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Mazda 2.6L \  Compression is 150/0/0/150

Compression is 150/0/0/150

Mazda 2.6L Mazda Engine Mazda Tech
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following 4
 
stink   +1y
Head gasket? Any other thoughts?
scotch   +1y
Most likely... blown between the two. Unlikely you had severe valve or ring issues on both cylinders. I have one in the driveway now with a blow-out between 2 and 3.

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If and when you go into it, here some tips.

1. Use a FelPro or OEM Mazda head gasket. You will have too much time and money invested to save a few bucks on a cheap gasket. You don't want to "re-do" it.

2. While you have the valve cover off, it's a good time to replace the PCV valve grommet. If it's old and hardened, it's almost impossible to get them out from the outside. If it won't come out that way, then you can just push it through, remove the baffle cover from the inside, remove the grommet, then reseal the baffle cover (high temp RTV).

3. The rear vent hose, (under the resonator) is often hard and brittle and can crack or beak when removing. Generic hoses don't make the turns too well and will usually be pinched nearly shut. Go with a new molded Mazda hose, if you need one.

4. There are lot of small coolant hoses that have probably never been replaced. While you have the head off, some are much easier to access. If they are old, replace them now. OEM Mazda hoses are top quality and fit better. Unless you know that some are only a few years old, I would replace them all. This goes for the oil cooler hoses as well. OEM Mazda will fit perfect and not require trimming to fit like many aftermarket hoses.

5. Your head bolts are NOT "Torque to Yield." So you don't have to replace them. However, there is a washer that goes under the bolt that holds the distributor drive gear and timing gear to the camshaft that is TTY. So get one of those from Mazda. It's not an ordinary washer.

6. Replace the thermostat while you have it apart unless you know that yours is relatively new. Mazda or Stant brand are the way to go. 195 is the factory thermostat temperature. You'll need both gaskets for that too.

7. If your valve cover gasket is leaking or is more than 5 years old, plan to replace that too.

8. Get a new o-ring for the distributor.

9. You'll need a new intake manifold gasket... the one that is between the manifold and the head. Shouldn't have any need for the one between the upper and lower half of the intake manifold. I point this out so that if and when you go to buy one, make sure you are getting the right one.

10. Clean the head up and check for cracks and also for flatness. You don't want to put it back together if the head has issues.

If you need any help with these p/n's, let me know and I'll get you a list.
stink   +1y
Scotch, thanks for your help. I had changed the head gasket 4 years ago when I got the truck. I had the head machined but I will look for any warping. There was no loss of coolant, therefore I assumed it was the computer. I should have checked the compression prior to sending the computer to Avpro. I have a Beck Arnley head gasket in my spare parts and have had good experience with them in the past. The gasket that is in now is a Felpro so I think I'm going to use this unless it is a P.O.S. I have not found any bad reviews. However, I would like the part # for the distributor gear to timing gear washer and the distributor o-ring. Thanks again for your quick response.
sincitylocal   +1y
If you only got four years out of it, is it safe to assume you didn't re-torque the head bolts?
stink   +1y
Re-torque, as in run it and let it cool and torque again? NO. I assume I should be doing that this time? Thanks for the heads up.
stink   +1y
Another question, do I install the gasket dry? My neighbour says to lightly coat it with grease. He said his dad was a mechanic and always did that. I'm thinking the material has changed over time and it is not something I should do.
sincitylocal   +1y
Install it dry.
Re-torque should be done between 250 and 500 miles after install. You need several heat cycles before the retorque. Most of us will retorque whenever we have the valve cover off, after the initial retorque.
Never loosen the bolts when you retorque... only tighten.
stink   +1y
Thanks! I will do just that.
scotch   +1y


You're welcome. Here are the p/n's:

Cam shaft washer: 148146019
Distributor O-Ring: F82918201A
stink   +1y
Thanks again, exact same fail with the gasket. I've cleaned everything up and am read to put it back together. Any chance you know the part number for the gasket for the cover of the timing chain tensioner? I believe that is what it is (the place where you lock the tensioner in place.
cheers, Sean
Ps. do you have the intake manifold part number also?