Electric Fan Woes

[crankin]

I added a 16" electric fan (pusher) to the front of my rad. I then removed the fan (making sure to reinforce the pulley). then installed an inline thermo switch on the bottom tube. With an IR gun I waited for the thermo housing to reach 182 degrees (three degrees over my brand new 179 T-Stat), at which point the electric fan kicks on. It will cycle on and off.

The electric fan kicks on and cools down in standing traffic. However, when under load (driving at 45-50) the thermo housing will reach up to 200~205 and the fan stays running until I idle for 5-10 minutes.

My gauge never went into the red with my fan unless I was maintaining highway speeds for a VERY long time.

I know that our gauges are notorious for reading bad...and I know that I can hookup an aftermarket gauge and get a better reading. But the IR gun is saying 200+ degrees when I pull over, jump out and take a reading.

I also I know that I can bolt back on the fan and eliminate the electric fan...and go back to factory specs. This can eliminate the bad rad theory and make sure that the system is running right. But it was running right before the electric fan...so, it should still be running right after the 45 minute job is done.

My thought would be that just running at normal road conditions would keep the ram air rad cool enough with out any help from the fan...even in 95 degree summer weather.

The rad is holding pressure, the cap is good, and I ran some rad flush through the system...No black/brown crap or anything like that in the system.

So, the questions are:
Are electric fans unstable like this on our 2.25? Is this sounding normal to those that have done it?

I have also thought about running the factory fan in conjunction with the electric fan for those extreme cases. Is this overkill?

Here is another thought...I am getting some pretty good chain slap when running at high RPMs. I know that the tensioner needs to be adjusted/rehauled...but would this mess up the temp that much!?

[albersj51]

Several old threads mentioned that the fan shroud is very important. Are you running a shroud? Another option may be a puller fan mounted behind the radiator/in front of the engine to provide cool air to the radiator and to the engine itself as opposed to the pusher in front.

[crankin]

Several old threads mentioned that the fan shroud is very important. Are you running a shroud? Another option may be a puller fan mounted behind the radiator/in front of the engine to provide cool air to the radiator and to the engine itself as opposed to the pusher in front.

A shroud even when you are not running a fan on the water pump?

[bkreutz]

Could be that the electric fan mounted in front of the radiator is blocking enough of the cooling fins to prevent sufficient airflow. This is the only thing that I can think of in this scenario given your description

[SafeAirOne]

Several old threads mentioned that the fan shroud is very important. Are you running a shroud? Another option may be a puller fan mounted behind the radiator/in front of the engine to provide cool air to the radiator and to the engine itself as opposed to the pusher in front.

A fan shroud is important when running an engine-driven fan. The purpose of the shroud is so that the engine-driven fan will suck cool air through every square inch of radiator surface instead of willy-nilly throughout the engine bay. Of course if you HAD a custom shroud that worked with a "pulling" electric fan setup, then it'd be a lot more efficient than the setup described in the OP.

Except when idling or at very low engine speeds, an unshrouded electric fan will almost never be as good at cooling as an engine-driven fan because it only sends cooling air through that part of the radiator it directly covers. All those other square inches outside the electric fan perimeter are not receiving anything but ram air from forward motion of the vehicle.

Crankin, it sounds as if your electric fan setup is working exactly as expected.

[crankin]

A fan shroud is important when running an engine-driven fan, not an electric. The purpose of the shroud is so that the engine-driven fan will suck cool air through every square inch of radiator surface.

Except when idling or at very low engine speeds, an electric fan will almost never be as good at cooling as an engine-driven fan because it only sends cooling air through that part of the radiator it directly covers. All those other square inches outside the electric fan perimeter are not receiving anything but ram air from forward motion of the vehicle.

Crankin, it sounds as if your electric fan setup is working exactly as expected.

Awesome. So, its only a case of a wonky gauge.

[crankin]

Wait..So, let me understand that the T-Stat housing should be running at about 200?

[SafeAirOne]

Awesome. So, its only a case of a wonky gauge.

Note that I edited my response (the one that you quoted) after you quoted it so that it better explains the benefits of an engine-driven fan and shroud and the drawbacks of an electric pusher setup.

My only purpose was to explain why one would expect to see WORSE cooling from your electric setup over the stock engine-driven fan and shroud.

I have no idea about your gauge. Just test it using a variable resistor to see what readings you get at the different resistances. If you suspect bad readings, it can really only be 4 things: Voltage stabilizer, gauge, wiring or temp sender.

[crankin]

Note that I edited my response (the one that you quoted) after you quoted it so that it better explains the benefits of an engine-driven fan and shroud and the drawbacks of an electric pusher setup.

My only purpose was to explain why one would expect to see WORSE cooling from your electric setup over the stock engine-driven fan and shroud.

I have no idea about your gauge. Just test it using a variable resistor to see what readings you get at the different resistances. If you suspect bad readings, it can really only be 4 things: Voltage stabilizer, gauge, wiring or temp sender.

Ah, see...One post makes you feel like you are king of electric fan setups...
And then there comes the edit....which makes you feel like the electric fan setup was a horrible idea.

So, i'll place the fixed fan back on. Next question...Whats the harm with running the pusher electric fan and the fixed fan?

[yorker]

So, i'll place the fixed fan back on. Next question...Whats the harm with running the pusher electric fan and the fixed fan?

