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Motorad Thermostat

12K views 30 replies 8 participants last post by  0dyfamily 
#1 · (Edited)
I installed a Motorad 82C thermostat in my 2003 Ody to increase the heating and defrosting here in the mountains. It ran quite a bit hotter than the OEM Honda thermostat averaging a temp of about 203-208F. A month later on a 1k mile trip I was running 208 to 217F to a couple of very short stints at just above 220F at 70+mph in around 90F ambient temp. Both my radiator fans were working well.If I downshifted to D3, my engine temp quickly fell down to around 200 from 217.
I bought a Honda thermostat (78C) and put it in a pan of hot water along with the Motorad thermostat and , low and behold, when the water was boiling (very near sea level) the Motorad was only opening about 1/3 as much as the Honda thermostat. That WAS the problem. The original Honda thermostat (yes I had all three in the pot at the same time :) ) opened about 80% as much as the new Honda thermostat and still at least as twice as much as the Motorad.
So, even though Motorad is a highly respected brand of thermostat, I would advise testing any new thermostat in a pot of hot water (using a thermometer) to make sure the damn thing is working properly before going through all the trouble of installing it. I sure wish I would have.
I am now running around 188F in my shorter test trips in aprox 90F ambient air temps.
Anyone else have problems with the Motorad thermostat?
Just thought I would share this info.

Buffalo4

PPS:I still might order another Motorad 82C thermostat, but I WILL test it first before I just blindly install it. That goes for any other brand also, including Honda. :) :eek:
 
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#2 ·
Buffalo, that is an excellent idea...test before installation. I'm amazed that a new one wasn't fully open in a pot of boiling water.

I'm running a MotoRad 82C in my 2003, and the ScanGauge II comes up with coolant temps of around 194F on days in the high 90's up to over 100F. No problems, so far.

OF
 
#3 ·
Since I had changed the thermostat at the same time I changed the radiator, I thought perhaps the radiator didn't have as much flow as the OEM. Glad that wasn't the problem. :)
Yep, the Motorad should have been wide open somewhere in the low 190's. I am now in the Chicago IL area on a visit and am experiencing some pretty warm weather and the Ody is still running at the cooler temps.
Guessing at the opening of each stat in boiling water:
Old Honda: 8mm
New Honda: 12mm
New Motorad: 4mm
I also noted that the new Honda stat started opening sooner than the old Honda stat and opened more than the old Honda one. So, if your Ody is starting to run a lot hotter going up long steep grades, perhaps your old Honda stat needs to be replaced. I guess they do have a limited lifetime.
Buffalo4
PS: Perhaps I will order another Motorad 82C stat and try it next year, but I am leaving well enough alone for this year. :)
 
#4 ·
The 82º thermostat I have been using for almost a couple of years certainly heats hotter and warms the inside faster when it does open fully. Never thought to test it.
 
#5 ·
I would imagine that the Motorad stat I received was just a defective stat. Your Motorad stat is probably working just fine. IMHO, the hotter Motorad stat should run just a little hotter than the original stat under normal driving conditions, since once it opens it is letting just as much fluid through it than the Honda, all things being equal.
Buffalo4
 
#6 · (Edited)
Yeah, the 82 deg stat would run the engine hot only until it opens up. Once fully open they are flowing the same amount of coolant into the system as the 75 deg stat.

When I changed my radiator last summer due to leaks at the seams but no over heating issues, I also changed the stat and hoses. I picked the AZ $13 duralast 75 deg. stat and compared its function with the original honda stat that had about 170K. I placed both inside the pot of boiling water, the old honda stat still opened fully but lazily- very slowly. While the new AZ stat was fully open right away. Seeing this assured me that I should change the old stat. Living in hot Las Vegas I don't find the need for a hotter stat and feel keeping wtihin the honda specs is better for my engine. The AZ stat seems to be doing its job after 1 year of use.

Anyways, I second that checking both new and old stat function inside a pot of boiling water is a very helpful step to do whenever you find the need to pull your stat out. Also been discussed before, failsafe type stat (one that stays open at failure) actually fails more often hence unreliable than the regular stat--like honda. No matter what brand you chose to get, always check your stats functionality before installation.
 
#7 ·
Buffalo and nitely...you men are both on the money here.

