1st2know wrote on 12/31/07 at 08:30:21:Another observation:
Would a plug made of aluminum be more reliable?
Thinking about this, if I could have someone mill me an aluminum plug, with a groove to hold an o-ring, the aluminum plug would expand and contract at the same rate as the head. The o-ring would be the week point, and would probably have to be replaced every 20k or so.
If I have to go back in to fix this leak, I'm going to fix it just one more time - this plastic part does not give a lot of confidence.
Interesting thoughts...
An aluminum plug might be doable with an o-ring...I think that someone else mentioned doing that sometime too. Of course, then you have to deal with the effects of heat on the o-ring as well. It's worth a shot if you have the resources. I've often wondered about using some kind of expansion plug too.
I have a couple observations concerning the head plug/cap (which may be mentioned in the Tech section)...
- it seams that Suzuki doesn't mention using sealer on the plug/cap in the manuals, and so that when dealers are doing an initial service they don't use any either. Along with that, I suspect that their mechanics while trying to do "timeclock" repairs, may not replace the plug or properly clean the sealing surfaces upon reassembly. The plug may not even get seated well...this was the case after my spouse's first (and last) dealer service...
- when I do them I've had great success by doing a little better preparation and RTV sealer. First, I thoroughly clean the hole and use a medium grit paper to rough up the inside surface. Then using a thin film of the sealer on the plug (which has a shallow groove around it too), I reinstall the plug and wipe off any excess that squeezes out. The roughened surface seems to allow the RTV to adhere better...
- The sealer may also compensate for an misshaped areas of the plug, but in the long run it is probably better to just buy a new one.