Notices
1999 - 2003 7.3L Power Stroke Diesel  
Sponsored by:
Sponsored by: DP Tuner

Major Install Ahead!

Thread Tools
 
Search this Thread
 
Old Apr 23, 2008 | 03:24 AM
  #31  
orng1's Avatar
orng1
Postmaster
Joined: Mar 2008
Posts: 4,158
Likes: 0
From: Paramount, Ca
Originally Posted by jwhitetail
Speraco intercooler, 203 stat while your at it.
While we're on the subject, what temp is the stock thermostat? I've been hearing about this quite a bit recently.
 
Reply
Old Apr 23, 2008 | 04:19 AM
  #32  
ron's power stroke's Avatar
ron's power stroke
Post Fiend
15 Year Member
Photogenic
Photoriffic
Shutterbug
Joined: Jun 2006
Posts: 9,714
Likes: 2
From: White Mnt's,New Hampshire
stock is 195*

Here's a little background on the Ford Powerstroke thermostat...
Until 1996, all 7.3L Powerstrokes that were manufactured used an International water pump and an International short stem 203<SUP>o</SUP> thermostat . In 1996, Ford changed to a lower degree 195<SUP>o</SUP> thermstostat. They changed water pump designs at this time as well. The new pumps required the new long stem 195<SUP>o</SUP> thermostat in place of the short stem to properly seat the bypass disk. All 1996-2003 Ford PSDs now come equipped with a long stem 195<SUP>o</SUP> thermostat. Recently the factory replacement thermostat available at the parts counter changed to 192<SUP>o</SUP>.
*If you have a pre-1996 vehicle, call us for the proper thermostat for your truck.
WHY IS 203<SUP>o </SUP>BETTER THAN 195<SUP>o</SUP>?
Diesels run most efficiently at approximately 200<SUP>o</SUP> or above. A factory equipped 192<SUP>o</SUP>/195<SUP>o </SUP>thermostat will maintain an operating temperature at approximately 165<SUP>o</SUP>-170<SUP>o</SUP>. The Powerstroke has such an efficient cooling system, that this low flow when the thermostat is slightly open is normally enough to keep the engine cool. The downfall to this is that the engine -- when our trucks are not under load --never begins to reach its optimal operating temperature. Our 203<SUP>o</SUP> thermostat maintains a minimum operating temperature of 190<SUP>o</SUP>. This brings the operating temps up from as low as 170<SUP>o</SUP> to as high as 203<SUP>o </SUP>depending on the operating conditions of the truck. This is closer to the operating temperature range that is preferable in our trucks for optimal efficiency.
When our trucks are under load and are producing higher combustion temperatures the 203<SUP>o</SUP> will allow the engine to run even closer to its optimal operating temperature. If the truck is under load and reaches the 203<SUP>o</SUP> setting, the thermostat is then fully open. This means you are at the maximum coolant temperature that the truck will reach. Your maximum temperatures are only a few degrees higher than in stock configuration, but these are degrees that you want for better performance. The best benefits come when the same truck is under a light load and would have a hard time reaching this optimal temperature. As stated above, you will never reach this optimum temperature with the stock 195<SUP>o</SUP> thermostat. The end result of installing the 203<SUP>o</SUP> thermostat should be slightly better fuel economy, less smoke, and maybe a few extra "ponies" to go along with it.
WHY A LONG STEM AND NOT A SHORT STEM?
Although International still uses a 203<SUP>o</SUP> thermostat in some applications and that thermostat is available at most auto parts stores, it is the wrong part for the 1996 - 2003 Powerstroke. DO NOT USE THIS! It has a shorter shaft and will not shut off the internal pump bypass. This will cause inaccurate coolant flow direction through the engine. This IH version thermostat mentioned is available by calling us.
The thermostat in the Powerstroke not only controls operating temperatures, but properly directs the flow of coolant through the engine. As the thermostat opens, it proportionally closes the bypass. With the thermostat fully open, the bypass is mostly closed, and vice versa. With the International (Pre-96 Ford) thermostat, this cannot be controlled properly because of the shorter bypass stem. The shorter stem of the IH(pre-96 Ford) thermostat allows the thermostat to be fully open while the bypass is fully open. This means the coolant can travel in any direction available -- whatever direction it chooses. It can either travel through the radiator or simply make the shorter, less restrictive path back through the front of the engine. This will cause uncontrolled overheating in the back cylinders of the block, with absolutely no signs of danger showing on the water temperature gauge in the cab. It is possible that the back of the engine can have no coolant flow at all yet the thermometer in the outlet of the water pump shows all to be normal. Multiple things can happen at this point. Cylinders can seize, freeze plugs can fall out and other normal symptoms of an overheating engine may occur. Worst case is a blown motor and it won't be covered under warranty.
We know the warranty departments and engineers at Ford have verified engine loss due to the short stem thermostats in previous cases where people were sticking into their trucks to increase their operating temperatures. As soon as they see the short shaft thermostat -it's your problem. Our 203<SUP>o</SUP> thermostat will not encounter these problems! It's designed to work as the OEM unit did WITH the long stem for bypass protection.
WHY USE THE DIESELSITE 203<SUP>o</SUP> THERMOSTAT?
Higher optimum operating temperatures reached safely by using our thermostat with the long stem for bypass protection. It's that simple. We've combined the two units to bring you a safe alternative. Now you can have the optimal operating temperatures without risking the chance of uncontrolled overheating in the back cylinders of the block due to an uncontrolled bypass.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
schlepprock250
1999 - 2003 7.3L Power Stroke Diesel
5
Jul 10, 2013 09:19 AM
schlepprock250
1999 - 2003 7.3L Power Stroke Diesel
8
Apr 19, 2010 06:21 PM
schlepprock250
1999 - 2003 7.3L Power Stroke Diesel
17
Oct 12, 2008 05:22 PM
schlepprock250
1999 - 2003 7.3L Power Stroke Diesel
11
Apr 28, 2008 02:53 PM
schlepprock250
1999 - 2003 7.3L Power Stroke Diesel
23
Apr 26, 2008 11:04 PM




All times are GMT -5. The time now is 09:36 AM.

story-0
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

Slideshow: The VelociRaptor Expedition gains a lift, upgraded suspension, Brembo brakes, and trail-ready equipment while retaining the stock 440-horsepower EcoBoost V6.

By Verdad Gallardo | 2026-06-12 11:01:55


VIEW MORE
story-1
Top 10 Fords at 2026 Carlisle Ford Nationals

Slideshow: Top 10 Fords at 2026 Ford Nationals

By Joe Kucinski | 2026-06-09 11:10:08


VIEW MORE
story-2
3 Best / 3 Worst Parts of Modern Ford Ownership

Based on years of owning multiple modern Ford products.

By Brett Foote | 2026-06-09 10:53:36


VIEW MORE
story-3
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

SPONSORED: From muddy boots to rain-soaked cargo, these upgrades address some of the most common frustrations Ford truck owners face every day.

By Pouria Savadkouei | 2026-06-08 18:50:34


VIEW MORE
story-4
Every 2026 Ford Engine Explained

Here's everything you need to know about every Ford engine available for the 2026 model year.

By Brett Foote | 2026-06-05 12:58:01


VIEW MORE
story-5
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-6
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 15:43:58


VIEW MORE
story-7
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-06-03 11:38:36


VIEW MORE
story-8
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-9
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE