Stuff shouldn't build up if you actually do a true flush. Which means flushing your coolant when recommended, brake fluid, power steering, and of course the oil!
The proper way of using the word seen. It is not I seen it that would be I saw it. He has seen the car is the right way to use the word. English class is Cool. By the way thats my sig
The problem is that the flush dislodges the stuff that was
already built-up, potentially allowing it to get into places where it may do damage. Proper oil change intervals should prevent
most deposits from forming, but even then, some minute amounts may form on cooler areas of the engine where oil isn't directly flowing (valve cover, oil pan walls, etc). It would be hopeful that IF some of these deposits are loosened by a flush, that they would be picked up by the oil pump screen (hopefully not enough to plug it), or if small enough to pass through that, the oil filter. The problem is that under some conditions, not ALL of the oil goes through the filter before going to the critical engine parts, which may allow some particles to end up stuck in oil feed journals, or bearings, etc. This can cause oil starvation to the affected parts, and I'm sure we're aware of what can happen without proper oil supply.
If someone wants to "clean" their engine out (for whatever reason), it's probably more advisable to use an oil that's high in detergents (Pennzoil Platinum for example) to do the job at a more controlled rate. Any newer quality oil, changed at recommended intervals, should eliminate any worry for the engines in our cars anyway. I don't think that any of our engines are well known to be "sludgers". There may be the odd exception, but I wouldn't think that it would be very common these days. Most of these services and products are just excellent money makers for chemical companies (and the shops that promote them). It just seems incredible to me that even some new car dealers promote such services for vehicles which clearly state right in their manuals that it is NOT required or recommended...
Sorry for another one of my rants...
John
P.S. - this rant only applied to engine oil flushes. Other ones such as coolant and brake fluid are entirely different...
Just a comment.The only thing I ever flush is coolant.I have used seafoam in the oil prior to a oil change(or gunks eng clean) u pour in nothing but kerosene is what it is basically.I only flush the brake stuff when repl caliper seals or whl cyldr leak only.I never have flushed power steering it is a sealed unit and unless u actually have a leak power steering fluid does not go south like oil,coolant do.I have never done 1 thing to my 21 yr mazda trks pwr strg fluid to this day with not 1 issue! Those shops promoting services like that are just trying to generate business with something that is not necess in most cases playing on the customers unknowing knowledge of vehicle maintenance and they pay for something they consider (good) while not the case.
Um I use seafoam in everything. Oil,and fuel system. From the info i have got seafoam isn't kerosene. It is suppose to be more like wd-40. Also John i think the main problem is with jiffy lube and all other shops performing the flush just let it run for say 5 mins. And drain the oil. When i use seafoam in my oil i run it for about 50 miles. That way if something were to get lodge on the oil screen it would have enough time to break it down. On another note John what for oil galleys or parts are you talking about that doesn't get filtered oil?
Also this is how i see it if you would change your oil,antifreeze,brake fluild, and power steering fluid like you are suppose too. You wouldn't have any deposits. Just like people going and changing there antifreeze and doing a system flsuh after like 5 years or 150,000 miles and wondering why there heater core gets stopped up. And as for deposits in the oil and using something to flush the gunk being bad for the motor. Then why do all the major oil companys put a addative in the oil for this very purpose? As for tranny flushs some people say not to flush all the tranny fluid out because it will cause parts to wear quicker. Which for some reason i believe. But why do manufactors recommend coolant flushes,tranny fluid changes and all that. It it would hurt your motor. Even though dropping the tranny pan and doing a fluid change still leave some of the old tranny fluid in it.
And for fuel system cleaners. I think that is really funny because manufactors recommend it,sell it, and do the services.
Blown Phoniex wrote:But why do manufactors recommend coolant flushes.
they dont, in fact if you check most *manufacturers* they will say don't flush anything at all. Most certainly don't flush a transmission! its to delicate of a system anyway the transmission filter + magnetized pan does a good enough job.
As fare as fluid left behind its all mostly left over in the torque converter, if it bother you that much do two oil changes. Do not Flush your transmission though especially not the 4T40e.
Just my 2 cents
For got to mention
if you mean flushing your radiator then yes you want to do that in order to prevent radiator failure. This is because your radiator fluid becomes acidic etc a
there was something very similiar posted to this about this 2 years ago with Jiffy Lube and flushes... its not new news
LE61T PTE6262 Powered 
"On another note John what for oil galleys or parts are you talking about that doesn't get filtered oil? "
Under some conditions, such as when the oil is very cold, or under high RPM conditions, some oil may bypass the filter if the backpressure it too high from the filter media. This is designed-in to prevent oil starvation under these more extreme conditions. This will occur sooner if the filter gets more restrictive (plugged). Based on this, ANY of the parts that are supplied oil are potentially subject to receiving unfiltered oil. Depending on the engine design, this bypass can either be part of the pump, or located within the filter.
Detergent oils have been around for decades - without them, we'd all be complaining about how sludged-up our engines were getting if we went more than 1,000 miles on an oil change. ALL SC or later oils (1964?) are considered to be detergent oils. Currently we're at SM. The detergents are designed to help prevent deposits from occurring, and keep them in suspension in the oil so that they come out when the oil is drained. If the oil is left in too long, so that it exceeds the "dump-out" point, then sludge deposits will start forming in the engine. The detergents in oil are much less concentrated than what would be in a "flush" product - so that they essentially slowly erode deposits, rather than try to rapidly remove them. The end result is similar, but over a very different period of time. With regular oil changes, no further maintenance should be required.
The main point of this was that shops are constantly pushing maintenance procedures that simply aren't necessary or recommended by the manufacturer - but making it sound as if they are. To me, that's essentially lying to the customer - and not a trustworthy way to do business in my opinion. It's one thing to offer the services - but not try to pretend that the manufacturer recommends them. The necessity of such services could be discussed for hours...
John
hey gentlemen a true trans flush (the ones required to keep from voiding warranty does not use a chemical product instead u bring it in to a dealership and they pull the trans cooler lines and plug them into a machine that has clean trans fluid on the in line and dumps the old dirty fluid from the out line and u are supposed to start the car and let it pump through till the fluid comes out clean (no detergents involved that would damage the gaskets in the trans valve body )
