Inline Thermostat Mod and Ultra Gauge: What exactly do I need?
 

Hey I guys I've been reading about this mod for some time now and I'm really considering it so I hopefully extend the life of my gaskets.


I know there has been some speculation as to which thermostat to get, but is 180 degrees the best option? I found this thread that's got a bit of a write up, the consensus seems to be 180. It also pretty much tells you what parts you need. https://landroverforums.com/forum/discovery-ii-18/d2-inline-thermostat-mod-32216/page2/

Are there different types of Ultra Gauges? Where can I get one?

Once the set up has been installed correctly, does the stock temperature gauge read lower than before? Or is it still in the range for "normal" operating temperature? Or does it not work at all?

Lastly, has anyone that has done had any problems so far? Does a mod like this effect resale value? I figure it would void warranty, but I don't really care considering I've never had LR warranty. I'm asking out of curiosity.

Sorry if this thread is redundant but I think it could be a good go to thread for other people also interested in the mod.

UltraGauge Automotive Information Center and OBDII Scan Tool

Just get the latest version of the UG and you will be fine, it gets its readings from the ECU which gets its readings from the sensors.
Yes your temp gauge will work, and it should still read normal.
The nice thing about that mod is if you want to play around with different t-stat temps you can easily and cheaply.
The only thing that will change, and your truck will not know the difference, is the way the coolant is routed.

As far as resale value, the only one whos going to know the difference is another LR person.

One thing to remember is that the thermostat is not inside the water in the block. So you need to have one or two 1/8 inch holes drilled in the stat flange to circulate hot water past the stat when it is closed. Also, the 180F is a good start, being remote the block will be just a little warmer.

Actually with this mod the t-stat is BEFORE the radiator not AFTER like the DII t-stat is now.
So the truck should run cooler and if it runs to cold the t-stat will need to be changed to a hotter one.

Ah i see. What about the issue of the truck running too rich because of cooler temperatures? Can you elaborate on that and is it something to worry about?

thanks

The DII uses a 180 t-stat because it has a smaller radiator than a DI and so it runs hotter than a DI.
With this mod it will lower the engine temp because it is just a better system, so instead of the engine running in the high 190's to low 200's it should run right about mid 180's.
If that is the case just pop in the next higher temp t-stat.
T-stats of this type are only $10.
The colder a engine runs the more fuel it needs, just like the choke setting on a lawnmower or weedwhacker.
The hotter the engine runs the better it combust's the fuel but if you run it to hot you will destroy the engine.

Lower engine temps also raise horse power but thats from burning to much fuel, which lowers your MPG.

I run a 195*F t-stat in my truck and she runs right at 195*F going down the road, about 200 sitting in traffic for a long time.

My point is that the stat is some distance from the block, just like the stock D2. In the D2 stock setup, coolant has to get to the stat thru those top metering holes, and warm it up to open. Same thing in the inline, hot water has to warm up the stat, and it has to get there just like when you turn on the hot water at home. The D2 runs a "open at 180F" stat, but being a little ways away, by the time it opens the block gets a little warmer (an offset). End result is temps in the 190s in the block and on the OBDII.

If the coolant temp sensor dies, the ECU uses a default value of 185F, so that must be beyond the "add more fuel" point for low temp.

I just completed this mod yesterday and have only been running it one day but I do have some small things to point out that may be helpful.
1. making sure u get all the air out of the system is very important. follow Rave and lift the overflow tank above the bleeder as you fill the system until it puts out a steady stream of fluid. I also found it helpful to fill the overflow all the way up and put the cap on before lowering it back down below the bleeder, this helps keep air out of the system (ie. the air in the tank)
2. Thermostat gets installed with the spring facing the bleeder and cone facing the radiator.
3. I agree with all the talk that Spike did in the write up about 180 being to cold. (I ran a constant 177 at 70mph on the highway and on my way home tonight I pulled code #P0126 that I think says that the temp at the block and the temp at the radiator are to far apart. 2 things that are important to know is that I drilled 2 1/8 holes in the stat, and I removed my clutch fan and installed an electric fan that kicks on at 185 and goes off at 165, it is also triggered when the AC kicks on. Anyway I will be switching it out for 190, at least for the winter.
4. And I am not sure you have to drill any holes in the stat, maybe someone will chime in.
5. I cut too much off of the fan shroud and the hose between the bleeder and the stat sits to low forcing the hose between the bleeder and the block to rub on the alternator pulley. It looked fine with plenty of clearance during the install but after it got fluid in it, it began to sag. I used a dremel tool but cut it to low on the engine side of the shroud.
6. over all I am very happy with the mod and love the constant temps (177-184)

Personally I see no reason to to drill holes into a t-stat, if they wanted holes in it they would have put them there.

Without the small bleed holes in the flange of the stat, water is stopped at closed stat. Now that water is cool because it brought the wax pellet in the stat back down to say 180F. The engine is heating up again, but now it has to warm the column of water between the block and the stat to make stat open. Block will be a lot hotter. Kinda like turning on the hot water in the sink, it takes time to get there. You would also need a hole, or a jiggle device, to allow trapped air to pass by, otherwise you make a steam room for the stat, it relaxes while engine keeps overheating.

Attached pages on that bottom of radiator sensor, not all D2's have it. The code seems to indicate that engine temp and bottom of radiator temp are too close together.

As for stats not having holes from the factory, the D1 stock stat has four sampling holes. And many stats today have the jiggle device, to allow air bubble to not get trapped behind the stat. Of course, this assumes that stat is opening and closing, not just staying partially open. Once stat opens, the tiny holes don't do much.

Having a stat not inside the engine block, surrounded by hot coolant means you have got to take the heat to the stat.