D2 inline thermostat mod ?
Mudding
Joined: Apr 2013
Posts: 180
Likes: 9
Dr. Mordo,
Which thermostat are you running? I've been running the TD5 180F T-stat now for over two years, and while I agree the system is NOT designed to hold 180F at higher ambient, I never see the temps you are hitting.
The only time I hit 207F-210F is triple digit ambient in 4-lo climbing Moab hills. I can usually get it back to the 190s as soon as the trail picks up. Never on the highway, I'm always 188-197, tops. And mine is black, so it should trap even more heat.
I just did a coolant flush as it seemed I was holding 193 when it should have been 188....seemed to help. I'm not sure how the thermostat really works, since everything is mechanical, but my ultraguage reads hotter baseline engine temps during the winter rather than the summer. My BMW 540i had an electric thermostat that made sure the engine ran hotter in low ambients (for the heater core), but I'm not sure how the D2 could do the same thing? Unless it is tied to the electric A/C fan. (My baseline in D2 for the summer is 188F, in the winter I'm around 193-194F. Strange)).
Which thermostat are you running? I've been running the TD5 180F T-stat now for over two years, and while I agree the system is NOT designed to hold 180F at higher ambient, I never see the temps you are hitting.
The only time I hit 207F-210F is triple digit ambient in 4-lo climbing Moab hills. I can usually get it back to the 190s as soon as the trail picks up. Never on the highway, I'm always 188-197, tops. And mine is black, so it should trap even more heat.
I just did a coolant flush as it seemed I was holding 193 when it should have been 188....seemed to help. I'm not sure how the thermostat really works, since everything is mechanical, but my ultraguage reads hotter baseline engine temps during the winter rather than the summer. My BMW 540i had an electric thermostat that made sure the engine ran hotter in low ambients (for the heater core), but I'm not sure how the D2 could do the same thing? Unless it is tied to the electric A/C fan. (My baseline in D2 for the summer is 188F, in the winter I'm around 193-194F. Strange)).
Mudding
Joined: Mar 2009
Posts: 142
Likes: 4
From: Los Angeles area
Off topic but I can't let it go. Hood louvers raise the air pressure under the hood when you are moving. The area in front of the windshield is a high pressure area (air builds up before it can go around the windscreen). The holes in the hood allow the air pressure to equalize between the top of the hood and the area in the engine compartment. That is bad! The greater the air pressure differential between the front of the radiator and the back of the radiator (engine compartment) the more air flow you have through the radiator. More air flow=more cooling.
Recovery Vehicle
Joined: Sep 2012
Posts: 1,169
Likes: 52
From: Tampa, FL
Dr. Mordo,
Which thermostat are you running? I've been running the TD5 180F T-stat now for over two years, and while I agree the system is NOT designed to hold 180F at higher ambient, I never see the temps you are hitting.
The only time I hit 207F-210F is triple digit ambient in 4-lo climbing Moab hills. I can usually get it back to the 190s as soon as the trail picks up. Never on the highway, I'm always 188-197, tops. And mine is black, so it should trap even more heat.
I just did a coolant flush as it seemed I was holding 193 when it should have been 188....seemed to help. I'm not sure how the thermostat really works, since everything is mechanical, but my ultraguage reads hotter baseline engine temps during the winter rather than the summer. My BMW 540i had an electric thermostat that made sure the engine ran hotter in low ambients (for the heater core), but I'm not sure how the D2 could do the same thing? Unless it is tied to the electric A/C fan. (My baseline in D2 for the summer is 188F, in the winter I'm around 193-194F. Strange)).
Which thermostat are you running? I've been running the TD5 180F T-stat now for over two years, and while I agree the system is NOT designed to hold 180F at higher ambient, I never see the temps you are hitting.
The only time I hit 207F-210F is triple digit ambient in 4-lo climbing Moab hills. I can usually get it back to the 190s as soon as the trail picks up. Never on the highway, I'm always 188-197, tops. And mine is black, so it should trap even more heat.
I just did a coolant flush as it seemed I was holding 193 when it should have been 188....seemed to help. I'm not sure how the thermostat really works, since everything is mechanical, but my ultraguage reads hotter baseline engine temps during the winter rather than the summer. My BMW 540i had an electric thermostat that made sure the engine ran hotter in low ambients (for the heater core), but I'm not sure how the D2 could do the same thing? Unless it is tied to the electric A/C fan. (My baseline in D2 for the summer is 188F, in the winter I'm around 193-194F. Strange)).
Off topic but I can't let it go. Hood louvers raise the air pressure under the hood when you are moving. The area in front of the windshield is a high pressure area (air builds up before it can go around the windscreen). The holes in the hood allow the air pressure to equalize between the top of the hood and the area in the engine compartment. That is bad! The greater the air pressure differential between the front of the radiator and the back of the radiator (engine compartment) the more air flow you have through the radiator. More air flow=more cooling.