I ran my ScanGauge ii on both Odys when we had 114-deg F temperatures. Our 2002 ran a 78-deg C stat, while my 2003 has a Motorad 82-deg C stat. On the road with good airflow through the radiator under normal driving conditions, even if only at 20 mph, the 2002 and its 78-deg C stat showed a 188-deg C temp on the ScanGauge, while under the same conditions the 2003 and its 82-deg C Motorad showed 194-deg C on the ScanGauge.

If I was forced into stop-and-go traffic with extended idling, with the radiator sucking in the hot air from vehicles in front of me, both stabilized at 202-deg C. In short, the hotter stat only runs hotter until both are fully open.

OF
 
#8 ·
That's what I figured it would do so I was really surprised with the much higher temps. Once the temp is high enough to fully open the hotter thermostat, it should be just as effective cooling as the lower temp stat. Even the old Honda stat didn't open as far as the new Honda stat so I'm glad I did put in a new Honda stat rather than using the old one.
Buffalo4
 
#9 ·
Just thought I'd add that I emailed Motorad and told them about their 82C thermostat only being open about 1/4" at boiling at near sea level (aprox 212F) and they sent me a replacement for free. I then tested it along with the old Motorad and the old Honda 78C t-stat in boiling water here at 8300 ft elevation in boiling water (aprox 195F) and got the following results. Old Honda thermostat - around 3/8+". Both Motorads were aprox 1/4". The Motorads should have been fully open at 195F.
So, again, I strongly suggest you check the new thermostat in boiling water before installing one as it is a pain to change with adding antifreeze and bleeding the air out of the system besides removing the old one. I'm glad I didn't just go ahead and install the replacement Motorad 82C thermostat.
However, I still wish I had a hotter thermostat in my Ody for this winter.
I noticed when it was below 0F, the other day, while driving on a fairly level road around 40mph, that the engine temp (Ultra-Gauge) dipped down below 170 a couple of times. Perhaps the new Honda thermostat is also not working so well at low temps. Going 70+ it would run in the upper 170s but the upper 180s would have been nicer. :)
Buffalo4
 
#11 ·
On a quick search to get myself a thermostat....Motorad price looks good...but I must be missing something. No way you guys are buying the cheapest parts out there for your beloved vans! But no idea if I have apples or oranges based on a need to find a certain temperature rated model. Certainly will try the boiling water trick when you guys make your part suggestions and the order comes in.

All quotes are from amazon prime...9/3/2014

[h=1]Motorad 302-170 Thermostat $11.70[/h][h=1]Mishimoto MMTS-S2K-00 60 Degree Racing Thermostat 47.28
Beck Arnley 143-0707 Thermostat 24.07
Stant 14337 Thermostat - 170 Degrees Fahrenheit 15.97[/h]
Suddenly I'm not having a good weekend until I have my van torn down and a magnetic tray full of 10mm bolts.
Beers for you all in advance.
 
#13 ·
+1 Buffalo4

I installed it to help with last winter's BRUTAL cold. Even on -20F days the van was nice & toasty inside! I even recall needing to turn the inside temp control up (cooler) from full heat since it was so warm even on the coldest days.
 
#15 ·
Honda only recommends the lower 170F temp stat, at least for my 2003 ODY. That is why Amazon says it will not fit. Motoradusa.com also only lists its 170F thermostat for the 2003 Ody.
The only reason I went back to the OEM stat was because I had too high a temp with the Motorad during sustained 70+ mph highway long distance driving. I seemed to be the only one who had that problem, which I believe was caused by the inadequate opening of the Motorad. I sure wish it was still in there this winter, though. :ahh:
If I could find a Motorad High Flow thermostat with the higher temp rating that would fit my Ody, I would put it in.
Anyone out there know which Motorad High Flow thermostat (180F) would work in my 03 Ody? PLEASE :) :)
I had just changed my radiator before putting in the Motorad, so perhaps that cheap replacement radiator had a poorer volume flow. If I took dropped down a gear to increase the revs, it cooled right down.
Buffalo4
 
#16 ·
The Motorrad 302-180 works in our 03s. I've had mine in for over a year now and love the improvement over stock.

Why does Amazon say it doesn't fit? In the automotive aftermarket industry, there is a master parts fitment table entitled 'ACES' that is managed directly by manufacturers. Most retailers and service shops use this table, but the automotive parts manager/division at Amazon chooses to make their resellers enter fitment info.

