Primary timing chain sprocket wear?
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Results 1 to 14 of 14
Northstar Engines and System Technical Discussion Discussion, Primary timing chain sprocket wear? in Cadillac Engine Technical Discussion; Was tearing down a 96 STS block and noticed what looked to me to be some excessive wear on the ...
  1. #1
    32vmonte is offline Cadillac Owners Member
    Automobile(s): none
    Join Date
    Mar 2009
    Posts
    98

    Primary timing chain sprocket wear?

    Was tearing down a 96 STS block and noticed what looked to me to be some excessive wear on the primary timing chain sprocket bearing, and intermediate shaft.

    Tell me what you guys think. I found the sprocket on rockauto but can't find the intermediate shaft.

    The sprocket from rockauto I would assume has the bearing already in it?

    Also can I reuse the oil distribution plate/gasket. I can't seem to find replacement for that either. The bottom picture will be the dist. plate. Not to sure on that item.


    I took one of my cams off and noticed too that the cam had left a dent in a couple of lifters. Possibly when the motor sat with the cam lobe point right on the lifter.


    My question is if I can see and slightly feel the indentation they need to be replaced correct?


    I think that's it for right now on the questions If any others arise then Ill prolly have to make a whole new topic.







    You can see here how on one side the end is all grooved up.




    And then here you can see the back of the shaft is grooved up but now the front is smooth.




    Then you can see here where it fades in on one side and fades out on the other.





  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    32vmonte is offline Cadillac Owners Member
    Automobile(s): none
    Join Date
    Mar 2009
    Posts
    98

    Re: Primary timing chain sprocket wear?

    Oh yea forgot to add a very important detail. The reason for the tear down was because I lifted the whole rear head thus dumping coolant into the oil pan over about a week or so It then slowly fried all my rod bearings until they almost all spun. So alot of bearing material has been around the motor.

    The rods I believe are done for because on a couple there is very deep grooves where the bearing was rotating in there no longer seated in its notch. That would make them out of spec I'm sure.

    My next question is do you think that my cam carriers (not sure if that's what they are) are ok after all that bearing material was passed around? I popped one cam off and the cam itself looks excellent not a scratch on them, but what they sit on have slight wear marks.

    There aren't bearing on the cams so what would you do if they where toast, head replacement?



    What is the exact procedure for checking the heads for warpage? I read in the FSM use a straight edge and a feeler gauge. Does anyone feel it is necessary, I overheated it a prolly 2-3 times but I pulled over the first two times, and the third drove maybe a half mile or so in 4 cylinder mode.

    I had other times when it went to 4 cylinder mode for maybe 20-30 seconds while cruising it then popped back to normal and I continued on.

  4. #3
    Ranger's Avatar
    Ranger is online now Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    70,492

    Re: Primary timing chain sprocket wear?

    If you spun the bearings you're looking at a complete rebuild and new crank? Why not just get a salvage engine and stud the heads. Lower ends are usually bullet proof.

  5. #4
    32vmonte is offline Cadillac Owners Member
    Automobile(s): none
    Join Date
    Mar 2009
    Posts
    98

    Re: Primary timing chain sprocket wear?

    Yes I am already purchasing a reman. crank from rockauto It includes bearings and all. So $280 and the crank and bearings are set. I then need rods. Im gonna upgrade to eagle's because I plan on a large shot for the motor. I already have the pistons, they are arias 13.1 compression.

    I read around and thought I seen the crank was good for some pretty high horsepower so Ill then have a fully built motor.

    So your saying my heads are messed up too from the bearing material. They had only about 10K on them and not ran long at all with the bearing material in the oil. I parked it right after it started to knock.


    Is there anyone who can answer any of these questions? A short block isn't the answer I just need to rebuild this one. Salvage motor would be a downgrade in about 100hp.




    Does anyone know where I can find a gasket for the backfire valve deal on the intake. It was missing a section and Im assuming it was causing my high idle due to a vacuum leak.

  6. #5
    32vmonte is offline Cadillac Owners Member
    Automobile(s): none
    Join Date
    Mar 2009
    Posts
    98

    Re: Primary timing chain sprocket wear?

    Bump for help that is needed. Hopefully I can get some of these questions answered. As you read through there are alot of Q's.

