1998 SUBURBAN 232,500 miles-coolant in exhaust?

Discussion in 'GM' started by phoebeisis, Dec 19, 2016.

  1. phoebeisis

    phoebeisis Well-Known Member

    You guys are motor heads
    I always get better info here than the trucks forums
    Coolant in exhaust
    Oil clear
    yes coolant was dropping
    'Yes overheated a little-
    showed 250 on gauge-but since the coolant system peak loss was 1.5 -1.75 gallons
    the 250 degrees was a bad reading-might have had steam next to coolant temp sensor
    ran it 10 miles-full radiator-down 1.5 gallons low-temp went up to 250 degrees
    1)Will intake gasket failure LEAK INTERNALLY-into manifold
    OR 2) is this much more likely a HEAD HEAD GASKET failure
    Currently-after adding BARS ALUMINUM particles stop leak
    The exhaust cloud is much less -and after 20 miles-no obvious drop in radiator level
    and engine running fine-
    below more detail-problem started with leaky uppper radiator hose-
    bad decision to drive home-might have actually been a problem for 3-4 days(temp gauge going higher than usual-but never in red)

    1998 suburban(best car I every owned $2950 in 2007 with 195,000 miles-now 232,500 miles)I am losing coolant
    and I have coolant in exhaust "smoke"
    No water/coolant in oil-
    It did barely start-stumble- (after repalcing hose refilling-it barely started then it stated and blew out plenty of coolant condensate in exhaust
    before I added the Bar's leak with aluminum particles to radiator
    but now the coolant is barely dropping-maybe not at all
    and very little vapor in exhaust
    yes it overheated- read between 210 and 260 on gauge-maybe 250-(but it doesn't read right if steam instead of liquid in passage by sensor)
    and it was down 1.5 -1.75 gallons-
    not for long-it was full-cool-and I drove 10 miles home-lost 1.5 1.75 gallons in 10 miles
    there was a hole in upper radiator hose-wasn't showing at idle-but once I got home-it was steaming out like a locomotive(yeah I screwed up but I had to get home-cool day and full radiator,so figured it would work out-it didn't)
    My question
    1)Will the intake manifold gaskets ever leak coolant INTERNALLY -into the manifold them into combustion chambers
    2) or is a HEAD GASKET internal leak or head crack MORE likely
    Motor is running VERY well now-with slight exhaust smoke(not oil no oil smell-coolant smell)
    and oil is clear-perfect

    So can intake manifold gasket failure leak internally?
    Which is more likely HEAD or Head gasket failure?
    or INTAKE manifold gasket failure(happened 5 years ago-leaked externally)

    Help-and thanks
    ps yes I'm sorta' broke-ish SS but work part time too-
    but a $2300 delivered curbside NEW Goodwrench engine is within reach-and doing a POINTLESS 10-15 hour intake manifold gasket replacement doesn't appeal to me(65 yo)
    I LOVE this truck-almost owner proof-and my late wife and I took and our dogs took long road trips in it
    so sentimental value also

    1998 suburban-
    1/2 ton

    199500 miles
  2. ALS

    ALS Super Moderator Staff Member

    My first opinion would be a head gasket with maybe a warped head involved due to over heating.

    With out seeing the vehicle in the flesh as they say.
    BillLin likes this.
  3. phoebeisis

    phoebeisis Well-Known Member

    Thanks for the best guess
    Unfortunately for me
    That is also the best guess of a very adept mechanic buddy of mine
    Obviously I was hoping for intake manifold gasket failure-a $50 -$70 or so gasket set plus new bolts+ $30 DEXCOOL-so $100 plus 10 hours of knuckle scraping back bending work
    Not HEADS many more hours machine work
    Hmmm I will probably give the various BAR'S leak stuff a bit of time
    carefully measure how much coolant I'm losing
    monitor the OIL for water and loss
    check MPG to see how much that drops
    I don't expect the "BAR'S stop head gasket leak stuff "$27.99 walmart TO actually stop a head gasket leak
    but the ALUMINUM particle Bar's stop coolant leak "stuff" did greatly slow the clouds of condensate
    and the suburban does start and run better since the BARS stuff
    So maybe maybe the leak will slow to 1 pint per 20 miles
    water is cheap
    and I only drive 2000 miles/yr

