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Oil this for real?

1997montez341997montez34 NJ, USAPosts: 202
edited March 2014 in Nissan
I have a 1995 Maxima with 132K on it that belonged to a family member. The oil was very dirty (black) so I had it changed. My dealer told me they recommend doing a pressure flush of my engine. They said my timing chain could be damaged by old oil. Is this necessary and/or effective? I am skeptical when a dealer tries to sell you additional services, but maybe they're right on this one. Anyone know?


  • zueslewiszueslewis Posts: 2,353
    sell oil flush products and services - what they don't think about is where the gunk goes when it's "flushed". It hits your oil pump screen, often clogging the pump and limiting or stopping oil flow, which kills the engine (especially and older motor).

    I think it's a crazy thing to do, unless you also have them drop the oil pan and clean the oil pump screen (3-4 hours labor, at least).

    the best thing you can do on a rig with 132K miles is just to keep changing oil frequently and on time.
  • pluto5pluto5 Posts: 618
    My oil is always black when I change it every 4 mos. after 2K miles. Engine flushes and trans flushes are a ripoff IMO. I might go for a radiator flush if I forgot to change the coolant for 4 yrs. but I expect to be riding the bus before I lose my memory.
  • I have run into similar filthy oil in the past, and changed it, just as you report (although I did the labor myself). Then, about 500 miles later, I changed it again, to get rid of the already darkened new oil. I then went back to regularly scheduled oil and filter changes-- and I ALWAYS change filters when I change oil. This will usually clean them up adequately.
    I have also run a quart of Bardahl to aid cleanup, but that may or may not add much cleaning-- I don't really know.
  • vidtechvidtech Posts: 212
    I wouldn't change the oil just because its black.It should darken if it is doing its job.Save your money and change it every 3-4 k miles.
  • zueslewiszueslewis Posts: 2,353
    since gunk and corrosion can stop up those small passages. A radiator also doesn't have a filter or screen like the engine that can stop the flow of fluid!
  • alcanalcan Posts: 2,550
    Gotta agree there. Regarding antifreeze, permanent doesn't mean forever. It means it can remain in the system year round, but after 2 years or so the corrosion inhibitors are pretty much used up. Much more of an issue with bi-metal (cast iron and aluminum) engines. I've had to replace intake manifolds and cylinder heads because their mating surfaces were so badly eroded.
  • 1997montez341997montez34 NJ, USAPosts: 202
    I am definitely doing a coolant flush since no one knows the last time it was done.

    Also, is there anything I need to do to make sure the timing chaim doesn't break? And if it does, will it tear up the engine?
  • but I thought them buggers were good for at least 200k before needing replacing? If you feel that uncomfortable, you could probably change it, although I believe it's a lot more complicated than a belt since it has no easy panels to remove... (of course on Honda and Toyota, even easy panels are a pain to remove...)
  • pluto5pluto5 Posts: 618
    If you don't exceed 7,000 rpm or whatever the redline is for your engine I don't think I would worry about the timing chain.
  • swschradswschrad Posts: 2,171
    GM used to use metal gear assemblies with the actual teeth made of nylon molded over the metal on the main drive gear for timing. this was allegedly for quieting, although if anything would wear in this system, it would be the main gear. I had timing slip in a 76 buick V6 and had to replace the timing set at about 128,000 miles.

    best of my knowledge, to prevent slip issues, all the "interference engines" use cogbelts instead of chains, and you need to replace those at the required intervals (or sooner) to avoid wrecking your engine when the valves and the pistons collide. there are some cases, such as hopped up engines using pop-up pistons and the like, where this may not be the case, such as a few hemi 'cudas I knew of back in the early 70s. but that was aftermarket work.

    in any other configuration, it gets bad, you run rough or not at all, just blowing smoke rings out the top of the throttle plate. it should not destroy things.
  • I came across this concept at Bob's website and they seemed to think it is a good idea I think. I am just wondering how often it is recommended, the best way to have it done, that kind of thing... also, any negatives to doing a flush?
  • swschradswschrad Posts: 2,171
    you have corners of the engine, some oil gallery endpoints, etc. that have big wads of cooked crud in there... left behind by old oil. you put hot solvent in there, even if it doesn't dissolve gasket compound and cause leaks and gasket failures, you are going to stir these demons out of their peaceful slumber. and they will rise up and shudder through your engine until they plug up something else. say, three oil galleries to the back of the cylinder head top, or something equally useful.

    also, when the rest of the loose oilsnot falls down into the oil pan, it's not going to be flowing gently out of the big hole in the bottom. so it will end up in all probability plugging the oil pump screen, and you could have general oil starvation. that wrecks engines.

    I had intermittent oil starvation due to gasket crud in my ranger due to factory issues... and I don't recommend that repair bill to pull the engine, take off the oil pan, replace the oil filter and screen/diptube, mike the crank bearings and maybe the OHC bearings depending on the precision level of the engine, and reassemble it.

    much better to go to very frequent oil and filter changes in my humble opinion.

    unless you are doing this steadily throughout the life of the car, going for an oil flush when it's old and goopy could be real scary.
  • 0patience0patience Oregon CoastPosts: 1,586
    I agree with swschrad. Whoa, never thought I'd say that. LOL!

    Oil flushing is great for engines that don't need it. But it is harsh on engines that are cruded up. I have seen numerous (as I have stated many times) engines that the flush pushed all the crud into the pan and plugged the pickup tube.

    If you have an engine that is in need of an oil flush, the only way to properly do it is to do the flush, drop the oil pan and thoroughly clean the pan and oil pump pickup and reinstall the pan.
    Not dropping the pan is asking for trouble.
    (Sound like a broken record, don't I?)
  • adc100adc100 Posts: 1,521
    I'm the guy that had the dreaded manifold leak to 2 different Corsicas (along with too many other problems to mention here). But thankfully they are both gone. Anyway my son has a 200 GrandAm with the 3.4 engine wich I understand is prone to this problem. Does this problem still occur with the Year 2000 3.4?
    Does DexCool help? And does it make sense to change it at the same interval (even though it advertises a longer interval)?? Does DexCool turn into DexBrick as I once heard? I also use a separate corrosion inhibitor. Any thoughts??

    Since this is an oil thread: I like and agree with your comment on an oil flush.
  • 8u6hfd8u6hfd Posts: 1,391
    There are many people who still do the quart of kerosene or ATF in the crankcase, let the engine idle for 5 minutes and drain method.

    My father is one of's proved well for him....a 300,000 mile 2.3L Pinto (before we got rid of it in 1994)....and now the current cars do the same thing (a 94 1.8L Corolla and 93 3.0L Caravan), both with over 100,000 miles with 3,000 mile oil changes.

    the "Gunk" engine flush is basically petroleum distillates.
  • My favorite flush is accomplished with a putty knife when I have an engine torn down, with parts sitting on the bench. Next comes solvent with a brush. When it's all done and the engine is reassembled, I like a high pressure blasting for the garage floor flush. There's no end to the things that can use a good flush... (:o]
  • swschradswschrad Posts: 2,171
    but then, he does his in plain view, with no mysteries hiding behind steel partitions........

    attempts at laughs aside, you really do always take somewhat of a chance when you are poking in a dark cave with a long stick. there is always the possibility a bear or dragon lives within.....
  • spokanespokane Posts: 514
    I agree with Swschad, Opatience, Alcan, Fleetwoodsimca, and others that engine oil system flushing is very likely to cause more harm than help. Even if the oil pump intake screen does not become clogged, isn't there also a major risk of damage associate with solvent being pumped through the engine bearings? A fundamental rule of bearing care is that a film of lubricant must always be present on the bearing surfaces - and solvents are poor lubricants.
  • Almost any fluid will form a hydrostatic barrier. If I was stranded somewhere and low on oil I wouldn't hesitate to pour water in to get me home.
  • Now, THERE'S, a nightmare in the making! Shazaaaaaaaaam! Steamed bearings, anyone? (:o]
  • swschradswschrad Posts: 2,171
    much better to pour in the spare PS fluid, ATF, etc. if you're out of oil... or... hitchhike for some.
  • 0patience0patience Oregon CoastPosts: 1,586
    Almost any fluid will form a hydrostatic barrier.
    Well, not exactly.
    The problem with a blanket statement like that is that there are many fluids that will cavitate under pressure. Water being one of them.
    Running water as a lubricant in an engine will cavitate the bearings in very little time.

    Various liquids can only be compressed so far. Once it reaches that point, it implodes (cavitates). Cavitation will literally strip metal off anything and water cannot be compressed very much before cavitation occurs.
  • tbonertboner Posts: 402
    that is why antifreeze in your oil is a very bad thing.

    Dumbed down to the third grade level 8^)
  • never worked. Water has a bonding strength close to steel. Cavitation is from expansion not compression. Many rotating machines use water lubrication. Oil/water emulsion is a pretty good lubricant. The advice for using water in an emergency is actually from an article from an SAE lubrication expert.
  • You can drive quite a distance on the oil clinging to the metal surfaces, before calamity precipitates.
  • 0patience0patience Oregon CoastPosts: 1,586
    Cavitation is when water is compressed to a point where the composite of it breaks down and creates a vacuum, which implodes. These implosions are what does the damage.

    The SAE "expert" must not work extensively in hydraulics then. He would then know that the definition of cavitation is;
    [by the way, the high intensity sound waves part is a common problem with diesels]

    Main Entry: cav·i·ta·tion
    Pronunciation: "ka-v&-'tA-sh&n
    Function: noun
    Etymology: cavity + -ation
    Date: 1895
    : the process of cavitating : as a : the formation of partial vacuums in a liquid by a swiftly moving solid body (as a propeller), by high pressure or by high-intensity sound waves; also : the pitting and wearing away of solid surfaces (as of metal or concrete) as a result of the collapse of these vacuums in surrounding liquid.

    Pronunciation: 'ka-v&-"tAt
    Function: verb
    Inflected Form(s): -tat·ed; -tat·ing
    Date: 1909
    intransitive senses : to form cavities or bubbles
  • zr2randozr2rando Posts: 391
    Cavitation is when a liquid is caused to vaporize due to a drastic lowering of pressure at the local site due to severe disruption in laminar flow, and it is destructive to material and flow at that point. The navy really worked hard to make the submarine propellers NOT do it so the noise would not give away position.
  • spokanespokane Posts: 514
    In your defense, I too would put water in the crankcase - but only in the very extreme emergency that dictated a need to drive a few more miles at the certain expense of a new engine.

    Can you please clarify your remark that "the steam locomotive never worked.."? Thanks.
  • ergo an engine can be flushed by using motor oil to wash it out: e.g., the old 'drive a hundred miles on the new oil and filter, then change them.' Cavitation seems to be a different topic, ya?
This discussion has been closed.