  7. #6
    Submariner409's Avatar
    Submariner409 is offline If it won't run, chrome it
    Automobile(s): 2002.5 F55 STS/65500mi, 2004 Ford F150 SuperCab4x4
    Join Date
    Feb 2006
    Location
    MD Eastern Shore - Kent Island
    Age
    74
    Posts
    41,621

    Re: Primary timing chain sprocket wear?

    The entire cam chain drive needs to be replaced, chains and intermediate sprocket. The slippers and tensioners are probably worn excessively. The hydraulic adjusters for the chains need to be cleaned well.

    All the hydraulic lifters need to be replaced. Once a cam has worn through the case hardening on the lifter face, wear progresses to destruction rapidly. You need to have the cams (lobes and journals) checked. With that kind of wear and debris circulating in the engine, cam wear is almost certain. The cam did not "dent" the lifter: that's wear.

    You need a new oil pump. Don't forget that crankshaft damper torque is critical because that insures the oil pump is driven correctly without slippage (total loss of lubrication). Break the new engine in on Shell 10W-30 Rotella Fleet oil. Find and use the correct WIX oil filter for the '96 engine.

    You need to completely strip the block and get it hot with water and detergent, and with a long engine overhaul brush set from Summit, scrub out every oil passage in the block and heads. Rinse well with HOT water and blow dry. You leave any metal in the oil passages and you're immediately back to Square One.

    With new (oversized ?) pistons and rings, talk to a GOOD engine shop about what ring gaps and honing pattern to use. If you're going to 13:1, you'll need to do some clever timing and fuel mixture adjustments, as well as run the highest octane pump fuels you can find. You mention a large shot of nitrous - your call, but very dangerous in this case, especially at 13:1. You should have the engine shop do a complete valve overhaul.....with the bearing material everywhere, the valve seals are probably toast. Use Iskenderian or CompCams assembly/break-in lube on the cam lobes.

    Be very careful with the new con rod lengths: the piston clearance is already very close at TDC. Deck height and compressed gasket thickness need to be checked so you don't hit valves or the combustion chamber quench area. I think you are using studs for the heads. Only way to go. Talk to CHRFAB about copper/stainless sandwich head gaskets.

    Lots more to consider........rebuilt the transmission and put new final drive gears in. Use the new synthetic DEXRON-VI fluid. Remember that it's a dry sump unit, so the fluid has to be checked at idle, in P, hot. There will be no fluid on the stick with the engine off - none.

  8. #7
    32vmonte is offline Cadillac Owners Member
    Automobile(s): none
    Join Date
    Mar 2009
    Posts
    98

    Re: Primary timing chain sprocket wear?

    That intermediate shaft still needs to be replaced correct? Where can I get it? If I get the new sprocket does it have a bearing in it?

    Also this really blows the heads are CHRFAB ported/polished, with new seals, guides, reground 272 cams.

    So these basicly brand new heads are completely useless? I am about to give up because this is more money than I can handle. Sadly it looks like it is gonna cost more than I make a year.

    If the journals on the heads are to far gone what do I do? Replacement will mean I take this whole car and motor to the junk yard. It's not worth the money.

    My rings should still be ok. They have about 10K if not less on them. I was planning on popping them back in.

    So all the timing components need to be replaced because they are causing wear on primary chain sprocket?

    Also there where only a couple of lifters that had the indentation in them. I wonder why that is?

    What about the oil distribution plate I am still unsure on what I need to do with it. Can't find anything for it.

    Thanks for the info.

  9. #8
    Submariner409's Avatar
    Submariner409 is offline If it won't run, chrome it
    Automobile(s): 2002.5 F55 STS/65500mi, 2004 Ford F150 SuperCab4x4
    Join Date
    Feb 2006
    Location
    MD Eastern Shore - Kent Island
    Age
    74
    Posts
    41,621

    Re: Primary timing chain sprocket wear?