    But I expect things won't go that way
    most likely the leak will suddenly increase-a lot-
    and that will be that-hope I'm close to home
    On the bright side
    a NEW- not rebuilt-Genuine GOODWRENCH L31 light duty motor is $2400 delivered curbside
    Yeah hard to beat that-new motor $2400
    Heck if I get ambitious I can get a
    383E-stroked with full warranty new GM PERFORMANCE 383 DROP in motor(comes with dist installed)
    the way I drive probably no mpg difference for $4900-
    forged crank etc- 75 more HP 80 more FT LBS
    Not that I need a hotrod suburban
    Thanks Al
    I'm still a pellet rifle in hallway shooter-lotta fun
    - lock Arty and cats out-(Muffy sometimes SLEEPS on the bed while I shoot down the hall
    but I double check her position before shooting-)
    judging from her barely raised head(despite the RWS 460 being noisy)
    she is unimpressed with my markmanship!
    Last edited: Dec 19, 2016
  4. ALS

    ALS Super Moderator Staff Member

    Charley there is always Car-part.com

    $1,000 seems to about average for a used motor.

    $2300 for a crate motor would be the way to go.
  5. RedylC94

    RedylC94 Well-Known Member

    That was an expensive hose leak! Sorry!

    Long, long ago, my parents bought a new Buick with no factory air conditioning, then promptly had the Buick dealer install an aftermarket AC system. Then the family went on a trip to the Saint Louis zoo, ~200 miles away. Shortly after leaving the zoo, just before crossing over into East Saint Louis, the car started making strange noises. Curbside investigation revealed the compressor pulley had cut a small hole in the upper radiator hose due to careless rerouting of the hose by the installers. Uh-oh! We coasted into the last service station (Remember those?!) on the Missouri side. The proprietor wrapped the damaged hose thoroughly in duct tape, and refused any payment. The tape held and we made it home with no further drama----very lucky.

    Next time, try duct tape.
    Last edited: Dec 20, 2016
  6. phoebeisis

    phoebeisis Well-Known Member

    Yeah any add-on even dealer add ons back when
    had the potential to bite you in some unexpected way.

    Initially I didn't actually KNOW the hose was the problem-
    when I arrived in the school parking lot-(sub teach some days) I immediately popped the hood-could smell coolant and the water temp reading was a bit higher than usual
    Popped hood-could immediately see coolant ALL OVER ENGINE BAY
    Turned engine back on
    But couldn't see any leak-spray
    So came out 1 hour later-added perhaps a quart to radiator-overflow was empty and not easy to refill-top held on by hose clamp- started it up-still no spray
    I would have had to idle it for 15 minutes to get STAT. to open
    So I took the chance-drove home with eye on temp gauge
    it NEVER got to red-260- so 250 or so
    But this time I could SEE steam coming from under hood-but didn't look at exhaust
    Yeah had to cross a bridge

    Well got home popped hood-
    and literally a steam vent venting from HOSE SPLIT
    really obvious
    so next day replace hose
    add 1.5 gallons to JUST radiator(engine must have been all but empty
    start it up
    run it twenty minutes-still haven't looked at exhaust
    No leak
    but restart 5 minute later-
    Wait 5 minutes-barely starts-running maybe 250 RPMS(didn't think they could run that long)
    and HUGE condensate cloud out exhaust
    shut it down-put in some BAR'S leak aluminum particle stuff i had at hand(in truck-old truck old person)
    run it-it started after cleaning out(must have had LOTS of coolant puddling in combustion chambers-hence the hard start)
    well after a few minutes-cloud is LESS
    starting better
    But it is still at least 3 qts down-so all total it was maybe 2 gallons low

    In hindsight 2-3 days earlier I NOTICED that the temp gauge was running a little higher before the STAT opens drop
    Normally I pop the hood and check the overflow tank-everyday when I arrive at work
    But it was dark- 635am- when I arrived so the last few days-didn't bother
    I checked the tank because 15 months ago
    I had "fixed" a manifold gasket leak to the outside-in front near wastewr pump
    with BARS leak black pellets stuff-worked great

    so like most failures it wasn't just one thing
    Just started it up-38 degrees -bitter cold by our standards
    after a few minutes LOTS of condensate-LOTS
    water-nice clear distilled water-coming out exhaust-some actually dripping
    so leak "not too fixed" in cold-much worse than post leak fix with hot engine and 55-60 degrees
    On the bright side-oil still clear-just the usual faint gas smell

    Oh well-another engine is probably in my future-the $2300 new crate engine-not the $4800 genuine GM drop in hot rod motor 383E(but it tempts me)

    One question-does the no oil leak no coolant in oil-make intake manifold leak more likely than head gasket leak or warp or crack?
    Perhaps I should get out compression gauge-yeah guess I will-guessing 150 psi is about right
  7. 08EscapeHybrid

