catastrophic engine failure

[rbi2112]

I bought my'97 in 2000. It is Diamond White with a black interior - Autobahn package. I kept hoping a club for the Aurora would someday pop up. That's the good news. The bad news is that my car is sick. Terminally sick, actually.

At 135K miles, it is the considered opinion of several hotshot GM and racing mechanics that this motor is done . . . It has had a worsening low-oil pressure condition for the last few months. Have already replaced the sending unit which didn't fix the problem. Changed oil with two quarts of Lucas a couple weeks ago and this helped for a little while, but just a little while. No one I have talked to thinks the oil pump is the problem.

I think the Aurora, for several reasons, will someday become a huge collector's item. I had planned on willing mine to my kids. Now I don't know. The cost to rebuild the engine correctly is in the neighborhood of $10K. I really wanted to keep mine a matching numbers car. I know that sounds outrageous, but it is a highly sophisticated racing engine.

I cannot afford that. My question for all my new best friends, is this: Where is the best place to buy a replacement? New engines are no longer available from GM. I have found used engines on the net for around $1,100 with a 3-year warranty but all these cars have been wrecked. I wanted to hear from some of you before making a decision. Except for the engine, this car is in near-flawless condition. What would you do?

[oldsAURORAmobile]

Beautiful car!
If it was me, I'd be looking at these options:
www.northstarperformance.com/main.php

[Paulaurora]

sorry to hear that you have that issue but I would get engine even if the car was wracked as longest the engine was not hit it will be good plus 3 year warranty is good thing as well.

[bobsblue95]

The guy at Northstar performance will rebuild your engine for about half that ridonculous $10K figure. He'll stud the block while he's at it, making it bulletproof.

[sall]

Have ya tried the 15 qts of oil trick? Do a search I don't remember the details exactly.

Looked it up...

Oct 16, 2006 10:46:29 GMT -6 aurorabrain said:

For anyone who wants to read the TSB.....

LACK OF POWER, LOSS OF OIL PRESSURE #47-61-32B - (Mar 1, 1996)
REVISION: 12/11/95

THIS BULLETIN IS BEING REVISED TO ADD THE 1996 MODEL YEAR. PLEASE DISCARD BULLETIN 47-61-32 (SECTION 6 - ENGINE). ----------------------------------------------------------------------

REVISION: 03/11/96

THIS BULLETIN IS BEING REVISED TO ADD CLARIFICATION TO CORRECTION. PLEASE DISCARD BULLETIN 47-61-32A (SECTION 6 - ENGINE). ----------------------------------------------------------------------

SUBJECT: LACK OF POWER, LOSS OF OIL PRESSURE (CHECK HARMONIC BALANCER BOLT TORQUE AND FLUSH OIL PUMP RELIEF VALVE)

MODELS: 1993 CADILLAC ALLANTE 1993-96 CADILLAC ELDORADO AND SEVILLE 1994-96 CADILLAC CONCOURS 1996 CADILLAC SEDAN DEVILLE WITH 4.6L ENGINE (VINS Y AND 9 - RPOS LD8 AND L37)

1995-96 OLDSMOBILE AURORA WITH 4.0L ENGINE (VIN C - RPO L47)

CONDITION:

SOME OWNERS MAY COMMENT ON LOW OIL PRESSURE WHICH MAY DISPLAY A "LOW OIL PRESSURE" MESSAGE AND/OR A "MALFUNCTION INDICATOR LAMP" (SERVICE ENGINE SOON) TELLTALE. VEHICLE OWNERS MAY COMMENT THAT THESE TELLTALE MESSAGES ILLUMINATE AT ENGINE SPEEDS OF 1000 RPM AND ABOVE.

CAUSE:

LACK OF OIL PRESSURE MAY BE CAUSED BY:

- PARTICLES FROM THE MANUFACTURING PROCESS STICKING THE OIL PUMP RELIEF VALVE, NOT ALLOWING THE VALVE TO SEAL TO ITS SEAT WHICH DOES NOT ALLOW THE PUMP TO PRIME.

- A LOOSE HARMONIC BALANCER BOLT WHICH WILL RESULT IN THE OIL PUMP NOT TURNING.

CORRECTION:

ENSURE THE HARMONIC BALANCER BOLT IS TIGHTEN TO SPEC. THE CORRECT TORQUE VALUE FOR THIS BOLT IS 60 N.M (44 LB FT) PLUS 120 DEGREES FOR 1993-95 ENGINES WITH AN M18 BOLT AND 50 N.M (37 LB FT) PLUS 120 DEGREES FOR 1996 ENGINES WITH AN M14 BOLT.

