2003 4.6

Last year I performed the Extinct Inline Thermostat mod as I did a full and thorough coolant flush. At the same time, I added an Autometer Cobalt Elite Digital temp gauge with two sensors- one installed in the upper radiator hose, the other installed in the lower radiator hose. I burped the system after adding in Prestone 50/50, and went about my business driving the Landy as normal.

For a couple of months, I was extremely happy. The way I set up the Autometer was so that the blue digital letters would show the upper radiator hose temp, and the outer perimeter populates with green bars once the T-stat opens and the lower rad hose fills with fluid. I would drive, the temp would reach 180°, then it would drop to about 170, rinse and repeat. Back in March, I decided to service the front serpentine belt and pulleys as well as the tensioner. I removed the clutch fan, replaced all of the pulleys and the belt to fix a squeal issue, put it all back together, and that was it.

Not.

Now when I drive, the temp in the upper radiator hose likes to hover between 179-188, behaving differently than it used to. I figured there could be an air bubble in the system, so I burped it again, only to find out my reservoir tank was almost empty! Topping it off, burping it again, the temps are still behaving differently.

Am I overthinking this? I'm looking for opinions on what I should do or not do.

 

Two questions.

1. Did you follow the bleed instructions from the inline thermostat when doing the work?
2. How did you store the clutch fan when it was off?

 

1. I followed the instructions to a tee. And I have to say, this thing was running perfect after I did the mod.

2. When the clutch fan was off, I stored it on the driver seat, I do believe. Genuinely curious: Does it matter how? I couldn't tell you what orientation, it's been several weeks.

 

It's a viscous coupling style clutch. If they are not stored vertically it can cause damage that will prevent the fan from operating at the correct speed. The fluid will leak into the bearing assembly and no necessarily out of the fan clutch, so just cause there wasn't a puddle doesn't mean it wasn't damaged. If they are laid flat for very long, then they should be installed and then allowed to sit 60+ minutes in the vertical orientation to help the fluid re-enter the correct chamber.

If it was laid flat on the drivers seat then you may have your culprit.

 

This is exactly why I asked. I have never seen them recover from laying flat. I suspected as much.

 

So then when getting a new one shipped it's best to install and say wait overnight before driving? As one can't confirm how the clutch was stored and or shipped..

 

Well I'll be danged.

Assuming that sitting vertically in the vehicle for weeks now hasn't done anything to change the behavior is a sign.

Do they squeal when this happens?

 

Doesn't seem to be a problem with new ones, probably because the seals are new.

 

I wonder if this is more so an issue with older clutches which are susceptible to this sort of leakage? I've not run into this problem before.

I guess I'll look into a Hayden clutch and Dohrman fan upgrade then.