Hydraulic Fan Question

southernls

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My car is a 2001 ls v6. I have the overheating problem that many have described on this forum (mostly at slow speeds, stop and go, with a/c on). I have looked at the hydraulic fan and it appears to be turning as it should. However, if I hold it still when the car is started and then release it, it seems slow to get up to full speed. Also, I can't tell a difference in the speed of the fan with or without the a/c on.

Could this be the actuator, or more likely the pump/motor?

I am tempted to replace the actuator, but want to have some idea that it will fix my problem. Any suggestions?
 
My car is a 2001 ls v6. I have the overheating problem that many have described on this forum (mostly at slow speeds, stop and go, with a/c on). I have looked at the hydraulic fan and it appears to be turning as it should. However, if I hold it still when the car is started and then release it, it seems slow to get up to full speed. Also, I can't tell a difference in the speed of the fan with or without the a/c on.

Could this be the actuator, or more likely the pump/motor?

I am tempted to replace the actuator, but want to have some idea that it will fix my problem. Any suggestions?

It should be the actuator, but it could be something more.
 
This repair worked for me and it has been almost 10 months since I did this with my LS. No overheating since. I am copying the post I made last year at LLSOC that explains the process. This should be read by all Gen 1 owners as it will happen to you sooner or later. I would like to hear from others that try this fix and see their results.

One of the weak spots on the Gen 1 LS's is the cooling fan setup. Somewhere about the 100,000 mile range, the high speed on the fan quits working and the car overheats with the air conditioning on. Both my father and I had the same problem happen at about the same mileage. He took his LS to the dealer and got out with a bill of about $1200.00 to have the fan and the pump replaced. It didn't make sense to me to replace the whole system on my LS, so I tried something different.

I figured that if the fan runs on low speed, then the pump actually works and so does the fan, so it must be a proportioning valve in the system that got varnished up or clogged. Every FLM dealer I spoke with would not look at testing the system to see if the pump or the fan was bad. Instead they would throw parts at it. I understand that they need to have a repair that they can depend on and replacing the entire system should be dependable but I did not think that this was the best idea, especially with my money. Among my automotive friends I tried to find a power steering analyzer to see if there was enough pressure and flow in the system to see if the parts were truly bad. No one i knew has one out there, so I could not test my system.

Here is what I did instead. Sea Foam makes a transmission and power steering flush product, so I bought a bottle. Drained the dirty fluid from the system and filled it with the Sea Foam flush product. I ran the car for about 30 minutes with the air conditioning on to give the Sea Foam a chance to work. Sea Foam instructions say to flush it with another bottle of Sea Foam, but I used a fresh quart of ATF instead. After draining the ATF, I replaced the fluid again with a synthetic ATF. This was over a 10 months ago and I have had NO OVERHEATING PROBLEMS since then. I have tried to stress the system by running the A/C temp at 85 degrees in stop and go traffic, and still no problems.

Don't know if this will work for everyone who is having overheating problems, but it cost me 2 hours of work and $22.00 vs. a $1200 repair bill, so I think it is worth a try. Has anyone else tried this?

I did look through the maintenance schedule, there is nothing that says to replace the fluid in the cooling fan system. When I drained the fluid, it did smell burnt and old and it was something I never really thought to check before. Maybe as 1st generation owners we should be changing the fluid in the system every 50,000 miles to prevent problems in the system.
 
could be either

could be pump or fan motor. fan speed should increase with rpm.
 
I did look through the maintenance schedule, there is nothing that says to replace the fluid in the cooling fan system. When I drained the fluid, it did smell burnt and old and it was something I never really thought to check before. Maybe as 1st generation owners we should be changing the fluid in the system every 50,000 miles to prevent problems in the system.

I've been thinking the same thing. Mine smells old and nasty, both the PS and fan fluid. I know my fan's high speed still work as I've heard it come on, it sounds like it's going really fast, but not too loud though.
 
I've been thinking the same thing. Mine smells old and nasty, both the PS and fan fluid. I know my fan's high speed still work as I've heard it come on, it sounds like it's going really fast, but not too loud though.