    08EscapeHybrid Moderator

    While it is possible that the intake manifold is bad, it is more likely the head gasket. The powdered aluminum leak seal is the best... I've used it in a few vehicles over the years where there was a mystery leak we could never trace down, and it always works. At this point, I'd just monitor it. Replacing the head gasket on a high mileage motor doesn't make sense... Might as well just replace or rebuild the engine if you want to keep the vehicle, or just look for another $3000 beater truck. Only downside to another vehicle is you don't know what issues you're dealing with. If you repair your current truck, you know what you have, and you know what to expect from it.
    phoebeisis and BillLin like this.
  8. phoebeisis

    phoebeisis Well-Known Member


    Hey "Great minds" must think alike.
    Couple of hours ago I came to the same thought
    96-99 5.7 Suburbans in the $1900 to $2500 range 150,000 to 240,000 miles
    All claiming the usual "runs good" and most claiming the AC works
    Frankly I'm a little surprised-$2000 for a running vehicle-with a functional AC tires that hold air
    easy and cheap to DIY repair-
    I expected with the low gas prices that suburban prices would be UP
    Perhaps that IS the case with 2008 on up
    but not the case in the ones -the 5.7-that I would look at
    I have some new 5.7 parts-and I'm somewhat familiar with their shortcomings( brakes aren't great intake manifold gaskets fail)

    and failing AFTER a clear episode of overheating-maybe an intake manifold gasket would fail from heating
    BUT heads cracking heads warping head gaskets failing after an episode of overheating-well seems a good bet
    Initially I used the BARS LEAK with the aluminum suspended in liquid-it seemed to greatly decrease the leak
    it was still leaking-some condensate in exhaust and the BARS LEAK aluminum stuff had a suggestion to use the BLOCK HEAD GASKET PERMANENT REPAIR if the aluminum stuff-didnt completely do the trick
    so I put it in the next day-yesterday-seems no better -but much colder today-35 degree low

    My plan it to run it gently-replace water(forget bothering with actual $14 gallon coolant)
    and drive it gently until it croaks
    or until I find water in oil
    while hunting for a cheap replacement 96-99 suburban
    there is a 2004 for $5900- 140,000 miles-but not so sure the 5.3 is more reliable
    mpg is better safety better brakes better-but 96-99 cheaper and easy to work on(heck $2300 for new OEM GMengine says it all)
    but I only drive it 2500 miles/yr(though I did drive it 1300 miles in the last 3 months-long term sub job 20.6 miles round trip-and over a MISSISSIPPI river bridge(climb maybe 300 feet)

    Thanks all
    PS Very adept mechanic buddy of mine suggests that I only screw the radiator cap on to the first "notch" so the system ISN'T pressurized -now that I figure the repair goo has done its best-I left it on in the hopes it would force more "gunk glue and particles" into the "holes"
    What do you guys think-loose radiator cap(hope it doesn't rattle off)
    Last edited: Dec 20, 2016
  9. I got an old van for nothing one time. It had overheated BAD. I bought a can of this super dooper stuff for 'fixing' head gasket leaks. It was like $20-25 for the quart. Came in a green bottle I think. One of those 'guaranteed to work' things. You have to totally drain the coolant system or something. I ended up scrapping the van and never used it. I think I still have it. Have Friday off, I'll poke around the barn and post a pic if I still have it. If I do still have it, I'd be happy to send it to you if you want to try it. Too lazy , too dark and cold outside to go look right now
  10. BillLin

    BillLin PV solar, geothermal HVAC, hybrids and electrics

    I thought you were saying that you still had the van... :D
  11. I wish
    BillLin likes this.
  12. 08EscapeHybrid

    08EscapeHybrid Moderator

    I've never used the liquid... I buy the stuff that looks like a test tube full of powdered aluminum. Have fun truck shopping... I love car and truck shopping, if you were closer I'd go truck shopping with you.
  13. phoebeisis

    phoebeisis Well-Known Member

    The Step
    Thanks for the offer-funny how you/me/all of us accumulate such things--you had better hang on to it-it might come in handy!!
    I had some of 08Escape's "aluminum powder"- but suspended in liquid - in the net pouch behind the driver's seat of the suburban(useful little storage place those net pouches)
    Not so luckily it worked "not bad" but not completely
    so I tried so "guaranteed" to fix head gasket stuff- the next day-didn't make the exhaust steam any better-but as it warmed up yesterday it seemed to improve

    08Escape-yeah I like car shopping too-even under the gun shopping is fun
    Thanks all-hoping with the slight warm up today the steam will decrease
    08EscapeHybrid likes this.
  14. RedylC94

    RedylC94 Well-Known Member

    If you're extremely lucky, it might continue to improve. For example ...

