question about new rebuild on 99 sts
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Northstar Engines and System Technical Discussion Discussion, question about new rebuild on 99 sts in Cadillac Engine Technical Discussion; Sounds good to me. :-). I do have another question though now. It seems that the valve train is very ...
  1. #1
    miwise is offline Cadillac Owners Fanatic
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    question about new rebuild on 99 sts

    Sounds good to me. :-). I do have another question though now. It seems that the valve train is very noisy Mostly near the rear of the engine. I added more oil b/c it's been burning oil (new rings and bearings) but the valves seem to be very very noisy. No overheating or anything though. I took it out on one trip so far to town and back. By the time i got back the valve noise was very distinct. Had a tick tick tick sound when running. I think something's wrong. Almost like not enough oil is getting to the rear of the engine. I put about 80 miles on the car so far. I did go up to approximately 3000 rpm once. For the most part hovered b/w 2000 and 2500 rpm the whole trip.

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    Submariner409's Avatar
    Submariner409 is offline If it won't run, stick on fender vents
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    Re: question about new rebuild on 99 sts

    Ticking and valve train noise is usually due to wear in a hydraulic lash system.

    Your engine was the last year to use flat tappet cam followers. 2000+ went to roller cams. The 1999 and back are prone to dishing the followers with subsequent cam lobe damage. ANY thought of overhaul should include a complete cylinder head(s) teardown and inspection - valve seals, cams, bearings, and followers (and make no mistake: cams and followers are literally worth their weight in gold - today's gold !).

    There was a thread (in the Northstar Performance Forum) done by Jake (www.northstarperformance.com) last fall with a bunch of pictures of worn followers and cams, and another by someone else where the follower had actually worn through, hit the valve retainer, and dropped the valve into the cylinder.

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    miwise is offline Cadillac Owners Fanatic
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    Re: question about new rebuild on 99 sts

    I'll look that up. I had them tested at a local machine shop. They said the heads were good. IDK. I'm gonna check into the pics of those tho.

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    miwise is offline Cadillac Owners Fanatic
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    Re: question about new rebuild on 99 sts

    It sounds almost like theres no oil getting to the last valves near the side with the waterpump.

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    miwise is offline Cadillac Owners Fanatic
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    Re: question about new rebuild on 99 sts

    Do you think that it just needs to be broken in some more? Scared to run it as is. I read a post about using thinner engine oil. May try that when I get back. I left the car in alexandria for now.

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    miwise is offline Cadillac Owners Fanatic
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    Re: question about new rebuild on 99 sts

    Also, how critical is it that the harmonic balancer be torqued down. Could this be the problem? Could I maybe not have torqued it enough and the oil pump not be giving me the oil flow required?

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    Re: question about new rebuild on 99 sts

    It is EXTREMELY important. The clamping force is what drives the oil pump. Not enough torque and the oil pump does not work.

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    miwise is offline Cadillac Owners Fanatic
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    Re: question about new rebuild on 99 sts

    I thought I got it tight but gonna Check. :-(

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    miwise is offline Cadillac Owners Fanatic
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    Re: question about new rebuild on 99 sts

    Exactly how tight should it be?

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    STSS is offline Cadillac Owners Enthusiast
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    Re: question about new rebuild on 99 sts

    I think the spec is 37 ft/lbs + 120 degrees.... That ended up being pretty tight when I did mine.... Not sure you can overtighten it.

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    Re: question about new rebuild on 99 sts

    TIGHT !!!

    37 ft/lb + 120 degrees. The flexplate needs to be locked to reach that torque.

    You'll need to remove the RF wheel and fenderwell liner for clear access to the harmonic balancer bolt and then lock the flexplate using the inspection port between the bottom of the transmission and engine block. Either a wooden wedge or an assistant with small crow bar to lock the gear.

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    Re: question about new rebuild on 99 sts

    Hi miwise,
    on another post you talked about some headlights at your local salvage yard.

    Could you email me when you have time?

    basscatt at hotmail dot com

    Thanks

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    miwise is offline Cadillac Owners Fanatic
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    Re: question about new rebuild on 99 sts

    That's cool basscat. I emailed you. Just let me know. I'll do whatever I can to help ya. Thanks sub!! Sounds doable. I didn't have a torque wrench. I believe I need to tighten it more. Gonna get my dads torque wrench and go do that today probably.

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    Re: question about new rebuild on 99 sts

    Micah, I go beyond 250 ft. lbs. I am very picky about torque on that bolt. That 250 ft. lbs is with the bolt soaked in penetrating lubricant and also WD-40 on the inside of the balancer. Remember to very lightly grease the outside of the balancer so the front crank seal is slightly lubed up.

    When the torque wrench clicks at 250 ft. lbs, I give it a bit more. In this case; better too much than not enough. A bit of extra torque will not damage anything. Too loose it will cost an engine. If you feel the bolt begin to stretch; remove it and get another one. I've thrown out 3 or 4 so far that did not handle the torque. I know what GM recommends. I'm not exactly content with that torque.

    Should the bolt ever snap in the crankshaft (crank threads will not strip out, don't worry), it will remove easily by tapping with a center punch in the counter clockwise direction or if need be; a small drill bit and an easy-out.


    Need parts for your Northstar Engine? www.northstarperformance.com

    Jake Wiebe, developer of the SureGrip™ Cylinder Head Stud Kit

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    miwise is offline Cadillac Owners Fanatic
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    Re: question about new rebuild on 99 sts

    I'll try that. Funny the low oil pressure light never came on. I'm prettycertain it's the culprit tho

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