Guys & Gals,

03DII, 161K, rebuilt by rover @ 80K.

I looked into the inline therm mod for this one (lucky rover #3) as my last two ran a little warm here in the ATL.

Mod completed 3/26/2012 and coolant flushed and changed to green.

We had about 2 weeks of very warm spring weather for awhile (80-82 as the high) and the rover was loving the new mod.

For the record, I have a 180 degree stat with 2 holes drilled, 5/32".

Then last week, the temps dropped back to normal for this time of year (highs in low 70's, lows in the high 40's) and......

P0126 & P0455.

Awesome.

Done some research on this site, and I get why P0126 is showing up. i'm guessing P0455 is another effect of that?

Here is my question: Am I, for the time being, doing anything other than hurting my gas mileage? I've read about sludge buildup in the oil, but this thing has synthetic in it, and frankly, I think its fine.

Its going to be hot here in not very long, and summers in the A are BRUTAL on cars. Lots of stop & go traffic, 90+ degrees, and shimmering asphalt.

A shop here says that they literally see DII's dropping like flies from May-August.

I personally don't see the harm in running a little cool for the time being, especially when it was only a 10 degree rise in ambient temp that made this thing purr.

Anyone care to weigh in? The SES light is really annoying, and I guess I could just pop a 190 stat in there for the next couple weeks, but I really don't like mucking around with coolant.

Thanks in advance for your insights, and Happy Easter!

 

Here is what I would do, put in a new t-stat, 180*F and forget about it.
No holes in it though, those are whats giving you the codes, the coolant is passing by the t-stat though the holes.

We also get into the '90's during the summer, I run a 195*F t-stat, I dont have cooling problems.
Right now they are predicting record high temps for us this summer, like 100+, that'll be fun.

 

At your mileage, if you have never changed your radiator, it is the cause of past over heat issues.
As for the codes, the 126 is indicating you are screwing too much with Rovers cooling system and there is too wide a range showing between your 2 temp sensors.
The 455 has nothing to do with your coolant system, you have a gross evap. leak in your system.

 

455 is evap system leak, may be another problem besides coolant temp. If your in-line conversion has the stat mounted in a vertical plane (coolant runs thru stat left to right as opposed to bottom to top), just use a 180 stat with the jiggle device, positioned to highest spot. Large air bubbles behind stat cause jiggle device to open, pass bubbles, when water returns to that level it closes back. Two holes is just too much.

 

Or make your truck real happy/cool, reinstall the old plumbing and then at a soft spring t/stat that runs at 180 and flows a lot more water then the standard Rover t/stat, and it is plug and play.

 

@discomike - there is a local guy here that sells a new radiator w/warranty for $210.00 - sounds like that might be the next step before summer. Only problem is they're special order....

I'll grab another 180 (or maybe a 190) t-stat this week (sans holes) and install, maybe that would help.

I know there is plenty of evidence on both sides, but I just flat don't like the rover designed thermostat. The holes and the temp are just not enough for a southern summer with a ton of humidity.

I learned my lesson the hard way with a 7.3L diesel on that.....$5850 later...gahhh. I'll never run a hotter t-stat again for the sake of fuel mileage.

In the meantime, I'll live with the P0126 until the new radiator arrives.

What causes the P0455? I guess I could search, but I'm just feeling lazy today.....could be that easter brunch with a few mimosas.

 

You may not like Rovers design, most of us don't but when you start messing with it get get in trouble as your code is showing.
Go to the LRO and read some of the write ups from a month ago and buy one of the soft spring system T/stat, starts opening at 170, open at 180 and will out flow your set up easily.
I hear Just is caryring the t/stat.

 

did the inline a few hundred miles ago. hot here. no new codes. 180 t-stat but no holes drilled. mine does have the toggle thingy tho.

 

ATLDisco,

I have spent a lot of time on this mod and will be posting all of my findings soon.

But for a quick answer it is the two holes in the stat that are throwing the PO126. I don't recommend no holes, but I would stick with the 180 stat (Part #45358 Stant advance auto parts stocks these) and dill one 3/32 hole in it.

This will assure you that the stat is not your problem and u can then start looking at the radiator and such.

 

P.S.
You might want to make sure your gas cap is screwed all the way down, it will cause PO455.