NOTICE: A SMALL NUMBER OF 1995 ENGINES WERE BUILT WITH CRANKSHAFTS EQUIPPED WITH THE M14 BOLT. IDENTIFY THE SIZE OF THE BOLT TO DETERMINE THE PROPER TORQUE SPECIFICATION.

IF THE BOLT IS TO SPECIFICATION, THE CAUSE OF THE LOW OIL PRESSURE IS INTERNAL TO THE PUMP.

TO REMOVE PARTICLES FROM THE RELIEF VALVE IN THE OIL PUMP, PERFORM THE FOLLOWING PROCEDURE:

1. ADD AN **ADDITIONAL** 10 TO 12 QUARTS (LITERS) OF ENGINE OIL TO THE ENGINE. THIS WILL IMMERSE THE PUMP COMPLETELY IN OIL.

2. START THE ENGINE AND REPEATEDLY OPEN THE THROTTLE (REV THE ENGINE) FROM IDLE TO 3500 RPM. THIS WILL ALLOW THE PUMP TO PRIME; CYCLING THE RELIEF VALVE FORCES ANY DEBRIS FROM THE RELIEF VALVE.

IMPORTANT: DO NOT OPERATE THE ENGINE ABOVE 3500 RPM. DOING SO WILL AERATE THE ENGINE OIL AND/OR FORCE EXCESS ENGINE OIL INTO THE PCV SYSTEM. **DO NOT DRIVE THE VEHICLE WHILE THE ADDITIONAL OIL IS IN THE ENGINE.**

AFTER THE ENGINE HAS SUFFICIENT OIL PRESSURE, ANY VALVETRAIN NOISE ASSOCIATED WITH THIS LOW OIL PRESSURE CONDITION SHOULD NOT BE EVIDENT UPON RESTARTING THE VEHICLE AND THE LOW OIL PRESSURE AND MALFUNCTION INDICATOR LAMP (SERVICE ENGINE SOON) MESSAGES SHOULD NOT REMAIN ILLUMINATED.

3. AFTER ENGINE HAS SUFFICIENT OIL PRESSURE, DRAIN THE CRANKCASE. REINSTALL THE ENGINE OIL PAN DRAIN PLUG.

4. ADD 7 QUARTS OF ENGINE OIL AND CHECK THE OIL LEVEL. MAKE SURE THE VEHICLE IS ON A LEVEL SURFACE AND THE ENGINE OPERATING TEMPERATURE IS 100 DEGREES CELSIUS WHEN CHECKING THE OIL LEVEL WITH THE ENGINE STOPPED FOR 15-20 SECONDS.

WARRANTY INFORMATION FOR VEHICLES REPAIRED UNDER WARRANTY, USE: LABOR OPERATION: J0989 LABOR HOURS: 0.5 HOUR

FIGURES: 0

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER". THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS THAT MAY OCCUR ON SOME VEHICLES, OR TO PROVIDE INFORMATION THAT COULD ASSIST IN THE PROPER SERVICE OF A VEHICLE. PROPERLY TRAINED TECHNICIANS HAVE THE EQUIPMENT, TOOLS, SAFETY INSTRUCTIONS AND KNOW-HOW TO DO A JOB PROPERLY AND SAFELY. IF A CONDITION IS DESCRIBED, DO NOT ASSUME THAT THE BULLETIN APPLIES TO YOUR VEHICLE, OR THAT YOUR VEHICLE WILL HAVE THAT CONDITION. SEE A GENERAL MOTORS DEALER SERVICING YOUR BRAND OF GENERAL MOTORS VEHICLE FOR INFORMATION ON WHETHER YOUR VEHICLE MAY BENEFIT FROM THE INFORMATION.

COPYRIGHT 1994. GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.

[rbi2112]

Thanks everyone for the sage advice. I will definitely look up this service bulletin and bring it to the attention of my mechanic.. Wish I had $5K for a rebuild but have decided to rebuild the transmission as well - since it's going to be out of the car. I wonder if NAPA sells a re-manufactured engine? Put one in an '87 Trans Am once and it ran perfect. Will post an answer as soon as I can.

[oldwino]

Sorry to hear about the engine. Another option might be Jasper.

www.jasperengines.com

[roara]

Welcome aboard 2112! Is that what I think it means? lol

Sorry you join us with grief in the well being of your Rora. Good luck with the fix. She will be fixed, I know it!

