I just buttoned up from an FES mode to replace a crank position sensor O-ring. It was huge PITA, by the way. I filled and burped the radiator and then went out for a test ride. I am using a Bluetooth ODB-II code reader to monitor the engine temp on my phone to check for temp issues. The temp stayed around 180 while driving. I pulled over at a gas station to check the coolant level and purge any air. With the car idling, the temp Rose to 200-205 and the fan did not come on.

Questions:

What temp does the fan come on?

I have confirmed the connector is seated properly. What other things can I check?

Thanks!

 

Per the Bentley manual, that isn't hot enough for the fan with the A/C off. The fan kicks into low and hi speed at 105C and 112C, respectively. I believe that converts to around 221F and 233F.

Monitor the temps and see if the low speed kicks on, if not, continue to monitor for the high speed. If it's only the low speed that isn't working, its most likely the resistor mounted on the fan.

 

Thanks

It never dawned on me to check for this issue before FES mode. Now I am in for another FES mode.
It should be quicker this time. I think I will go for the whole fan replacement rather than just the new resistor. It would be my luck the fan motor would die in a few weeks as I am at 75k miles at the moment.

 

From what was posted about coolant Temps it sounds like your fan is working fine. Doesn't sound like you got hot enough to kick the fan on.

 

The app that I was using to monitor my temperature was showing RED zone. I assumed it was getting close to overheating. What are the actual temps that start to cause overheating and blown head gaskets?

This is the tool and App:

 

Well I don't know what a danger temp is for these cars but the fan doesn't even cut on in my camaro till the temp hits about 220

 

The fans themselves aren't really the problem with R53s. People replace the fan assembly because the burned-out resistor is encased in it, and it sounds easier and wiser to replace the whole thing - not to mention the entire assembly is cheap as hell. But then you're left with the same buried resistor setup in the new assembly, which was the problem in the first place. And it will fail again and again. The answer, if your fan isn't cycling as it should, is to replace the resistor with an aftermarket solution. I hate to recommend the Dorman resistor replacement because you have to physically drill and bolt on the wires (they fall off the soldered contact points right out of the box) but having an external resistor is a logical solution.

To check your fan circuits: with the engine warmed up and running, turn on your A/C. The low-speed fan should come on, no matter how cold the engine is.
a) if it does come on, you're probably fine
b) if it does not come on, check for current at the 3-wire connector plug (engine running, A/C on) near where the hood latch release is. You should be getting power to the thinner of the two red/blue wires (which goes to the fan motor via the resistor). If you have power there, but...
c) if the low-speed fan never comes on, but the high-speed cycle runs on and off (once the engine gets that hot), the fan resistor is the likely culprit.

This link is in the middle of a huge 53-page discussion on the problems and solutions for the fan relay issue, but the pic in post #183 will show where to check for current. https://www.northamericanmotoring.co...olution-8.html

The prognosis gets dicey depending on what year model you have. This info is for '04 and up, with the fan relays in the engine-compartment fuse box. If this is your case, you may have a bad or sticking relay in the box. There would be one each for low- and high-speed fan; they're green, down the center of the fuse box. Tap on them if the fan still isn't kicking on. Or unplug and reverse them - they're the same relay for both circuits.

This is the easiest stuff to do before going the "replace the fan assembly" route.

 

This is an AWESOME summary. Yesterday I confirmed that the low speed was not working via the A/C test. I then went ahead and bought a new Fan from ECS that has the updated resistor (so I was told). I am pretty handy but did not want to replace the resistor on a 10 year old fan. FES mode is a PITA and the less you have to do it the better.
I wish I had your information handy before I ordered the fan so that I could do some of the other tests before placing the order. I will do the relay tests tonight just to double check. I suspect it is the resistor since that is the culprit most of the time based on my reading.

Thanks again for the excellent summary.

 

Looks like you're moving ahead with the transplant. Just remember that any "updated" resistor that's mounted in the same place as the OEM version will also get too hot (no airflow over it while it's tucked in that hole). So if you can figure out a way to modify that hole/box, I would do it. Weather and the elements aren't really an issue up in that area, so open it up.

Also, there are a couple of pretty good videos on how to change out the fan assy without going full frontal. Good luck!

 

"I then went ahead and bought a new Fan from ECS that has the updated resistor (so I was told)"

So even the updated resistor is still susceptible to overheating and burning out? On the new aftermarket fan assemblies, in my naive way I assumed that they upgraded the resistor to address being in a hot confined space. I have read about all sorts of "MAcGyver" type fixes for this darn resistor including but not limited to using the large Aluminum bumper as a heat sink. I guess I was hoping to spend the $100 bucks on a replacement unit that would last several years and did not require me to re-engineer things.

Wishful thinking...

Since the car is a "Garage Queen" and will not be driven in the Winter, I will go ahead and expose the resistor for cooling purposes.

 

I have no idea what resistor replacement ECS sells, so I can't comment on what they call "updated." What I do know is that the resistor gets very hot while it's resisting current flow. If you've seen pics of the trashed green OEM resistors you know what I'm talking about. Certainly, there were improvements that could be made on the OEM version. Maybe ECS' version is bullet-proof.

The Dorman kit I mentioned uses an exposed wound-wire type of resistor, which allows airflow to cool it. And it's too bad their manufacturing process is so sh!tty, because it's a simple, elegant (and factory-style) solution.

 

I will follow up with pictures and part numbers from the new unit when it arrives. Maybe that will help shed some light on what their version of "upgraded" is.

Thanks!

 

I just installed the new fan yesterday, and I have cut up hands as a reward. Having never done this before I elected to remove the entire radiator from the car to gain the access that I needed. It also allowed me to blow all of the crap out of the fins from behind (sand, bugs etc).
The new resistor is the same ceramic wound setup as the original, but has larger gauge windings, which I was told would handle the heat better.

