Question about 1994 Mazda 626

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My car, 1994 Mazda 626 4cyl,would not pass emission testing. The shop said I had no compression in one cylinder. I was told I needed a valve job. As a part of that, I went ahead and had a new head gasket set. The shop has since replaced all the machined parts and the car won't start. I don't know much about car repair, but my theory is that it may be related to the timing belt and all the shop did was remove the parts that I mentioned above, sent the parts to the machine shop, got the parts back and just reinstalled. My question is: Is the timing belt a consideration in the above repairs? If yes, could they have not known that the timing belt has to be taken into consideration when you perform this kind of work?

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  • virtualinter Mar 25, 2011

    I asked a specific question about whether or not the timing belt needed to be taken into consideration when this kind of repair takes place.
    I am very worried that they have screwed up and do not know where to turn.

  • virtualinter Mar 25, 2011

    Did I just pay $20 to get yelled at?
    I asked questions because I don't like being in the dark.



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"Is the timing belt a consideration in the above repairs? Yes, the timing belt must be installed correctly or the engine will not start. The timing belt was removed and reinstalled when this repair was performed and any mechanic would know this. I would suspect it was not installed correctly and that is why your car will not start. If it will not start then it must still be at the shop that did the repair. The timing belt must be replaced every 60,000 miles so you more than likely needed a new one anyway. Let the shop you are paying to repair the vehicle sort out why it will not start.

Posted on Mar 25, 2011

  • NOT ME Mar 25, 2011

    Wow, you ask a question, and I answered it to the best of my ability. Then you accuse me of yelling at you. Nothing in my answer can be construed as yelling. I am trying to help you but your question is hard for me to understand exactly what you want to know. Lets start over and please ask me exactly what it is you want to know. No way am I yelling and so I am very sorry if you interoperate my answer that way. I am simply trying to provide you with the answer you paid for.


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  • Mazda Master
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I dont say that you have one bad work, but I suggest check this procedure, according with the repair manual... 1.5L, 1.2L DOHC (except K2) and 2.0L Engines
(see Figures 2 through 14 / click over images for zoom)

  1. As necessary, unbolt the power steering hose securing brackets from the valve cover. It may be necessary to remove the power steering pump in order to allow the hose enough range of motion to clear the valve cover.
My car, 1994 Mazda 626 - zjlimited_927.jpg

Fig. 2: Exploded view of the 1.5L engine valve cover assembly-1.2L DOHC (except K2) and 2.0L engine is similar


Fig. 3: To remove the valve cover, first unbolt any components which are attached to the valve cover...


Fig. 4: ..and ensure that any components which may obstruct cover removal are positioned aside

Fig. 5: Next, label and remove the spark plug wires from the plugs

  1. Label and remove the spark plug wires from the plugs.
  2. Disconnect the vent hose from the coMy car, 1994 Mazda 626 - zjlimited_931.jpg>

Fig. 6: Also detach the PCV valve and ventMy car, 1994 Mazda 626 - zjlimited_932.jpgm the valve cover


Fig. 7: Loosen tMy car, 1994 Mazda 626 - zjlimited_933.jpgtaining bolts evenly, over three steps ...


Fig. 8: ...then remove them. Keep the bolts in order as sMy car, 1994 Mazda 626 - zjlimited_934.jpg of differing lengths and must be returned to their original hole


Fig. 9: Remove the valve cover. Some gentle tapping with a soft faced hammer may be necessary to break the seal

  1. Disconnect the PCV hose from the cover.
  2. Loosen the cover bolts evenly over three steps.
  3. Remove the valve cover bolts, keeping them in order. Some bolts are longer than others and should be returned to their original locations. Remove the cover from the engine.
To install:


Fig. 10: Remove the old gasket from the valve cover and discard it. Clean all gasket mating surfaces thoroughly

  1. Clean all old gasket material from the cover and the cylinder head.
  2. Install a new gasket onto the cover. zjlimited_936.jpg

