: Blown NorthStar



speedyman_2
06-09-05, 05:55 PM
Well, I took my caddy to a dealer. 1998 Seville STS. They're telling me that my piston is hitting the head. But, this is only a diagnosis from the sound. So basically I paid for them to tell me what they think it sounds like. So now I don't now what to do. I just got off a 6 month deployment and It sucks because I can't get around. And, it's getting expensive to tow this car to different places. Especially out here in San Diego. Does anyone know where I can get a running used Northstar. The dealer quoted me $10,000 to replace it with a new one. I would love a brand new engine but, there's not way I can afford $10K. ANy help would be appreciated. Thanks

ktills45
06-09-05, 09:29 PM
Well, I took my caddy to a dealer. 1998 Seville STS. They're telling me that my piston is hitting the head. But, this is only a diagnosis from the sound. So basically I paid for them to tell me what they think it sounds like. So now I don't now what to do. I just got off a 6 month deployment and It sucks because I can't get around. And, it's getting expensive to tow this car to different places. Especially out here in San Diego. Does anyone know where I can get a running used Northstar. The dealer quoted me $10,000 to replace it with a new one. I would love a brand new engine but, there's not way I can afford $10K. ANy help would be appreciated. Thanks

Theres an outfit that's in a thread here that sells rebuilt N* motors for about 4.5k. Timeserted and everything. Do a search on rebuilt engines, you'll get a hit.

ktills45
06-09-05, 09:36 PM
Found it! Jasper engines, probably jasperengines.com or some such. 4-4.5k for the engine. Good luck!

Ranger
06-09-05, 09:38 PM
Wait a minute. How can the piston be hitting the head? Can't happen unless something (piston or rod) becomes disconnected and in that case the motor would literaly self destruct. You may have carbon build up in there from babying it and that is what the piston is hitting which causes the piston to rock on the wrist pin and then the skirts slaps the wall (aka piston slap). If that is your problem, take it out and beat the living hell out of it. Out it in 2nd gear and plant your foot to the floor. Do not release it til you hit 70 mph. Then let it back down to 50 and nail it again. Do it about 10 times then drive it normal to let it cool down. By the tenth time you should not see any carbon out of the pipes. That'll clean the carbon out of the cylinders.

Give us more details. Why did you take it in? what are the symptoms?

94CaddyConcours
06-10-05, 01:09 AM
I agree with Ranger, there is no way a piston hit the heaed unless it is not attach. That is BS that they charge you or you pay them to listen to your engine. They have no fact to back it up by listening for a sound.

speedyman_2
06-10-05, 06:49 PM
Yeah guys, I know. How could they just tell me what they think it sounds like. Well, I still need a new motor though. They didn't find anything external. My dad found a used Northstar for $1,600. It has 70K miles on it though. Someone can install it back home in Florida for $700. So, $2,300 total to put in a used motor. That's looking like my best deal as of now. Although I'd love a rebuilt one. I can't afford much right now. Thanks for your help.

yeabuddy
06-10-05, 07:13 PM
hey just want to tell you that your insurance will reinburst you for the towing if you check in to it,so ask them!

Ranger
06-10-05, 09:49 PM
How do you know the motor is shot? So far all we know is that it is making some kind of sound that sounds like a piston hitting the cylinder head.

Raze
06-11-05, 01:42 AM
Hey check out remanufactured.com, I actually spoke with 'Dave' today about a reman N* as my N* is now eating coolant at the clip of 1/2 a jug every 2 weeks, and it's only going to get worse. These guys were the cheapest at $3885 for the full assembly + S&H both ways, - $500 for the core so total around $3400 which is damn good. He said they used full timeserts on the main head bolt holes, new internals, set it up and break it in. Oh and it comes with a 1 year/unlimited mile warranty, and for $290 a 3 year/50k mile warranty parts & labor.


