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Chevy Tahoe Maintenance and Repair



  • In July I was traveling down 95 in NC and with out noticing my speed on open highway, my Tahoe stumbled sort of like shutting-down. I looked at the speedometer and realized I was just under 100mph. I pressed the gas again and the thing stumbled when reaching 100. My question is, does these SUV's have some sort of governor on them?

    Replaced the CKP- Crankshaft Positioning Sensor and the Tahoe started up immediately- HOWEVER- a new problem arose. It idled perfectly, I reved it, and turned it off again after only a minute or so since the air cleaner was off and I didnt want to suck anything bad into the engine-- BIG MISTAKE. :confuse:

    Apparently there is a Learn Procedure for new CKP's that reprograms a timing aspect in the Vehicle Controle Module. Any time you replace a CKP you need to hook up a scan tool right after so that when you start it you can run the Learn Procedure. I did not do this and now the car wont start again- when I shut off the car it erased my previous timing codes so it will not start again until it learns a new DTC code..... I had to study the manual to find all this out :sick:

    Anyways, I am soon to be back on the road again, I need to get the car to a real scan tool (I have a basic 1996+ one), but it still wont be that easy. Since the codes are erased I'll have to manually run the program, hopefully everything will work out fine--- just a WARNING to anyone else who has a similar problem-- if you change the CKP, be somewhere with a proper GM SCAN TOOL.

    Again, any input is more than welcome-- Thanks
  • arriearrie Posts: 312
    I replaced my Crankshaft Position Sensor and did not have any problems. And I did not need to run any re-learn process.

    By my Chevy dealer shop new crank shaft position sensor can set the DTC (Diagnostic Trouble Code), i.e. lit up the check engine light but even when this happens the truck will run. Re-learn will then take care of this 'false' code.

    I don't think your problem is with the crank shaft position sensor. In your earlier post you mention that you have plenty of spark and that you have plenty of fuel pressure in the fuel rail. Then when you pour fuel in the intake the engine tries to start.

    Sounds like you have fuel injecting problems, i.e. injectors are not injecting fuel in the engine. Sounds weird when you say that after changing crank shaft position sensor it started up immediately but then would not again after you shut it off. Could there be some short of loose wire connection with the crank shaft position sensor that messes up other circuitry.

    It almost sounds like your computer has gone bad as I think it controls injectors directly. That would be quite bad news as they can be costly to replace.

    Check your engine ground wiring. Make sure engine is well grounded to the vehicle body and that the ground wire from the computer is well connected to the engine.

  • The wife's 03 Tahoe has started to lock or unlock the rear doors when it feels like it. You stop and put the vehicle in Park, they unlock.. sometimes. You then put the vehicle in gear and they lock.. sometimes. Yor press the door lock button and the either lock or unlock.. sometimes.

    Help is evidently needed.
  • Last update. Had to re-post

    Cant believe it, turned out to be a bad fuel pump after all. Even though we tested 55+ PSI at the rail, it turned out sporadic. It wasnt holding a constant pressure, so the tests we got were completely misleading. What makes it worse is that it was replaced only about 8 months ago.

    Even worse- DONT buy from "Global-Automotive" on Ebay. Stated in auction was a new AC Delco fuel pump warranteed for 1 year. After attempting to contact many times, filing with ebay, and finally contacting AC Delco, turns out he's selling counterfeit parts and its an open scam on Ebay, Delco is mounting a case against him and took my info as well as many others. Ebay will not suspend him since he generates so many sales (10,000 transactions + in about a year). So, im out my money.. and I'll have to pay more for a new pump- sucks