It surprises me how many LS owners have never changed the fluid in the fan pump and then are looking to fix the fan. I do believe that just by changing that fluid every 60k or so that it would eliminate 2/3 of the fan failures. I especially believe that after "fixing' mine with the SeaFoam. It has to be a stuck actuator that the SeaFoam unstuck. Probably a lot of varnish and gunk in there that just needed to be cleaned up. Every GEN 1 owner should stick their nose in the reservoir and smell the fluid and it is smells burnt and used to just change it now.
:steering:steering:steering
 
Can you post a how to? I have never had a car with a hydraulic fan. Is there a draiin plug? Based on your description, it sounds like the fluid it uses is ATF.

Thanks!
 
I just pulled the hose off the bottom of the reservoir and turned the car on for a few seconds to drain it out into a can. Pretty simple but messy.
 
Thanks for all the info. Craigh. I will try the Seafoam approach this weekend. I was concerned that since the fan seemed easy to stop or hold when starting up the car that the pump or motor was the problem. Maybe the actuator is stuck and restricting flow. I will let you know how it works. Thanks again for your response.
 
The real problem with diagnosing the cooling fan is that there is not a good way to check the pressure in the system. I took mine to a couple dealers and various shops and all they could say is that they would throw parts at it. There is a power steering pump tool that will measure the pressure, but no one has one and is not willing to use it if they do. That got me to thinking that if there are no leaks and the fan turns it must be an obstruction in the system. With no maintenance on the system I was thinking bad fluid or varnish buildup causing the obstruction. I was at the auto parts store and found the SeaFoam for transmissions and power steering systems and thought I would try it. There really was nothing to lose by trying it and it worked. Good luck and I hope it works for others here.
 
my 00 ls v8 is overheating i replaced thermostat and reservor cap also i did the hydrolic pump flush with the sea foam and still the fan not kicking on high speed.now my question is do i have to replaced the head temperature sensor ?or does anybody know where i can get the actuator ?
 
my 00 ls v8 is overheating i replaced thermostat and reservor cap also i did the hydrolic pump flush with the sea foam and still the fan not kicking on high speed.now my question is do i have to replaced the head temperature sensor ?or does anybody know where i can get the actuator ?

Here's an easy way to tell if it's most likely the actuator or not.
Turn the AC on. The fan should go to full speed. If it doesn't, then it's either the actuator, the pump, the fan motor, or the PCM.
 
Seafoam Treatment for Gen 1 Cooling Fan Hydraulics

I have to endrose CraigH and his Seafoam treatment to fix the Gen 1 LS cooling fan hydraulics: Today my 2001 V6 LS with 108k miles started to overheat at low speed. I quickly determined that the cooling fan was not ramping up to full speed and searched the many existing posts on this forum for the causes and solutions.

Not liking the sound of replacing the hydraulic pump/actuator etc., I tried the Seafoam treatment right away and IT WORKED. Follow CraigH's instructions and run the Seafoam in the cooling fan hydraulics for AT LEAST 1/2 to 1 hour to allow it time to work its magic. As my pump actuator started to unstick itself, the cooling fan pump began to make a buzzing noise and tiny air bubbles could be seen coming up through the fluid in the reservoir (with the cap off, of course). A few moments later the noise subsided and the fan came smoothly up to full speed once again. I gave the system a few more minutes then flushed out the Seafoam mix with fresh ATF and all is well.

This is well worth a try and a great time and money saver vs. replacing hardware on an elderly Gen 1 LS :).
 
Hey, good to get some positive feedback on flushing the system. I have to tell you that this worked for me and solved my cooling problems for about a year. Just had the cooling problem come back and this time I replaced the actuator. It actually is a fairly simple job. Just make certain that you use a T-40 bit when taking out the actuator. My experience is that the Seafoam works well, but in the long run the actuator might need to be replaced. $100 from Max at 5 Star Ford.
 
Thanks for the update CraigH. If I get a year out of it too, I'm happy!
 
I am also starting doing some preventative maintenance on the power steering fluid and the fan fluid. If I remember correctly there is nothing in the maintenance schedule about changing those fluids. So with each oil change now I am pumping out as much fluid as my hand pump will get out of the tanks and refilling with synthetic Mercon. At least I get some of the fluid out every 5000 miles and I suspect this will help the systems last longer. Overall it might be overkill, but maintenance is cheaper than a repair.
 

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