    At about 476K miles, my Mazda suddenly started guzzling coolant and blowing it out the tailpipe. The problem was not that the head had warped, or that the head gasket failed, but that coolant passages in the aluminum head had eroded away badly near the head gasket. So much material was missing that the gasket was no longer clamped to the block between that coolant passage and a cylinder, thus the leak. To make a long saga short, I fixed it by replacing the head with a rebuilt one. When I eventually got it back together and started the engine, coolant resumed dripping and fogging out the tailpipe just as before---very discouraging, at first! However, further investigation revealed the level in the radiator hadn't dropped, and the cooling system seemed to hold pressure ok. The dripping was apparently just residual coolant that had been in the muffler, not fresh leakage. Gradually, it stopped. The replacement head went another 130K and 11 years before the same (or similar) problem came back.
  15. phoebeisis

    phoebeisis Well-Known Member

    Good news-the goo must have "fixed" the leak
    Yesterday I drove 20.7 miles-10 city 10 hy 55 mph-
    marked the coolant in the overflow tank-closely marked it
    Drove it-parked it
    this am-exactly the same level to within 1 mm- and checked radiator-it is at the usual cold level-couple of inches below top
    and I have a scan gauge gadget(copied this from a GM truck forum-they aren't as familiar with SG) that reads mpg gph water temp trip mpg
    and at 55 mph it read 22-24 mpg-(with CC on no P&G)dead on what it read before the problem
    and the last 16 miles averaged 19.2 mpg horrible for a normal car but about right 1998 suburban driven cautiously- for hy city (10 6) mix

    Anyway it is running well-no increase in idle RPMS the way it did when the leak was "not too bad" ( it was about 720 instead of 620)) compensating for the coolant induced miss I guess.
    With any sort of luck it will hold for "a while" and at 2500 miles per year-who knows.
    It will give me time to hunt up a "different suburban" noticed 2004 2005 for just $5900(asking)
    they are rated 13/17 14/18 I think vs my 12/17- the 2006 are "a lot" better 14/20
    but they have oil consumption problems somehow related to the AFM cylinder shut off-
    Thanks for the help
    ps still whirring-but… one problem at a time
  16. ALS

    ALS Super Moderator Staff Member

    Glad it's fixed for now. At least you have a few weeks to find another vehicle before yours goes tits up as they say.
    phoebeisis and BillLin like this.
  17. phoebeisis

    phoebeisis Well-Known Member

    lucked out-
    hard to believe how effective those "seal leaks" products are
    even if they don't hold very long-still amazing
    it was literally "almost water-locked" very low rpms loads of coolant out pipe-
    obviously not fully locked-rod etc-would be bent broken-
    but there must have been many mls in some of the combustion chambers
    now NOTHING
    I have a good nose and up until 2 days ago-3 days after last sealant added-I could smell and SEE coolant in exhaust
    I could smell it-and see a faint reddish dexcool color in it

    Hey has GM ever solved the AFM cylinder shut off-oil consumption problems-2007 on 5.3 have it
    Well probably would stick with 1996-1999 so cheap and I trust the 5.7 and under the hood-easy to work on

    I did see a couple of 2004 2005 $5900 150,000 miles- 14/18 vs 12/17 EPA and better brakes
    the 2007 are much pricier $9000 and up
    the 96-99 are $2000 maybe $2500-amazed a running "car" is so cheap
    one easy to DIY with easy to find inexpensive parts
    one that it practically OWNERPROOF even ME PROOF
    Thanks again all
    PS Too bad you aren't an air rifle nut-Krale a netherlands gun shop-sells fancy German HW97 Weirauch(sic) FOR JUST $360 delivered in just 4.5 days-from across an ocean!!
    Last edited: Dec 24, 2016
    BillLin likes this.
  18. 08EscapeHybrid

    08EscapeHybrid Moderator

    SInce you have the water under control, I would remove all the plugs and clean them.
    phoebeisis likes this.
  19. phoebeisis

    phoebeisis Well-Known Member

    It is miserable looking today-
    yesterday it was 80 degrees-no kidding 80 degrees-house ac on -
    today is overcast-maybe 70 degrees now 7:40 am-
    and it is Christmas
    but the plugs are 1st order of business
    actually I have 5-6 new ones I meant to install a year ago when MPG dropped because of a chewed up rotor
    Thanks again
    Merry Christmas happy holidays
    08EscapeHybrid and BillLin like this.
  20. BillLin

    BillLin PV solar, geothermal HVAC, hybrids and electrics

    Merry Christmas!
    phoebeisis likes this.

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