Normal Engine Temperature, All Stock

[mrhimself]

Hi all!

I bought a wrecked 03 marauder with 34k miles on it back in 2004, I've been sitting on the parts ever since.

Bought an 03 marauder in August with 140k miles and a bad motor (1 cyl has 1/2 the compression of the rest). Swapped the 34k mile motor in and it runs pretty good now.

I replaced the thermostat with a 190F Murray from O'Reilly's. I flushed the coolant system really well with flush and distilled water. Refilled it with 50/50 mix of Prestone AM/M and distilled water, following the burp procedure in the sticky. When it idles with the AC on or driving around at slow speeds (<30mph) it sits around 228F when reading the coolant temperature over OBD. Cooling fan is running at full speed. I'm in Texas and it's about 95F outside air temp.

Is this a normal temperature?

I'm debating whether to pull the tstat and replace with motorcraft.

Thanks!

[RubberCtyRauder]

you prolly have air in system, there is a specific burp procedure to get air out. look at Reische performance website for detailed instructions. plus most autoparts generic chains give out tbe wrong tstat for theze cars.

[Zack]

It is never supposed to exceed 210, as that is the factory fan on setting. Re-Burp. Also, clean the radiator/condenser with a garden hose. It is common for road debris/cottonwood to plug them, especially the radiator

[RF Overlord]

I'm debating whether to pull the tstat and replace with motorcraft. Yes, do it.


most autoparts generic chains give out tbe wrong tstat for theze cars.What RCR said.


Also, clean the radiator/condenser with a garden hose. It is common for road debris/cottonwood to plug them, especially the radiatorWhat Zack said.

[mrhimself]

Like I mentioned, I followed the burp procedure from the sticky to the letter. So, I'm leaning towards the wrong tstat. It's a Murray 4089 (https://www.oreillyauto.com/detail/murray-temperature-control-plus-4222/cooling---heating-16773/thermostats-and-gaskets-16977/thermostats-12876/thermostat/4089/4436281/2003/mercury/marauder?q=thermos).

I had the radiator out of the car from swapping engines. I flushed/cleaned it really good (inside and out) using a garden hose before reinstalling it. I'm reasonably sure it's ok.

Thanks for the advice! I'll be swapping tstats this weekend it looks like! :)

[Zack]

Like I mentioned, I followed the burp procedure from the sticky to the letter. So, I'm leaning towards the wrong tstat. It's a Murray 4089 (https://www.oreillyauto.com/detail/murray-temperature-control-plus-4222/cooling---heating-16773/thermostats-and-gaskets-16977/thermostats-12876/thermostat/4089/4436281/2003/mercury/marauder?q=thermos).

I had the radiator out of the car from swapping engines. I flushed/cleaned it really good (inside and out) using a garden hose before reinstalling it. I'm reasonably sure it's ok.

Thanks for the advice! I'll be swapping tstats this weekend it looks like! :)

Following the burp procedure does not mean you got all the air out. Trust me.
Wrap the end of a funnel in teflon tape, then screw it in the COT fill plug hole. Let the car run half hour or more. Replace that t-stat with a Motorcraft or NAPA THM 109

[mrhimself]

Wrap the end of a funnel in teflon tape, then screw it in the COT fill plug hole.

Did this twice.

New motorcraft tstat is already in the cart on rockauto!

[ByronRACE]

I fought this not long ago. Make sure you put a new o-ring on the filler/bleeder. If after the burp, top off, drive, and cool down...you find ANY air in the system when removing the filler/bleeder screw, change the water pump. Mine was the water pump seal allowing air into the system during thermal cycles. Made me insane. It would run fine for a day or three, then start doing the characteristic warm running thing...and never showed a drip on the ground.

[sailsmen]

Check to make certain you are getting the airflow over the rad including the air deflector on the bottom of the rad.

The cowling between the fan and the radiator needs to be intact.

[BAD MERC]

There's a difference between overheating and undercooling. Car get hot while idling in traffic? It's an airflow issue. Get hot cruising at 50MPH? It's a coolant flow issue.

[03Merc]

Should do the cooling mod too. While You have Your hands in it.


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[mrhimself]

Should do the cooling mod too. While You have Your hands in it.


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Which one is that?

[GLRSR1951]

What cooling Mod?

[RubberCtyRauder]

Head cooling mod for 4.6 dohc engines. most mustang parts sites sell them. there is poor cooling flow at number 8 cylinder.

[FordNut]

Even without the mod, it shouldn't run that hot. Sounds like the wrong thermostat was installed.

[mrhimself]

Pretty late follow up, but it ended up being the thermostat. Replaced the Murray with a new motorcraft RT1110 and it runs much cooler now.

[NorthShoreChiMM]

How hard is it to install this cooling mod if your only experience is brakes, minor suspension work, basic stuff.

[88LTDCV351]

Not all aftermarket T-stats listed for Marauder are the correct one. Ask me how I know.

Some are missing the thermal bypass.

Can't speak for certain on Murray though.

[RF Overlord]

Since the VIN for 2003 Marauders comes up as a Grand Marquis, many auto parts catalogues have the wrong one listed.

[rocco313]

what part of texas are you in

[rocco313]

hey im in fort worth whos doing the work on your car can ypu text me please 817 999 5902 i have an 03 to i need to see why to motor light is on just done a swap

[03Merc]

How hard is it to install this cooling mod if your only experience is brakes, minor suspension work, basic stuff.



You can do it, not hard at all!


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