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2003 Suzuki w/ bad engine... Any advice?

Discussion in 'General Truck Info' started by DYNOBOB, Feb 8, 2011.

  1. DYNOBOB

    DYNOBOB Member

    I'm going to recommend they replace the chain, followers, and tensioner if we can get new.

    It appears both cams are off by one link.

    Bob
     
  2. DYNOBOB

    DYNOBOB Member

    Update

    Well here is what I'm finding. After a lot of work the crossmember, oil pan, and front cam chain cover are off (motor is suspended from above). Once I could see all the gears it appears the marks on the sprockets all lined up w/ their corresponding marks on the block. The colored links on the chain never would line up as shown in the manual however no matter how many times I rotated. It seems that the chain has stretched to the point that the tensioner bracket was hitting the back of the tensioner and wearing away both parts (see arrows in pics). There is a lot of slop in the whole tensioner system. Since the sprockets marks all seemed to line up on the block marks it has me wondering if it did jump time. Before ordering all new tensioner parts I decided to put everything back together and recheck compression. Before putting it back together I removed some metal from the tensioner bracket so it doesn't hit the back of the tensioner thus giving the tensioner more travel to keep the chain tight. Here's what is weird, I lined up all sprockets marks and installed colored links on chain to correct marks and put back together. When I rotate the crank the colored links on the chain will never return back to the marks on the sprockets they started from. Even after 6-8 full rotations of the chain (20-30 of the crank) the closest they ever return is one link off of all three sprockets. I reinstalled chain 3 times and same results. The sprocket marks however still index to the block marks.

    Any thoughts???

    Tensioner connector bracket bottoming against tensioner...
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    Worn areas...
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    Area I clearanced on the bracket
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    Last edited: Feb 15, 2011
  3. fupabox

    fupabox Active Member

    If you keep on turning the crank they will eventually line back up...takes a ton of rotations(same # of ratations as teeth on the crank if I remember ,but don't quote me on that)...as long as the chain remains tight the relationship between the cams and crank will not change (# of links) the chain marks are only for initial installation to make sure you have the correct # of links between each.
     
  4. greg0187

    greg0187 Moderator Staff Member


    I thought as long as the sproket marks indexed with the block it wouldn't matter? I guess like you say its just for initial installation. Now I see why willyboy had so much trouble timing his zuk. Kinda confusing...
     
    Last edited: Feb 15, 2011
  5. DYNOBOB

    DYNOBOB Member

    Yeah, you take the valve cover off and it appears to be out of time. The repair manual just says you may have to rotate several times to line up marks.

    I'll spin it tomorrow to see if they eventually line up.
     
  6. fupabox

    fupabox Active Member

    can't remember the method for figuring out how many rotations,but I'm sure I can google it ...something like the # of teeth per sprocket-links in the chain x the circumference of the earth on Tuesday...I'll see if I can find the true math cause now I want to know for sure as well.:frustration:
     
  7. DYNOBOB

    DYNOBOB Member

    Tight valves?

    I had not checked the valves because it seemed unlikely that all cylinders would be down on compression due to that and the cust says it was running fine all last year until Nov. Since it appears to be in time and fupa explained why the chain marks aren't lining up I decided to check the valves.

    Unless I've gone retarded it appears that the valves are all tight. I cannot get any feeler gauge under any intake (not even .002). The exhaust are all 9-10 thou. Service manual says intake 7-9 thou and exhaust 12-14 thou. To measure I had the lobe totally opposite the valve...don't know how else it could be done. Sure seems weird.

    Any thoughts?

    Bob

    [​IMG]
     
  8. fupabox

    fupabox Active Member

    yeah that is odd...any oil coking on the shim surface? all being tight suggests maybe an additive was used at some time that built up a glaze on the shim buckets or surface of the shim..dribble some seafoam or kerosene on one and let it sit a while...see if it loosens a tad...maybe engine restore or some other additive that builds up with friction was used...can't see all the valves having combustion chamber deposits,but I guess that's possible as well..looks like you found the culprit though,which is good.....my only other suggestion is carbon build up in the head,but I wouldn't pull it to check until you find if the shims are glazed ..you may just need to polish them down....also you could pull all the loosest shims and put them on 1 cylinder then check compression again on that cylinder..if the compression is up than machining/replacing the shims should be the cure
     
    Last edited: Feb 16, 2011
  9. DYNOBOB

    DYNOBOB Member

    Leakdown results

    I should have done this sooner.

