2003 Marauder overheating issues. any help greatly appreciated.

[JesseJames84]

2003 marauder was running fine then began overheating out of nowhere and havent been able to figure out on what's going on. I've replaced thermostat. I've replaced the water pump. Nothing has changed. Car gets up to normal temp. Sits there for a lil bit (id say 20 mins) then slowly starts to over heat. Car has no leaks. Car doesn't need reservoir filled or anything. I did remove the reservoir cap after it was hot (let it kool down about 15-20mins before cracking the cap) and it burped out air and a splash of coolant. Figured it was good and jus bled out some air. I also noticed the service bolt on top of the cross tube, I removed the bolt and its bone dry in there. I woulda figured it to have coolant in it since it was attached to all the radiator hoses.

I can squeeze the lower radiator hose and hear it burble up in the coolant reservoir. Squeeze top hose...nothing of any sort. Feels like air. The neck coming off the block will get pretty damn hell hot, but the little 8-10" rad hose with the springs in it and the split off at the thermostat are cold to the touch. Was thinking a blockage somewhere?

[fastblackmerc]

Need to burp the cooling system.

http://reischeperformance.com/refill.html

Also make sure you but the thermostat in the right way.

[fastblackmerc]

And welcome to the site.

[RubberCtyRauder]

air in the system, need to burp system as FBM said

[ctrlraven]

Did you replace the thermostat BEFORE or AFTER it started overheating?

[RF Overlord]

What they said ^^^ about burping. The fact that your reservoir was full, yet the COT was dry confirms this.

[babbage]

It's very easy to get the wrong thermostat for Marauders. They have a unique thermal bypass. Just a hunch that you got the wrong one, while this wont cause it overheat, it ruins the efficiency. Worth double checking...

Refill and burp like suggested above.

Good luck

[Badass_forever]

Need to burp the cooling system.

http://reischeperformance.com/refill.html

Also make sure you but the thermostat in the right way.

This is a great write up on how to bleed the air, if you have done this, and you are still over heating you need to drill a hole in the t-state, not enough coolant is by-passing it and allowing it to get hot.

Had this problem with my first cobra build, i drilled 2 small holes in the outer part of the t-stat so warm coolant could flow past it faster and allow it to open sooner.

Picture of said holes

[Logizyme]

This is a great write up on how to bleed the air, if you have done this, and you are still over heating you need to drill a hole in the t-state, not enough coolant is by-passing it and allowing it to get hot.

Had this problem with my first cobra build, i drilled 2 small holes in the outer part of the t-stat so warm coolant could flow past it faster and allow it to open sooner.

Picture of said holes

You must not understand how the bypass system works on our cars. Even on a more traditional non-bypass thermostat setup drilling holes in your thermostat is not a great idea - if they worked better that way they'd come that way.

The bypass system on a Marauder has full coolant flow through the engine, into the COT, down the bypass hose, through the thermostat housing and back into the engine when below operation. As the engine coolant warms up the thermostat begins to open and simultaneously shuts the bypassing side, directing coolant through the COT to the radiator, to the thermostat housing and into the engine.

--

Important that you got a correct bypassing design thermostat, also performing the proper bleed/burp method of the cooling system. Coolant should always be checked and topped off at the COT plug. If the vehicle still overheats be sure to check electric fan operation.

[Badass_forever]

Important that you got a correct bypassing design thermostat, also performing the proper bleed/burp method of the cooling system. Coolant should always be checked and topped off at the COT plug. If the vehicle still overheats be sure to check electric fan operation.

Is that not just a thermostat with the floating brass plug that expands when hot?

like so?

[fastblackmerc]

Just installed my FORD-4D 170° Performance Thermostat.

http://reischeperformance.com/#anchor

[Comin' in Hot]

stupid question, but is your cooling fan running?

[ctrlraven]

stupid question, but is your cooling fan running?

That's another possibility. Mine went up without any notice on a 95 degree day, had to drive for 15-20 mins then stop for 30-45 mins multiple times to make it to the dealer. Then got bent over real good on the $652 bill ($4xx parts, $200 labor) for a 15-20 min replacement.

[Logizyme]

Is that not just a thermostat with the floating brass plug that expands when hot?

like so?

IDK what you mean about the floating brass plug, but the bypassing design means it has the lower 1/3rd of the thermostat in this pic.

[babbage]

Is that not just a thermostat with the floating brass plug that expands when hot?

like so?

Nope wrong. Please stop giving bad advice on this site.

Wrong one on left - correct unit (Motorcraft RT1085) on the right.