I swapped out the spring loaded hose clamps after fighting with the lower clam for 15 minutes trying to get it back on.

Low speed fan came right on using AC test during the burping process.

I also replaced my leaking power steering hoses as well. It looks like you can get away with just replacing the clamps and not the hoses. Those crimp type clamps just can't be tightened. Cut them off and replace them if you are OK with oil and dirt soaked hoses. Otherwise replace the hoses as well. I got mine from ECS along with new washers etc... for $88. It is all nice and clean now. I was sold 2 quarts of fluid and only needed 80% of 1 can. If I want to be **** I could use the remaining fluid to continue to "flush" the rack by putting the return line into a container and turning rack to rack, but I ran out of time and patience.
The existing fluid was dark brown, now it is nice light blue.

 

Thanks for the order , and glad you got things fixed, yea you have to watch your hand on that sharp plastics and metal, when i did my front fan , cut on hand also. I had a frozen, rusted front fan. I cracked the core support a hair also. yikes.

 

JIM, did you disassemble the front again to swap the fan?

 

Yes, see post #13 above. Give me a shout if you have any questions.

 

Didn't specify if you did or not in that post. I assumed you did but was hoping not lol.



So, I've just discovered my low speed does not work. I don't really wanna go through replacing with a stock fan for the chance of this happening again. What's stopping me from installing two side by side universal fans and wire one to come on at low temp and second to cut on simultaneously at high temp? Or wire the factory fan to come on full blast at low speed?

As I understand resistors, all its doing is limiting power to the fan to cause it to spin slower. That's how home ac fan motors work anyhow. So mechanically the fan can stand to spin full speed, with more wear on it I understand.

 

I have seen a few postings that included people talking about bypassing the low speed resistor and basically running the fan on high all the time. That's plausible.

I do not see any way of avoiding taking the front end apart to get in there and do that work. At least not with my size hands.

For $100 I got a new replacement TYR unit with a supposedly upgraded resistor. I now have a new fan, an old fan that I can play with and put a new resistor in to use as a spare; I cleaned and blew all of the crap out of my radiator and AC coil and replaced the worn out antifreeze with new Mini coolant ($25) 50/50 with distilled water.

All totaled up, lots of productive work and maintenance.

If you can do all the rewiring work without removing and draining the radiator, that is impressive.

Mod Mini has a great FES Service Mode video on YouTube if you decide to go that route.

HTH

 

This is a bit Rube Goldberg for something that has already been designed and produced for you. I mean, there have been other fixes/options on the main 'fan resistor fix' thread page with external resistors, etc, but a lot of them haven't turned out to be long-term solutions. I think the fan motor's fine; the wiring, design, relays... all fine. The only problem is with the resistor - or rather, where the resistor is hiding. The Dorman exposed-coil resistor kit seems to be an excellent (if QC-flawed) solution.

 

I know how to do the FES, it's just that I'll be ordering a pulley and doing a supercharger service in a few months I hope and I'd rather not pull it all apart and put it back now, then pull it all apart and put it back again in the near future.

Looking at the wires, I might be able to bypass the resistor without pulling anything. I have pretty slender hands, I think I'll just splice around the resistor. Will look at it more closely after work tomorrow.

 

Another thing to check while you are in FES mode is the Crank Position Sensor O-Ring which is usually leaking at 50k+ miles. It takes 5 minutes to replace while in FES mode and costs around $5 .

It took me 20 minutes and a can of degreaser to clean up the mess before I replaced it. Just being OCD and wanting a clean engine.

I noticed while in FES mode that I could get to the left side super charger fluid plug. I wish I had a bottle of fluid to top it off while I was at it. Looking at taking the SC off to do a full service left me thinking that was an entire weekend project!
I am saving that for down the road.

Just got my Redline MTL today. Yet another box my wife tripped over.

Tranny fluid flush is next.

I may be sleeping in the garage with the car soon when my wife kicks me out.

BTW,

I found the upgraded Dorman resister on Fleabay for $26.87 delivered. So if you can get your hands in there you might be able to swap out the resister with the upgrade instead if bypassing and running the fan on high.

http://www.ebay.com/itm/Engine-Cooli...dVm9XY&vxp=mtr

Have fun!

 

Well I have a new problem that needs to be addressed. I put my car in service mode, jumped the resistor so when "low" speed comes on its at full blast, should be abyway. Wouldn't kick on, so I go okay relay must be bad. Just for giggles I broke out the multi meter and tested the signal wires for the relay. The relay is never getting a signal to cut on. (My resistor was fried by the way). So now that I have it wired correctly it's not sending signal to the relay to switch on "low" speed. So the saga continues.

I jumped the resistor and ran the loop long enough to add an external resistor, which I have on order but now I have to figure out why the car is never sending signal to the relay to turn on low speed.

If this headache continues its getting an aftermarket relay switch and external resistor for low speed and leaving the high speed to function as is. I'll make the necessary splices on the fan side of the plug so I don't cut the harness on the car side. Another thing I noticed is the car has been in a front end wreck of some sort. The radiator support is all cracked to crap. For all I know there's a broke wire somewhere.

 

My fan kicked in with the AC on and the temp set low enough to call for AC. Did you have the correct scenario to call for fan?

 

Yep. And the high speed was cycling on and off. Which means the low speed should have been running already.

 

"The relay is never getting a signal to cut on"


Did you swap the relays to make sure low speed relay is not bad?

I have read in similar threads the relays are the same and other threads where people have to whack them to engage.

Look for the simple solutions before concluding the harness is hosed from a possible front end whack.

I feel your pain...