November 19th 2012
          Now that the Durango is no longer suffereing from pre ignition with the SCT tuner, it's starting to burn some oil - more than it has previously. I think the transmission won't last the winter as it has slipped a few times and is slow on occasion when taking off from a stop. So, factor in suspension bushings front and rear ($150), intermediate steering shaft ($320), shocks ($250), front axle seal ($40), exhaust leak (Y pipe and headers - $500) and add on labour just to make it road worthy for the winter will set me back $2300. The engine will knowingly cause me grief in the next couple of months, along with the transmission it's not worth while for me to fix at this point. Before the new year it could potentially cost me five figures to keep on the road. This is also assuming that the axles and transfer case won't cause any issues. I might go back to GMC, with a 2007 Envoy but that's yet to be determined.
October 16th 2012
          My original thermostat finally bit the dust. Turned down onto the street I live on and the pressure cap starts spewing out overheated coolant. Walk up the road to Canadian Tire I went. I bought a new 192F thermostat and 18psi pressure cap. I've replaced no less then 10 thermostats over the last fifteen years and this one was by far the worst. There was no coolant left in the top end of the engine so the mess was kept to a minimum other then the brake booster and such covered in coolant as it sprayed out from the old cap.
          One of the bolts holding down the t-stat housing I couldn't access as a smaller cooling hose wasn't in the way, but the metal screw on strap, was. I couldn't get a screwdriver or 8mm socket in there so I had to remove the accessory belt and pull the alternator forward a couple inches. This was no small feat! Finally, I was able to turn around the clamp on the smaller cooling hose so I could access the thermostat housing and finally remove it to replace the old thermostat. I purchased a fail-safe unit, that allows some coolant to pass through although it will lead to slightly longer engine warm up time. Even more so in the winter months. It's all Canadian Tire had in stock. Normally this location has NOTHING I need; an associate normally tells me which store that has what I need, and to go there! Two and a half hours later and the Durango is running back to its normal self. I washed the engine and took it for a good drive in the city to verify that it's not leaking or overheating.
October 12th 2012
          I received a new tune for the Durango. It's an 87 octane "economy" tune. I'll see if it helps once this tank is burned off. Last fill up I put in 87 octane out of habit while I had the 91 tune installed. I purchased some octane boosters to alleviate any engine knock, and under moderate to heavy thottle there is still some engine knock. I believe the oil that I'm slowly consuming is getting burned in one of the cylinders. A future compression test will be in order to confirm if I am burning oil through the cylinder(s) or not. Hopefully this tune will help mileage as well as reduce engine knock. One can only hope after how many years or trying....
September 9th 2012
          Second tank is more on par with the OH computer reading. On 80.135L (21.2 US gal) of fuel I drove 377km (234miles) works out to an even 11mpg, or 21.2L/100km. Overhead computer showed that I had burned 21.6L/100km. There is some variance with the fuel pump used, ambient temperature at the time, and how much, if any, that I overfilled it. I'm cautious to round the pump up to the next $0.25 to keep things easier to manage. 94 Octane went up a cent to $1.479/L. 91 octane isn't much of a bargain like the 94 is, at $1.459/L. It's best to choose the 94. The Petro Canada I get it from doesn't have a dedicated 94 octane fuel pump, but rather shares the same pump with all grades of fuel. Chances are good that it was previously used for 87 octane, and I did get half a litre or so of that before my 94 made its way up the hose. I'll also say that this tank of fuel was used to haul three loads out to the dump (hour drive round trip) which had a grand total of over 1200Kg (2640lbs). Due to sheer volume, I couldn't run it all out in one load, thus is why I had to do three separate trips. I also drove through town for each trip which knowingly didn't help mileage any.
August 28th 2012
          First verdict is in. After a bit of highway, with mostly city driving and more idling in traffic than the last tank, I managed a very respectable 17.44L/100km on 94 octane. This is much better than the 20-21L/100km I was averaging over the last several months. Midrange has more oomph as I can ascend steep hills not only without downshifting as before, but increase my speed without downshifting and not lugging the engine. I thought I heard some engine knock on one acceleration run onto the highway, but I did have the iPod playing at a reasonable volume. Average so far is $24.97 to drive 100km on 94 octane versus $26.76 to drive 100k on 87 octane. Savings of $1.79. Worth it? - YES it is definitely worth it. Better performance and lower cost for running a much higher octane fuel with the engine in a better state of tune. Can't say no to that!
