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1999 Cadillac Seville STS
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447 Posts
Discussion Starter #1
Ok. I'm about 1000 miles into this rebuilt engine. Can anyone tell me why I would still be smoking? It smokes terribly when I downshift and anytime I am braking after exiting the interstate or after traveling at high speeds. 99 Seville STS. Here's what was done:

Jakes head kit installed
new rings Sealed Power
New bearings (main and rod)
New gaskets upper and lower
Heads pressure tested before installing. Tested ok.
Ran it at less than 3500 rpm first 500 miles. (very difficult for me)

I was told by the mechanic that it would probably take a while longer for the rings to seat since they aren't cast steel. Anyone know what I should do. One guy told me b/c these are the type of rings I need to pour drano down into the engine. Another said put some type of pellet and cold crank the engine to seat the rings. Another said drive the hell out of it. I'm confused. What should I do. I'm this far >-< from parting it out and buying another seville that already runs. Ugh!!!! One with a/c too. LOL.
 

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White Diamond '03 DHS (with DTS floor shift)
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I have no answer, but why in the hell did you replace the rings and bearings? The lower end will last til the car rusts into a pile of dust.
 

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1999 Cadillac Seville STS
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447 Posts
Discussion Starter #6
The rings were a mess. Water had gotten into the engine. The rings were stuck and walls had some rust (weren't pitted tho).
 

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1999 Cadillac Seville STS
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447 Posts
Discussion Starter #7
I may have to start over and get a whole new engine I suppose. This one I will do completely myself rather than waste 1400 dollars paying someone who doesn't know what they are doing only to stud the engine and redo the lower end. The original bearings all looked good too when he removed them. Not many good mechanics in the area here. I may just try and see if Jake has an engine he will sell me, save my money up and do it that way. Very disappointed.
 

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97 ETC x2, 04 GXP, 04 STS x2, 97 ESC, 99 Deville, 05 SRX
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2,602 Posts
Micah - please contact John Livingston (also has a thread about a damaged crossover in the Northstar section) and ship that spare crossover you have to him please - I will pay for the shipping because I promised John one a while ago and never got to it (I feel so bad)-

UPS shipping kind of didn't tell me the full truth - engines are still costing me $400-$600 to ship after all is said and done. If you're interested in one; and have about 2-3 weeks to receive it, and can pay me now, I'll waive the shipping costs. That 2-3 week advance on money is worth a lot to me right now. It won't smoke or overheat, it'll run like a champ and it will be all remanufactured, studded and re-sealed. $3950 to your door. Subtract $50 to please ship that crossover to John- $3900 even. I pay the duties and taxes. I need to order some exhaust valves and bearings before I can build it up.

Ranger - the odd Northstar does need bearings and at least have the pistons removed and rings/grooves cleaned manually. On higher mileage units, the exhaust valves need to be ground or replaced. Quite often the exhaust valves have such deep pits in the seat area that machining is not an option - you run out of valve material. And while the bottom end is almost bulletproof, I've seen a few that have had scoring and pits in the bearings and replacing them in time will prevent the need for crank machining. I think for the most part, bearing condition relies heavily on oil change intervals, oil type, and not overheating too much...
 

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1999 Cadillac Seville STS
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447 Posts
Discussion Starter #10
This project has pretty much soaked up all my money. LOL. It'll have to wait. I emailed you about it. I have about 3000 into this engine alone already. Seriously. Anyways, I can't pay now. I might just drive it up there, smoking and all. LOL. My bumper is black from the dang smoke coming out.
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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67,921 Posts
Burning oil after coastdown isn't rings - it's valve stem seals. Were the heads disassembled and checked ? Cams and cam followers ("lifters") inspected for excessive wear ?

Don't pour anything into the engine - not even seafoam. None of that will give you anything but grief.

Piston rings aren't spring or cast steel - they're cast iron. The oil control scraper ring may or may not have spring steel side rails or a waffle pattern backing ring.

......and exactly where is the oil level on the dipstick - right now ???

<------- ADD ?????????? OPERATING RANGE -------------------O
 

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1999 Cadillac Seville STS
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447 Posts
Discussion Starter #13
<low-[x------]=======. X marks the spot. Not quite in low but also not normal. The rings are sealed power. Waffle design on the oil scraper. I had heads tested. Not rebuilt. Tested ok so didn't rebuild at machine shop
 

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97, 97, RIP 98, 99 STS with Jakes studs
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718 Posts
Burning oil after coastdown isn't rings - it's valve stem seals.
Glad to know that. But what causes a huge puff at acceleration after idling for for 5+ minutes?

Miwise i usualy top up and hit the reset on the trip meter to watch oil consumtion. Just wait till is says "check oil level" then do the math. How fast can valve stem seals lose your oil?
 

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1999 Cadillac Seville STS
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447 Posts
Discussion Starter #16
It was in the middle of ok range day before yesterday after oil change. Now needs oil again 100 mi later bc it's already low.
 

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1999 Cadillac Seville STS
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447 Posts
Discussion Starter #17
Ok. Talked to the guy who pressure tested the heads. He seems to think that the rings were improperly installed by my mechanic. he doesn't think the heads are bad. Said the rings could have been installed upside down or a number of other things. He doesn't think its the heads because of the sheer amount of oil its producing.
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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OK - I didn't go there: If the oil rings are installed upside down all 8 pistons literally act like an oil pump and, yes, you will burn oil at an incredible rate. Oil rings are tapered - by only a couple of thousandths of an inch, but they're designed to act as a scraper on the downstroke.

If the oil rings were installed upside down that's not your labor or repair problem. The new ring package instructions are very specific on where and how to install each ring.
 

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1999 Cadillac Seville STS
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447 Posts
Discussion Starter #19
I talked to the guy who installed them. Of course he says he installed them correctly but I'm not so sure. I'm very annoyed. Ugh. I paid him a lot of money. I guess the only thing I can do is to either sue him or to trash the car b/c i'm so sick over the whole ordeal its just incredible. I may put it to the side a few months until I cool down about the whole thing and just park it for now. I can keep driving my mustang until I get around to it. BTW. Would the engine even have compression if the rings were upside down? just curious.
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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67,921 Posts
Sure - some upper compression rings are stepped in order to allow combustion pressure to literally "push" the ring into intimate contact with the cylinder wall. You install them upside down and you still have compression -

BUT there's a hint here - your earlier post says compression of 127 - 140 psi. That is uniformly about 20 psi low for your year Northstar. Something is amiss, and with new rings and checked heads the compression pressures should be a LOT closer together than 13 psi.
 
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