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Determining internal state of engine.?

Recently noticed yellow custard and moisture on oil filler cap. 1998 Grand Prix GT, 3.8L. non super. I'm inclined to suspect plastic upper intake, but don't want to bother changing it before determining if crankshaft/bearings are chewed up due to coolant getting into crankcase. No custard on dipstick, yet. I had a problem and let an oil change go for 6000 miles. Could I strain the old oil, have just changed it. Or drain new oil, less then 100 miles on that, to look for flecks of metal? Is that the way to determine if engine will need overhaul? How fine a screen would you need to see whatever needs to be seen?

13 Answers

  • Anonymous
    2 months ago
    Favorite Answer

    That occurs with short trips as it's condensation in the valve cover. It normally disappears with long runs. It's not harmful per se. If you are using fully synthetic oil it shouldn't happen. BTW we go 12,000 miles on fully synthetic in the UK as recommended by the car manufacturers. But it has to be on fully synthetic oil.

  • Anonymous
    2 months ago

    Don't talk nonsense.  It is OK to just say you don't know anything.  Everyone has been there.  Just go see mechanic guy at a good shop.

  • 2 months ago

    HELLO! GM was SUED for every engine made around the world between 1996-2003 for the PROVEN FACT that DEXCOOL coolant and GM choices of GASKET materials do NOT MIX! You CANNOT strain the oil to reuse it, but the BUICK 3.8 is a VERY DURABLE engine, just a little bit arcane! What has happened is that the COOLANT has eaten up the INTAKE MANIFOLD GASKETS and if you look you can find FEL PRO gaskets to replace them and DIY!  do not use DEXCOOL, use either TOYOTA COOLANT or AUDI COOLANT instead.  Check your COOLANT LEVEL to see how much has been lost! You can do a simple COLLING SYSTEM FLUSH and MIOLD oilsystem flush to get the MUCK out! I use AMSOIL POWER FAOM mixed with GUNK ENGIEN CLEANR< ORIGINAL ORANGE! I add it to the crankcase before an oil change and drive for about twenty minutes! YOU WL NOT HAVE INTERNAL ENGIEN DAMAGE YET< but check the DIPSTICK for signs of GAS SMELLS! What happens to may engines is that if the AIR/FUEL MIXTURE gets too RICH< the unburnt fuel gets into the OIL and thins it down, and eventually you get bearing damages! It cost my brother in law $2400 to clean up his 2002 BUICK PARK AVENUE at the BUICK DEALERSHIP!.  You can do this yourself pretty much!  Remove the upper INTAKE MANIFOLD made of PLASTIC on most models and see how the gasket has deteriorated! MOP UP what you can and expect to get a full OIL and COOLANT FLUSH! ALSO when things are CLEANED UP< install A set of DENSO TWIN TIP IRIDIUM LASER plugs found at ADVANCE AUTO! There is NOTHING BETTER! Now that we are using EUROEPAN LOW SULFUR formula FUELS, the IRIDIUM will REACT at the molecular level to get MORE POWER and up to twenty per cent MORE MILEAGE! it is AMAZING!  NEVER USE VALVOLINE OIL or PRESTONE or even PEAK products! Once things are CLEAN< use only PENNZOIL ULTRA PLATINUM "0" series oil, as in 0W-20, 0W-30, that protects bearings down to 35 BELOW ZERO! And get a warranty on the engine out to 500,000 miles with PROOF of use! It is made from NATURAL GAS and NOT crude oil! VALVOLINE is made by the CHEAPEST refining, WAX REDUCTIONI method and has TOO MUCH ASH in it! It WILL return to ASH and dissolve gaskets and the vapors will eat up RUBBER HOSES, ESP in the PCV system! PENNZOIL has next to ZERO vapors and cleans the engine as you DRIVE IT! Expect NO ISSUES, then, with the O2 sensors or the EXHAUST system over time! >>>NO FACTORY ON EARTH WILL USE VALVOLINE OIL in car building for a GOOD REASON!>>>>> PENNZOIL is the official oil of FERRARI and is a FULL SYNTHETIC! ONE change each year is USUALLY ENOUGH!>>>getting back to your issue, Remove the LOWER INTAKE MANIFOLD GASKET, which is where the problem usually is! it will be misshaped and folded over itself.  TOTALLY disfigured and WARPED!  