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Everything posted by Luke

  1. I replaced the ISC motor a few weeks ago. It moves very smoothly. I replaced the defective cruise control servo last night. It ran beautifully last night after changing it but chugged all the way to work today. Not sure I’ll have time tonight but tomorrow night, I’ll open the dash and start working with the computer. Hopefully that fixes it. If the computer isn’t the culprit, my last resort before deciding it’s some sort of wiring issue is the catalytic converter. I have a spare one on hand that fits this car. I’ve read quite a bit online where people have had similar issues with 4.9’s but rarely posted a solution. Occasional new distributor or computer is all I found. This is my 4th 4.9 but the first that didn’t run right. It ran right when I picked it up in Las Vegas and the whole trip back to Texas then slowly developed over the past few months.
  2. I actually had a discussion with “the guru” about this years ago. I had a 93 or 94 STS at the time and was considering putting an SLS engine in the car. He actually told me the computer would run the engine fine as the fueling curves were very similar. If you have any trouble with it, have Jake at Northstar Performance do a custom tune for you.
  3. Thanks for the reply. It has been cleaned maybe 4K miles ago. I forgot to mention that the EGR valve has been replaced too.
  4. Hey guys, I have a 92 Seville 4.9 with 107k miles. I bought it in September with 99k. It has gotten to where it will sometimes stall at idle or it will hunt for idle, like 600-1300+ rpm. Sometimes it revs all over the place. Then sometimes it’ll run perfectly smooth all day. It drives perfectly fine on the highway. Maintenance and repairs done since I’ve owned it: Spark plugs, wires, cap, rotor, coil (then later replaced entire distributor), map sensor, throttle position sensor, idle speed control motor, coolant temp sensor, intake air temp sensor, cruise control servo, idler pulleys, belt, battery, radiator, heater core, fuel injectors, fuel filter, fuel pressure regulator, one trans cooler line, new receiver drier and charged AC with R12. Anyone have any Idea what causes the idle issues? The TPS and ISC motor were properly calibrated and idle learn procedure done. The only code is E062 which is a cruise control servo fault. I have a new warranty replacement I need to install. I have the factory service manual. Could the cruise control service cause these issues? Only other thing I can think is that the computer has gone bad. I actually have a new one but wanted to ask if anyone knows what could cause this before I put it in. Can anyone offer any ideas?
  5. I didn't. But I never removed the oil filter adapter. And, after tightening the bolts, it isn't leaking any oil anymore.
  6. Mike, I replaced both oil cooler lines when I bought it because one of them leaked. When it started leaking quite a bit, I looked closely and could see oil bubbling from under the intake manifold under the distributor towards to front of the car. A little forward of the oil filter adapter. Tightening the three manifold bolts on that end stopped that leak. I think just oil splashing under the intake manifold was bubbling out. The problem doesn't appear to be valve seals nor rings. The car never smokes from the exhaust at all. Not on cold start nor ever while running. That's why I'm at such a loss. If there were bad valve seals or rings, not only would it smoke from the exhaust, it would affect power. This is my fourth 4.9 and it has more power than the previous three. It will roast the tires and pulls hard up to full throttle shifts. So, I just can't figure out where the oil is going! Oh, and I did use high mileage 10w30 when I changed it 300 miles ago.
  7. Hey guys, I bought a 92 DeVille a while back for $800 that I'm using as a daily driver. It was more of just a project as I also have a 1980 Seville Limo, 92 Allante, 98 DTS, and 09 STS-V. The DeVille has 151k miles now. After complete tune up, new injectors, and various minor repairs, it runs excellent and has probably better power than other 4.9's I've owned. No drivability issues at all. I'm pretty sure it has an intake gasket leak. MPG is lower than it should be. It was leaking oil which I tracked down to the intake manifold near the distributor. I tightened the intake bolts on that end and the leak stopped. I changed the oil at that time and have not seen any more leaks. That was only 300 miles ago and it has already lost one quart. My question is, can a bad intake gasket cause oil consumption? Is it leaking oil into the combustion chambers internally? None of my previous 4.9's ever burned any oil. With the power it has, I can't imagine the problem is valve guides or rings. I don't really want to put the time and effort into doing intake gaskets unless I think it will fix oil consumption. Anyone have any input?
