Engine Flush??

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    So, on my “new” TD, I have already done 2 oil changes in the first 500 miles and finally decided to adjust the valves.  On taking my first good visual inspection “inside” the engine, I am somewhat surprised that it is not sparkly clean.  I seem to have a crust of sooty dirty oily stuff on everything inside.  It wipes off quite easily. 

    What would you do?  And then how about what is inside the rest of the engine?  Does anyone ever “flush” out the engine?  (I did that once on an old engine about 40years ago and it burned oil like crazy afterward.)  

    I could just clean out as best I could around the rocker arms and button it up, but it doesn’t seem like the right thing to do.  The engine is a 69 1500SP with a reported 13000 miles on it.  Seems to run great.  Reportedly spent its entire life in Florida.  No smoking and doesn’t seem to burn any oil (that is noticeable in only 500 miles.)  The PO said that the oil had recently been changed, but I changed it immediately.  So, with only 200 miles on the oil, I am going to clean the strainer and put some more Castrol GTX 20w50 in.   


    edward ericson


    I don’t know if it’d be right, but I’d just clean off the valves and rockers by hand to facilitate the adjustment. Maybe shoot some starter fluid on them to degrease. Don’t think I’d go crazy trying to “flush” out all the gunk though. ‘specially if she’s running fine.

    Anyone have any actual knowledge to correct me with?

    Peter C. King



    According to John Muir (VW for the Compleat Idiot}, VW specified single grade non-detergent oil so that the engine would build up deposits that served as lubricants in the engine. Switching to detergent oil scrubbed all that stuff out of the engine.

    Noboby runs single weight oil today. But he makes the point that buildups inside the engine are a good thing.    

    A VW runs hotter than a water cooled engine, particularly the heads. My VWs always had buildups inside the valve covers. That was not a flaw. I regularly ran Type One engines over 100k with regular oil changes and valve adjustments. .

    Unless your oil is black and old I wouldn’t worry about it.

    Don’t forget to clean the plate the screen sits on. That’s where the real sludge builds up. 





    Thanks guys, the deposits are definately oily.  I guess that I’ll just put her back together.  The oil looks nice and clean.  You have convinced me that the Alfred E. Neuman approach “what me worry” is best. 

    Hugh Coffey


      Are you sure it is not getting a little hot? If the oil pressure gets lower when it warms up it is probably running a little hot. That will cause a build up. Does it still have the heater boxes? If so you need the flex pipes from the fan connected, this will keep the boxes cooler They can cook the oil in the rocker covers. VW incorporated a small by pass hole to get rid of the heat when the heater is off. If you don’t use the heater then install J pipes to replace the heater boxes. I read an article on the Web that said full synthetic oil does not work well in VW’s because it does not conduct heat as well as non synthetic, it was designed for water cooled. VW’s are oil cooled! So I ran some synthetic and checked the oil temp, and the changed to a synthetic blend 20w 50 and it ran 20 degrees cooler on the blend. That has been my experience.



    I am quite sure that I am not running hot but, the oil pressure definately does drop as the engine warms up.  I start out at about 40# but it drops to about 15# at temperature.  I just installed an oil temperature gauge but the weather has turned so it may be next summer before I get some good comparison readings.  If I believe the readings on both gauges, I run at about 190 degrees (reads 170 – see below)(30 minute run at 55-60mph with 70 degree ambient).  During that run, oil press at 3000rpm was about 22#.  When I stopped, the oil press dropped to about 12#.  I am running 20w50 Castrol GTX.  All my heater hoses and tin are intact.  This oil temp gauge that I installed is on a “T” by the oil pressure sender and I checked it against a infrared gun.  The new temp gauge reads 20 degrees low.  I am really rusty on air cooled VW’s and am trying to get smart.  Right now everything works great and I want to keep it that way. 

    Gwyneth Smith


    When you go in for an oil change or basic tune-up, your mechanic may offer an engine flush. Motor flushes are among those services that are offered much more frequently than they are really needed. Source of article: The basics of an engine flush.

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