August 22nd 2012
          Tuning time. After a couple tanks of fuel, and keeping RPM under 2000 outside of towing my utility trailer, the first tank was 20.76L/100km and the second tank was 19.13L/100km. The second tank included a couple quick highway jaunts around the region but the average would be roughly 11.75mpg US, or roughly 20L/100km. I cleaned the throttle body & IAC (the TB was overdue for a cleaning) and filled up with 94 octane fuel. I preloaded my SCT tuner with the 91 octane tune. As I've had issues running the same octane to the corresponsing tune octane, I've decided to not use the SCT 93 tune - for now. The downside is that 94 is only available at PetroCanada gas stations (they bought out SunCor Energy (Sunoco). The upside is that I'm averaging under 19L/100km in 100% city driving so far - 48km in. After driving on the 87 tune for about 5km, I pulled over and loaded in the 91 octane tune. Needless to say the engine feels smoother in the 1500-3000rpm range, which it regularly sees, especially when towing. I had my utility hooked up with about 400lbs in the box (roughly 1000lbs total weight) and still managed to achieve in the city, under 19L/100km. Now, with the trailer off, I'm hoping to better my mileage and get closer to the 17L/100km mark; roughly 14mpg US in 100% city driving. My old 1990 GMC Sierra C1500 5.0L ate 17.5L/100km in the city under similar conditions.
          The GMC had 175hp and rear wheel drive, where as the Durango has full time AWD and 250hp (stock). I'm hoping with this tune/fuel octane I've decided on all but gets rid of any engine oil use. I believe my previous problems were solely from pre-ignition. If my oil use stays down, and my mileage increases, I'll stick with the 94 octane. The 94 octane runs 17cents more than 87 octane. When I fueled up, 94 went for $1.469/L. It'll run me roughly $11 more a tank over 87 octane. If I can decrease fuel use and up the mileage even by 1mpg, it will pay for itself. If my oil consumption stops, that too is an added bonus. I'm currently adding 3 quarts a year with the 5W30 Amsoil full synthetic. I've opted (read below) to try the Amsoil OE 5W30 oil and see if that helps reduce oil consumption. Time will tell!
July 8th 2012
          I've noticed that when towing heavy I can actually see oil burning out the exhaust. Perhaps my valve seats are toast? When the engine is cold and I start it up, there is a pronounced injector noise that I believe is on the drivers side cylinder bank. It almost sounds like a missfire yet I hear it every 2-3 seconds for about a minute and then it goes away. I'm hoping to run a compression test this week and that should tell me more of what's going on.
June 26th 2012
          Yearly oil change is done. The 5W30 full synthetic Amsoil was very black but poured like new oil would. As my engine is consuming some oil (quart every 4000kms or so), I've decided to down grade my oil to Amsoil 5W30 OE. I'll knowingly put on 6-7,000kms before changing it. I also wentw ith the WIX oil filter, for about $6 each. In other news, my fathers G6 GT, went TWO YEARS on the same signature Amsoil 5W30 full synthetic. In that time only 25,000kms were accumulated and that's including two winters. Last winter was fairly mild so I wasn't too concerned with changing it right after the season. It too, poured out like new oil would going into the engine. On a trip to Sudbury last fall the G6 achieved a stellar 7.0L/100km at a trip average speed of 109km/h over 1300kms. If only my Durango could get that mileage on the highway! In other news I haven't yet done a visual inspection of the rear suspension, as I'm positive new bushings will be in order.
June 5th 2012
          Pulling the trailer results in less suspension noise! Mileage is getting better as the weather warms up. 87 octane definitely cuts down performance but I've been averaging 20L/100km in mostly city driving, along with towing the trailer which is better than the 21-23.5L/100km I was getting a month earlier under similar city driving conditions. An oil change is due shortly and I'll have to have a closer look at the underbody to see what is in fact due for repair/replacement.
April 29th 2012
          I now have a small hole in the front bumper thanks to my foot. The rust is quite pleniful on both sides. City mileage is stuck at around 11mpg, or roughly 21L/100km with a few trips with the trailer to the dump. Suspension squeaking is getting worse. I'm hoping to pinpoint it this weekend as I know the rear spring bushings are shot, and I believe the front bushings may be shot also. SCT tune with 87 octane is working great. No engine knock when towing or not at any engine speed!
"Did you hear about the guy who finally figured out women? He died laughing before he could tell anybody."
Free Hit Counters
Free Hit Counters

This site and all of it's contents are operated and maintained by Brian Wilson for Bio Diesel Technologies and BAW Enterprises 2003 - 2006.
All rights reserved. Updated when I have free time.