  8. Yes. That is what the upper intake looks like. I've heard it will fit the 4.9. Would be interesting to see what power the 4.9 would have with that intake. But I think we will repair the existing engine. Hopefully it just needs intake gaskets. But, I'm tempted to replace the head gaskets anyway to avoid problems down the line. Is this overkill? I just don't want to do the intake gaskets and then find the head gaskets are bad and have to take the intake off again.
  9. Sadly, I recently totaled my 2006 DTS. Since I already had my 2008 DTS performance, I used the insurance money to buy a 1992 Allante. It only has 40k miles but I was told it needs head gaskets. The only thing I can think is it sat for so long that the gaskets just rusted out. But, there is a possibility it only needs intake gaskets. According to "the guru" back in the day, the majority of head gasket failures on HT4100's and 4.5's were misdiagnosed intake gasket leaks. I am going to have my mechanic tear into it next week, most likely. I've read very little about 4.9's being direct swaps with the 4.5 which is tempting but would probably rather stick with the existing engine since the Allante 4.5 has aluminum heads and has just as much power as a 4.9. Can anyone offer any advice? Anything specific I need to watch out for? Is there a specific brand of head gaskets I should buy that would be the most reliable and last the longest? I want to make sure and do this right the first time so it will be a reliable car. It will most likely be driven quite a bit once it's running good.
  10. I emailed Gmpartsdirect and the part number for the export license bracket was very close to the US bracket. 25729325. It cost only $13.16 but $15.27 for UPS ground shipping. They said it comes with the screws to attach it to the bumper. I suppose I should invest in some wheel locks as wheels seem to be a hot commodity in Europe. I once saw a Range Rover on cinder blocks in a nice neighborhood in broad daylight in London after the wheels had been stolen. I won't likely drive to London but I'll maybe drive to England once in a while. And I definitely plan to drive it to Germany sometime and test it out on the autobahn! It won't get much for high speed workouts in Ireland. Anyway, after it has the more European look, I'll post some photos.
  11. Thanks for the replies. This will be an interesting project since they never actually exported STS-V's except a few to the Middle East. Bruce, I have actually found a source for the rear fog lamps for $300 for the pair. I'll be ordering them shortly. Jim, the license plate bracket you found is the standard US one. I am looking for the longer EU/UK license plate bracket. Funny thing is that Gmpartsdirect can seem to order any part if you have a part number but only has diagrams for US parts. I came up with a part number for the bracket for the Chinese market and punched it in and it came right up with a price, no problem. If only I could find a part number for the EU bracket, I could order one. Local Cadillac dealer was no help at all.
  12. As the title says, we will be moving to Ireland in the future. Although the steering wheel is on the wrong side, we plan to take our 2009 STS-V with us. I have sorted out tail lights already. I have been unable to find any parts numbers for other parts specific to STS's that were exported to UK/European markets. Does anyone know a part number for a front license plate bracket or where to find one? From what I can tell, UK cars had a piece between the exhaust outlets with the rear fog lights, where the rear grille is on the STS-V. I think I will put some lights behind the rear grille to act as rear fog lights. Anyone know of any other parts that will need to be changed in order to be approved for registration in Ireland? Regulations would be the same as the UK. The STS-V obviously will not be my daily driver as it isn't now. I plan to buy a 2009-2010 Cadillac BLS Turbo Diesel. I wish they would make the ATS in right hand drive! Any idea if Cadillac plans to do so?
  13. Very impressive! I will have to try this on my 2006 DTS headlights. I've polished them numerous times but they do become hazy again quickly. Hopefully this stuff will really last a long time!
  14. All I have been able to figure is that if I drill and tap the hole, I'd have to go up from M8 to M10. That may be too big. So, I found a slightly larger SAE bolt and put it in for now. It has held for about 300 miles and the car is running better than it has in probably 9 months. It has not dinged and no traction control or stabilitrak messages. I ordered an M8-1.25 heli-coil set to fix the holes. I am also replacing the catalytic converter, O2 sensors, and spark plugs. After all that, it should last me a while.
  15. I don't believe it goes all the way through. Only place the metal chips would really go is in the EGR holes. I'll tape over them to be safe and I'll vacuum up afterwards. I'll stop by a parts store today and see what I can find for tools to tap and die. Looking forward to having this all fixed after months!
