Thermostat replacement

[Ranger_T]

I’ve got the 98’ Ranger with a 4 liter 6 cylinder engine and picked up the thermostat for replacement. It comes with the rubber o’ring type gasket it seems to be part of the thermostat. In this short YouTube video done by a reputable company, they make no mention of any other gasket needed. There also seems to be a paper gasket not so easily obtainable, I have some 1/32” gasket material if needed. Has anyone performed this repair?
Is this rubber seal around the thermostat sufficient enough to get the job done properly or is there an additional gasket needed?


Thank you in advance

 

[superj]

lots of thermostats have only the ring around the outer edge. they have worked with only that on all my vehicles that used that type of setup

 

[RonD]

+1 ^^^

The rubber around the thermostat plate will seal it

Thermostat should be rated at 190deg to 195deg, 192deg is fairly standard
It should also have a "jiggle valve", a hole in the plate with loose metal pin, this lets any air out when refilling or if air gets in from a leak
Jiggle valve should be placed at 12:00 position, where air would be behind the plate

 

[Ranger_T]

I picked up the 198° thermostat as it seems that the majority of them are, I tried getting the 195° which wasn’t easy and then thought, well what’s 3°?
The 180° one easily found definitely seems too cold for my preferences and I’m reading the original Motorcraft was 196°, someone please correct me if I’m wrong with that last comment? The temperature gauge was always just below the halfway mark before. I guess unless it seems any closer to or rides just above it I’ll be fine. It was always steady as a rock before it started failing. Thank you for the replies I’m now comfortable replacing with just the o’ring gasket

 

[SenorNoob]

That all sounds about right. Beware of bad new parts. I picked up one of each brand from every parts store within 40 miles of me (so like 10 places) and none of them worked out of the box. I took to boiling them before I put 'em in. Water boils at 212, and they didn't open at that point. Had to buy a Motorcraft to get a good one.

 

[Ranger_T]

Thank you for the help. I had successfully installed the T-stat today, not without a couple of bumps in the road. I took the outlet cover off and cleaned up both ends where the thermostat sits, started cleaning the outlet cover and noticed how pitted it was

So I called and found out they sell the outlet/hose cover with the thermostat. I went down to Autodrone and returned the new T-stat, picked up the new parts thinking all the way home, no wonder they sell them together this is probably an automatic purchase for the seasoned auto mechanic that does this all the time, which I certainly don’t consider myself.

Only to get home and find out this ain’t the right part after all

So I had my daughter re surface the old cover while I went back down and returned the kit, picked up the original thermostat I had purchased before and installed it, my daughter did a great job

I have a thick piece of glass that I’ve used many times, then wrap the sand paper around it and it’s a flat surface. It was good enough to make a good seal.

Just be careful with the aftermarket parts, anyone who reads this before replacing the thermostat, great idea and well thought out by the parts industry but make sure it’s the right part. The original steps up to a larger diameter to make the hose connection work

The replacement part didn’t have this as seen in the picture above, just had the same diameter all the way through and was too small. Overall a successful day it just took 6 hours to complete a job that may have taken 2 hours lol

 

[RonD]

The pitting is from Galvanic corrosion which happens when two dissimilar metals are in contact and there is a fluid present that can transfer electrical current

The t-stat housing is steel, the intake is aluminum

But..........if you change the coolant every 2 years, as spec'ed, this corrosion is minimized
Standard coolant, the Green stuff, has corrosion inhibitors that last about 2 years

You will find the same pitting/corrosion where the aluminum intake and cast iron head's coolant passages meet up
In fact it is a common leak point as this corrosion eats away at this connections gaskets as well as the metal
But as said, change the coolant on time, and no leaks and minimal corrosion

 

[Ranger_T]

The pitting is from Galvanic corrosion which happens when two dissimilar metals are in contact and there is a fluid present that can transfer electrical current

The t-stat housing is steel, the intake is aluminum

But..........if you change the coolant every 2 years, as spec'ed, this corrosion is minimized
Standard coolant, the Green stuff, has corrosion inhibitors that last about 2 years

You will find the same pitting/corrosion where the aluminum intake and cast iron head's coolant passages meet up
In fact it is a common leak point as this corrosion eats away at this connections gaskets as well as the metal
But as said, change the coolant on time, and no leaks and minimal corrosion

Interesting I didn’t know that about the electrolysis & the 2 year recommendation, good information. It looked extremely nice and clean inside the thermostat housing

 

[cbxer55]

I have run a 180 in my 98 3.0 Ranger for over 20 years. Never been a problem. Temperature gauge needle never even gets close to the half way point. I also run a 180 in my 07 Mustang 4.0. Again, no problemo. Run a 170 in my 04 5.4 blown Lightning, stock is 180.