[rbi2112]

Greatest Three-Man Band in the galaxy...

[roara]

Agreed, lets fix your car now ;D
A lot of knowledgeable people here willing to help!

[Randy T.]

Putting Lucas in is the last thing you want to do if you engine is having oil delivery problems, Lucas is so thick, it does the exact opposite of what you are trying to do. What weight oil are you running? What pressure is your dic reading? Is your motor actually making noises and stuff, or are you just having low oil pressure? Where do you live? Check if you have any pick n pull type salvage yards in your area, get a 4.6 from a Cadillac. Around $240 with a 1 year warranty, if you are worried about it breaking down, buy 5 of them, along with the transmissions. Motors in these cars are easy to change and you can do it yourself.

Sall that service bulletin is insane awesome, I want to do that sometime, just because, lol. I may flush out the 4.6 like this once I get it installed. It says an additional 10-12 quarts of oil, lol, that's almost 20 quarts. My motor holds exactly 8 quarts after an oil change.

[rbi2112]

Well, the Lucas was on the advice of one of those hotshot GM mechanics and was intended only for the test. The low pressure situation developed over the course of the last few months. Very infrequent at first, but now is constant. When I did the oil change, I first started the car to warm the oil up. It was reading 45 PSI. Over the next ten minutes it dropped all the way down to 25 PSI. The warmer the oil became, the thinner it got and the pressure began slipping. It would eventually drop down to 4 PSI at idle and set off the alarm.

After draining the car, I carefully emptied the drain pan. All I found was carbon. I thought this was a good sign - until another mechanic said that there isn't always metal shavings, that perhaps there was none left. I have always ran 10W-30 oil and changed it pretty religiously every 2500 miles. The engine has had a mild chattering sound for some time, but it sounded like the valve train to my untrained ear. After the Lucas was added it sounds as smooth as silk.

When I purchased the car in 2000, it had 64K miles, which is quite a lot for a three-year old car (that is how I was able to afford it). It was originally owned by a state senator here in southwest Ohio. He bought a new one every three years. Apparently, he was commuting daily between Cincinnati and Columbus. I plan on calling my local salvage yard tomorrow.

I see that Northstar Performance sells a re-manufactured engine for 4-grand plus $500 shipping. That is intriguing. . . Can I ship my motor off to them for a rebuild? They didn't answer their phone today. Now I must tell you something else. I've been having this dream the last few nights. It is of Mecum's Auto Auction set way in the future, probably around 2056. To a chorus of oooohs and ahhhhs, the announcer proclaims to an audience giddy with anticipation, "And now, that rarest of classic American automobiles, a 1997 numbers-matching Oldsmobile Aurora." That's when I wake up in a cold sweat, realizing I will be 100 years old."

One other question, my mechanic says that he can increase the horsepower from 250 back to the original Cadillac spec. of around 300 or so just by reconfiguring the engine computer. Is that true?

[Randy T.]

Our 4.0 motor has a different bore than the 4.6, I guarantee your mechanic does not have a clue about our cars if he thinks he can easily tune the computer to bring your 4.0 up to 300hp. Have you been using Penzoil? Flush the motor like Sall said, it sounds like your motor is covered with sludge on the inside. You can look inside the oil cap with a flashlight and see some stuff, most Northstars always look like new. I would also add 4 quarts of engine flush, I like Heartland extreme engine oil flush, but there are many others available that are equal. Switch to Valvoline Max life, go with 5w30 for now. After that it may become more extreme, your oil pump screen may be clogged with gunk, flushing it could make it worse, but yours needs help either way.

[rbi2112]

Well, that's certainly something to chew on. I will bring this up with my mechanic next time we speak. In his defense, he works on all brands of cars and has quite a bit of experience building racing engines. Apparently, not so much on the Northstar.

As to the issue of oil choice. I need to clarify something. I used Pennzoil for the oil test. I have never been loyal to any particular brand over the years, using most at one time or another. My main criterion was making sure it had the latest A.P.I. rating. Following your instruction, I took a flashlight and looked inside my engine. It is in very good shape. I took a picture but see no where to add it to this reply.

I spoke with Jake Weibe, owner of Northstar Performance today. During the course of our conversation, he commented that, in his experience, the Aurora engines were a lot closer to their Cadillac brethren in horsepower, than GM was letting on. Based on that conversation, I decided to make a long-term investment in this car and went ahead and scheduled to put the car in the shop June 21st to pull the engine and most likely ship it off to Canada for a rebuild.

