[GMCBEAST]

This question is for the folks who have experience with the older model Suburbans and Blazers. As I'm sure you know when the exhaust exits the rear on these beasts and the tailgate window is down exhaust fumes fill the inside of the truck. If all windows are up, no fumes, all down except tailgate window, no fumes, it's only when that window is down. Every one I've owned (2 Suburbans, 1 K-5 Blazer, and 1 Fullsize Jimmy) have all had this problem along with several friends who've owned these trucks as well and it's ranged from stock rebuilds, high mileage and performance motors. Two of my four had exhaust pipes exiting at rear bumper, one had 90 degree turn outs behind rear tires and one with dumps before rearend, all with same problem. My question is has anyone done a 45 degree angle exit in front of the rear tires with these trucks and did it help with this problem? Gonna put a different exhaust system on my 'Burb to quiet it down some (after a run in with Kingsports finest) and would like to eliminate this problem in the process. I have a feeling Cats' are going to be mentioned and the problem exists with the cats' on as well, 3 of my trucks had them. Thanks for your help in advance.

[OneMoreTime]

That issue has to do with the aerodynamics of those trucks..any of the square body type SUV style has that issue when running with the tailgate or tail glass open..I have no idea how one would fix that..

Sam

[1971BB427]

Pretty simple fix...I just open the front side windows a little and it lets fresh air travel through. I don't get exhaust smell in my '69 Burb if I open the front door windows a bit. Mine exit out the side right behind the rear tires.

[GMCBEAST]

I appreciate both of your responses. All of mine have done this with the front windows down along with the tailgate window. I wonder if because the '69 Burb is slightly more aerodynamic that plays a part in it. Either way I do appreciate your responses. Taking the old 'Burb to the exhaust shop next week and I'm going to try the 45's in front of rear wheels. Another suggestion that was given to me was to put a spoiler on the roof by rear of truck, it's funny 'cuz I always laughed when I'd see them with a spoiler but they might have known this to be a cure all along and were laughing at me as well for huffing fumes, lol. Thanks again guys.

[ssimpala]

I put an old junkyard station wagon air deflector on the back of my K5 Blazer to try to keep caliche dust off the back window. It helped some and also helps to keep some of the exhaust smell out.

[1971BB427]

It might also have to do with the '69 Burb having the lift up rear window, which might be blocking the air across the roof from circulating around the tailend, and being drawn in. It sits sort of unhill when open, and like a big air dam.

[GMCBEAST]

Originally Posted by ssimpala

I put an old junkyard station wagon air deflector on the back of my K5 Blazer to try to keep caliche dust off the back window. It helped some and also helps to keep some of the exhaust smell out.

After reading your post I did a search to see if someone might make/sell a rear air deflector for this model and sure enough good old Summit came through. It cost less than a tank of gas and doesn't look to obnoxious. Hopefully between this and my new exhaust I won't have to keep my tailgate window up. My five-fiftyfive a/c (5 windows down @ 55mph) will work much better with that window down. lol. Thanks a ton fella's I think if anything these two things will make it better.