  16. Hey Bruce, did you ever get around to trying out smaller supercharger pulleys? I am to a point I am starting to consider putting a smaller pulley on my 2009 STS-V. Just wondering what size would be safe yet still yield a good performance boost.
  17. Quick question... would it work best to use a tap and die or tap it and use a heli-coil? The crossover is kind of soft aluminum and I wanna make sure its gonna hold permanently!
  18. Thanks for the info, Logan. But, as it turns out, it's definitely a vacuum leak. On a hunch today, I decided to inspect the (new) EGR valve... the one Sewell Cadillac (<=horrible) charged me $500 to put a new gasket under. As it turns out, when they removed it, one of the bolt holes was stripped. They must have noticed this and put a slightly larger spare bolt in the hole. It may have grabbed a few of the remaining threads and then stripped them out. It was barely finger tight. Wouldn't one think they would have properly rethreaded the hole? If they had, I'd have been happy and they could have kept the $500 they had to refund to me. Anyway, I put a little larger bolt in just to test it. It ran like new!!! No rough idle, no jiggling engine!! I don't plan to drive it this way. I am going to buy the tools I need to rethread the hole and a fitting bolt that can be properly tightened. After I have it all fixed and can drive it some, I will report back as to the success of the repair.
  19. Actually, from what I understand, it's not a software bug. It's programmed that way. Northstars 2000+ do this. At least the front wheel drive ones as far as I know. It's rather common on the 2000-2005 models when the intake plenum eventually develops a tear and causes a vacuum leak. It's not so common on 2006+ models since the plenum was redesigned. I guess I just got lucky. I'm going to replace the plastic tube that runs from that tube in the manifold to the valve cover for good measure. But the tube that's part of the intake manifold is molded in. It's plastic and tough to get to. Not sure how easy it would be to weld plastic. We'll see how long the spray foam insulation stuff will hold. I got a can today. I'll try it out tomorrow and report back how it worked.
  20. I have driven an XTS, ATS, and CTS. The XTS felt massive. And that was after I had driven a 98 DeVille for years! And with the 3.6, performance was lackluster at best. Very underpowered. It's only redeeming quality was the cool gauge cluster. The CTS was okay. My favorite of the three was the ATS. Certainly a different beast but with the turbo 4, performance was surprisingly adequate. I wouldn't mind having one for a grocery getter but to get one optioned the way I am used to, it would cost $50k+. Not really worth it. I was in Ireland last month and rented a Jaguar XF. I was actually very impressed with the quality of the car! The shifter knob that rose out of the console and the AC vents that rotated when the car was started was pretty neat. It certainly wasn't a performance car with the turbo diesel I-4 but performance wasn't too bad and it averaged 44 mpg over the 1645 km that I drove it! We are actually planning to move to Ireland in about 3 years and I'd consider buying one! Although, to save money, I'll likely buy a used BLS turbo diesel. If I decide to go with performance over economy, I'll test out a BLS 2.8t. If they made RHD DTS's, I'd buy one but I don't think they did. Good luck with your Jaguar! I'm sure it's a beautiful car!!
  21. If you search for DeVille, SERVICE TRACTION COBTROL, and P0171/P0174, you'll find that it's quite common to have the suspension/brake messages show up due to vacuum leaks. They never do set suspension codes in these cases. The 00-05 Northstar had an intake plenum design that would eventually tear and cause the messages. Why Cadillac programmed it so these messages show up when lean mixture codes are set, I have no idea. But that's just the way it is. A mechanic friend has a Snapon computer that cost thousands and it'll read any code the car can produce. It has set no suspension or brake codes. He has used it to watch what each wheel speed sensor is doing as I drive and all were correct. Even when the messages started. He has used it to watch a bunch of different parameters involving brakes and suspension on the car and has found nothing wrong. The problem is with the lean condition. I believe what is causing my problem is a crack in the PCV tube sticking out inside the end of the manifold. This requires a new intake manifold since the tube isn't removable. A new one is $500+. I may fill the end with expanding foam insulation to see if it'll fix it temporarily and buy a new intake manifold later. Used ones are cheaper but may have the same problem.
