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2008 Cadillac CTS



  • I drive the same DI AWD. My commute is 12 miles one way and I only averaged 16 to 17 mpg on a tank. I now have over 16k on the car. I did not see better mileage until I hit about 15k. I am now getting about 18 to 19 mpg. The one thing I did notice is I get better mileage without using the AC. I talked to another guy today who has the same car. He started out just getting around 14 and is now averaging 17. He had not one complaint about his car....he, like me just loves it to darned much to say anything bad. My only complaint is the dealer requires anywhere from 2 to 6 times to fix a warranty repair. :shades: From sunny Palm Springs.....
  • I have not seen or heard what CTS, STS and DTS represent.
    I came up with what seems reasonable:
    1. CTS, Cadillac Touring Sedan
    2. STS, Sport Touring Sedan
    3. DTS, Deville Touring Sedan
    Has anyone seen information from General Motors?
  • I dunno if there is any official explanation. But working backwards, the DTS evolved from the DeVille so that makes sense. The STS evolved from the Seville so I suspect that the Seville is what the first letter stood for. To my knowledge, the CTS was designated as that from the start as the replacement for the Catera, but I don't think GM wants to remember that name, so maybe it just stands for CTS.
  • Well, perhaps I have less reason to be concerned. I have a 2009 CTS DI RWD. I'm nearing the 1000 mile mark and I've been averaging 15.5MPG. My main commute is 21 miles each way with a fair amount of congested highway each way. The thing that concerns me is that, driving pretty much the same way as the 96 Accord I replaced, I'm getting much worse mileage than I expected. WIth the Accord, I'd average around 25MPG. The CTS averages 10MPG worse, but only runs about 4MPG worse on the ratings.

    I love the car, but filling up about every 270 miles is pretty painful.
  • paopao Posts: 1,867
    not to add to your frustration..but if you have to be concerned about filling up the $40K cadillac over a honda.....then perhaps you should have stayed with Honda....was the honda a 4-banger..manual or auto?

    21 miles in congested traffic..highway or otherwise will dramatically impact MPG,,you will not see high 20's in the CTS until an extended highway road northern averaging 22-23 around town with stop and go....and 28-30 on the highway....over 100 miles steady highway driving at 70 plus..09 with 4k on it none DI engine
  • dmathews3dmathews3 Posts: 1,739
    Plus I bet the Caddy weighs a whole lot more than the Honda too. From cracker box to limo you have to give up something. :P
  • cdnpinheadcdnpinhead Forest Lakes, AZPosts: 4,054
    was that CTS stands for Compact Touring Sedan (compact only by Cadillac standards), but I'm curious too if there's a real answer out there.
  • richw5richw5 Posts: 152
    "C" class Touring Sedan. The CTS was developed to be Cadillac's compeditor for the Mercedes "C" class.
  • plektoplekto Posts: 3,738
    That's a common mistake. They were following an alphabetical pattern only.

    They had the huge DTS, the Middle Sized CTS, and the BTS(which never was sold in the U.S.) The current CTS was meant to compete with the base 5 series at a *much* lower price.
  • cdnpinheadcdnpinhead Forest Lakes, AZPosts: 4,054
    "They had the huge DTS, the Middle Sized CTS, and the BTS. . ."

    So, given that and GM's current "situation," there is surely an FTS somewhere in the mix in the not-too-distant future.
  • I love this car...but really....$20,000 more for the additional 252 HP......

    I got 304 HP now....she's plenty fast I just dont see the value VS the added expense. BUT...Great car I agree!
  • arby1arby1 Posts: 83
    Now that it is freezing in NY , I noticed that my cold tire pressure was 30-31 , so I added air till 35 . However , during driving , when the tires get warm , the pressure goes up to 37-39 . Should I keep it under inflated , so that it is normal when hot , or keep it inflated at 35 , and ignore the fact that the pressure rises to 37-39 when hot .
  • bingomanbingoman Posts: 373
    Always check tires cold and set the pressure to 35psi. Do not underinflate, the manufacturer has allowed for heat inflation.

