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Thread: Noisy Valve Train Troubleshooting

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    Noisy Valve Train Troubleshooting

    My engine was abused my previous owners not using the OEM Toyota oil filter.
    This is my next step before a top end rebuild.

    http://www.hilux4x4.co.za/views/view...hp?f=3&t=19982

    Best info begins about post 7, from mr B.

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    Re: Noisy Valve Train Troubleshooting

    I agree with him, but one possibility he didn't mention is an improperly installed rocker shaft. On the 4y it's possible to install this upside down (I've seen it before). The shaft has flat spots machined in it at the mount locations. The flat spots for the bolt heads are not as big as the flat-spots that contact the head. If it's mounted upside down the valve clearance will be increased dramatically and will make noise. Check to make sure it's right side up. (Note: on the rear mount, the bottom is machined flat all the way to the end of the shaft). Tim




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    Re: Noisy Valve Train Troubleshooting

    Thanks Tim!

    One thing I have noticed is that I have a different ticking noise when engine breaking / coasting.

    I have 220,000 miles. Supposedly the bottom end was rebuilt before I got it. I think it was an only what it NEEDED effort.

    As soon as I have time to dig into this I want minimum down time.

    What's the chance I will find excessive wear to the timing cogs, chain, pushrods ect????
    I'm planning on replacing the lifters and cam. Timing Chain tensioner.

    Can push rods we welded up and re ground to length?
    What is proper preload on the pushrods and lifters?

    Thanks!

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    Re: Noisy Valve Train Troubleshooting

    Quote Originally Posted by coronan View Post
    What's the chance I will find excessive wear to the timing cogs, chain, pushrods ect????
    I'm planning on replacing the lifters and cam. Timing Chain tensioner.

    Can push rods we welded up and re ground to length?
    What is proper preload on the pushrods and lifters?

    Thanks!
    If it's got over 200k miles on it I'd replace the entire timing set. You'll get the best price when you buy everything in a kit (chain, sprockets, tensioner). Before purchasing the timing set, I'd recommend reading this post: https://www.toyotavantech.com/forum/...2491#post12491

    I would only modify pushrods as a last resort. These are still available from Toyota. Pushrods are one of those rare things that Toyota actually sells for less $$$ than aftermarket. Unless the head has been over shaved or the valves were ground incorrectly you won't need to worry about preload. Valves are not adjustable on the 4y. As long as parts are machined to factory recommended specs the preload (lash) will automatically fall into the happy zone. Even if things aren't perfect the 4y uses hydraulic lifters and they will compensate for minor variations to machine tolerances.

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    Re: Noisy Valve Train Troubleshooting

    Good news: Rocker shaft is right side up!

    Any advice on getting lifters out of their bores with the head on?

    They begin to slide up with a magnet about 3/4 of an inch then stop. (Mushroomed???)

    It's pretty tight in there. I don't see how to grip them with pliers.

    While in there I measured up push rods but I don't have a tolerance.

    146.23mm at the shortest
    146.30mm at the longest

    My book doesn't mention a torque spec for the Rocker arm shaft.

    Tim, I eagerly await part 13 of the 4y rebuild!

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    Re: Noisy Valve Train Troubleshooting

    It's normal for lifters get stuck in their bores. Over the years the parts that don't touch the bores get an accumulation of residue and this makes them hard to remove. They can be very tricky to remove without 1st removing the head. There is a special tool for removing them. It has a shaft that clips into the top of the lifter and the top of the tool is a slide hammer. It can be a challenge to get a good bite on the lifters with the tool, but if you remove the spark plugs and spark plug tubes you can get your fingers in there for better access.

    Here's the torque information from the service manual:


    As for the blog, the engine rebuild has been compete for some time, but my time has been very limited. When I get caught up on other things I plan on finishing the rebuild blog. Thanks for your patience. Tim

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    Re: Noisy Valve Train Troubleshooting

    Thanks!
    It damages the old lifter but I've herd of screwing a bolt or screw into the top of the lifter to pull it out. And clean the area with solvent.

    A number 10 machine screw is too big. A # 6 wood screw might work.
    Ill gather reinforcements and report back with what I come up with.

    Have a picture of that tool?

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    Re: Noisy Valve Train Troubleshooting

    Just be careful with screws and the like. Anything you drop down there will probably require disassembly or a lengthy fishing expedition. I have a tool similar to the one shown HERE and it works quite well. If you don't have the budget for the tool you may be able to rent from an auto parts store or you might be able to pull it out with a paint can opening tool or 90 deg pick. Just try to grab onto the snap ring groove and pull it out. I think the open part of the snap ring is large enough to possibly get a paint can opening tool in it. Good luck. Tim

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    Re: Noisy Valve Train Troubleshooting

    last week we got a 4y head back from the shop with the rocker arm shaft on upside down. my trainer said " what the is all that racket? this truck only has 8000+ hours" so we tore it down flipped the shaft, and she purrs like a kitten on propane.

    I had an 88 4wd, and it clattered from the day i bought it. I eventually figured out why the owner didnt mind letting it go cheap. the oil level sensor was missing two of the screws that hold it on the oil pan, so everytime I changed the oil, half of it would pour out into my drain pan.

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    Re: Noisy Valve Train Troubleshooting

    Quote Originally Posted by timsrv View Post
    I agree with him, but one possibility he didn't mention is an improperly installed rocker shaft. On the 4y it's possible to install this upside down (I've seen it before). The shaft has flat spots machined in it at the mount locations. The flat spots for the bolt heads are not as big as the flat-spots that contact the head. If it's mounted upside down the valve clearance will be increased dramatically and will make noise. Check to make sure it's right side up. (Note: on the rear mount, the bottom is machined flat all the way to the end of the shaft). Tim



    This lip is supposed to go towards the rear of the engine correct?

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    Re: Noisy Valve Train Troubleshooting

    Quote Originally Posted by Headhunter38 View Post
    This lip is supposed to go towards the rear of the engine correct?
    Yes, the two pics above are the back end of the rocker shaft. That lip is a good reference point when installing. It's always pointed up and at the rear of the engine. Tim

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    Re: Noisy Valve Train Troubleshooting

    Thanks for confirming that. I'm trying to track down the source of a noise in my engine and I had read this thread incorrectly. I thought I had found the source of the noise when I pulled my valve cover to check for anything loose and "found" the shaft was oriented wrong. Oh well now to check other things.

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