    The timing chains and sprocket sets are probably dealer only. The sprockets and axles in your car are shot. The way those sprocket axles are grooved looks like an improper assembly job after some sort of timing chain work. Try www.gmotors.com (Palm Chevrolet/Cadillac, Gainesville, FL), www.gmpartsdirect (Flow Chevrolet/Cadillac, Winston-Salem, NC) or Luke at Lindsay Cadillac in Parts, over there ----------->

    If the complete heads are from CHRFAB, they have to go back to them with an explanation and pictures of what happened. They will also tell you they need to replace all the lifters. Pray than one or more cam lobes aren't already worn. Don't forget that the head oil passages and lifters are now full of bearing dust.

    New pistons, old rings ?? No cylinder-to-piston fitting ?? That's a no-no, even in a used car lot midnight special........

    My opinion is still out on the crankshaft machining. The Factory Service Manual specifically states that the crank NOT be remachined. It must be replaced with a new unit. After this head fiasco, I'd hate to see you throw one of those new rods out the side of the block........

    The distribution plate needs to be cleaned to brand new specs and reused.

    I don't want to burst your bubble, but putting together the pictures, bits and pieces of this thread into what now looks like an attempt to build a sand rail Northstar for a daily driver appears to have been the start of a vast project with half-vast ideas....... You really needed to tear down the entire engine and start from scratch. Based on a lot of engine building experience, I'd guess that type of Northstar, built on a good core, with studs, using some custom parts, would cost in the area of $8,500 - $10,000. I'll bet you already have $2000 in the pistons and rods, not to mention what CHRFAB hit you for the heads the first time. (It's good that they left the cams at a fairly mild street grind.) Check out the thread close to this one...."Check out my head gasket job in the car....". Might be some insight there.

  10. #9
    dkozloski's Avatar
    dkozloski is offline Cadillac Owners 10000+ Posts
    Automobile(s): 2006 STS V8 AWD, '95 Ford Ranger
    Join Date
    Jul 2004
    Location
    Fairbanks, Ak
    Age
    74
    Posts
    26,108

    Re: Primary timing chain sprocket wear?

    A NorthStar crankshaft cannot be reground in the field because the journals are rolled to prevent cracking and this cannot be duplicated outside the factory.
    Don't mess with Binky Bear!


  11. #10
    32vmonte is offline Cadillac Owners Member
    Automobile(s): none
    Join Date
    Mar 2009
    Posts
    98

    Re: Primary timing chain sprocket wear?

    Quote Originally Posted by submariner409 View Post
    The timing chains and sprocket sets are probably dealer only. The sprockets and axles in your car are shot. The way those sprocket axles are grooved looks like an improper assembly job after some sort of timing chain work. Try www.gmotors.com (Palm Chevrolet/Cadillac, Gainesville, FL), www.gmpartsdirect (Flow Chevrolet/Cadillac, Winston-Salem, NC) or Luke at Lindsay Cadillac in Parts, over there ----------->

    If the complete heads are from CHRFAB, they have to go back to them with an explanation and pictures of what happened. They will also tell you they need to replace all the lifters. Pray than one or more cam lobes aren't already worn. Don't forget that the head oil passages and lifters are now full of bearing dust.

    New pistons, old rings ?? No cylinder-to-piston fitting ?? That's a no-no, even in a used car lot midnight special........

    My opinion is still out on the crankshaft machining. The Factory Service Manual specifically states that the crank NOT be remachined. It must be replaced with a new unit. After this head fiasco, I'd hate to see you throw one of those new rods out the side of the block........

    The distribution plate needs to be cleaned to brand new specs and reused.

    I don't want to burst your bubble, but putting together the pictures, bits and pieces of this thread into what now looks like an attempt to build a sand rail Northstar for a daily driver appears to have been the start of a vast project with half-vast ideas....... You really needed to tear down the entire engine and start from scratch. Based on a lot of engine building experience, I'd guess that type of Northstar, built on a good core, with studs, using some custom parts, would cost in the area of $8,500 - $10,000. I'll bet you already have $2000 in the pistons and rods, not to mention what CHRFAB hit you for the heads the first time. (It's good that they left the cams at a fairly mild street grind.) Check out the thread close to this one...."Check out my head gasket job in the car....". Might be some insight there.

    I found the sprockets on rockauto, but I still can't find that intermediate shaft. Which will prolly be at the dealer like you said.

    The oil distribution plate should be ok from what I gather, you say clean it and reinstall. It just seemed like that seal should be replaced.

