In search of a 185 degree thermostat to end P0128 PART II

It was warm enough (30 degrees!) to change my stat this morning. I installed the new one from Autozone, their part 4128, it was boxed Duralast, stamped MOTORAD GERMANY on its body, and 180 on the element.

I take out the JET that was running at 176 degrees in the cold weather and giving me P0128 every other day. Funny thing, it was stamped MOTORAD on the body and 180 on the element too. But the two are obviously different production, metal shapes, spring sizes etc. and the JET came with a black gasket installed while the other has no gasket availible.

I used the gasket from my OEM stat, only had 3,000 miles on it. Tried to install the new one, too tight to fit. Remembering other posts, I measured the OD's: stock 2.480, JET 2.490, Autozone 2.510 inches. Using the bench grinder, I carefully reduce the new one's OD to match the stock, and install.

So, will it run any different?

On the trip into work, the car was running at 179 now, not 176 (still looking for 185). I will wait and see if this is enough of a difference, only due to the varuiability in production I'm sure, to stop the code. This would be so much easier if there was a way to reprogram the ECU.:stars:

 

You could always email a vendor and have them send you a tune with the T-stat sensor turned off.

I run a digital engine temp gauge and had Diablo disable the code since it used to go off every other day with my 170 Tstat.......

 

Napa191 will run 181* but you need to drill a 1/8th hole due to no bleeder. The Motorad 180* from Autozone Valuecraft part# 4128 will run 187* .

 

Exactly (actually mine runs 185-186). Only thing I can think of is that he got a bad one OR it's really cold there and his fans are still set around 179-180. I'd imagine that the high speed fan might be good enough just blowing air over the block even if the radiator is shut off if it's cold enough?

haha, you lived at the North Pole for a good while, is that possible?

 

The :cold:hell it will...I just put that one in and got the P0128 on my second trip...it is running at 179 degrees

 

Mine is going off every other day with a 180 stat. Thanks for that tip...I didn't know a tune could deactivate the code setting circuit...if this is a somewhat comon problem and the Preditor "stock" tunes are supposed to be used with a 180 stat, why doesn't these tunes already do this?

Never felt that my almost stock engine needed a custom tune...is this costly?

 

Fans not even coming on, they are not set that low... it is cold when you get out of Cali in the winter..actually snowing here now.

 

Actually the Predator tunes come with the fans set for the stock t-stat (stock fan settings). They just have the capability to set the fans where you want them with the handheld and the 180/185 t-stat is the most popular one people swap into their cars. The hardcore strip guys go with the 170 or 176 and deal with the codes (especially when it gets cold). It's not really a common problem. A VERY few people throw that code with the 180's and only where it's really cold. The 170 and 176 guys throw it pretty often winter and summer.

You might want to take it back and exchange it and give another Motorad 4128 a try. Or you might want to just drop in a stock t-stat for the winter.

No, you probably don't need a custom tune. If you want that code suppressed then you could try posting up on Diablo's forum here. There is always a chance they might do it for free. Sometimes they do that. You email them your current tune and they email it back to you with the tweak. If not then you could contact some of the email tuners. Like Steve at RDP. Just tell them you only need that one code turned off and I would expect they'd do it for far less than the regular custom tune price. A regular email custom tune would run you somewhere in the ballpark of $250 - $300? (it's been a loooong time since I got mine). I'm guessing they'd just charge you some nominal fee since it would just be disable that code and send it back. No logging or tweaking or back and forth that's usually involved with a regular tune.

 

Again...just install stock stat until it warms up. Free, no codes or CEL to worry about, plus your heat will work great.

Good luck bud!

 

try letting the car warm up before driving it.179* is not cool enough to set the code.......the bigger issue is the secondary bypass on the t-stat does not seal or open the same as the stock stat and the car does not warm up as fast(or in the time frame the PCM looks for).If you let it get to 100+ in the driveway the code should not set.
Don't turn off the T-stat code in the tune unless you are in a non OBDII state.You will never pass OBDII emissions as your readiness monitors won't run.

 

I have all the heat I could want, and more, after all there is 176 degree water availible - heat is never an issue even when it is 10 degrees outside. I just reread the info on P0128 in the service manual, and I'm starting to think the stat might not be the answer. The code is thrown depending on outside temp, engine temp, vehicle speed AND TIME to reach some unmentioned value (of engine temp). Maybe the real issue is that the engine just doesn't warm up fast enough? (even with the fans off) If that is so, the stat really is not the issue..I bet the stocker will still give me problems. I have been driving around for days with the display showing the real time engine temp and it seems to take over 10 min. to reach its stable level (with the current stat 179 degrees). More to burn up gray cells over.......:stars:

 

Hey.....I just said that! ....lol

 

I use that as my threshold every morning. Crank up, let idle till I hit 100, then leave. Colder mornings take longer, but my heated seats warm up quickly to keep me from freezin my nutz off. When I leave I will auto stick it and not go above 3rd gear, keeping the RPM's up and it warms up to temp pretty rapidly from there.

 

Hey, now that makes sense! Thanks for the tip on the emissions pass, I'm sure it would mess me up here in Penna. Now, what if I close off the secondary by-pass hole???? :hmm:

I can't imagine how long it wouold take at idle to reach 100 degrees, but I will have time this weekend to try it as the snow falls again (crap)

 

Time for a remote start.

 

I have used the Napa pn191 T-stat which is just a single disc 180*setup and even up here in sub zero temps I have never seen a 0128 code.......so that tells me you either want the bypass to open sooner or get rid of it all together.

 

Car came with it from factory...BUT it won't work if there is a thrown code!...that's one reason why this is all a PITA

 

Sounds like its time for a trip to the "friendly" local NAPA store...thanks for the tip.

 

Now THAT'S irony.

 

Yeh - when a code is activated, using the remote start gets the engine cranked, started, and then it shuts down in about two seconds as the computer catches up to itself and realizes that it should not have allowed the start in the first place. Remember, the computer is our friend.....:dumb: