STS Scott Posted October 6, 2005 Report Share Posted October 6, 2005 My Catalytic Converter is rattling like a pop can again...and I just spent a few hundred bucks last August to replace the old one with the same symptoms! The exhaust has a very rich smell to it, which I never thought 'that' much of until now! I am assuming that would be the cause of the Cats. accelerated wear, but what could be the cause of the rich burning of fuel? The plugs and wires were replaced last year, with a faulty #2 spark plug caught and replaced as well. I was told to run a thicker oil (20W-50) due to the mileage (199999 MI), and that would seal up the rings, and prevent oil from burning off... but I don't notice excessive oil burning symptoms... the level stays consisent with other Northstars oil consumption rates, and I have never noticed 'blue oil smoke'. I know other things could cause it to run rich, like and EGR valve, injectors, etc... but where would be a good place to start troubleshooting? Thanks for a hand! I don't want to go about replacing the Cat. again, if I don't get this condition fixed first! Thanks again. " ...'took my Cobra down t' the track, hitched to the back o' my Cadillac..." - Jan & Dean, 'hey little cobra' Scott Link to comment Share on other sites More sharing options...
Ranger Posted October 6, 2005 Report Share Posted October 6, 2005 Most likely cause is a bad FPR. Link to comment Share on other sites More sharing options...
JasonA Posted October 6, 2005 Report Share Posted October 6, 2005 I was told to run a thicker oil (20W-50) due to the mileage (199999 MI), and that would seal up the rings, and prevent oil from burning off... but I don't notice excessive oil burning symptoms... the level stays consisent with other Northstars oil consumption rates, and I have never noticed 'blue oil smoke'. I'm not sure on the other stuff, but I wouldn't be putting 20W-50 in that engine...way too thick. Who told you that? At the THICKEST, I might put in 15W-40, but 10W-30 should be good. If you don't notice any additional oil usage with 10W-30, I don't see what you'd be gaining (besides poorer economy) with a much thicker oil. Mine is knocking on the 150k mile door and I've always ran Valvoline or Pennzoil 10W-30 in it. 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...
Bruce Nunnally Posted October 6, 2005 Report Share Posted October 6, 2005 Good time to change oxygen sensors also? Bruce 2023 Cadillac CT4-V Blackwing Follow me on: Twitter Instagram Youtube Link to comment Share on other sites More sharing options...
Regis Posted October 6, 2005 Report Share Posted October 6, 2005 I was told to run a thicker oil (20W-50) due to the mileage (199999 MI), and that would seal up the rings, and prevent oil from burning off... but I don't notice excessive oil burning symptoms... the level stays consisent with other Northstars oil consumption rates, and I have never noticed 'blue oil smoke'. Wow! I'm just about to roll 220,000 miles and I'm still running 10W-30 with no problems. People will tell you lots of things that "You should Do" but when in doubt default to your manual or even here. I think the person that recommended that you put 20W-50 in also would like to sell you a new engine in the near future. The cold start ups are going to be killers with that heavy of an oil. I would drain and refill with 10W-30 asap before the weather really gets cold. And if it matters I use Pennzoil..... and just the regular stuff, not the high mileage formula. Why bother when I'm topping off with fresh oil regularly right? "Burns" rubber " I've never considered myself to be all that conservative, but it seems the more liberal some people get the more conservative I become. " Link to comment Share on other sites More sharing options...
Scotty Posted October 6, 2005 Report Share Posted October 6, 2005 With the cold weather coming I just changed my oil today and used 5W30 Link to comment Share on other sites More sharing options...
Dadillac Posted October 6, 2005 Report Share Posted October 6, 2005 Hell I run 20w50 in my Harley. It is an air cooled engine, which gets much hotter than a liquid cooled engine. The oil is sprayed at the bottom of the pistons, to aid in cooling the engine. When the oil is hot, it is still plenty thick. Using 20w50 in a liquid cooled engine, without the ehat to thin it out, would be devestating. It is way too thick. I would not recommend it. Don "Modern warriors saddle iron horses of chrome." Link to comment Share on other sites More sharing options...
bigjayzway Posted October 6, 2005 Report Share Posted October 6, 2005 I have seen people add 20w50 to their oil(10w30) to thicken it up, but to run it straight will be NO good for the engine. When it gets cold, it will be as thick as corn syrup, and will be hard to start, and your milage will plumitt. Big Jay Life is too short to grow up! Link to comment Share on other sites More sharing options...
JasonA Posted October 6, 2005 Report Share Posted October 6, 2005 And if it matters I use Pennzoil..... and just the regular stuff, not the high mileage formula. Why bother when I'm topping off with fresh oil regularly right? kger2, are you topping off due to internal consumption or an external leak? Depending on the severity of the leak, the High Mileage forumla may help swell it up. The bottom of my oil pan is much drier when using Pennzoil High Mileage, and oil consumption hasn't increased at all. It's about a quart every 3000 miles or so. 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...
STS Scott Posted October 6, 2005 Author Report Share Posted October 6, 2005 Most likely cause is a bad FPR. Ranger, FPR: Fuel Pressure Regulator? Thanks for the help guys, I'll take care of the oil ASAP. I hindsight you're all right. I have always trusted the 10W-30 too, but I figured "well, it is getting old and tired". " ...'took my Cobra down t' the track, hitched to the back o' my Cadillac..." - Jan & Dean, 'hey little cobra' Scott Link to comment Share on other sites More sharing options...
Scotty Posted October 6, 2005 Report Share Posted October 6, 2005 You kind of answered your own question with the running RICH comment. Like everyone said, it could be a bad FPR (fuel pressure regulator) or a leaking injector. What is your average gas mileage per gallon? The excess fuel probably caused the CAT to go again I recall the GURU stating that 20W50 is very bad for the NS, get it out ASAP. Try the high mileage oils. The thick stuff may indeed stop leakage and burning BUT at what cost, damaged bearings? In the future when someone suggests something, run it by the board before acting on it to be safe, there are too many "off the cuff" idiots out there Link to comment Share on other sites More sharing options...
etcxtc Posted October 6, 2005 Report Share Posted October 6, 2005 I recall the GURU stating ... I'm very curious as to whom the "Guru" was and what happened to him. Link to comment Share on other sites More sharing options...
Scotty Posted October 6, 2005 Report Share Posted October 6, 2005 I recall the GURU stating ... I'm very curious as to whom the "Guru" was and what happened to him. This individual helped design the Northstar and was a genious. That is all that I can tell you, if I tell you anymore, I will have to hunt you down and wipe out your memory ... Fortunately his genious has been preserved with some of the individuals on this site, but he will NEVER be replaced and ALWAYS will be missed.... Now look at my neuralyzer, that "flashy-thing" used by the Men in Black to erase the short-term memory of those innocent citizens who inadvertantly come into contact with aliens and count to three! Link to comment Share on other sites More sharing options...
anengineer Posted October 9, 2005 Report Share Posted October 9, 2005 ....... I know other things could cause it to run rich, like and EGR valve, injectors, etc... but where would be a good place to start troubleshooting? ....... As previously mentioned by our host, check or change the oxygen sensors. One fouled on me. Engine ran rich and rough, mpg dropped. Any codes? Link to comment Share on other sites More sharing options...
Regis Posted October 9, 2005 Report Share Posted October 9, 2005 kger2, are you topping off due to internal consumption or an external leak? Depending on the severity of the leak, the High Mileage forumla may help swell it up. The bottom of my oil pan is much drier when using Pennzoil High Mileage, and oil consumption hasn't increased at all. It's about a quart every 3000 miles or so. Hi Jason, For me it's about 1 qt per 1000 miles. It's always been that way since day one. I'm told it's the chronic half seal leak. I say "about 1 qt per 1000 miles" because it's dependent on my driving style. If I go out and do the romp and stomp driving style, similair to how one would drive to decarbon the engine then my oil consumption increases. If I exercise a more moderate to conservative driving style then my oil consumption is very low. And I have noticed that if I keep the oil level just below the Full line on the dip stick then my consumption is even less. I've tried the high mileage oils before. I personally couldn't notice enough difference to justify the price difference. The few mechanics that have touched my car seam to share the same opinion as myself. If the high mileage oil makes a big difference then the common belief would be that something needs addessing or fixing. But.......if price wasn't an object I'd be using the high mileage oil all the time Jason. Had to throw you a bone. "Burns" rubber " I've never considered myself to be all that conservative, but it seems the more liberal some people get the more conservative I become. " Link to comment Share on other sites More sharing options...
JasonA Posted October 9, 2005 Report Share Posted October 9, 2005 For me it's about 1 qt per 1000 miles. It's always been that way since day one. I'm told it's the chronic half seal leak. I say "about 1 qt per 1000 miles" because it's dependent on my driving style. If I go out and do the romp and stomp driving style, similair to how one would drive to decarbon the engine then my oil consumption increases. If I exercise a more moderate to conservative driving style then my oil consumption is very low. And I have noticed that if I keep the oil level just below the Full line on the dip stick then my consumption is even less. Exact same model here. The harder I drive it, the more oil it uses. Makes sense...GURU said before that in general, oil consumption will be a function of engine speed (as long as the rings haven't failed). The more engine revolutions you see, the more oil will be burned...at an infinetessimal rate, but it adds up over a few thousand miles. In fact the quickest I ever burned two quarts of oil was in two weeks. The two weeks I had my K&N cone on the car. Don't ask, don't tell. Now that I've been generally driving much more conservatively, not only has my gas mileage gone up over 20 mpg in stop-n-go (using 89 octane), but I'm down to adding only about a quart of oil over the 4000-6000 mile oil change interval. I think the oil pan gasket is just a bit seepy on mine. The case-half seal looks dry, but the oil pan is unusually wet all the time. It'll drip 1-2 droplets overnight. With high mileage oil, I've seen that decrease a little bit. However, looking at Pennzoil's spec sheets for their HM oil, even the HM 5W-30 is thicker than their standard 10W-30. I'm running the HM 10W-30, which is thicker still. None of the HM oils achieve the "Energy Conserving" status on the API symbol. This next oil change (currently at about 63% after almost 2000 miles), I'm going to switch back to the all climate Pennzoil 10W-30 (which is an Energy Conserving SM oil) and watch my mileage go up. It's already gone up over 20 due to the cooler weather and not running the A/C much. My goal is to hit 22 mpg sometime this fall during my normal commute. 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...
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