's. CV769C. This valve is used on GM cars from the early 70's to 2004 according to AC Delco's website. 2004 CADILLAC DEVILLE DTS V8 4.6L 281cid GAS FI N Engine VIN = 9 Qty Req Qty ACDelco Part# Description EMISSION / PCV VALVE AR CV769C VALVE,PCV STRAIGHT FITTING HIGH FLOW 5.2 CFM 01 CV769C VALVE,PCV Not so on the 2004 engine and possibly on the 2000+ engines. ACDelco's application chart is wrong. The left cam cover is plumbed to filtered intake air at the throttle body. The right cam cover is plumbed to intake plenum pressure through a calibrated hole in the cam cover fitting. Jim Drive your car. Use your cell phone. CHOOSE ONE ! Link to comment Share on other sites More sharing options...
clarkz71 Posted March 9, 2007 Report Share Posted March 9, 2007 Well then I guess members with 2000 & up Cadillacs need to check if they have valves. Link to comment Share on other sites More sharing options...
clarkz71 Posted March 9, 2007 Report Share Posted March 9, 2007 OK, after doing some research, all the online auto parts stores list a PCV valve for 2004 DTS. But..... I checked on GM parts direct, and they list 2001 as the last year Cadillac's have a PCV valve. So it appears Jim is correct about the 2002 STS & his 2004 DTS. However 2000 & 2001 cars do have the PCV valve, according to GM. Link to comment Share on other sites More sharing options...
95SevilleSLS Posted March 12, 2007 Author Report Share Posted March 12, 2007 Just changed my spark plugs. Took me about an hour or so. I'll report back if I get any better mileage. I also gave up on trying to lube the steering shaft myself so I took it in last week and it made a HUGE difference. I love it! -Dusty- - 02 Seville STS, white diamond - 93 Sixty Special, Tan with vinyl top - 79 Coupe DeVille, Tan with Tan top - 06 GMC Sierra Z71, Black - 92 Silverado C1500, black and grey - 83 Chevy K10 Silverado, Black and Grey Link to comment Share on other sites More sharing options...
daniel812 Posted March 15, 2007 Report Share Posted March 15, 2007 I just got 15 MPG on my 98 SLS almost all city driving. Link to comment Share on other sites More sharing options...
95SevilleSLS Posted March 15, 2007 Author Report Share Posted March 15, 2007 Is that your average MPG on your DIC? -Dusty- - 02 Seville STS, white diamond - 93 Sixty Special, Tan with vinyl top - 79 Coupe DeVille, Tan with Tan top - 06 GMC Sierra Z71, Black - 92 Silverado C1500, black and grey - 83 Chevy K10 Silverado, Black and Grey Link to comment Share on other sites More sharing options...
kdaddy Posted March 15, 2007 Report Share Posted March 15, 2007 I have never had good gas mileage with any of my caddy's. For example, my 1976 DeVille with the 8.2 liter 500 cubic inch V8 got about 9 miles to the gallon. My 85 DeVille with the 4.1 liter V8 got 16 miles to the gallon. Now I have the 84 Coupe DeVille and a 91 Fleetwood and I don't think either of them will break the 20 miles per gallon mark. But then again you don't drive caddy's for the gas mileage. Link to comment Share on other sites More sharing options...
95SevilleSLS Posted March 15, 2007 Author Report Share Posted March 15, 2007 9 mpg with a 500, that's pretty good. -Dusty- - 02 Seville STS, white diamond - 93 Sixty Special, Tan with vinyl top - 79 Coupe DeVille, Tan with Tan top - 06 GMC Sierra Z71, Black - 92 Silverado C1500, black and grey - 83 Chevy K10 Silverado, Black and Grey Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.