  22. My guess is that it's unlikely it's a valve problem. If that was the case, I am guessing that it would be P0171 OR P0174 rather than both. It is always both codes. But, just in case, I am going to put some Marvel Mystery Oil in the oil to clean the engine out. Maybe something is sticky that it'll free up. Honestly, I don't have a lot invested in parts. I watch ebay closely and snag new OEM parts for cheap before buying them. I am going to get a fuel pressure gauge this weekend and try to rule out the fuel pump. I'll probably go ahead and change spark plugs to and rule that out. At this point, it's an extra car so I am not in a huge hurry to get it going. Although I'll likely start driving it again daily when it's fixed, I am able to take my time and really figure it out.
  23. I forgot the codes. It has only showed P0171 and P0174. When I reset these codes, traction and stabilitrak codes go away. It has had new front hubs/bearings/wheel speed sensors. All wheel speed sensors are running within spec. It does not set any suspension or brake codes. It is common for them to show the SERVICE TRACTION CONTROL and SERVICE STABILITRAK when these lean codes are set. Northstars thru 2005 would do the same thing when the intake plenum leaked. All signs point toward a vacuum leak. But there just doesn't seem to be a vacuum leak. Somewhere there is some phantom sensor that is causing it to run lean or perhaps a coil or fuel pump. It's a mystery!
  24. I posted this in a model specific forum with little response. My 2006 DTS has 165,000 miles. I've since purchased a 2008 DTS Performance Ultra Luxury but still love my 2006 and would like to get it going again. Sometime a couple of years ago, my DTS started occasionally dinging and showing SERVICE TRACTION CONTROL & SERVICE STABILITRAK. Over time, it became more and more frequent. The car had always had a slip in the transmission. I assumed the two were related. So, I had a used transmission with 24k miles installed. Not only did the transmission not fix the problem, it is worse. Still get the dinging and messages and now the engine idles rough. In all my searching online, and all the different recommended repairs, NEW parts the car has had: *intake gaskets and plenum *MAF sensor *MAP sensor *throttle body and gasket *evap purge solenoid *gas cap *EGR valve and gasket *valve cover gaskets *alternator (bad alternator was causing the engine to rev and I almost rear-ended someone) I took the intake manifold off last night to inspect for cracks and found nothing. There just doesn't seem to actually be a vacuum leak. I have blocked off every vacuum connection to the engine and none have improved the problems. Whatever is wrong, it's fooling it into thinking it's a vacuum leak. I even took the car to Sewell Cadillac in Dallas (very poor dealership). They found nothing wrong. Charged me $500 for a new EGR gasket and to charge the battery. I fought it and got a full refund. I have searched everywhere more for a solution. Ideas I have found online include bad O2 sensors, bad coils, bad spark plugs, bad/clogged fuel pump, bad injectors, etc. Spark plugs only have maybe 20,000 miles on them. These codes and messages are not uncommon on 2005 and older Northstars due to the intake plenum tearing but seem very rare on 2006+ cars. I have no idea where to go from here. Does anyone have any idea? Anyone experience this on a 2006+ DTS and found a solution?
  25. The saga continues... In trying to find the cause of my engine running rough and codes P0171 and P0174, here is what has been done... used transmission with 24k miles (this is when it started running rough) intake gaskets plenum valve cover gaskets EGR valve and gasket throttle body MAP sensor MAF sensor alternator (volts were dropping and causing the engine to rev) gas cap I know it just sounds like I'm throwing parts at it but this has turned into more of a hobby. I've already replaced it with a 2008 DTS performance. I buy new OEM parts cheap on eBay and put them on myself so I don't have a whole lot of money into it. And I figure, once I find the problem, I'll practically have a new car. LOL Anyway, I just finished replacing the alternator today. If voltage drops, the computer raises idle to around 1200-1300 in my case to try to increase voltage. This happened often. If in traffic, it would fight the brakes and the engine would run hot. One day, on the way to work, it decided to rev right after a car in front of me stopped. I had the brake pedal on the floor and barely got stopped in time. So, no more revving. But, I still have P0171 and P0174. What else could it be? I did take it to Sewell Cadillac in Dallas (I do NOT recommend Sewell) who charged me $500 to change the EGR gasket. I fought it and got a full refund. They couldn't find anything causing the poor idle. Anyone have any ideas? Catalytic converter? AIR injection check valve? Purge solenoid? I'm at a loss.