However, based on your recommendation, I will flush it this weekend and switch to Valvoline Max Life 5W30 and see what happens. One question for club members: Could someone drive their Aurora and then check to see what the oil pressure is at idle? I have never heard a spec. on that.

[Randy T.]

That's understandable. There are a lot of handheld tuners that do work on many GM cars, but the Northstar computer is a little more complicated. You can bring out more horsepower by doing certain things if that is what you are interested in doing. You can have the computer tuned by Madtuner, if you check in the performance sections for some threads about that. You can also switch a pair of the cams which will make your engine similar to the Shelby Series 1 engine, which was a 4.0 with the certain 4.6 cams, with a different trans and computer.

When you pull your drain plug you may also be able to see up inside with your flashlight and get another view. I did state it earlier, but just so you know, if you do have a little gunk on your oil screen and more in your motor, doing this flush could make it worse. I changed the oil on a '03 Dakota V6 that had not had regular oil changes. These Dakotas have an indention that causes the oil pump screen to totally get surrounded and clog. The previous owner let the motor really sludge up, changing the oil set enough sludge free to make the engine stop getting oil. I had to clean under the valve covers, and pull the oil pan 3 times, I am still worried I will have to pull it again, but I can get it out in about half an hour now.

But it sounds like yours may not be sludged up if it looks clean inside the valve cover. I would talk to your mechanic about the suggestions and go from there. I would not want you to do anything that I suggest and make your motor worse.

Good luck!

[Randy T.]

My oil gauge has not worked for years, it either says 0, -----, or 125, easy fix, but I don't need gauges to know how my motor is doing. It is not unusual to have 10-15 at idle, if I recall correctly.

[rbi2112]

Well, my Great White Stallion is now in the shop waiting to have it's engine/trans pulled. The motor is headed for Canada for a rebuild at Northstar Performance. I spoke with them today regarding shipping logistics and such.

During that conversation, they made what I found to be a startling revelation. I asked which synthetic oil I should use. They replied that they do not recommend the used of synthetic oil in the Northstar engine. Their position is based on their experience using both oils. They found that traditional oil was much more "sticky" compared to synthetic, which was almost water-like in nature, in that it displayed a tendency to just run off the metal surface. Non-synthetic oil adhered much better. They also pointed out that the oil was going to get contaminated, whether it was synthetic or not, and going over 3,000 miles between oil changes was just inviting trouble.

I had always believed synthetic was clearly superior. Now I am not so sure. Does the club have any official position on which oil and which brand, is the best to use in these cars?

[oldwino]

No official forum position, though most probably use synthetic. A lot of opinions in this guy's forum;

www.bobistheoilguy.com/

[Randy T.]

I use Valvoline Max life which is a partial synthetic. My engine holds 8 quarts, I run 7-8000 miles between oil changes and it comes out pretty clean. Conventional oil has changed over the years, it used to be clean when you looked at it when new, now it looks browner and darker, so if I was running that dark matter, I would probably change it sooner.

[renaldo0613]

^^ second that to Randy.

[bobsblue95]

My biggest concern is oil viscosity breakdown due to high temperatures. If the engine overheats, conventional oil gets thin as water and can permanently lose some of its lubricating properties, thus maximizing damage. Synthetic keeps working. You can change the filter every 3000 miles without changing the oil, so contamination is not a great concern. Just my $.02.

[oneye]

Mine too ... make that fore sense.

[rbi2112]

I think I will probably stay with traditional motor oil, mostly due to the cost. This car sets in my garage most of the time. It is driven about 3K per year, so there really is nothing to gain by going to synthetic. On another, more central topic: The car is still in the shop awaiting removal of the engine and trans. There were some unforeseen delays but I am told they plan on starting Monday, 6-30.

Anyway, I wanted to pick the expert's collective brain on this topic. The cost to ship my motor to Northstar Performance is causing me to reconsider trying to keep mine a "numbers matching" car. I can save shipping costs and put 50 extra ponies under my hood by dropping in a Cadillac 4.6 litre engine. How difficult is this? The purchase price of each engine is the same - $3,950 dollars. Can I still use my Aurora engine cover? Where do I find the two electrical harness plugs that have to be replaced? And the biggest question of all revolves around the engine mounts. Can I use the old brackets off my existing engine and bolt them in place directly with the new engine, or will new mounts have to be fabricated for the frame? This could be a deal-breaker in and of itself. I have to make a decision on this in the next 48 hours or so. Any advice or recommendations you can provide will be greatly appreciated.