Chalk up another fan of removing the hood's rear weather strip - Mazda 6 Forums : Mazda 6 Forum / Mazda Atenza Forum
Especially this post, though others are good as well:
Mazda 6 Forums : Mazda 6 Forum / Mazda Atenza Forum - View Single Post - Chalk up another fan of removing the hood's rear weather strip
At some point I found a thread with graphs where a guy measured temp differences with and without the rear weatherstrip and he saw underhood temps drop significantly. But he was driving some japanese car. The only way to know if it will help our trucks is to try it, which I haven't done yet.
Camel Trophy
Joined: Aug 2014
Posts: 4,743
Likes: 985
From: Southwestern Virginia
Is the rear weather strip the plastic cowl between the hood and the windshield? I've had mi e removed for about a year since I removed it in a million pieces. I have no under hood temp measurements to compare, but I can yell you it hasn't caused me any problems. The only thing is that you do have to fashion some kind of rain cover for the cabin air intake so that water doesn't get in your floorboard. All of my fluids have leaked at some point since I've had it removed and none have ended up on my windshield.
Recovery Vehicle
Joined: Jan 2013
Posts: 801
Likes: 84
From: Seattle, WA
I can confirm that my under hood temps have dropped significantly. I wish I still had access to a thermal imaging camera. A visiting relative sat in the passenger seat with his camera (he's a home inspector) and you could see the heat escaping from the Louver both while at rest and at speed. It was pretty cool to see!
It would be a challenge to install a Louver close to the windscreen as you'd be cutting around/into the washer nozzles.
It would be a challenge to install a Louver close to the windscreen as you'd be cutting around/into the washer nozzles.
Mudding
Joined: Mar 2009
Posts: 142
Likes: 4
From: Los Angeles area
Cowl induction is the perfect example of what I am explaining. If you notice car that have cowl induction, the opening is sealed to the carburetor throat thus utilizing the high pressure to force air down the carb (free super charging). Remember, the point of this thread is to lower the water temps not the "under the hood" temps. If you want to save your plastic and rubber parts then using the high pressure air on top of the hood to create air flow is fine but you are decreasing the air pressure differential at the radiator. That air differential=air flow=cooler water. I also would love to see the thermal imaging from Robert's camera.
Mudding
Joined: Apr 2013
Posts: 180
Likes: 9
I remember reading about the design of the 5.9L Jeep ZJ which needed additional cooling. It has active louvers on the hood, but the louvers needed to be placed such so that it actually aided cooling rather than hindered it. I remember reading the Jeep engineers placed them such that it actually caused a natural draft out of the engine bay. (The ZJ chassis is so old now, I can't find the link, if it even exists).
The dP across the hood IS real, but I believe the main advantage of hood louvers is heat rejection at low-speeds (warm air rises). At highway speeds, the louvers aren't necessary as you have free airflow through the radiator. I fail to see how the linked ZJ hood louvers would cause additional dP at the radiator at speed, but they can really aid airflow at idle/wheeling, which is extremely important. However, just cutting your hood isn't advised, because you could create local heat-pockets with a misplaced louver which could potentially shorten the already brittle-life of your plastic under-hood components.
http://carphotos.cardomain.com/ride_...0009_large.jpg
For what it is worth, on other vehicles removing stripping and even adding holes in the hood with no thought of drainage has been known to cause coil/crankshaft sensor issues from water making it's way to those components during rainstorms.
I was looking at adding a "real" louver on my wife's Hummer H3, mainly for summer wheeling and the fact the "fake" one looks...well..."fake". Reading threads on it and some people have had coil issues and misfires due to water ingress.
The dP across the hood IS real, but I believe the main advantage of hood louvers is heat rejection at low-speeds (warm air rises). At highway speeds, the louvers aren't necessary as you have free airflow through the radiator. I fail to see how the linked ZJ hood louvers would cause additional dP at the radiator at speed, but they can really aid airflow at idle/wheeling, which is extremely important. However, just cutting your hood isn't advised, because you could create local heat-pockets with a misplaced louver which could potentially shorten the already brittle-life of your plastic under-hood components.
http://carphotos.cardomain.com/ride_...0009_large.jpg
For what it is worth, on other vehicles removing stripping and even adding holes in the hood with no thought of drainage has been known to cause coil/crankshaft sensor issues from water making it's way to those components during rainstorms.
I was looking at adding a "real" louver on my wife's Hummer H3, mainly for summer wheeling and the fact the "fake" one looks...well..."fake". Reading threads on it and some people have had coil issues and misfires due to water ingress.
Yep the I5 H3's could have water pool around the coil packs. I have an Alpha with the 5.3L V8 and that wouldn't be a problem. Add a pusher fan to the front of your H3 and if's an 08 or up you can get the PCM enabled to control the efan during AC use or for extra cooling all PCM controlled.
Recovery Vehicle
Joined: May 2012
Posts: 863
Likes: 18
Sorry for resurrecting. Can somebody tell me why it is necessary to punch a hole in the thermostat. One of the benefits is the availability of the in-line style thermostat but if you have to punch a hole in it before you can use it that's not going to help you when you're stranded on the side of the road.