So to make a long story short, Amazon is at fault for saying that something doesn't fit when it does. I went through the same dilemma last year when I was researching fitment for our '03 EX and finally went to Motorad's site to find the correct info.
 
#18 ·
The Motorrad 302-180 works in our 03s. I've had mine in for over a year now and love the improvement over stock.
So to make a long story short, Amazon is at fault for saying that something doesn't fit when it does. I went through the same dilemma last year when I was researching fitment for our '03 EX and finally went to Motorad's site to find the correct info.
Where on the Motoradusa.com site did you find that it was compatible? I sure couldn't find it.
When I put in 302-180 in their search box, no Hondas were listed.
Motorad only lists the 302-170 and the 7302-170 (fail-safe model which nobody seems to care for) for the 03 Ody. I even called them up.
Any ideas on where I could find a 'high-flow' 180F thermostat for my 03 Odyssey?
Thanks,
Sontakke,
The model is 302-180 and not 320-180. You probably just mis-typed.

Buffalo4
 
#17 ·
Beck Arnley also makes an alternate temperature thermostat for the 2003 Odyssey. It is model 143-0845 and is an 180F.
Beck Arnley Online Parts Catalog
I don't believe it comes with the gasket, however.
$21.84 with free shipping from ebay:
Engine Coolant Thermostat Beck Arnley 143 0845 | eBay
I may buy one and try it out. Hopefully it will have better coolant flow than the Motorad 320-180 (made in Germany) that I previously tried out.
I would really like to find a 'high flow' 180F model somewhere.
Buffalo4
 
#19 ·
Hmmmmm.....a year is a long time ago. Pretty sure it was on their site back then. It would be nice if Motorad would actually talk to us shade tree mechanics! :relaxed:
 
#21 ·
I keep making the mistake of calling the Motorad 180F thermostat a 320-180 instead of what it actually is, a 302-180.
I also noticed that the original Motorad 302-180 that I installed had the following stamped in the bottom of the wax tube: 83C, just below that was IVS and just below that was FDI. On the replacement Motorad sent to me for free by Motorad, it said 82C, just below that was 180F and then just below that was FDI.
Buffalo4
 
#22 ·
Reviving this one from the dead.

My Acura TL with its J32A2 V6 ... I was tired of not being able to readily clear ice from my windshield during our last snowstorm. Also, my feet were just not feeling the warmth from the heater. It has the same thermostat setup (housing, 78°C tstat, etc.) as my 2002 EX Odyssey's J35A4 V6.

Motorad 302-180 thermostat (82°C) to the rescue. Now, the box says that the packaging and the thermostat are made in Israel. Fine by me!

That engine bay is tight. Took me about 2 hours to do this job (drain radiator, remove OEM NTLC 78°C thermostat, put both tstat's into a pot of water on the stove (tested okay with a cooking thermometer), installed, filled and burped the cooling system with my old school Lisle funnel setup.

While warming it up, I rotated the tires.

Took it for a drive. What a difference. Getting good heat out of the vents, my feet are toasty. (y) 🍺 Just in time for the snow that's forecast for this Wednesday. 🥶🥶🥶

OF
 
#23 ·
Reviving this one from the dead.

My Acura TL with its J32A2 V6 ... I was tired of not being able to readily clear ice from my windshield during our last snowstorm. Also, my feet were just not feeling the warmth from the heater. It has the same thermostat setup (housing, 78°C tstat, etc.) as my 2002 EX Odyssey's J35A4 V6.

Motorad 302-180 thermostat (82°C) to the rescue. Now, the box says that the packaging and the thermostat are made in Israel. Fine by me!

That engine bay is tight. Took me about 2 hours to do this job (drain radiator, remove OEM NTLC 78°C thermostat, put both tstat's into a pot of water on the stove (tested okay with a cooking thermometer), installed, filled and burped the cooling system with my old school Lisle funnel setup.

While warming it up, I rotated the tires.