Get the FEL PRO updated gasket set! ALSO remove the VALVE COVER GASEKTS and have them STEAMED or use SIMPLE GREEN or AMSOIL POWER FOAM and a sponge to clean the MUCK OUT! Amsoil can be used AFTERWARD to run through the INTAKE MANIFOLD and PCCV VALVE to clean baked in CRAP on your PISTON RINGS and VALVE HEADS! expect A large CLOUD OF WHITE SMOKE FROM the TAILPIPE FOAM removes YEARS of baked in SLUDGE and COKE from your piston rings! Use it to clean BOTH SIDES of the THROTTLE BODY PLATE< and the IDLE AIR CONTROL VALVE nearby! You can run the AMSOIL POWER FOAM through the INTAKE HOSE to reach other areas! ONCE DONE it is a DONE DEAL! use ONLY PENNZOIL ULTRA OIL to get that warranty out to 500,000 miles!  use Toyota or Audi COOLANT ( made by Pentosin company of Germany) to protect your WATER PUMP, radiator and HOSES from internal ROTTING!  It is BEST to replace the IDLE AIR CONTROL VALVE with a NEW ONE made by BORG WARNER! This device adjusts FUEL MIXTURE around town in stop and go traffic and adds EXTRA AIR to the system based on OXYGEN SENSOR signals! >>>>EXPECT IMPROVEMENT OF 20% in FUEL MILEAGE and in POWER around town afterwards! The BACK of your VALVE COVERS will be FULL of yucky yellow foam as well! once you remove them, you will SEE IT! It interferes with the workings of the PCV system!>>SO THERE IS IS! You can get to 500,000 MILES by following my instructions! I SUED GM for this and WON! I have replaced FOUR ENGINES this way as well, FREE!  GM plugs FAIL PLUG TESTS! They are JUNK!!!! they waste fuel and DENSTO TT IRIDIUM PLUGS will earn you SAVINGS IN GAS like you WILL NOT BELIEVE.. I CANNOT TUNE any car>>> even PORSCHE or AUDI>>> without AMSOIL POWER FOAM! It removes YEARS of baked in TAR, and SLUDGE from RINGS and restores to SHOWROOM CONDITIONS! Most engines these days will NEVER GET BLOW BY! They use hypereutectic PISTONS with SILICON that stretches to meet the engine temperature demands! >>>PENNZOIL 0W-30 will protect to 35 BELOW ZERO so there will be NO bearing damages! I have MANY CARS out there with 450,000 MILES on them, and there is a MILLION MILE club for many of them as well! >>>SEND ME A THANK YOU>>> and a check for $100, as I have just saved your ENGINE and showed you the SECRET of ENGIEN ETERNAL LIFE (LOL) Bob Muske, 31800 VAN DYKE AVE, 152, WARREN, MICHIGAN 48093! >>>you will NOT believe how much POWER and extra MILEAGE there is HIDING in that BUICK ENGINE! It will SHIFT better too and you will FEEL it in the AIR PEDAL (modern injected cars do NOT have a "GAS" pedal, only an "AIR" pedal! your FOOT only opens the throttle body doorway to allow AIR into the system!) To PUMP this pedal only exercises your FOOT! >>NOW your engine should start with ONE LIGHT tap of the key>>>RIGHT NOW GM has a problem with AIR BAGS and ignition switches that catch on FIRE and cause issues for CHILDREN and PETS from air bag and fire damages! start with ONE LIGHT turn of the KEY! and your STARER will last for nearly EVER! >>>getting the YUCK out of the VALVE COVERS will improve the workings of the PCV system!>>>ALSO when the BRAKE FLUID turns DARK BROWN< it is a DEAD fluid and must be FLUSHED and CHNGED at a dealership! This saves you money on ABS pump, MASTER CYLINDER and CALIPERS and BRAKE LINES and HOSES! GOOD LUCK ALWAYS!>>>ALSO never buy a BATTERY from AUTOZONE< they are JUNK! you are BETTER OFF with a good USED BATTERY from a recent wreck at a local JUNK YARD! >>>HOPEFULLY there will be PEACE this year with that DAMN VIRUS. I hope they throw TRUMP into prison for his wastefulness and REFUSAL to deal with GREEN HOUSE GASSES and GLOBAL WARMING! Doing as I say will LOWER EMISSIONS to nearly ZERO< and make your car HAPPIEST as well! BYE for NOW!

  • 2 months ago

    I'd just change the oil every 3,000 miles and use Valvoline high Mileage Blend. Condensation forms on the oil filler cap and can cause it to look like an antifreeze leak into the motor. If the oil doesn't turn into a milkshake the bearings are fine. I've owned 4 Pontiac's with the 3.8 liter and they all went over 280,000 miles. That motor is one of the best ever built.