    From the owners manual:
    How to Check
    Use a good quality pocket-type gage to check
    tire pressure. You cannot tell if your tires are
    properly inflated simply by looking at them.
    Radial tires may look properly inflated even when
    they are underinflated. Check the tire’s inflation
    pressure when the tires are cold. Cold means your
    vehicle has been sitting for at least three hours
    or driven no more than 1 mile (1.6 km).
    Remove the valve cap from the tire valve stem.
    Press the tire gage firmly onto the valve to
    get a pressure measurement. If the cold tire
    inflation pressure matches the recommended
    pressure on the Tire and Loading Information
    label, no further adjustment is necessary. If the
    inflation pressure is low, add air until you reach
    the recommended amount.
    If you overfill the tire, release air by pushing on
    the metal stem in the center of the tire valve.
    Re-check the tire pressure with the tire gage.
    Be sure to put the valve caps back on the valve
    stems. They help prevent leaks by keeping out
    dirt and moisture.
  • arby1arby1 Posts: 83
    Thanks a lot for the info . My concern was that when the weather was warm the cold tire pressure was fine , but the pressure got lower because of the outside temperature getting cold . I guess that during warm days when my cold tire is at 35 , the pressure also increases a lot too while I am driving . Thanks again .
  • topgun7topgun7 Posts: 412
    I am shopping for a used CTS DI. Is there any way to tell a CTS is non-DI or DI? There are a lot of used CTS advertised in our local market but I am not sure if the salesman really know wether a particular car is DI or not. I would like to have an independent way of verifying the engine..
  • There will be a small badge on the left side of the trunk lid that says "3.6 direct injection".
  • dfusnikdfusnik Posts: 10
    I've been wanting to install a set of bracketless all-season wipers(i.e. Bosch Icons or Valeo) on my 08 CTS, but can't seem to find a web site that sells them for my car. Can the CTS only use the factory wipers?
  • jrceejrcee Posts: 6
    I have experienced this also. That is a perfect description of the noise that I hear around 40 mph. I just bought an 09 CTS V6 DI and it's perfect except for this odd noise/vibration around 40 mph. If I shift into the sport mode and downshift, it goes away. At first I thought maybe it was a tire balance issue, but I am now thinking it must be a drive shaft issue. I will continue to monitor Cadillac bulletins to see if anything comes out. Until then I guess I'll have to go slow or fast. ;)
  • paopao Posts: 1,867
    there have been some cases of rebalancing the drive shaft..some refer to it as drive train lash or you have AWD or RWD?

    look at this bulletin:

    #PIP4435B: Phasing Drone Moan Or Vibration At approximately 50MPH Or 1200-1300 RPM - keywords accelerate light throttle - (Sep 5, 2008)

    Subject: Phasing Drone, Moan, or Vibration at Approximately 50 MPH or 1200-1300 RPM

    Models: 2008-2009 Cadillac CTS

    --------------------------------------------------------------------------------- -

    This PI was superseded to update model years and EVA diagnostics. Please discard PIP4435A.

    --------------------------------------------------------------------------------- -

    The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

    Some customers may comment of a boom, moan or vibration during light acceleration which phases in and out in intensity.

    The condition may be most noticeable at about 50 mph (80 kph), or 1200 - 1300 rpm, and occurs over a speed range of 3 to 5 mph (5 to 8 kph). This condition can be caused by the rear axle assembly responding to frequencies generated by the transmission when the Torque Converter Clutch (TCC) is engaged.

    Perform the procedure in SI Document ID 1578733: "Vibration Analysis - Road Testing". This condition can be identified as a third-order engine disturbance by using the J 38792-A, Electronic Vibration Analyzer (EVA) 2. Verify the concern by duplicating the condition and then commanding the TCC off with the Tech 2. If the condition is verified, it may be reduced or eliminated by indexing the propshaft. Ensure that the rear axle damper is in place and not grounded out.

    If the damper is in place and indexing the prop shaft does not eliminate the concern do not attempt any further repairs at this time. Engineering is aware of this concern and is developing a repair at this time. Further repair information will be available when a procedure is developed and verified.

    Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

    now with all this said..supposedly there is another PIP out stating GM is aware of the problem and working a fix...and to not attempt any repairs..but no one has seen it yet?
  • I love my 08 CTS w/AWD, but it just doesn't seem to like snow. I came down a hill sideways the other night and everyone was trying to get out of my way. The 12,000 miles tires are original, but some have said I need to purchase better tires. Has anyone else had this problem and, if so, what did you do? I love this car, but am ready to get rid of it if I can't get better traction.
  • bdymentbdyment Posts: 569
    Yes, it is probably your tires. Install a good set of winter tires and I'll bet you will be fine.
  • nathessnathess Posts: 11
    About once every couple of months my CTS has automatically locked its doors. Each time I have noticed this has been in the garage. Well, the other day I was standing by the car as my wife pushed the garage door open button and I saw the doors lock. Periodically there must be a frequency interference.

