Why Buy OEM (Thermostats)

Post by **Jesda** » Thu Mar 31, 2005 2:33 pm

My Q has been running hot on occasion around town and on the highway, requiring me to turn the heat on full blast. Today I went to the dealer and grabbed a t-stat for $12. Stopped by at Wally World for the green stuff and some distilled water. Headed to Autozone for Redline Water Wetter.

When I pulled out the old thermostat (Stant, has been in there for about a year) I saw something truly bizarre. A photo is attached below. There's only a $2 difference between the Stant and Nissan thermostats. The Nissan thermostat is actually $2 cheaper if you go through Joe.

Lesson learned.

While I was there, I introduced myself to the service manager and talked to him about chain guides, plenum jobs, and the like. We hit it off well (no, not like that) and eventually got to talking about the black 2000 Q45t he and a tech were looking at. We discussed how it compared to the G50 and he offered to let me sit inside. Obviously, it was comfy and roomy.I also parked my butt in a new M35 (black/black/rosewood). Let me tell ya, the new M's look a LOT better in black. Less chubby, sleeker, and with the aero kit they're kind of hot! The seats are just right. Still, the previous M tugs my heart strings.

Post by **elwesso** » Thu Mar 31, 2005 2:35 pm

Wow that Tstat didnt look too good.....

Good thing you replaced it with oem!!!

Post by **Rex** » Thu Mar 31, 2005 2:42 pm

Jesda is turning into a DIY-fool.

That T-stat looks fubar'ed. Glad you made some dealership friends.

Post by **Mr1der** » Thu Mar 31, 2005 3:42 pm

did you chew on that?

Post by **97Q45t** » Thu Mar 31, 2005 3:46 pm

I too, second that. I replaced a Stant thermostat only less than about a year ago and it's going bad already. The engine now won't be fully warmed up until after I start driving for 5 minutes. Getting OEM thermostat soon.

Post by **PoorManQ45** » Thu Mar 31, 2005 7:04 pm

What are the advantages and disadvantages of using a lower temperature thermostat? Say a 170?

Oh yeah, let me guess Jesda, you lost another tool in the Engine compartment

Post by **AZhitman** » Thu Mar 31, 2005 7:19 pm

Jesda - Send it to PMQ, he can fix it!

Recycling PWNS jo0o0!!!!

Post by **PoorManQ45** » Thu Mar 31, 2005 7:27 pm

I probably could fix it.

Nah, I just used my last heat sensitive springs today

Post by **Jesda** » Thu Mar 31, 2005 8:10 pm

I was extra careful not to lose tools this time. I'm running a bit low.

I thought the OEM t-stat was 170F?

Post by **maxnix** » Thu Mar 31, 2005 8:20 pm

One can tell by looking which one is manufactured to a higher standard.

One must be very careful when not using OEM.

Post by **97Q45t** » Thu Mar 31, 2005 10:12 pm

OEM thermostat opens at 180 degF while Stant opens at 170. Fitting a lower temp thermostat would slightly improve throttle response because cooler engine triggers a richer mixture. I hardly feel it though because the change wasn't much (only 10 degF). Friend put a TRD thermostat in his GS400 (20-25 degF below OEM spec) and said he felt a little diffenrence.

Post by **DAEDALUS** » Thu Mar 31, 2005 11:32 pm

Q45tech wrote:All 90-00 Infiniti use the same thermostat specification just opens at 174F fully wide open at 194F.....stablized at 183-184F..........that is far from what would be called HOT............just average to a little on the coolish side compared to US made big 3 models.

At 170*F the engine is in closed loop. Running richer improves throttle response? I don't think so.

Hey Jesda, why don't you email Stant and send them a link to the pic? See what they say. Of course, that melted-looking chunk doesn't look like it's needed for functionality, but who wants to see that pulled out of their engine?

Post by **gniknave** » Fri Apr 01, 2005 6:42 am

Damn. I had my 240 overheat on me like crazy the other day (after owning it for 1 month now), and it was due to a collapsed belt tensioner (don't ask please). I was driving the Q yesterday, and all that kept running through my mind was people saying "You do NOT want to overheat the VH45DE!!!". My temperature gauge stays less than a notch below normal at all times, but after seeing that picture I'm taking no chances. I'll be replacing mine tomorrow since I don't know when it was last done.

Post by **elwesso** » Fri Apr 01, 2005 10:48 am

97Q45t wrote:OEM thermostat opens at 180 degF while Stant opens at 170. Fitting a lower temp thermostat would slightly improve throttle response because cooler engine triggers a richer mixture. I hardly feel it though because the change wasn't much (only 10 degF). Friend put a TRD thermostat in his GS400 (20-25 degF below OEM spec) and said he felt a little diffenrence.

Id rather not lose the gas mileage personally...

Im amazed how and why the Q and most nissans run so much cooler than the GMs... The caddy northstar runs between 210-230 most of the time......

Post by **PoorManQ45** » Sat Apr 02, 2005 3:59 am

elwesso wrote:Im amazed how and why the Q and most nissans run so much cooler than the GMs... The caddy northstar runs between 210-230 most of the time......

IIRC, the reason for this is to gain a little efficiency. Higher temp = better burn, or something like that.

DAEDALUS wrote:At 170*F the engine is in closed loop. Running richer improves throttle response? I don't think so.

WOuld using a 170 thermostat actually cause a problem? I mean, no matter what the engine is going to heat up to normal opperating temp, but with a 170 thermo it'd just take a little longer, correct?

Post by **Jesda** » Sat Apr 02, 2005 4:48 am

I emailed to Stant a link to this thread.

Post by **PoorManQ45** » Sat Apr 02, 2005 5:02 am

GOod job. Hopefully someone will join Nico and become a resident "expert"

Why Buy OEM (Thermostats)

Why Buy OEM (Thermostats)

Re: Why Buy OEM (Jesda)

Re: Why Buy OEM (Jesda)

Re: (Jesda)

Re: (DAEDALUS)

Re: (97Q45t)

Re: (elwesso)

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