    Cyl 1 @ 87%
    Cyl 2 @ 77%
    Cyl 3 @ 61%

    They match their relative compression numbers. Air escaping out the intake. Seems weird that all of them tightened up that much. I guess next move is figuring out what new shims I need. In anyone's opinion does this point to a mechanical problem other than normal seat wear? The whole inside of the motor is glazed brown but the top of shim and cam lobe are shiny. Deposits in combustion chamber or seats would cause loose not tight valves I think.

    Bob

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    Last edited: Feb 16, 2011
  10. greg0187

    greg0187 Moderator Staff Member

    Well... The valve loses its heat through the valve seat. If it doesn't seat the valve will get hot and eventually melt or burn. Could be a reason why the truck eventually got to the state it is in now. Other than that I don't have any other suggestions. Is there clearance at any point of the stroke other than TDC?
     
  11. greg0187

    greg0187 Moderator Staff Member

    After going back and looking at some of your pics (hard to tell for sure) Im guessing you wont get any clearance no matter what the position is. The intake cam lobes look shiny all the way around like they are constanly riding on the shim whereas the exhaust does not.
     
  12. fupabox

    fupabox Active Member

    I think you are correct in assuming that combustion chamber deposits would cause a loose instead of a tight clearance...I think I mis-stated what I meant by carbon build up in the head..I was referring to the coked/burnt oil on all the internal surfaces..it may be built up under the lifters as well causing the loss in clearance..it definitely looks as though the engine has missed a few oil changes or idled a lot..hopefully not stretched valve stems.shims generally have a tighter clearance than regular adjustable rockers inorder to ensure the shims remain in place. Is there any scoring on the shims ?
     
    Last edited: Feb 16, 2011
  13. DYNOBOB

    DYNOBOB Member

    No clearance at any point. I'm going to pull the intake cam and see what it leaks then and what shims are in there now. The problem is if you cant get a gauge in you cant figure out what size shim you need. I guess you put in the thinnest shim they make and see where you are.

    I wouldn't say the shims or lobes look abnormally worn. Can valve stems stretch?

    Bob
     
    Last edited: Feb 16, 2011
  14. fupabox

    fupabox Active Member

    I know they can stretch on high rpm street bikes...so I guess these little engines would semi-qualify in that category ..Although myself I have never had a stretched valve stem(serious knocking on wood..don't upset the engine gods) My bet is still build on up under the shim cups and on the tops of the spring retainers
     
  15. DYNOBOB

    DYNOBOB Member

    Update

    Today I pulled the cams and did another leakdown. All cylinders now below 20%. Pulled the shims/buckets, a lot of oil crud under the buckets. Cleaned everything, recorded shims, put together. Still can't get a gauge in the intakes. Going to order the thinnest shim avail (about 12 thou thinner) and see what happens. Hoping they give me at least 7-9 thou clearance.
     
  16. DYNOBOB

    DYNOBOB Member

    Some pics.

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  17. fupabox

    fupabox Active Member

    wow..that poor little truck definitely missed a few oil changes...has the cleanout given you any clearance?? oops..never mind..the answer is in the previous post still
     
  18. DYNOBOB

    DYNOBOB Member

    Update

    Installed the new shims and got correct valve clearance back. Compression is now around 200psi on all cylinders. Waiting on new water pump to put it back together. Leaving for BikeWeek Friday so it will be a couple weeks before it's running.

    Thanks to everyone for your input and links to manuals.

    Bob
     
  19. greg0187

    greg0187 Moderator Staff Member

    Who did you end up sourcing shims from? Expensive? I heard that they can be a bit overpriced for some vehicles. Recommend to the owner he sell it. ;)
     
  20. DYNOBOB

    DYNOBOB Member

    Update...

    I ordered the shims and special tools from the local Jacobson/Cushman Turf dealer. Shims were between $10-15 each. The killer was the special tools needed to remove the shims w/o pulling the cams...$377.00 for two little pieces of machined metal you can hold in the palm of your hand. Without them you have to hang the motor, remove the lower x-member, front drive shaft, oil pan, harmonic bal and front timing chain cover to pull the cams...

    I got the truck put back together yesterday and it started up like a new car. Runs & idles perfect and has great power. Waiting on an air filter and new water pump(back ordered) and it will return to owners. Finally Supra is back in its place in the garage :)

    Now I can get some stuff done on my truck before next trip to TN Apr 1st...

    Bob
     
    Last edited: Mar 17, 2011

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