No announcement yet.

Need advice from experience for an M42 rebuild

  • Filter
  • Time
  • Show
Clear All
new posts

    Nope. Just take the belts off. The only pulley to remove is water pump.

    Sent from my SM-G930F using Tapatalk


      Toby probably had to remove the AC bracket in order to remove the crank sensor wire.


        At the rapid easily available rate of an m42 used engine it is definitely not worth to rebuild an engine with so many miles especially not to have just buy another used engine bro

        Sent from my SM-G928T using Tapatalk


          I received a replacement head for a reasonable price off a forum member here. I need to look for a machine shop to resurface the head.

          Sent from my iPhone using Tapatalk


            i found a local shop and getting the replacement head resurfaced and valvetrain inspected since it came with valves and springs already installed. i am going to start with the teardown but i had a question regarding the camshafts.

            i would need to remove the camshafts off my cyclinder head to transfer to the new head once it comes back from the machine shop right?

            is there a proper way of doing this? i saw a youtube video by M3NACE but i think he was doing a 6 cyl S52 head. is it the same process for an M42?

            do i have to worry about setting to TDC if i am going to remove it and transfer to new head anyways?

            does this change the process of removing the timing components?

            i was going to follow the steps set forth in the posts above in sequence:

            - remove radiator/shroud/fan+clutch
            - drive belts
            - intake manifold
            - coil packs/plug wires
            - valve cover
            - exhaust manifold
            - set cams to TDC 1
            - remove upper timing case/thermostat
            - remove all cooling lines to head
            - remove chain tensioner
            - mark and wire cam sprockets and chain together
            - remove head bolts


              Since your head is coming off, no need to worry about cam TDC being kept after you take the cam gears off, but you do want to keep bottom end TDC (which I see you did not mention) set if possible. Remember, you set TDC on the bottom end and use the top end to verify that you are at TDC1, not 180 out.

              From experience, don't bother wiring the gears to the chain, rather prevent the chain from moving where you can't easily access it (it can bunch if allowed to go slack). You can do this by gathering the chain and zip tying it away from your work area without letting the bottom move. Be certain to note the position of the dowel pins on the gears (only where the cam sensor matters) are when removed. A good approach there is to mark the cam gear to cam interface with a scribe tool or anything sharp (always use separate and unique marks where precision is desired).

              Tying the chain to the gears is also fine, but they just get in the way more than needed.


              To remove the cams/buckets just carefully and evenly loosen the fasteners. When reinstalling you will have more difficulty as the cam will probably not sit flat, but just use some pressure and go slowly. Or if you are really nervous your machine shop can reinstall the cams in the worked over head.


                Shouldnt the chain be replaced at this stage or is the chain an unnecessary replacement?


                  Chain and guides if you want to strip down the lower timing case as well. If it's an unknown change it all, if in good shape just leave it.


                    Originally posted by roguetoaster View Post
                    Toby probably had to remove the AC bracket in order to remove the crank sensor wire.
                    Yeah- might also have made the exhaust manifold easier to get off.

                    now, sometimes I just mess with people. It's more entertaining that way. george graves


                      OP, as an aside, if your budget permits you should get a 90 degree cordless ratchet. Makes this job go so much more quickly.


                        i'm for sure gonna get some new tools. i dropped it off at the machine shop last week and a couple days later they called back after inspecting it recommended to re-do the valves. ughhh, but since its out i might as well to give the car a longer life before it comes out again.

                        i need to get the timing cover to the machine shop too so they can get it even level with the head.

                        the previous owner records indicate the timing chain was replaced was serviced by quality motors in laguna niguel at 196K miles in Jan 2006. The work order showed the following parts replaced:

                        replace oil pan upper & lower gasket
                        replace valve cover gasket set
                        replace front cover gasket (timing cover) set
                        replace timing chain
                        replace chain tensioner
                        replace chain guide rail
                        replace chain rail
                        replace timing rail
                        replace p/s, a/c & alternator belt
                        replace oil filter housing gasket & o-ring
                        replace thermostat & gasket
                        replace timing case gasket

                        the odometer shows 378K now, so is this due for another overhaul since it's been supposedly 180K miles since?


                          Yep, overhaul it. Also, seems like they didn't replace the idler gear, which is big bucks now.

                          Bet your ODO has been swapped too as those miles seem suspiciously high.


                            well thats just fantastic. good thing I love this car haha


                              Are you getting the bottom end inspected?

                              at 378k miles Id be looking at making sure the cylinder walls and rings are still in spec.

                              Its probably time for valve guides to be inspected as well on the top end.


                                Yes, if that mileage is accurate it's a full fat rebuild that you'll need.

                                Glad you love the car, just hope you can afford to fix it correctly.