The other guys I spoke with that were close in price but had a better warranty was Quality Engine Rebuild (http://www.quality-engine-rebuild.com/) that had total cost of $4695 for the full assembly and S&H both ways, -$700 for core so around $4k even. They have a 3 year/unlimited mileage warranty which makes them more competitve with Jasper which has the engine for 5kish, -$720 for core, HOWEVER, Jasper Installers apparantly can save you a bunch in labor charges because they do so many N*s. Jasper's warranty is 3 year/75k miles.

cart69
06-15-05, 02:22 PM
i just want someones old motor to play with and i havent even gotten one yet!!! dont care if its blown up or not!!!

greggbruce
06-15-05, 09:25 PM
Wait a minute. How can the piston be hitting the head? Can't happen unless something (piston or rod) becomes disconnected and in that case the motor would literaly self destruct. You may have carbon build up in there from babying it and that is what the piston is hitting which causes the piston to rock on the wrist pin and then the skirts slaps the wall (aka piston slap). If that is your problem, take it out and beat the living hell out of it. Out it in 2nd gear and plant your foot to the floor. Do not release it til you hit 70 mph. Then let it back down to 50 and nail it again. Do it about 10 times then drive it normal to let it cool down. By the tenth time you should not see any carbon out of the pipes. That'll clean the carbon out of the cylinders.

Give us more details. Why did you take it in? what are the symptoms?
if there is carbon in the cylinders, this is a way to help reduce some of it. but seems a bit hard on it. (even though some of us drive like this anyway just cuz it's fun -- myself included) (I just had to race this little hot-rod rice grinder the other day, yeah, my 2 ton car waxed your little turd...)

go to a gm dealer and buy 2 cans of "top engine cleaner" (liquid, not aerosol) and follow the directions on the can. it is the best carbon remover I have found in the last 25 years of working on cars.
if you do this twice and the knocking is still there, then I would say you have an internal engine problem.
the way the piston hits the head is if the bearing is worn out in the connecting rod. it lets the piston and rod travel higher in the cylinder and lets it hit the head. ( there's only thousandths of an inch between the piston top and a part of the head called the "chamber")
you would also see a lower oil pressure because the bad bearing is a gushing oil leak inside the engine. this will eventually lead to what's called "throwing a rod" because it gets so hot, the bolts or bottom half of the rod melts and just comes apart, then whats left gets jammed (sometimes) outside the block by the next revolution of the crank, and thus, "punches a hole in the block" THEN it's time for a-whole-nother engine.....

Ranger
06-15-05, 10:00 PM
gregbruce,
Go to the top left side of the page and click on Technical Archive. Read the section Occasional Full Throttle Acceleration Is Good For Your Car. It was written by a GM Powertrain engineer who regularly posts here.

speedyman_2
06-16-05, 02:33 AM
if there is carbon in the cylinders, this is a way to help reduce some of it. but seems a bit hard on it. (even though some of us drive like this anyway just cuz it's fun -- myself included) (I just had to race this little hot-rod rice grinder the other day, yeah, my 2 ton car waxed your little turd...)

go to a gm dealer and buy 2 cans of "top engine cleaner" (liquid, not aerosol) and follow the directions on the can. it is the best carbon remover I have found in the last 25 years of working on cars.
if you do this twice and the knocking is still there, then I would say you have an internal engine problem.
the way the piston hits the head is if the bearing is worn out in the connecting rod. it lets the piston and rod travel higher in the cylinder and lets it hit the head. ( there's only thousandths of an inch between the piston top and a part of the head called the "chamber")
you would also see a lower oil pressure because the bad bearing is a gushing oil leak inside the engine. this will eventually lead to what's called "throwing a rod" because it gets so hot, the bolts or bottom half of the rod melts and just comes apart, then whats left gets jammed (sometimes) outside the block by the next revolution of the crank, and thus, "punches a hole in the block" THEN it's time for a-whole-nother engine.....

Carbon is definately not the problem. It's an excessively loud knock. Definately internal. Cadillac dealer in San Diego says rod bearing or whatever. I've managed to find a used engine. Less than 10,000 miles on it. Paid $1,700 for it. Gonna pay $500 or so to get it installed. Hopefully next friday it should be done. Thanks for the help everyone.

Spyder
06-16-05, 05:06 PM
That's an incredible deal on the engine and the installation...good find!

speedyman_2
06-19-05, 11:12 PM
Well, three more days and my car goes to get it's transplant. I can't wait. I've decided that since I'll have a whole other engine left over I can mod some parts. Does anyone know of a machine shop or something near San Diego that can do maybe a throttle body or something. Also, what other parts are relatively easy to replace and mod??

greggbruce
06-21-05, 03:29 AM
gregbruce,
Go to the top left side of the page and click on Technical Archive. Read the section Occasional Full Throttle Acceleration Is Good For Your Car. It was written by a GM Powertrain engineer who regularly posts here.

key word in that statement:

"occasional"

and I completely agree.
almost EVERY entrance to the highway..... right?? that's one of my favorites.
and when I road race the corvette, it's after every turn....

just keep an eye on the temp gague, and if there IS something wrong with the engine, you'll find it before you're done.....

claudia
06-25-05, 05:49 AM
Hi Everyone,

I need some advice about a 1994 SLS with a 4.6 Northstar engine that I recently bought with 70,000 miles on it. It started overheating and leaking a lot of water recently so I had it towed to a mechanic that was recommended to me and he tells me the engine is blown but by the way, he'd be willing to buy it from me. I live in Phoenix, Arizona. Does anyone know a trustworthy mechanic that can diagnose this problem for me?
Thanks, Claudia

davesdeville
06-25-05, 10:44 AM
Damn, every time I see "blown northstar" I think someone stuck a supercharger on a northstar... and every time so far I've been disappointed.

Ranger
06-25-05, 11:18 AM
Sounds like almost any mechanic might be more trustworthy than the one you found. Is it leaking internally or externally?

Spyder
06-28-05, 01:43 AM
Yea...definately need to find someone new...

eldorado1
06-28-05, 12:41 PM
Damn, every time I see "blown northstar" I think someone stuck a supercharger on a northstar... and every time so far I've been disappointed.

I hear ya. I was expecting a supercharger as well ;)

greggbruce
06-28-05, 01:07 PM
Damn, every time I see "blown northstar" I think someone stuck a supercharger on a northstar... and every time so far I've been disappointed.

anyone know of a kit for this yet??? I'd be interested....
nitrous too....

N0DIH
06-28-05, 01:17 PM
Me too, bummer!

Guess you will have to do one so we can have a proper blown thread....

Katshot
06-28-05, 01:29 PM
if there is carbon in the cylinders, this is a way to help reduce some of it. but seems a bit hard on it. (even though some of us drive like this anyway just cuz it's fun -- myself included) (I just had to race this little hot-rod rice grinder the other day, yeah, my 2 ton car waxed your little turd...)

go to a gm dealer and buy 2 cans of "top engine cleaner" (liquid, not aerosol) and follow the directions on the can. it is the best carbon remover I have found in the last 25 years of working on cars.
if you do this twice and the knocking is still there, then I would say you have an internal engine problem.
the way the piston hits the head is if the bearing is worn out in the connecting rod. it lets the piston and rod travel higher in the cylinder and lets it hit the head. ( there's only thousandths of an inch between the piston top and a part of the head called the "chamber")
you would also see a lower oil pressure because the bad bearing is a gushing oil leak inside the engine. this will eventually lead to what's called "throwing a rod" because it gets so hot, the bolts or bottom half of the rod melts and just comes apart, then whats left gets jammed (sometimes) outside the block by the next revolution of the crank, and thus, "punches a hole in the block" THEN it's time for a-whole-nother engine.....

Greggbruce,
Don't ya just hate it when nobody listens to you? You were totally right here. Very possible to be a carbon knock and your advise was on the money. I've used Top Engine Cleaner to fix many a supposed "rod-knock" over the years. Damn shame some people don't listen. He "may" have done an engine swap for no reason. Oh well, he isn't the first and won't be the last.
Very surprised that Ranger didn't pick-up on your point, he's usually pretty good.

greggbruce
06-29-05, 12:03 AM
Me too, bummer!