:confused: Why would you? The factory fan has more than enough capacity to properly cool the engine. The additional electric fan would be pointless unless you anticipate your mechanical fan failing and if that were to happen you'd have other problems to worry about. :eek:

[SafeAirOne]

:confused: Why would you? The factory fan has more than enough capacity to properly cool the engine. The additional electric fan would be pointless unless you anticipate your mechanical fan failing and if that were to happen you'd have other problems to worry about. :eek:

Agreed. You'll never do much better than the factory setup unless you add radiator area (more rows).

Also, 200 degrees is nothing to loose any sleep over, if that's the highest it ever gets with your electric setup.

[bobzinak]

the chain slap you mentioned is the timing chain hitting on the front cover...not bad news if you deal with it soon... the chains get really stretched out. this will put off the cam timing and could be a cause of your running hot..when you pull the front cover off and put the crank on top dead center, the small "p" stamped on the cam gear will point to one of the bolt holes in the block. whitch will tell you theat the cam timing is on the money..as you chain stretches you may have to realign the cam gear. it shoulkd have six slots in it so you can reposition it to compensate for the stretched timing chain..or if you don't want to deal with that, a close inspection of the cam tensioner will reveal that it is almost to the point of ratcheting to the next cog on the tensioner lock. I have used a wooden dowel to give it a good rap and force the tentioner to the next tooth on the tensioner lock..if that does not work you can remove the bolt and refit the tensioner to the next slot..this has happened to me many times...the first time I had the chain rubbing like you..but the timing chain broke and ruined the crank gear and the cam gear..aside from that the rubbing will put metal filings into your crankcase..like I said this is not hard to do, just a little time consuming. I got so I could remove the rad panel, remove the front cover, put it all back together in just over an hour..But I had done it several times by then...Oh the joys of owning a old land rover..you will eventuall have to buy a new timing chain. if you choose to..but don't wait to fix the rubbing..it could cast you alot more money if you have to buy new cam gears and a chain..also the chain vibration pad will be toast too..fix this before things get much worse..bobzinak

[crankin]

the chain slap you mentioned is the timing chain hitting on the front cover...not bad news if you deal with it soon... the chains get really stretched out. this will put off the cam timing and could be a cause of your running hot..when you pull the front cover off and put the crank on top dead center, the small "p" stamped on the cam gear will point to one of the bolt holes in the block. whitch will tell you theat the cam timing is on the money..as you chain stretches you may have to realign the cam gear. it shoulkd have six slots in it so you can reposition it to compensate for the stretched timing chain..or if you don't want to deal with that, a close inspection of the cam tensioner will reveal that it is almost to the point of ratcheting to the next cog on the tensioner lock. I have used a wooden dowel to give it a good rap and force the tentioner to the next tooth on the tensioner lock..if that does not work you can remove the bolt and refit the tensioner to the next slot..this has happened to me many times...the first time I had the chain rubbing like you..but the timing chain broke and ruined the crank gear and the cam gear..aside from that the rubbing will put metal filings into your crankcase..like I said this is not hard to do, just a little time consuming. I got so I could remove the rad panel, remove the front cover, put it all back together in just over an hour..But I had done it several times by then...Oh the joys of owning a old land rover..you will eventuall have to buy a new timing chain. if you choose to..but don't wait to fix the rubbing..it could cast you alot more money if you have to buy new cam gears and a chain..also the chain vibration pad will be toast too..fix this before things get much worse..bobzinak

Good to know...Thank you.

[crankin]

Agreed. You'll never do much better than the factory setup unless you add radiator area (more rows).

Also, 200 degrees is nothing to loose any sleep over, if that's the highest it ever gets with your electric setup.

The factory fan is really a great over engineered piece of kit...
I just wanted to tinker around and thought that an electric fan would cut done on noise and give me a chance to piddle. My thoughts about leaving it in place is...well, its already there...why not.

[TedW]

I added a 16" electric fan (pusher) to the front of my rad. I then removed the fan (making sure to reinforce the pulley).

Clint:

I've run the exact same setup since '95 or so with no problems at all. My new 2.25 motor (5 yrs old) has not utilized the fan shroud and I have detected no cooling issues, even when towing a 23" boat in the summer. And I have the 88c t-stat.

So I'm wondering if something else is going on with your setup. Or maybe everything is fine, as you seem to suspect.

Question for you: What is this reinforcing of the pulley that you refer to? I just took off the fan and replaced the screws with some extra washers. Have never had a problem that I knew of. What should I do to reinforce the pulley, and why does it need reinforcing? Thanks in advance for your (or anyone else's) reply.

Ted

[scottlong]

This may seem obvious, but check the fan direction, and with a piece of paper. I had the same issue and even though it felt like the air was moving the right way to my bare hand, the paper showed I was wrong. Almost cost me an engine....

[crankin]

Clint:

I've run the exact same setup since '95 or so with no problems at all. My new 2.25 motor (5 yrs old) has not utilized the fan shroud and I have detected no cooling issues, even when towing a 23" boat in the summer. And I have the 88c t-stat.

So I'm wondering if something else is going on with your setup. Or maybe everything is fine, as you seem to suspect.

Question for you: What is this reinforcing of the pulley that you refer to? I just took off the fan and replaced the screws with some extra washers. Have never had a problem that I knew of. What should I do to reinforce the pulley, and why does it need reinforcing? Thanks in advance for your (or anyone else's) reply.

Ted

I went to ace and got a large machine washer that was the diameter of the pulley. Individual washers would work too. The reason i reinforced the pulley was because I ripped through the first one (after I removed the fan) within tow days.