    Thanks for the help- Ed
  • dochou

    Hope I didn't take to long. Your compressor belt is comming of because of the adjustement spring. If you have the grinding noise it may be because your compressor is going out. I have heard from other writers that a lubricant can fixx this. But what a dealer is going to tell you is that you need not only replace your compressore, but also your need to replace your rear compresssor. This is wrong many times.A true mechincie will examine wheather or not enought material has gotten to your rear area. If it has not you will save nearly a thousand dollars. None the less the price the dealer charegs is much higher than a specialist.
    Check rhe price from the dealer to an auto parts store. Then ask for the dealers wholesale dept. The price will be about $200.00 Less. Part only.
  • I live in the desert and don't get too much rain. Last week experienced downpours and the leaking got worse to the point of getting the fabric wet. Took the car to dealership for second time and got the same answer: There is a "drip pan system" and some water will leak from the gasket to the drip pan and channel out of the car. I even poured water on another new tahoe from the lot and the same thing happened.... My car is getting excessive leaking and will be looked at again this week. I am still not convinced of this "new engineering" as I did also notice condensation of water on my windows as a result of moisture from the leakage. My recommendation DO NOT PURCHASE SUNROOF OPTION with the '07 Tahoe (Suburban, Avalanche, etc). I am very curious to see what other owners are experiencing, especially those living in temperate areas. By the way, GM still has not answered me.
  • Hello;
    I have a 1997 Chevy Tahoe with 4WD and the 5.7-liter with the CSFI system. Getting a “check engine” light that is coming back with a P0300, Multi-port misfiring error code. I am having a problem getting this fixed and I am not able to pass the NJ DMV inspection. I can feel the rough idle when sitting waiting at a light or stop sign, but feels fine during regular driving and/or on the highway. To make a long story short I got a full tune-up (plugs, filters, etc.) and the # 2&4 fuel injectors replaced, but still getting the error.
    I took it to the GM dealer and they trouble shoot it to a bad fuel pressure regulator and it is leaking fuel into the # 3&5 cylinders, causing the misfire. The cost will be $800+ to replace the regulator, replace the throttle body gasket and do fuel systems flush. What I don’t understand why is it only leaking in only two of the injectors as the regulator looks centralize? It sounds like the two mentioned injectors are the parts going bad. Any advice on this matter and if it sounds like it will take care of my problem. Thank you.
  • arriearrie Posts: 312
    $800 ! What a rip off!

    Go buy the pressure regulator and change it yourself.

    The leak causing the problem on cylinders 3 and 5 I think means that fuel is leaking from the pressure regulator and dripping on the spark plugs around cylinders 3 and 5 causing a short on the spark plug boots and misfire. It would not make sense that due to pressure regulator going bad it would make only the injectors 3 & 5 to leak by. And a small amount of extra fuel in the cylinder would not cause a misfire anyways.

    If it is dripping externally please have the pressure regulator replaces ASAP as it is a serious fire hazard.

    Fuel system flush will not fix your problem. If it would, your vehicle now certainly would not run fine with higher speeds.

    Do you have the aluminum heat shields around spark plug boots? They can cause a spark leak to engine ground if not installed correctly. Also, old spark plug wires / boots lose their resistance over time and cause more spark leak.

    One easy trouble shooting step is to have your spark plug wires replaced. A set cost around $30 at car part stores (not dealer). Just make sure that the boots go deep enough on the plugs to minimize the spark leak. You can also replace the wires with high quality set that does not require use of the heat shields like I did. Set like this cost around $80, which is the cost of normal set from the dealer.

    Another item that could be the problem is the crank shaft position sensor. They are notorious of going bad and a rough idle is one of the symptoms. Sensor cost is about &70 or so from the dealer. To change it I think your starter motor must come down as it is located behind the motor. At least in my '04 tahoe it is.

    For the fuel system the only thing you need to do,in addition of changing bad pressure regulator, is to make sure your fuel injectors are clean. If you don't use injector cleaners in a regular basis it could be that injectors have build up deposits that do not allow a correct spray pattern and idle gets rough. With more throttle opening there is much more oxygen to burn and the injectors must open more. More open injector then woks better as the build up disturbs spray pattern less.

    Run a few tanks of fuel with injector cleaners to see if it helps. Sounds simple but this could fix the whole problem and cost you only about $10 - $15 extra. This is what I would do first (after replacing dripping fuel pressure regulator).

    About the throttle body gasket: Why do they want to change that? It certainly is not a problem source unless your throttle mounting bolts are so lose the gasket does not seal at all. I don't think that is the case.

    If you do find help for your problem based on this post or if you don't would you please post back the results. This forum does not work if the other readers can't see the end result.

    We all would appreciate that.


