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head gasket theory

Discussion in '80-Series Tech' started by landtank, Jan 13, 2004.

  1. landtank

    landtank SILVER Star

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    Well to start I had my coolant system flushed yesturday by a dealer as I couldn't get to it myself this year. The last flush I did was 2 years ago. I'm aware of what is recommended on the board but can't see why 2 years shouldn't be enough. Two years ago everything was fine with no contamination. This year is a different story. Heavily contaminated with the grey sludge. They use a mild cleaner and did it twice!

    This started me to thinking. Where the hell is this sh*t coming from? It wasn't there 2 years ago at 65k. And I'd expect if it was casting sand or something left over from manufacturing I would have seen it then.

    This is what I've theorized. The sludge is actually carbon from the combustion process entering the cooling system. The HG fails ever so slightly and combustion/exhaust gases are forced into the cooling system and slowly start to accumilate. Just as we see carbon build up in the EGR system. This build up, if goes unchecked eventually compromises the cooling system by clogging the radiator and creates a condition that results in a catostrophic HG failure.

    If I'm correct then the yearly flushes are merely treating the symptom and not resolving the problem.

    It has been thought that the sludge was the cause of the HG failure but I'm thinking that the HG failed and caused the sludge. I have some mandatory time to take off by April and a head gasket is in order for me as I need this truck for work. Besides it will only get more costly later.

    What do you guys think?
     
  2. sleeoffroad

    sleeoffroad Supporting Vendor

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    Rick, I do believe that what you have experiences might be the case in certain situations. We have seen that same situation in at least one truck.

    However, I think if the flushes are not done, you will loose the head gasket sooner since the cooling system can not keep up.

    Just had another email from someone stating that they were just driving their truck and suddenly it started missing and blowing white smoke. Not good. No idea on the service history etc etc.
     
  3. landtoy80

    landtoy80

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    If we should do yearly flushes and use flush cleaner, does it mater what coolant we use?
     
  4. Asiarider

    Asiarider

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    [quote author=landtoy80 link=board=2;threadid=10071;start=msg89651#msg89651 date=1074008526]
    If we should do yearly flushes and use flush cleaner, does it mater what coolant we use?
    [/quote]

    I think it will matter because the wrong coolant can still build up more sludge or lead to other damages. Just flush every year and stick with the right coolant. Then you will be fine, even with a S/C.

    Mike
     
  5. Pitbull

    Pitbull

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    [quote author=landtank link=board=2;threadid=10071;start=msg89579#msg89579 date=1073991662]

    The last flush I did was 2 years ago everything was fine with no contamination. This year is a different story. Heavily contaminated with the grey sludge. It wasn't there 2 years ago at 65k.

    [/quote]

    Your signature indicates that you now have over 125K miles on your LC. That means you went 2 years and over 60K miles on this last change. Am I reading that right? That might be part of the problem seems to be more than Toyota recommends. Why would you replace your head gasket? Do you know for sure it is failing?
     
  6. semlin

    semlin discouraged user

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    Didn't someone have this stuff analysed at a lab a while back?

    the sludge could be sloughing from a part within the cooling system due to a chemical reaction. That reaction may be dependent in part on running temperature, coolant, or wear on the part itself removing a coating, all of which might vary after 65k.
     
  7. Asiarider

    Asiarider

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    [quote author=semlin link=board=2;threadid=10071;start=msg89811#msg89811 date=1074025405]
    Didn't someone have this stuff analysed at a lab a while back?

    the sludge could be sloughing from a part within the cooling system due to a chemical reaction. That reaction may be dependent in part on running temperature, coolant, or wear on the part itself removing a coating, all of which might vary after 65k.
    [/quote]

    Yes, that what I think too :beer:

    Mike
     
  8. Safado

    Safado

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    Just do another flush the day before you tear into the HG. Measure the ammount of sludge. Flush again the same period of time/milage later after HG replacement and see if you still have any. This should be a viable test to see if replacing it actually gives you any results, assuming that there is at least some build up by April.
     
  9. PHAEDRUS

    PHAEDRUS

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    Just a thought here that you mihgt have missed a step, I like your theory and there is possibly something to it. I am just playing devils advocate and asking the question. Now what is diffirent between HOW you flushed the cooling system and how the dealer did it. did the dealer use an automated machine (wynns comes to mind) if so there is a lot of residual sludge that lives in the lines they use on these especially one that sees dual usage (red and green). the second part of this question is what additives do they add to the coolant when they are flushing? most (again my experience is with wynns) flush machines use some sort of seal conditioner or other varied snake oils. Did they use any in this instance or was it a straight red for red? just a couple of questions to go over before you go tearing the head off.
    Dave
     
  10. landtank

    landtank SILVER Star

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    Phaedrus,
    Your probably right on the machine. I have the invoice which lists a WNN COOL KIT TOYOTA and sealant. This is something I usually do my self however I didn't get a chance this year. It was explained to me that the tech would flush the entire system with a mild solvent solution. Allow the truck to idle for 15~20 minutes and then that flush again with Toyota red. The whole process took just under an hour.

    Pitbull,
    You are reading that correctly. When the red first came out I was told it was a high life fluid with a change cycle of 6 years. Since 1992 I have owned 2-Camrys 3-4Runners 1-Corolla and 1-LC. At one point I was driving more than 50k a year and never leaving the Boston area. With all those vehicles and all those miles I've never seen anything like this and never had a problem. These were all new purchases and I did all the maintenance. My wifes 4Runner is a '96 with 78k on the clock and no evidence that I can see in the recovery tank while the LC had a thick layer.

    I'm not buying the sloughing effect, as what is so different in this engine's makeup over all the other Toyotas I've owned. The truck had 38k on it when I bought it and I think that up to this point I'm the only one in there except for the tranny service and coolant flush.

    As for why do the head gasket, I need this truck for business as well as pleasure. The risk is to high for me to drive it until it breaks. I could be 400 miles away and at the merchy of a dealership which would greatly increase the cost in both the repair and lost wages. For me a planned R&R of the head gasket makes a lot of sence since it won't negatively impact either of those areas. Who knows maybe taking a look at a gasket before a complete blowout might yield some answers.

    Besides it's just a head gasket ;)
     
  11. Pitbull

    Pitbull

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    Interesting??
    Color has nothing to do with the type of coolant a motorist should use. Most conventional American antifreeze is green. Prestone® antifreeze/coolant is yellow with a green tint. The majority of American extended-life antifreeze/coolants are orange, including Prestone® Extended Life 5/150 antifreeze/coolant. However, many automobile manufacturers use specific colors in their vehicles, which are not related to the type of antifreeze that vehicle contains. For example, Toyota uses red, some DaimlerChrysler vehicles have orange coolant, and Volkswagen and Audi use pink. “A motorist may very well add a yellow coolant to a pink coolant making it orange, and that’s okay, as long as both formulas are similar in chemical composition,” says Courtney.
     
  12. floatinghat

    floatinghat

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    With the concern why not have a pressure test performed on the cooling system? If you are seeing a loss in pressure you have some type of issue.

    With all of these head gasket questions one thing I have not seen mentioned is retorqueing the HG, why not?

    andre
     
  13. Beowulf

    Beowulf

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    Andre,
    To torque the head you have to remove a lot of stuff, including the cams. The advice from a couple of experts was that it may or may not work. Nobody had tried it when I posed the question a couple of years ago. The advice at that time was to go ahead and replace the head gasket if you have it torn down to the point where you can re-torque the head.

    -B-
     
  14. - S.A. -

    - S.A. -

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    Rick,
    How much did the dealer charge you for the flush?

    I think i need one..as i just got my rig about 1 1/2 years ago..and i can gurantee the PO didnt do crap to it as far as maintienence. I would do it myself..but, you know how freakin cold it is up here now!

    Also, let me know if you need help with the HG.

    later,
    Joe
     
  15. landtank

    landtank SILVER Star

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    The dealer charged me 103.05 here in NY.

    Thanks for the offer Joe. I'll probably start it over the weekend so I'll have a whole week to get it done. I was contemplating retorqueing the head. There was some issues on the 96 v6 4Runners where the heads were torqued wrong and they were blowing gaskets. I don't remember it being so involved but I trust B and his memory.

    Probably will attack it near the end of march. Hopefully the weather will be warmer. Near the date I'll try to remember to pst something for some ideas of what to look at during the tear down. Things like checking the torgue on the head bolts before removing them.

    Oh Ya, part of the service was a pressure test. I'll be doing a compression test when I get home to see if any thing shows up there of any concern.
     
  16. PHAEDRUS

    PHAEDRUS

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    Rick,
    I am also jsut wondering still if the detergents they used cleared some deposits that were left on the rad rows or hoses due to pressure differnece and dtergent action of the process. I understand why you would want to pop the head anyways, just curious for the others on board who use theirs as a daily driver. some of us are lucky and the cruiser is for when we want it.
    Dave