Guess you will have to do one so we can have a proper blown thread....

....alls I gotta do is find a kit, then it's off to the races.....

I'm ready, let's make it happen...

greggbruce
06-29-05, 12:15 AM
Greggbruce,
Don't ya just hate it when nobody listens to you? You were totally right here. Very possible to be a carbon knock and your advise was on the money. I've used Top Engine Cleaner to fix many a supposed "rod-knock" over the years. Damn shame some people don't listen. He "may" have done an engine swap for no reason. Oh well, he isn't the first and won't be the last.
Very surprised that Ranger didn't pick-up on your point, he's usually pretty good.

I HAD had some that actually DO have a bad rod bearing or loose piston or piston pin and usually it will get worse trying to get the carbon out-- we used to use antifreeze before oxygen sensors and sometimes auto trans fluid. if it didn't fix em, it made em easier to figure out what was making noise....

I am learning as I get older that people will do what people will want to do, even though they sometimes know they should do different.

eventually, I know they will show up at my place and I will take care of them. it's still their life and their choice and their money, so I'll let them do what they want. no sweat off my back.....
thanks for the support, but I also know I'm not ALWAYS right either...

I would like to see what really happened to his old motor too....
I hope an update is forthcoming from speedy

davesdeville
06-29-05, 05:25 AM
I don't think any carbon knock/piston slap would do this...

http://cadillacforums.com/forums/showthread.php?t=44090

Jarhead
06-29-05, 07:29 AM
I just bought a 97 STS with 49,000 mies for my wife, it's very clean and very fast! However I here allot on the oil consumption on this model? What kind of oil should I run in this thing? Any advice on this car would be great? My wife loves this car, but I want it to last. I'm Also looking to improve the performance on this car, where should I be looking?

davesdeville
06-29-05, 07:46 AM
^^The search button at the top of the page. Basically do the occasional WOT treatment and oil consumption will decrease (again search if you want to know how or why.) Pretty much the only worthwhile things to do performance-wise would be exhaust and nitrous. Try to keep threads on their original topic, and if you want to ask/discuss something search first, then post a thread in the appropriate forum.

greggbruce
07-01-05, 11:23 AM
I don't think any carbon knock/piston slap would do this...

http://cadillacforums.com/forums/showthread.php?t=44090


YEP, THAT'S AN OWIEE!!!!

heya speedyman, what are you doing with the old motor/ heads??

Ranger
07-01-05, 11:50 AM
I just bought a 97 STS with 49,000 mies for my wife, it's very clean and very fast! However I here allot on the oil consumption on this model? What kind of oil should I run in this thing? Any advice on this car would be great? My wife loves this car, but I want it to last. I'm Also looking to improve the performance on this car, where should I be looking?
Use what the factory recommends, conventional 10w30. Go to the top left of this page and click on "Technical Archives" and read up on "Occassional Full Throttle Blasts" aka WOT. It should help the oil consumption (not really a bad thing when you understand it).

Not much left on the table performance wise. That puppy is already putting out 1 hp per cubic inch. General consensus seems to be opening up the intake AND exhaust might help a bit.

Mountie
07-04-05, 04:22 AM
Well, I took my caddy to a dealer. 1998 Seville STS. They're telling me that my piston is hitting the head. But, this is only a diagnosis from the sound. So basically I paid for them to tell me what they think it sounds like. So now I don't now what to do. I just got off a 6 month deployment and It sucks because I can't get around. And, it's getting expensive to tow this car to different places. Especially out here in San Diego. Does anyone know where I can get a running used Northstar. The dealer quoted me $10,000 to replace it with a new one. I would love a brand new engine but, there's not way I can afford $10K. ANy help would be appreciated. Thanks