  • lnuttlnutt Posts: 3
    1999 tahoe.keep getting service engine light,last 6 months,error codes p0430,p0420,p0304,p0300,have been trouble shooting(and spending big bucks) to correct,
    new catys,muffler& exhaust
    all new filters thru outincluding fuel&trans.
    fuel presure test,ok
    new plugs,wires,cap & rotor
    trans.flushed & oil changed,and fuel cleaners used.
    get the problem at high rev on highway,(65plus) engine gets rough,light gos on, smooths out,now getting hard to start takes two trys... frustrated!!!!! local mechs,are lost!!!
    help please anyone!!!!!!! :confuse:
  • lnuttlnutt Posts: 3
    just got email,suggesting bad coil/ignition module,or bad pcm???? any coments,sugguestion????
    need help bad..... :sick:
  • ok, my mom's boyfrind has a 1999 tahoe with around 65,000 miles on it. on day we were driving down the road and all of a sudden the thing dies. comeletely dies, i mean all power to the vehicle. the lights went out, no power worked, and the clock on the radio reset itself. he got it to a stop, not easily but he did, and even the steering locked up???? when we coasted to a stop, he put it in park and turned the key, and it started and ran fine for the rest of the day. a few days after words it did the exact same thing, but this time when we went to start it, it cranked and tried to catch, and we got only a few revolutions out of it before it died again. the next time we tried to fire it up it ran perfectly normal. he also noted that and apm's gage dropped down to zero, and then back up to normal in a few seconds before restarting. now, i know that when most people read these posted by young kids like me, they disregard them...however, we really need help as this is getting worse and worse. it is also out hunting vehicle so we cant really have a car thats gonna die driving down the road and have no steering or brakes...YIKES!! so, please if you have any ideas, or have had this hapen to you, write back! i'm kinda thinking it might be the main brain, but its too new for that
    thanks in advance!
  • 73shark73shark Posts: 325
    Surprised that no one weighed in on why you were going 98 mph or whatever in the first place. I'm sure there's a good excuse like someone's dying, having a baby, etc.
  • arriearrie Posts: 312
    Sounds like your battery might be shorting out.

  • right. This could very well be a bad connection at the positive battery terminal. Same thing happening on my 1997 Tahoe. Very easy fix thankfully. Pull your positive cable from the battery and clean all the contacts with baking soda and steel wool/sandpaper. And if you havent done it yet and it happens again just open the hood and move the positive cable around and walla!
  • oh wow thats way easier than the problem i was thinking of! thanks i'll have him try that right away! BUT, how does a bad connection result in the car dying while driving, as the alternator is what supplies power to the electrics when driving??? also, wouldnt a bad connction result in the car not turning over at all?
  • not exactly. The alternator will only run for a little bit before dying. It needs to work in conjunction w/ the battery from what I understand. Also the connection may not be fully blocked but only partially. For example during a few episodes my lights would turn on and everything else but the starter wouldn't engage. At first my mechanic thought it was the starter until we determined that not enough juice was flowing to the starter in the first place(STARTERS ARE AMP HUNGRY)!! Hope this helps.
  • ok. he checked all the conections and they were all very secure, and the points are clean and prestine. it actually did it again a little while ago, on our way home from kung fu. it was really scary cuz evetything went dead, and it was only semi-lit with street lamps. when we finally came to a stop, he shut everything to the off position and started it, ran for a sec or 2 then slowly dies. this is the exact thing his bronco did when the computer went, ran then dies. but the next time we tried, fired right back up w/ no problem. however, once the engine is running, a cars battery does nothing but get charged, which is why a person can take the battery out when the engine is running (which have to do a few times.
  • arriearrie Posts: 312
    But if your battery is shorting out it will consume all power the alternator makes.

    When you say that everything goes dead when the car stalls, what do you mean by that?

    If everything electrical dies then it almost for sure means your battery shorts out. For example, if your radio dies at the same time why would the problem be the cars computer? The radio has nothing to do with that.

  • I have a 2005 Chevrolet Tahoe LS. The side mirrors don't have the turn signals. I'd like to add them. Are the mirror "holders" already wired for them, so that all you have to do is attach a mirror with the turn signal and maybe plug it in? Or would additional wiring be required? Thanks.
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