Roughly a year ago I posted a question on this forum on the advisability of leaving my grill-blocking pipe insulation in or removing it before going to the dealer for scheduled maintenance. Well, last year I was nervous about voiding my warranty, so a took out the insulation before visiting the dealer. Last week, when the weather was in the low 20s, I had to bring my Prius in for its 30,000-mile maintenance. It was just too damn cold for me to mess with the insulation, so I left it in. The dealer staff did whatever they had to do, and washed my car before I picked it up. They never said a word about the blocked grill. So, I'd conclude that there's no problem with a blocked grill--unless, of course, you have engine overheating problems. --Joe
There are probably several ways to do it. I split some copper pipe insulation in half or if it has the lengthwise slit already, either squeeze it between two of the grills or over one, on the lower grills. You may need to cut some narrow slits on the back side, perpendicular to the tube, at the center so it can take that curved shape. Also, you may want to cut a bit out on the back for the vertical grill supports. The upper grill may need some ties at each ends and a larger insulation tubing. I carefully used some safety wire I have in the garage.
That is basically what I did. I used some 1" OD for the bottom, which I then sliced longitudinally, giving me two sets for each $1.29 piece. After cutting them to fit the right lengths and small pieces on the back for the vertical supports, it fits snugly when each piece is folded in half. I ran my EBH plug through the center of the lower grill and tied the cover to one of the nearby supports, so there is a small 2-3 inch opening between them. For the top, I used either 1 3/4 or 2", also sliced longitudinally. I also cut out places for the slats and narrowed the thickness at either end. Both sets fit perfectly without needing to tie them down. Last winter, I drove from the Twin Cities up to Grand Forks going at least 70 mph into 30 mph winds and did not lose anything. Of course when you have cold snowy winters, by December or January, the pieces will freeze in place anyway until spring thaw. I also took mine into the dealer last winter to have something fixed and I did not hear a peep about the insulation. I would guess that it would make sense up here, but I still have not seen another Prius with a blocked grill, even though there is at least one more PC'er in this area.
I took mine in today for the 5,000 and left the foam pipe insulation in. I told them I read the contract and it has nothing about blocking the grill. They agreed and left it in, though they said it's advisable even in this cold (it's 20 degrees in Philly) not to do this because blah blah blah I tuned them out at the point when I knew my warranty was safe. Essentially, you're not modifying the car since it's really not attached.