I just discovered this site to learn more about an STS I may buy. It has the same rod knock noise ( piston hitting the head) ...2 mechanics agree, the awful sound is a biggie. A friend wants to sell me the '93 STS for $2,000, 122,000 miles, all black with a very clean tan interior. The car is in great shape other than the engine glitch. I will be able to negotiate the final price, if I can AFFORD the repair. I have racing friends that are searching for a good used Northstar for around $1,500. It's the R&R that is the real problem!!! I am trying to find out if the repair is worth the purchase. The car is very clean. If you are searching for a simular engine, I may be able to help you find one!!!

speedyman_2
07-04-05, 02:49 PM
What's up guys. The old motor is at the place where I got the new one. I have no room to store it. So, I'm not sure if I can get anything off it. If someone wants something I can try and ask them. I took the plug wires, throttle body, mounting plate, and the top noise cover. Other than that there's a complete engine sitting there minus accessories. I'm sure the intake manifold and heads are inperfect shape. except the side where the knock was. I'm not too sure about that side.

greggbruce
07-04-05, 08:51 PM
What's up guys. The old motor is at the place where I got the new one. I have no room to store it. So, I'm not sure if I can get anything off it. If someone wants something I can try and ask them. I took the plug wires, throttle body, mounting plate, and the top noise cover. Other than that there's a complete engine sitting there minus accessories. I'm sure the intake manifold and heads are inperfect shape. except the side where the knock was. I'm not too sure about that side.
so what city do you live in?? I can't access your public profile for some reason,
have you TOLD them you want the old motor?? I mean, it IS yours, they didn't pay for it, and I assume they didn't quote the labor as needing your engine as part of the deal....
email me, if you can read my profile, I might be interested in your old motor.

greggbruce
07-04-05, 08:54 PM
I just discovered this site to learn more about an STS I may buy. It has the same rod knock noise ( piston hitting the head) ...2 mechanics agree, the awful sound is a biggie. A friend wants to sell me the '93 STS for $2,000, 122,000 miles, all black with a very clean tan interior. The car is in great shape other than the engine glitch. I will be able to negotiate the final price, if I can AFFORD the repair. I have racing friends that are searching for a good used Northstar for around $1,500. It's the R&R that is the real problem!!! I am trying to find out if the repair is worth the purchase. The car is very clean. If you are searching for a simular engine, I may be able to help you find one!!!

I dunno, book value here is around 3600, I gave 1300 for my 256,000 mile 93, I'm driving it every day, but it does need some tlc, and paint. .... and 4 new struts, boy I wish I could find a set of good active struts for less than 450 bucks a piece.

speedyman_2
07-04-05, 09:04 PM
so what city do you live in?? I can't access your public profile for some reason,
have you TOLD them you want the old motor?? I mean, it IS yours, they didn't pay for it, and I assume they didn't quote the labor as needing your engine as part of the deal....
email me, if you can read my profile, I might be interested in your old motor.

I can't send you PM's either. I'm located in San Diego. I'm not sure but I can see if they'll give me the engine. if you're not nearby I dunno how I can ship it. I'm in the military so it would be really hard for me to keep it anywhere. And, I plan on going on leave soon. I can call tomorrow and see what they've done with it if you want. My email is speedyman_2@yahoo.com

cart69
07-05-05, 02:19 PM
again i just want someones old trashed motor to play with wanna build it and put into something, possibly a 3rd gen firebird??

98SEVILLESTS
07-05-05, 10:38 PM
I also have a 98 Sts with 119,000 miles on it, still in pefect condition. I had that knock sound and the cadillac dealer told me on friday tht the piston is hitting the head. Before this problem me car poured smoke out the tailpipes (coolant smell). Where did you find that motor Speedy Man 2? The dealer told me it would be $6000 for a reman motor but i said no so they're lookin for a used one.

greggbruce
07-06-05, 01:57 AM
I can't send you PM's either. I'm located in San Diego. I'm not sure but I can see if they'll give me the engine. if you're not nearby I dunno how I can ship it. I'm in the military so it would be really hard for me to keep it anywhere. And, I plan on going on leave soon. I can call tomorrow and see what they've done with it if you want. My email is speedyman_2@yahoo.com
hey, thanks for the offer, but that is too far away for me, I'm in Kansas City, so let someone else have it, I'm sure it's not the last one up for grabs.....
thanks again,
---gregg

speedyman_2
07-06-05, 02:17 AM
I also have a 98 Sts with 119,000 miles on it, still in pefect condition. I had that knock sound and the cadillac dealer told me on friday tht the piston is hitting the head. Before this problem me car poured smoke out the tailpipes (coolant smell). Where did you find that motor Speedy Man 2? The dealer told me it would be $6000 for a reman motor but i said no so they're lookin for a used one.

