tj95eldorado

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About tj95eldorado

  • Rank
    Reader (10+ posts)

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  • Car Model and Year
    Eldorado ETC 1995
  • Engine
    Northstar 4.6L V8 (LD8/L37)
  1. I saved my old rear ones, and have actually discovered that you can rebuild these rear shocks - IF the shock body is not rotted through..They are not actually sensors - they are solenoid actuated valves controlled by the sensors that input the module in the trunk. The front and back solenoids are exactly the same. 12 volt on and off is all they are... I'm from Northeast PA, it doesn't get as cold here as it gets in Albany, but I know what ya mean... When you go to connect the air lines into the compressor and shocks - you should make a flair on the end of the plastic line. I installed the little o-ring first, pushed it back on the line aways, then flaired the line end with a heat gun by applying heat ot the cut end...Practice it with some extra line and you will see what I mean...It works pretty easy once you do it a few times.. Maybe getting a tiny sized vaccume line coupling and using a heat gun to soften the air line may work for your situation now..
  2. I have the exact same car - and I did the exact same rear shock replacement....My factory full service manual says " the MINIMUM air pressure is 7 to 14 psi is maintained by the compressor (actually the air drier valve which is part of the unit) for the MINIMUM load" As your load increases, the compressor increases the pressure, it does so by using inputs from the leveling sensors. It doesn't list a maximum pressure... I changed the entire compressor unit, it's not as bad as it looks. Remove air lines, electric plug, and 3 - 8mm headed bolts (I think) that connect the unit tray to the frame and the compressor/tray comes out as a unit. Did you have any problems getting the shocks off? I had to cut mine off.... What did you do with the old shocks you took off?
  3. I had to replace the compressor, and seeing how much line is in those kits, I just replaced the old lines too. One thing I had to do is use a heat gun to make a 'bubble flare' on the air lines - where they connect to the compressor - to retain the super tiny o-rings. I changed every suspension part on the rear and haven't had a chance to get it to the alignment shop so thanks for the reply. Those shock nuts (for me) were impossible to get off, and I had to cut them off. Thank God there is a Fastenall store close by, I bought 2 new nuts. If anyone reads this - the nut size on the Arnott AS-2163 shocks are M16 x 2.....
  4. KHE - I did not say knock sensors are useless - If I implied that my mistake. I did say the combustion of 87 octane gasoline (or gasoline not rated to combust at it's proper time inside of a 10:1 compression engine) will happen BEFORE any spark happens inside of the combustion chamber - thus taking the computer and all it's related sensors (knock sensor included) out of the problem and rendering them useless. Another way to put it, if the knock sensor is doing it's job, there is something wrong - and that something will cause serious damage if not corrected. If your engine has 10:1 compression, and you run 100% 87 octane fuel, it will damage all the stuff I have already mentioned - for all the reasons I have mentioned. And I am sure barczy01 will be happy to fix it for you. Compression ratio is compression ratio - no computer, knock sensor, or redesigned combustion chamber can change that. barczy01 - there is a reason that just one person (you) has worked on thousands of these engines for the same problem, which indicates a design problem. After the horses have been out of the barn for many years, GM would never say that - would they? Fixing them is great, but finding the flaw seems to be so illusive.
  5. Where there is air - there is moisture. The air/moisture corrodes the steel bolt, and over time the clamping force, required to hold the 10500lbs of lifting force applied on the head everytime the cylinder fires, is compromised to the point of letting coolant enter the combustion chamber and the bolt threads - then everyone blames the head gasket... I am no engineer, I'm just a guy who learned from all of his failures, and learned why the failures happened. I don't google my knowledge, I lived it. Knock sensors and computers can do nothing about fact that gasoline (and ANY liquid) will combust under a certain pressure. When it happens at the wrong time inside on ANY engine, all they can do is sense it and try to adjust for it. If you can't (or don't) understand how gasoline and octane work, I suggest you learn about it. And try to read and comprehension things before comment on them....
  6. It is obvious you are clueless when it comes to compression ratio, gasoline, and octane. And you can't read between the bullshit lines the GM Engineer is feeding you. Regular unleaded is 87 or 89 octane. It will detonate in an engine with a compression ratio of 10.3:1 or 10:1. The timing event that the computer controls will have no effect on the combustion of the gasoline, thus rendering computer aided retardation of the timing (knock sensor included) USELESS. GM thinks 92 octane fuel is regular? Not in the real world.... The type of engine has NO BEARING on the fact that gasoline needs to be 'tamed' (so to speak) inside of the combustion chamber. The cheapest way it is tamed is by adding octane. The more octane, the more tame, and the more likely it won't detonate in a high compression engine like the Nstar - or ANY OTHER high compression engine. Do you know what causes the "knock" that a knock sensor is searching for? I remember when engines (even fuel injected ones) actually ran without the use of computers. What the heck, Sprint Cars don't even have a battery.. It matters not how many computer controlled devices are attatched to an engine - or how many computer designs are rendered. The mechanics of the crankshaft, rod, piston, piston rings, and the explosive power of gasoline remain the same. I can't believe I'm still replying to this topic....I hope mostfocused' 99 sls overheating problem is solved
  7. I am doing this exact same replacement. I was wondering how the Arnott shocks ride/perform?
  8. I found the vibration on my 95 Eldorado to be the rear knuckle bushings. Replaced them and vibration is gone. Not sure if your car has the same set up - just a thought...
  9. Compression ratio dictates what octane your fuel has to be. Gasoline will combust, without a spark, at a certain compression (which is exactly how a diesel engine works). The higher the compression, the easier gasoline will combust so, the higher the octane has to be. Higher octane (premium gas) is less volatile than lower (regular gas). The tick or ping you hear when a lower octane fuel is used in a high compression engine, is the slamming of the piston pin, rod bearing, and main bearing against their respective clearances - because the piston "fires" before it is supposed to - to early before top dead center - with no spark. If this happens too much there will be catastrophic failures in the engine. This is called 'detonation' and rightfully so. Compression ratios for the Nstar are - prior to 2000, 10.3 to 1. After 2000, it went to 10 to 1. @ 10.3:1 you need minumum 93 octane. @ 10:1 you need minimum 92 octane. Where I come from regular unleaded is 87 octane, which would set the knock sensors off and probably shut down the engine. There is NEVER a performance edge from using a higher octane fuel in an engine that does not require it with repect to the compression ratio, and it is hard to believe that an engineer said that...No wonder the Nstar is famous for leaks....wow It is true that what is good in racing isn't always good in in the street - but using 4 fasteners to clamp a combustion chamber, IMO, requires the strongest type of fastening, which is a stud....
  10. Top Fuelers use studs because (simply put) studs are better, and you can measure stretch much easier. The fasteners around a cylinder (in a street engine) have to hold (or apply a clamping force) of about 42,000Lbs in order to hold the head/gasket/block around the combustion of the chamber. In a Top Fuel engine it is probably reaching 100K plus. The Northstar has 4 fasteners around the cylinder (chevy small blocks have 5) which puts a load of around 10500Lbs per fastener in order to hold everything together. Also, a Nstar has a compression ration of around 10.3 to 1 - which is pretty high for a street engine, and it is also the reason you MUST use at least 93 octaine fuel..... When a bolt is used two things have to be overcome before any clamping force is applied - the friction of the threads in the block and the friction where the bolt head contacts. When a stud is used (simply put) the friction of the threads in the block is illiminated. Keeping the friction/heat source out of the block has many benefits. ALSO, studs use more of the block surface to apply the clamping force because they are set deeper.. This argument can go on forever - but there is one thing I guarantee - Hendrick, Childress, Rousch, Fisher, Gaerte to name a few builders, ALWAYS use studs - the reason (apparently) is debateable....
  11. 2001 northstar engine into a 1995 ETC

