1999 4runner 3.4 Engine H E L P ! ! !

Discussion in '95-older Toyota Truck Tech' started by snowcruiser, Jun 21, 2005.

  1. snowcruiser

    snowcruiser

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    Here goes....The girlfriend's '99 4unner 3.4 liter 4runner with 5 speed manual tranny is having some issues. She purchased 2 years ago from an area Toyota dealer with 35,000 miles and it now has about 72K. Couple of days ago the check engine light came on with 2 codes (P0125 and P1135). Oil level seemed a hair low but nothing crazy and was recently changed with a filter and Mobil 1 5w 30. I reset the ECU and disconnected the battery overnoght but the codes retruned within 5 minutes of driving the next day. In searching for information on these codes I have become a bit concerned. It seems as if it may need an 02 sensor but some have said that the o2 sensors are treating a symptom and not the problem which may be Engine Sludge! Toyota seems to have had a problem with some engines (mostly 3.0 liter) and sludge and they replace the engines, but I have heard of 3.4s having the same issues. However, this certified pre-owned truck is now out of warranty and since I change the oil myself, I have no receipts of maintenance. I am planning to test the voltage across the o2 sensors as someone suggested but in the event the sensors are ok, I am not sure how to proceed. I've looked on Yotatech but have never had any sort of quality tech response from that site and after three hours researching this issue I am at a loss. Anyone have any advice about how I should proceed. I have been very unhappy with our local Toyota dealer in the past and have since completed all the work on my 80, my sister's 4unner, parent's 100, and girlfreind's 4runner myself. I do not really trust them to examine/diagnose this problem but if I do have to take it there I want to know everything about the problem beforehand so that if the engine needs replacement we are not out $5000. Please help....anything technically related or advice is greatly appreciated.

    Thanks

    Snow
     
  2. nakman

    nakman addict.

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    Ok I'll start.. your O2 sensor is not the symptom, it is the disease. Swap it out, drive around for a couple-few tanks then change the oil again. maybe toss some cleaner or ATF in there towards the end... then decide for yourself if there's sludging when you watch the oil drain out.

    But my guess is your O2 sensor is sending erroneous info to your ECU, which is screwing up your mix. Swap the O2 sensor, reset the ECU, then drive. That's what I'd do first if it were me, hth.. . :cheers:


    edit: Haynes manual is pretty funny tonight. I went to look up the codes and turned to the start of chapter 5. it says "check engine light.. see chapter 6" so I go to chapter 6, it says "check engine light... see chapter 2." Suddenly I'm 8 years old reading a Choose your own Adventure book.. well chapter 2 sends me back to 6, so fuggit. :beer:
     
    Last edited: Jun 21, 2005
  3. snowcruiser

    snowcruiser

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    Thanks for the suggestion Nakman. I wanted to see what else I could do before spending $200 on an A/F (O2)sensor as it is a California speced truck and I don't have the equipment to test the voltage across the sensor. Also the truck has a manual tranny so no ATF. I thought the O2 sensor was the disease also but after a bit of reading, some others who have had this problem who have replaced the O2 sensor get the same problem back within a year and replace the sensor again and again and again. Sounds like a symptom of something else to me. I am having the sensor checked in the morning so hopefully I'll know something soon. In the meantime please continue to post suggestions....

    Thanks
     
  4. nakman

    nakman addict.

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    the ATF is for the engine.. has detergent in it that will stir up some of your oil sludge. Not Dextron, but type F. Just an alternative to the more expensive snake oil additives... that's all. :)
     
  5. snowcruiser

    snowcruiser

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    thanks. how much atf do i add? in place of oil or add to oil?
     
  6. calamaridog

    calamaridog

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    Suggestion #1 is to do a search at Yotatech and/or TTORA if you haven't done so already. Or post a thread. There are some people over there who can help you with the tech stuff.

    Are there any symptoms other than a check engine light? How is it running?
     
  7. Outback

    Outback

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    I second calamaridog's suggestion to take this to the TTORA.com forums and see what they have to say. I would SEARCH over there first and be sure to tell them you HAVE SEARCHED when you post. Just a little advice :D

    But, you may try a seafoam treatment as described on TTORA.com. That sometimes helps. If I had any questions on my Taco's 3.4, I'd take them to the TTORA forums for answers. They know their shizzle over there and have LOTS of experience to back it up.

    Good luck buddy, you're on the right track asking questions....

    Jody.
     
  8. snowcruiser

    snowcruiser

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    Thanks for the suggestions. Checked out TTORA and came up with a few leads. Cheers
     
  9. Eric Winkworth

    Eric Winkworth

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    I know that ATF works but as for using it I wouldn't, it has friction inhibitors in it designed for wet clutchs in an automatic tranny, not something you want in you engine.

    I personally would get some amsoil engine flush, there are many different typoes of engine flush you could put in right before the end, just my 2 cents
     
  10. calamaridog

    calamaridog

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