[rbi2112]

Okay, it's Wednesday morning, 07-03-13. The engine/trans is coming out of the car, slowly but surely. Have not been in contact with NorthStar Performance since last Thursday. None of my calls have been returned. Not sure what is going on. May have to hire the NSA to track them down . . . I do know Monday was a national holiday in Canada. Hopefully, I will hear from them soon. Has anyone else had any experience with NorthStar Performance? Also, I would still like to know if the Cadillac Northstar 4.6 engine will bolt-in directly to the mounts on my frame by simply installing my Aurora mounts on the engine. Any insight or comments will be greatly appreciated.

[rbi2112]

Late Friday night, 07-07-2013 - Finally made contact with NorthStar Performance this afternoon, speaking with owner and founder, Jake Weibe. I learned the best way to contact them is via email, which goes directly to his smartphone. He reported they have been keeping their nose to the grindstone for the last week playing catchup with back-orders on their cylinder head stud kits.

I inquired as to the viability of perhaps dropping in a Cadillac 4.6 NorthStar variant in my Aurora, thus saving on shipping charges sending my engine to Canada and picking up 50 extra horsepower. He assures me that it will bolt right in if I use my old Aurora engine mounts. Mr. Weibe also stated that there are no issues regarding electrical harness plugs, mine will work perfectly. The timing curve has to be changed to accommodate the larger engine and I will have to use my original sending unit from the Aurora engine (apparently, Cadillacs of that era didn't provide the driver with a digital oil pressure readout like the Aurora).

Has anyone in the club tried this before me? I'm dying for some feedback but everybody seems to be away on vacation.

[Randy T.]

Here is a link to almost every thread regarding installing Cadillac motors into
Auroras. I have a 4.6 waiting to be put in my '97 Aurora as soon as I get caught up at work. I recommend contacting madtuner if you need any computer adjustments, although your Aurora computer will run it, check around in the performance section of the forum.

aurorah.proboards.com/index.cgi?board=Zoom&action=display&thread=26816

Here is my thread on the progress I have made, it also has good info about different Cadillac motors and transmission options that you may want to consider. I am using a 275 horsepower 4.6 along with the Autobahn ration transmission, similar to the '04-'05 Bonnevile GXP setup, along with a tuned computer from madtuner.

aurorah.proboards.com/index.cgi?board=Zoom&action=display&thread=26586

[rbi2112]

Thanks man, I really appreciate the voluminous info. Still haven't gotten through all of it, though. It appears my biggest decision is Y or 9. I see you are going with the Y code which is the 275 HP variant. Is that for the increased torque between 20 and 80 mph? With all I have read, I am afraid I have forgotten the torque on the 300HP version. What is it?

Since I have the 3.71 trans, wouldn't that compensate for the difference? On the other hand, I don't plan on red-lining this car anytime soon. (Except when I need to put my know-it-all son-in-law with the two college degrees and his six-banger Acura variant Accord back in his place...) I just can't make up my mind which is the better option for me. Ideally, I want the best of both worlds. What do you recommend?

[rbi2112]

Well, its Thursday (7-11) night. The engine/trans is on the floor. No turning back now. Haven't heard anything back on which engine to go with. I reckon it'll be the 9-code. My mechanic, who has also done a lot of tuning, is confident he can boost torque at a lower RPM.

Is there a preferred website where members can purchase OEM parts at a reasonable price? I plan on replacing the P/S lines. the A/C lines and the brake lines as well as the rusted sway bar links, the cradle bolts & bushings and so on.

[Randy T.]

300hp has less bottom end torque, but if you have the computer properly tuned, it could possibly be a benefit and not a problem. I have driven a 300hp Caddy recently, I like my Aurora better, it seems faster in the takeoff and sounds a lot better, but the Caddy really gets up there quick once it gets going.

I chose the 275 hp 4.6 along with the 3:71 trans, so it's setup like a Bonneville GXP.

If your mechanic thinks he can easily tune an Aurora, he does not have a clue what is going on with our cars. If you want a tune, I recommend Madtuner.

aurorah.proboards.com/index.cgi?board=Zoom&action=display&thread=26701

[rbi2112]

Called my local GM dealer today in search of parts. I want to replace the front-end brake lines, the P/S lines and A/C lines. I figure it is cheaper to do it now. Nothing is available. All the tubing for the brakes will have to be made from a 50' roll with a flare tool. Does anyone have experience locating hard-to-find Aurora parts? I sure could use some help.