    Thanks for the info. What years will work in a 1995? I can get the 2001 engine for $300 - so I may take Jims advice and get another 2001 caddy....or just rip it apart and learn...
  12. WHen loosening the head bolts a pronounced "crack/pop" noise will be heard if the threads are sound. If the bolt is tight but backs out without the signature noise, the threads are compromised. The head bolts do not stretch - they are not torque to yield bolts. The only reason the head bolts cannot be re-used is that there is no way to apply the microencapsulated threadlocker in the field so the service manual states to replace the head bolts. If the coolant gets acidic, it will eat the gaskets - finding a path to the bolt holes. If you have ever had a Northstar apart you will see that the head bolt holes are close to the water jacket. The clamping force is the same with bolts or studs. There are many Northstars that have been repaired with the inserts that are the factory recommended repair that are just fine. The '97 STS I have has almost 90,000 miles on the repair. There is nothing wrong with using studs but they are much more expensive than the inserts that were developed by the factory for this repair. When you use an aftermarket product you are doing the validation of the product. Wow.... All bolts (and studs) stretch when tightened - especially head bolts. Rod, mains, flywheel, wheel studs - to name a few. The clamping force is not the same. Bolts apply clamping force differently than studs. If you don't know that or believe that then it is pointless to explain. I guess I may have been a head gasket in a past life - that's why I defend them against failure -- lol. FYI - My experience with the northstar is limited, but from what I see it is a very similar design to the Ro5 NASCAR engine, which was phased out of NASCAR....My experience is with high performance 800 to 900 hp sprint car motors, and some street engines. And I will tell you, if you ever see a HP engine builder using a torque wrench to install rod, head, and main cap bolts - it shows that that builder does not understand the concept of bolt stretch and clamping force - and chances are that, that engine will not run as smooth as it could, or as long as it could.... I just bought my first northstar powered car (cheap) and I anticipate issues with it - cus I will not baby it. The knowledge I gain here will be priceless down the road. So thanks for your side of the head GASKET/Bolt over heating issue, but please excuse me if I keep it in my brain a head BOLT/Gasket issue.... lol
  13. I have a 1995 Eldorado ETC vin "9" - with no problems yet. I also have an opportunity to get a 2001 northstar engine vin "9", cheap, from a guy who has it laying around his garadge. I am thinking of having the 2001 engine on stand by in anticipation of an issue with the 1995 engine. My question is will the 2001 swap into the 1995 with no issues?
  14. How does coolant get to the threads of the head bolt? Special coatings wear off when the bolt is 'streteched' during the process of torquing - threads heat up everytime torque is applied and the bolt is stretched. Moisture is always present inside of an engine and around the threads. This is what causes the clamping force to lessen - thus causing coolant to get to the threads and do it's magic. Just because a bolt is tight when you remove it doesn't mean the clamping force needed to hold the combustion chamber sealed is present. Without knowing how long the bolt was before it was installed (at the factory) - as opposed to when you took it out (during a head bolt/gasket issue) - you cannot say that the bolt was tight. There sure are lots of aluminum blocks with steel head bolts - and they may last a long time - but like I said, it's only a matter of time before they fail. It's best to install studs in any block especially a performance block/engine like the northstar. Studs are never torqued into a block. They are installed deep in the meat of a block - which uses almost 100% of the clamping area around the cylinder - and they are stretched by the nut - which pulls the head down into the block - as opposed to a bolt pulling the block up to the head.... IMO of course.
  15. Buy one of these, very simple test to detect exhaust in coolant. If the test is positive - then it is a head bolt (gasket) issue. They are available at any auto store and walmart.