    Problem solved.
  • jrceejrcee Posts: 6
    I have RWD. I took it into the dealer today and they said that they have attempted several, but have not had much luck. We'll see what happens with mine. I'm hopeful, but expecting it not to work. They just keep saying that Cadillac is aware and working on a fix. I just wish it would be quicker.
  • jrceejrcee Posts: 6
    I hope this is good news. Although the dealer said they couldn't do anything, and I already have picked up my car, there seems to be a new bulletin out as of yesterday to address the vibration problem. It is #08-07-30-044A: Phasing Drone, Boom, Moan or Vibration at 80 km/h (50 mph) or 1000-1300 RPM with Torque Converter Clutch (TCC) Engaged (Reprogram TCM and Install Insulator Washers [On Vehicles Built Without Washers]) - (Feb 11, 2009). Apparently the insulator washers were part of the later built cars. They have to be added for VIN prior to 90159377, which mine is. I have a 2009, but I think it was one of the first built ones. I plan on having this done when I go back the next time. Until then, I'll keep my fingers crossed.
  • srynsryn Posts: 27
    By coincidence, I was scheduled to bring my '08 CTS in this morning for several electronic gremlins that are keeping me company. I provided the rep with the bulletin number you provided in your post. He punched it in and replied that no such bulletin number exists in the GM network (I stood next to him, thus could see his computer monitor as he did it).

    Are you sure the bulletin number you cite above is accurate?

  • jrceejrcee Posts: 6
    That's interesting, I called my dealer today and gave him the same bulletin number and he was able to track it down. He said that there are two insulating washers that they need to order which is exactly what the bulletin says. I have double checked the bulletin number and it is correct. There is a document ID listed too. I don't know if that will help, but it is Document ID: 2233290. Here is the bulletin again, I have cut and pasted the following straight from the bulletin: #08-07-30-044A: Phasing Drone, Boom, Moan or Vibration at 80 km/h (50 mph) or 1000-1300 RPM with Torque Converter Clutch (TCC)
    Engaged (Reprogram TCM and Install Insulator Washers [On Vehicles Built Without Washers]) - (Feb 11, 2009)
  • paopao Posts: 1,867
    here is the complete bulletin:

    This bulletin is being revised to update model years and add insulator washers (only for vehicles built without washers). Please discard Corporate Bulletin Number 08-07-30-044 (Section 04 - Driveline/Axle).


    Some customers may comment on a drone, boom, moan or vibration during light acceleration which phases in and out in intensity.
    The condition may be most noticeable at about 80 km/h (50 mph), or 1000 - 1300 engine RPM, and occurs over a speed range of 5 to 8 km/h (3 to 5 mph).


    This condition may be caused by the rear axle assembly responding to engine firing frequencies passed through the driveline when the torque converter clutch (TCC) is engaged.


    For All Vehicles -- Calibration Update
    This condition can be verified by driving the vehicle to duplicate the concern and using the Tech 2® to turn off the TCC. If the noise stops when the TCC is turned off, the calibration detailed below should help to eliminate the noise or vibration.
    • This calibration may result in decreased fuel economy up to approximately one mpg/kpg. Because of this, the software should not be used in a vehicle without this concern.
    • There are two calibration part numbers that are "selectable" for this controller. Read the description to determine the correct calibration for this condition.
    • DO NOT replace rear drive axle or propshaft for this concern.
    A revised calibration has been developed to correct this condition. Technicians are to reprogram the transmission control module (TCM) using SPS with the latest software available on TIS2WEB. Refer to the Service Programming System (SPS) procedures in SI. As always make sure your Tech 2® is updated with the latest software version.
    For Vehicles Built Prior to VIN Breakpoint 90159377 - Install Insulator Washers After Reprogramming
    1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in SI.
    2. Place a transmission jack stand under the rear differential assembly.

    3. Remove the two front differential mounting bolts

    4. Install the rubber insulators (2), GM P/N 20827776, between the rear drive axle and the body
    5. Install the rear differential mounting bolt.
    Tighten the rear differential mounting bolt (1) to 220 N•m(162 lb ft).
    6. Remove the transmission jack stand.
    7. Remove the support and lower the vehicle.

    Parts Information

    Part Number Description Qty
    20827776 INSULATOR ASM - DIFF CARR 2

    Warranty Information

    For vehicles repaired under warranty, use:
    Labor Operation Description Labor Time
    K9532* Transmission Control Module Transmission Reprogramming with SPS 0.4 hr
    Add Install Rubber Insulators in Rear Differential 0.3 hr
    *This is a unique labor operation for bulletin use only. It will not be published in the Labor Time Guide.
    GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
    © 2009 General Motors Corporation. All rights reserved.
  • Thanks for the information.
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