  • Anonymous
    2 months ago

    There is bound to be atmospheric moisture.  If dipstick is clean, then don't worry. 

    Clean your filler cap with solvent and reinstall it.  Check it a bit.  Likely what you see took years to form.

    Make sure your PCV valve is loose inside and not stuck.

  • arther
    Lv 5
    2 months ago

    lower intake manifold gasket gone off with the inlet manifold replace gasket 

    what are you saying you are too tight to change the oil ? Just drive it till it dies is the rest of the car roadworthy?

  • 2 months ago

    If a car has not been running at operating temperature the emulsifiers in the oil can create a gunk from condensed moisture. So there might be nothing wrong. If there has been no loss of coolant (or very little) then it is not coolant causing the problem.

    There are testing labs that cay do a spectrum analysis of the engine oil. This would say if there is metal in the oil or not.

    Pulling a few plugs and "reading" them can give a clue as to how good the engine is.

    The 6000 miles does not worry me provided the oil level was kept up to the right level.

    Change the oil and filter. Refill the crank case, put a new filter on, crank it over to get oil pressure. Recheck oil level. Then run the engine up to operating temperature and keep it running for 45 minutes. Then shut it off, change the oil and filter again.

    If there isn't a lot of smoke or funny noises, more then likely the engine is just fine.

    There are other techniques such as this one:

    Some people use AFT fluid with the oil and one old boy I worked with used kerosene mixed 50/50 with oil. I don't suggest using kerosene at all. Just a cheap grade of the right weight oil that is run, drained and disposed of.

    Make sure you change the filter! Before attempting to de-gunk the engine and afterwards.

  • Anonymous
    2 months ago

    I would not bother.   I had an air cooled beetle.  So no coolant for cooling the engine. I would occasionally get the "mayonnaise. 

    I wondered about it but as a 16 year old, I thought for a minute. Then forgot about it.  That was YEARS ago. Sometimes it was there and sometimes not. Mainly in the winter(snow) and not in the summer. I never worried about it and changed oil every 3000 miles. Drove car for 10 years and then sold it and got an MGB.  Less driving in the winter.  It creamed a bit too.

    .  What it is, is condensation as the engine cools off every night. Humidity is ALWAYS IN THE AIR.  So it gets inside up through the exhaust into the engine.   It gets into the motor oil.  When I did an oil change I would wipe out the cream out of the oil cap(which is a bit rusty too) and put in fresh oil 20-20W for the winter.  If you don't want to see the cream, you have to drive you car farther than a short drive(under 10 miles and then shutting it down for the workday and then drive home after 8 hours and it sits again for 16 hours.  You NEED TO BOIL OUT THE WATER, SO IF YOUR JOB IS LONGER DISTANCES, THAT BOILING OF THE OIL HAPPENS AND THE WATER(CREAM) disappears.  I never worried about it because I knew the crank was coated in oil and so was other parts and it was a daily driver.

    It is not COOLANT.  It is because of your short drives. Don't worry about it.  Everything is coated in oil.  If the car is not driven for a few MONTHS then "maybe" rust "MIGHT" start to form on the engine block.  Bearings will remained lubed for the lead Babbitt's(aka bearings) absorb some oil into the pores of the soft metal.

    I have started Caterpillar motors that sat 15 years with no problem turning over the engine.  If there is rust, it got scraped off on the start up.   

    50+ year mechanic.

  • Anonymous
    2 months ago

    Change the oil immediately and pressure test the cooling system.  Head gasket is likely shot.

  • 2 months ago

    Oil and coolant are mixing. Damaged gaskets and cracked heads or manifolds cause that. You have to take things apart to tell the extent of the damage. It takes a long time to ruin a bearing when there is sufficient oil pressure. Try this, since you don't want to take anything apart; Use engine flush, change the oil, then keep you eyes peeled for more emulsion in the crankcase and radiator. Oh, did you check the radiator yet? It has emulsion in it too that needs to be cleaned out and coolant replaced. 

    Refinishing a crankshaft is no fun and should be left to experts, but you can slap a set of new bearings in . That has no effect on emulsion in the crankcase.

    If you're lucky the emulsion only came from a bunch of short trips that never got the engine hot enough to burn off condensation in the engine. People with that kind o fluck have lots more good stuff happen for them.

  • L.N.
    Lv 7
    2 months ago

    Are you losing coolant? If the oil doesn't look like chocolate milk and coolant isn't low, what you are seeing in the oil cap is just condensation. You will see sparkles in the oil if the bearings are being damaged.

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