Bucky, IMO, the best thing you can do is to keep the coolant at maximum full level at all times. It has been my experience that when Dexcool gets low and mixes with air for an extended period of time, it becomes really nasty and gunky. Also, although the extended coolants are suppose to go 100,000+ miles, I think you would be best served to flush and refill the system a little more frequently than that. Some of the intake manifold bolts are easier to access than others. I do not advise retorquing retorquing the easy bolts and not the others as this may actually put more uneven pressure on the gasket and potentially cause a leak. I do not see any benefits in spending the time and/or money to simply retorque the intake manifold bolts because of accessability issues. Once you get to them you might as well take the few additional steps (removing valve covers, rocker arms, pushrods, intake, etc.) and go ahead and replace the gaskets.

OMG, did I write this: like blinkers on a horse???? BLINDERS on a horse. My excuse: I typed this out 3 times--I kept losing it (deleted it from the pasteboard bcs I didn't know how the buttons work; kicked the power strip and turned the machine off). It's a typo; same finger, different hand. Thanks, all! There's still more that can come out; one of those boxes has out-of-season clothes in it for DD, and I know that not a one of them will fit her. But I put my blinDers back on, and put it on the shelf. I can only tackle so much at a time, and I had a deadline. i think I may get to those clothes before month's end.

Very sorry to hear about your experience aa1notary. I have no experience whatsoever with that product nor any bias one way or the other, but most often times water infiltration is due to installation issues as opposed to the product itself. The video has expired, but it sounds like perhaps you have horizontal sliders? Something as simple as caulked over or clogged weep holes could cause water to accumulate in the sill... Again, sorry to hear about your experience. I'd recommend having the installation company out to inspect, and possibly in conjunction with that manufacturer rep so that they cannot each blame each other when the other is not present.

Your situation really doesn't surprise me, if I have seen it once I have seen it a thousand times. While the bedroom / bonus room have low air as you stated the combination of this problem plus no return or thermostat control in those areas just due to where the equipment is placed or the longer run of those ducts can create comfort issues in the heat of summer. When there is light exposed to what the real problem is gives a better ability to offer things that will rectify the issue. In dealing with hot spots a zone system is a higher cost option to rectify the issue for the simple reason a zone system has the ability to better control a system. The caveat if you will is the 'design'... the other thing is architectural limitations of the structure. While some situations in which a zone system is used can reduce equipment costs, that is not it's only function. If rooms are a considerable difference from the equipment that serves it, a zoned system may be the best method to rectify that issue. The other method would be to relocate the equipment to a more central location within the structure so that the ducting to each area is more equal. In a zone system the equipment will cool / heat each zone independently so while location of the equipment is still some what important, not as much as a non-zoned system. A new return added to a hot spot will help, but it may not rectify the issue 100% for the simple reason the thermostat location now can not sense temperature in that area. If you move the thermostat then the problem is merely shifted to a new area outside the reach of the thermostat. This is how a zone system excels. Provided the design is done correctly. While it's true that 2 speed, 5 speed and full on inverter systems excel in a humid climate, that is not the only purpose of those machines. Because of the high utility cost in the location of where this structure is... it is in the interest of this home owner to choose the most efficient equipment they can. If it were me I would go with Inverter system 20 SEER or higher. (5 speed or full inverter variable) If you can't afford both at once or you want to make sure a company is worth their salt, consider awarding a company with the system that has the problem area first. Tell them if they rectify the issue with the trouble spots you will reward them with replacing the other system as well. If you hire them and it goes terribly wrong, hire in another contractor to fix the problems and then you have something to use leverage to get another contractor to take over the maintenance and service of both systems... the contractor who fixes the problem system gets the right to replace the other system. Additionally given the information of those hot spot problems, trying to drop this to total of 5 tons of cooling would be a disaster. For others that happen to read this thread with similar problems I service the Katy, Texas area.