Took it for a drive. What a difference. Getting good heat out of the vents, my feet are toasty. (y) 🍺 Just in time for the snow that's forecast for this Wednesday. 🥶🥶🥶

OF
I wish my 180 stat would have worked but I feel that the replacement radiator I put in is part of the problem.
I put in a cheap one that 'sounded' great and fit really good. but for the time it took me to change the radiator, I should have spent an extra $30-50 and put in a quality. At least the replacement is not leaking. :D
If I had a decent place to work inside, I would put that Motorad 302-180 back in just for the winter.
The OEM one is just too damn cool for when it really cold out and the windshield takes too long to clear and the vent temp would be SO much better if I could raise that temp 10F, I don't let the cabin air filter get clogged up either. :eek:
But, since I don't really drive that much anymore, it's just becomes another minor annoyance and it is only slightly uncomfortable.
But the OEM one does have a higher flow volume than the Motorad 302-180 as indicated by the much lower temp on a hot day doing 75 or so on a long trip. With a quality radiator, both most likely would have been fine on hot days.
Once the coolant temp get above 94F or so, the radiator fan runs, so, more wear on that motor also, But?? :).
Buffalo4
 
#24 ·
From all appearances, the OEM thermostat, when wide open, flows more than the Motorad in a wide open state. True that!

The Motorad is a "one size fits all" for a lot of cars with bypass style thermostats and that particular diameter and "back end."

Getting the 2015 Acura RDX thermostat has me grating my teeth. Yes, it's the same as the Odyssey thermostat in terms of dimensions, and it's an 82°C thermostat, and it's made by Nippon Thermostat ... but it's 70 bucks! 😭😭😭

I'm going to monitor temps with my ScanGauge II when the weather warms up.

The OEM thermostat from my old Acura TL is still sitting on my desk, just in case.

OF
 
#25 ·
I think my problem is my low cost replacement radiator.
Hope it works out well in your Acura. I sure would like a warmer thermostat in my Ody in the winter.
Amazingly when I went to IL on I-80 during 90+F temps and my temps were around 110-120, I got the best gas mileage I ever got on that long Easterly trip. Course it could also have been the wind directions, but?
Enjoy the extra heat!!!
Buffalo4
 
#26 · (Edited)
The last time I had a Motorad 82°C thermostat in my 2002 Odyssey, I was getting really good MPG in the winter during my "high altitude" driving, like diving up into New Mexico to go skiing.

Yes, tailwinds are helpful!

I am really loving the extra heat in the footwells. Right now, my V6 Acura was not delivering good fuel economy numbers during freezing weather. Hopefully, this little modification will help.

The 2002 EX Odyssey will probably receive a Motorad 82°C thermostat next week. Like the Acura, I'll keep removed OEM thermostat handy, as well.

OF
 
#27 ·
Whoops, I meant my coolant temps were between 210F-220F+ and NOT 110-120F
I have to remember to 'proof read' before I hit Post Reply. :eek:
I'm sure you enjoy the added heat in the winter. I know, I would.
Buffalo4
 
#28 ·
Just got back from a drive in the current blizzard. 🥶🥶🥶

The extra 8°F (give-or-take-a couple °F) makes a positive difference. Was able to keep the windshield warm enough, and the footwell heat is finally enough. :)

No more driving for a while! ;)

OF
 
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#29 ·
What engine temp did you have during that blizzard?
Just curious. Was it around 190 or 185 or? On my Ody when it gets down below zero, the engine temp is just around 170 or so with the OEM thermostat.
Buffalo4
 
#30 ·
I did not have my ScanGauge connected. When I go out tonight to check on my daughter at work, it will be below freezing again. I'll run everything as before (defrost, footwell heat) and report back.

OF
 
#31 · (Edited)
16°F this morning, had to drive to my workplace. There is a short run at freeway speed going there, I got out did not shut down, and came back home. At almost 60mph cruise, 198°F per the ScanGauge. That's a little hotter than what I would expect, but I have no "pre modification" basis, since I didn't have the ScanGauge on this Acura prior to swapping thermostats.

16°F is a lot warmer than 0°F, relatively speaking. That all-aluminum V6 sheds a lot of heat through the block and heads. It's on those sub-zero (°F) days where the 302-180 stands out.

We had 0°F about ten days ago. Wished I'd had the ScanGauge hooked up to my Acura.

If I'm sitting still, idling, with defrost on and footwell air flow enabled, that coolant temperature will slowly drop. :oops:

I'll keep an eye on it and report back when temperatures come back up to the 40's this week. The OEM thermostat is still sitting on my desk .... just in case. :cool:

OF
 
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