    Fig. 11: Apply sealer to any point on the cylinder head mating surface where the gasket must arch over a cam cap


    Fig. 12: Close up example of a cam cap arch where sealer should be placed

    1. Apply silicone sealer to the shadeMy car, 1994 Mazda 626 - zjlimited_938.jpginder head as shown in the figure.

    Fig. 14: Valve cover bolt tightening sequence for the 1.2L and 2.0L engines

    1. Install the cover on the cylinder head with the retaining bolts. Tighten the bolts in the order shown in fig33 to 52-63 inch lbs. (6-2 Nm).
    2. Install the spark plug wires to the spark plugs. Connect the vent hose and the PCV hose to the cover.
    3. Start the engine and bring to normal operating temperature. Check for leaks.


Posted on Mar 25, 2011

  • ZJ Limited
    ZJ Limited Mar 25, 2011

    Keep in mind that its possible that you need make some valve adjust; these engines use solid cam followers with a removable adjustment shim.
    The valve lash clearance is measured with the original shim installed
    and checked against the specification. If adjustment is necessary, the
    original shim is removed, and a thicker or thinner shim is installed to
    obtain the proper clearance. Special tools are required in order to
    adjust the shim without removing the camshaft.

    With the engine cold, standard valve clearance is 0.010-0.012 in. (0.25-0.31mm) on intake and exhaust sides.

    1. Remove the cylinder head cover.

    2. Measure the valve clearance by turning the crankshaft clockwise until the No. 1 piston is at TDC.

    1. Measure the valve clearance at
      . If the clearance exceeds specifications, replace the adjustment shim.

    1. Turn the crankshaft clockwise 360 degrees until the No. 4 piston is at TDC. Measure the valve clearance at
      . If the clearance exceeds specifications, replace the adjustment shim.

    2. Repeat this procedure for all the camshafts.

    3. Turn the crankshaft clockwise until the cam on the camshaft requiring the adjustment is positioned straight up.

    1. Remove the camshaft cap bolts as follows:

    2. For exhaust side No. 1, 2, and 3 cylinder adjustment shim removal use

    3. For intake side No. 1, 2, and 3 cylinder adjustment shim removal use

    4. For exhaust side No. 2, 3, and 4 cylinder adjustment shim removal use

    5. For intake side No. 2, 3, and 4 cylinder adjustment shim removal use

    6. Install special tools 49-T012-002 and 003, using the camshaft cap bolt holes. Torque the bolts to 100-125 inch lbs. (11-14 Nm).

    7. Align the mark on the 49-T012-002 (shaft) with the mark on the
      49-T012-003 (clamp). Tighten special tool 49-T012-004 (bolt) to secure
      the shaft.

    8. Position special tool 49-T012-001A toward the center of the
      cylinder head, and mount it on the shaft where the adjustment shim needs

    9. Position the notch of the tappet to allow a small pry tool to be inserted.

    1. Set the special tool on the tappet by its notch. Tighten the mounting bolt
      securing it on the shaft.

    2. Tighten bolt
      , and press down the tappet.

    3. Using a small pry tool, pry the adjustment shim upwards through the notch on the tappet. Remove the shim with a magnet.

    4. Select and install the proper adjustment shim. Loosen bolt
      to allow the tappet to move up, and loosen bolt
      to remove special tool 49-T012-001A.

    5. Remove special tools 49-T012-002, 003 and 004, and tighten the camshaft cap bolts to 100-125 inch lbs. (11-14 Nm).

    6. Repeat the procedure for all necessary adjustment shims. Check the valve clearance.

    Additionaly, must to checl the right firinr order for 1994 Mazda 626 2.0 liter DOHC L4

    Keep us updated.



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There is always a better alternative than the dealership as far as costs. They want to put a new motor in a 2003 model? That is ridiculous to me- cost-prohibitive. Find a reputable independent shop. Look for references and customer satisfaction. A used, low mileage replacement engine is a better alternative, probably less than half the cost of a new engine.
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