Having been a transmission mechanic (before they renamed them to technicians) way back when lockup convertors were first implemented by Chrysler(1977/8) I would not count on the new trans tech hired to actually have any hands on experience. GM will eventually get it right. Whenever they release new technology there is a problem phase. No manufacturer can test or trial all driving conditions or test all possible driver habits. If these issues were happening to 100% of the sold units, that would be poor design. The only people that will start a thread on the 8 speed are the ones having problems with them. The only 8 speeds the techs see are the ones acting up. When I was working at the Chrysler dealer I bought a brand new Mustang. My service manager asked me why didn't I buy a new Chrysler product instead. My 21 year old logic was "I never saw a good one" . Every Plymouth I saw was broken. Had I worked at the Ford dealership I likely would have picked up a E58 equipped Volare instead of the King Cobra..
Doug_Scott started following DTC C0267, Replacement NAV Radio reprogramming. How long does it take?, 2007 chevy silverado v-6 fuel pump control module and and 3 others
Doug_Scott replied to Mossyoakglock's question in Ask the GM TechnicianYou need to understand getting repairs done is not like eating a meal. The mechanic is not going to be waiting with the bay open in anticipation of your arrival. They cannot predict at what time he will be able to start the job. That's all they are saying.
You may want to ask your salesman to get you a service history on it. Rentals where I am typically appear with 30,000 km on them, and usually being in service for 12 months. They are usually a good deal if you get a dealer that gets a load of them at a time. We don't generally ever see trucks though. My brother in law has bought a couple of those cars when his daughters got drivers licenses. Paid about half price for a current model year(just) Impala a few years ago. Paid $16.5k for a car that listed for $32k 11 months earlier. Car had 28,000 km on it.
Never been a fan of these "cleaners". The big difference in how direct injection has changed the carbon world is back in the intake ports. Moving the fuel injection into the cylinder removed the wash down effect of spraying fuel ahead of the intake valve, helping wash the oil misting off the valve stem. The pcv system pulls oil vapour from the crankcase and dumps it back into the intake. Oil does not vaporize in the air stream and hits the stem and back of the intake valve head. Injected fuel used to help a bit to wash some of it off. Not any more. Using an oil trap on the pcv line will help alleviate the oil from hitting the intake in the first place. You would be surprised at how quickly it can gather a cup of oil. Misting water into the intake AFTER the MAF sensor will remove carbon from top of piston. I find it hard to believe your engine managed to get enough carbon like they described in the first place. Your truck has high mileage for its age. 40,000 miles is usually over 3 years, your truck is probably half that age. That means a lot of highway mileage, not the traditional carbon build up driving.
The easy way to decarbon the engine is to simply go to the closest highway on ramp and from a dead stop floor it and hold it there till you hit speed limit. Watch the crap come out the exhaust. Do it a couple of times to get it all. If the idle is too rough you will get a code thrown for excessive misfires.
Not entirely sure I am understanding what you are trying to say. To me, it sounds like you are describing what happens when the parking brake cables are not routed correctly under the truck. I don't have that generation of truck to refer to, but, I think you have one or two of the following issues: 1. Incorrectly routed middle cable leading to the cable being too long. 2. Front cable starting to seize up. 3. Incorrectly adjusted parking brake. 4. Parking brake components incorrectly installed/setup. The first place I would look is the routing of the intermediate cable. Make sure you have all the correct hangers and they are where they are supposed to be. Get a helper and take a look at one sides brake shoe action when your helper applies the parking brake. You should see the brake shoes moving. Only expose one side at a time for that test. You are looking for the shoes to move in both directions. Double check that all parts are installed correctly.
Brake fluid is tough on paint, but is also easily neutralized with water. It doesn't go everywhere, it simply overflows the reservoir and flows straight down. First step to servicing brakes is to remove reservoir cap. Leaving the old style cap on would make it near impossible to push the second caliper piston back if someone had topped off the fluid recently without checking brake pads. If the fluid was down so far to turn the light on, you will want to physically check the pads for wear.
Try waiting 5 or 10 minutes before checking oil. Manual says check oil at operating temperature. If you check it cold it will be half a litre low, but when at operating temperature it will be full. Most dipsticks will either have a hot and cold full lines, or a checkered region that indicates an acceptable range. It is normal for it to take a few minutes for all the oil to return to the pan. Any longer than 15 minutes is too long. Engines are not designed internally to capture and hold oil, it serves no purpose to store a litre of oil that is not under pressure. If the rocker covers/top of cylinder head is holding oil, it will leak past valve seals and into intake or exhaust ports and be burnt. A litre is a lot of oil. Hold up a litre bottle up next to the engine and try to imagine what could be retaining this as being normal. I think if you simply wait 15 minutes after shutting engine off you will find it far closer to full. You could even just wait 5 or 10 minutes and see it as being near or full.
As disc brakes wear the caliper pistons extend out in their bore and brake fluid fills the void. As this happens the fluid level in the reservoir goes down. Typically the reservoirs have sufficient volume to be able to handle the needs of the calipers. You can simply add brake fluid to the reservoir and see if it corrects the fault code. Make sure you have the correct fluid before adding. DOT4 is likely the fluid to use. Do NOT use DOT5 fluid thinking it is newer and therefore better. It is not compatible.
Doug_Scott replied to mckpaul's question in Ask the GM TechnicianWas your truck running normally with those pressures? I understand that you can't monitor and drive, or even hope that by luck when the truck acts up you have the scanner connected and on the correct screen, does this scanner have a record option where it can record all items? It would be nice if it could record so you could just let it run until it finally captures a "bad" trip. As far as proper fuel pressures I don't know what is considered normal but, on systems with a regulator on the line that were vacuum controlled, when accelerating, the drop in manifold vacuum would cause the fuel pressure to rise, not drop. To me, under acceleration the pressure shouldn't be 15psi lower. I had a GTP back in 1998 that had an issue with blowing the fuel pump fuse when under boost at low speeds. GM ended up replacing the fuel pump, it apparently controlled pressure by controlling voltage to the pump on supercharged engines. Perhaps they are using that system on all engines now.
Doug_Scott replied to mckpaul's question in Ask the GM TechnicianI come from pre-computer times. I went to all the Chrysler tech training starting with "Lean Burn" and then the Imperial EFI stuff. They always pushed that the last thing you look at is new technology. You can spend hours chasing the symptom instead of looking for a cause. They also pushed that the various sensors are used to tell the ECM what the engine needs. For example, the TPS and MAP sensors combine to be the accelerator pump on a carburetor. You should put your trucks shifter in 1 and take note of rpm and speed @10mph increments, then shift to 2 and repeat, then 3 and you can see where I am going with this. If you can get these numbers when truck is running normal, you can use the list to determine what gear it is actually in when it acts up. Remember that 6 and maybe even 5 also have lockup. My truck has the 4 speed and it appears to lockup in 3rd and 4th.
Most OnlineNewest Member
Who's Online 90 Members, 0 Anonymous, 510 Guests (See full list)
- Jake Gould
- B R A D
- Fire Chop