    The pistons and rings have very low miles on them. Im not using old rings on new pistons . They barely have the miles on them that I put on in a month in my daily.

    The crank that I found is also from rockauto. It is more than likely just a J/Y piece that is still in spec that they polish and pair with oem size bearings I'm sure they would not try and sell a crank that they can not turn. Here's what it says.

    MARSHALL Part # C2076 More Info {Reman CRANKSHAFT; KIT INCLUDES MAIN & CONNECTING ROD BEARINGS}
    CASTING #3525774, WITH TRIGGER FIRE WHEEL BUILT ONTO CRANK, 8 BOLT FLANGE, 18mm CRANK SNOUT BOLT HOLE
    * Non-stock item--shipping delayed up to 7 business days

    $282.79


    The story behind this is I bought a 95 Monte Carlo that had been swapped with the N* and tranny from the caddy.





    So I started to have some issues. Well eventually I spun some bearings in the lower end some how, I'm guessing it was from all the coolant in the oil. Pulled the dipstick out multiple times to check the oil and it was never milky.

    Well I call the shop who built the motor and the guy remembers the motor off hand and says they had to repair a couple of head bolt threads with helicoil (sp) . That is my main cause for the HG fail.

    The guy who built the car spent around 8K on the motor alone. It was brand new built from top to bottom before the bearings where spun. It had the CHRFAB head package with cams, and the 13.1 pistons.

    So the motor was already built mildly with all brand new components and very low miles when I purchased it, the only thing that it needed was the head studs and that would had prevented this whole ordeal......

    Thanks for all your advice guys.

  12. #11
    32vmonte is offline Cadillac Owners Member
    Automobile(s): none
    Join Date
    Mar 2009
    Posts
    98

    Re: Primary timing chain sprocket wear?

    Talked to a tech at the caddy dealer for about three hours and he helped alot. There is a shop right down the road from me that does all the head work for the N* they do HG jobs on. Looks like thats where Ill take my heads to get all checked out.

    He told me also not to re-use the oil distribution plate. He said to purchase a new one because the gasket it's self can't be changed. He also said to use the rtv sealant on the oil plate to better seal it. They are known to leak also you can't see it tho.

    The deal with the primary timing sprocket, the tech said it could be because the bearing material combined with the bearing being worn already. If the tensioners are not visibly worn they are ok.

    The tech even started tearing down a motor for me to show what to look for.

    Real cool guys at my local dealer. Even offered to install my rear seal for me so I don't have to track the specialty tool down.

  13. #12
    tateos's Avatar
    tateos is offline Cadillac Owners Connoisseur
    Automobile(s): 1997 ETC (GAVE TO STEPSON 2011), 2000 DTS (RIP)
    Join Date
    Jul 2007
    Location
    FOUNTAIN HILLS, AZ
    Age
    57
    Posts
    1,711

    Re: Primary timing chain sprocket wear?

    Yeah - I payed almost $300 for the rear main seal tool direct from SPX. 30 seconds of use and it was done - collecting dust now. I did see someone here on the forums found one on e-bay for around $25 - what a deal!

    Anyway, you are fortunate to find someone at the dealer to help you. I think his help is worth some green cash, or least a case of beer - probably multiple cases!

  14. #13
    Submariner409's Avatar
    Submariner409 is offline If it won't run, chrome it
    Automobile(s): 2002.5 F55 STS/65500mi, 2004 Ford F150 SuperCab4x4
    Join Date
    Feb 2006
    Location
    MD Eastern Shore - Kent Island
    Age
    74
    Posts
    41,621

    Re: Primary timing chain sprocket wear?

    32V...........You're lucky to find a GM tech that will assist you.......stick an 8 gig flash drive in your left ear and suck up all the info........

    Good luck with the engine job........!!!!!

  15. #14
    cl1986's Avatar
    cl1986 is offline Cadillac Owners Connoisseur
    Automobile(s): 94 Eldorado, 94 SLS got crushed
    Join Date
    Jun 2003
    Location
    South Dakota
    Age
    35
    Posts
    1,485

    Re: Primary timing chain sprocket wear?

    32V

    what did you end up doing?

    Im trying to find your info on the N* in the monte, where is that at? Do you just bolt the N* down to the monte cradle?

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting