Pusher Vs. Puller Electric Fan

[BBK]

My AK 1216 is in the shop to have a number of items addressed, mostly deferred maintenance items from the prior owner due to it sitting a while but some other more involved matters.  The car is running a bit hotter than it should (120 degrees C vs. 90).  The shop says the radiator needs to be rodded out and he suggests changing the fan arrangement, which currently has the electric radiator fan in front of the radiator inside the air intake pushing air through the radiator.  He suggests changing the fan set up to inside the engine bay with a shroud and having the fan suck air through vs. it being pushed.  The current "push" arrangement has the fan covering a limited surface area of the radiator in the front of it and also blocks part of the radiator.  The "pull" arrangement with a shroud inside the engine bay allows the fan to pull air through the radiator and the shroud makes the fan's efforts more efficient.  His explanation makes sense.  I believe the current arrangement is stock and been on the car for 25 years.  With that said, his arrangement sounds more efficient and allows better cooling for the engine.  Looking for opinions of the collected expert masses here as to what they think and how their Mk IVs are set up.  Thank you in advance!  I may have other questions come up as well as the mechanic delves into my car.

[French Frie]

hello, I do agree with him regarding the cooling efficiency,and I always put the fan behind the rad on other cars, and there is a lot of room on MKIV for that... that said, it is mounted at the front on my MKIV, and cooling is fine! and 120°C is definitely too hot!
   
   just one (silly) question: did you check that the fan is sucking the air ? it seems obvious, but it's a really common mistake ! a friend of mine blew a headgasket, just by cleaning connectors on the fan and wired it the worng way when reconnecting ...

[Gus Meyjes]

I have a high speed puller on my car and it NEVER runs hot (even in 95 degree weather in very slow traffic) and I have a pretty "hot" engine. Cleaning the radiator and installing a proper fan can help. I assume the thermostat is of the right temp and working.
   Engine is not running too lean? A good new 3 or 4 core radiator will make a huge difference.

[BBK]

Thanks for your thoughts.  I know that many cars are set up with the fan assembly in the engine bay pulling air through the radiator into the engine bay area.  Seems to make sense to do this in my Mk IV even though not the stock set up.  I believe that the current set up is working correctly and "pushing" the air through the radiator vs. what happened in your friend's car....I mostly think that the radiator is plugged up with debris and needs a good cleaning.
   
   

quote:Originally posted by French Frie
   
hello, I do agree with him regarding the cooling efficiency,and I always put the fan behind the rad on other cars, and there is a lot of room on MKIV for that... that said, it is mounted at the front on my MKIV, and cooling is fine! and 120°C is definitely too hot!
   
   just one (silly) question: did you check that the fan is sucking the air ? it seems obvious, but it's a really common mistake ! a friend of mine blew a headgasket, just by cleaning connectors on the fan and wired it the worng way when reconnecting ...
   
   

[BBK]

Hi Gus.  Glad to hear that your set up works so well.  The mechanic is going to install a new thermostat and clean the radiator...assuming it is salvagable.  It may make sense to put a more modern and larger radiator in the car (the mechanic also suggested this) and paint it black so it looks stock.  Based on yours and French Fries comments I think it makes sense to change the fan arrangement to a "puller" arrangement.  The one thing that is a huge stress inducer is getting caught in traffic on a hot day and watching the needle rise!  It was 103 degrees here yesterday (only a cool 95 degrees today! [8D]  ) so this is a sensitivity for me.  Thanks!
   
   

quote:Originally posted by Gus Meyjes
   
I have a high speed puller on my car and it NEVER runs hot (even in 95 degree weather in very slow traffic) and I have a pretty "hot" engine. Cleaning the radiator and installing a proper fan can help. I assume the thermostat is of the right temp and working.
   Engine is not running too lean? A good new 3 or 4 core radiator will make a huge difference.