I got lucky. I went and searched a bunch of Auto Dismantlers. I found they only guy that deals with Cadillacs. No one else did. By some miracle he had a 1998 STS. With pretty much nothing but the motor left. He's been there for a long time and he said this was probably the 3rd or 4th STS he's had. They we're pretty much waiting for someone to come get the motor so they could junk the rest of the car. So, now, there's no STS motors there anymore. Except mine, which is done for. If you're near San Diego I can give you his phone number. Email me at: speedyman_2@yahoo.com

98SEVILLESTS
07-06-05, 06:37 PM
I am in Minnesota so no thanks. They dealer found a used motor for $3900, screw that ill find a cheaper one....if i even need a motor, what are someone elses opinion? Or does anyone else know of a usedmotor for sale?

Spyder
07-06-05, 08:12 PM
I found a whole helluva lot of them on junkyarddog.com All kinds of price and miles variations, and most all of those places will ship them to you. You should be able to find one on there with some kind of warranty... good luck!

cl1986
07-06-05, 10:26 PM
Damn, every time I see "blown northstar" I think someone stuck a supercharger on a northstar... and every time so far I've been disappointed.

Yeah whats the deal??

Syder, arent you blowing one sometime or was that someone else?

chevyorange
07-08-05, 09:05 PM
I am in Minnesota so no thanks. They dealer found a used motor for $3900, screw that ill find a cheaper one....if i even need a motor, what are someone elses opinion? Or does anyone else know of a usedmotor for sale?

$3900? Ugh.

My beloved STS is in the shop right now, engine being rebuilt for $2850 (7 year, 100,000 mile warranty) + $1300 R&R labor.

I was trying to find used for a couple months but they were just too expensive and no guarantee that they weren't already in decline.

My car had 91k miles on it, major leak sprang at the split block (right on to the cat-con, can you say "fire risk"?), cracked head, and head gasket problem. I decided to go all the way because I do love the car and it was paid for.

I can't wait to get it back, I wonder if I'll get a few extra ponies?? (Like it needs it).

Adam

Canuck97
07-09-05, 01:40 PM
Ebay has a bunch of VERY cheap N* motors. Buyer beware of course. I've got a 97 that is getting long in the tooth (runs good for now), anybody know if a 2000 or newer engine will work? Would i just need to utilize my old ignition system?

Canuck97
07-09-05, 01:44 PM
Check this one out.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7985522621&category=33615

eldorado1
07-09-05, 04:04 PM
Just FYI, that's a 2000 engine. I tried sending the seller a message, but ebay said the "message system was down"...

It will not work in a <99 car. At the very least it uses a different crank sensor angle.

maydog
07-11-05, 02:17 PM
Hell,

I know where you can get a whole lot more than just the motor for $3000

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=6151&item=4560688196&rd=1

(A shameless plug, I know)

greggbruce
07-11-05, 03:46 PM
heya maydog, have you tried just changing the solenoids??
usually when you have 1st and 4th, or 2nd and 3rd, one of the solenoids is bad and replacing them both helps-- might be an inexpensive fix, and an increased sale!!

maydog
07-11-05, 05:54 PM
This has been addressed in another thread, the solenoids are melted indeed - but I also cleaned out a significant amount of metal and debris from the pan. I think that I could get 2nd back if I tried.

If you want to find prices on used engines and transmissions, www.partshotlines.com has a nice LIVE search. It helped when I was replacing the engine in my car.