Author Topic: Toyota Corolla 1600 thermostat replacement for K75  (Read 2448 times)

Offline foliver

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Toyota Corolla 1600 thermostat replacement for K75
« on: February 03, 2021, 03:25:19 PM »
Hello all.
I’m repairing some stuff on my K75 and I’ve found a replacement for the thermostat.
It’s a Toyota Corolla 1.6 one.
Diameter is the same as oem, I’m not at home to test it, but here I’ve some pictures.
Rubber oring seems to be a little larger than the oem.
Here some pics .
It’s a little bit shorter, do you think it can be a problem?
Txs!

  • Montevideo, Uruguay
  • Bmw K75C 86

Offline foliver

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Re: Toyota Corolla 1600 thermostat replacement for K75
« Reply #1 on: February 03, 2021, 03:26:38 PM »
I forgot: 82 degrees
  • Montevideo, Uruguay
  • Bmw K75C 86

Offline The Mighty Gryphon

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Re: Toyota Corolla 1600 thermostat replacement for K75
« Reply #2 on: February 03, 2021, 03:57:21 PM »
The thermostat has TWO functions:

1. Open to let hot coolant into the radiator

2. Close off the bypass around the radiator that allows coolant flow to equalize engine temperature while the engine is warming up.

The round disc is what closes the bypass.  Being shorter than the OEM it may not completely close off the radiator bypass and cause the engine to overheat. 

Since it's fairly easy to change the thermostat, maybe you can try the Toyota unit and let us know if your engine overheats. 
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline Scott_

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Re: Toyota Corolla 1600 thermostat replacement for K75
« Reply #3 on: February 03, 2021, 05:22:20 PM »
What I see in the pictures, the Toyota one is both shorter in length, and the bypass element is a smaller diameter-- it may not seal the hole anyway.
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Offline rbm

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Re: Toyota Corolla 1600 thermostat replacement for K75
« Reply #4 on: February 03, 2021, 07:02:03 PM »
I collected this information from the forums some time ago so I'm not laying claim to its veracity.  Not sure if it was this one or the other one,

Quote
Yes, I am using a 1994 Toyota Corolla thermostat (fits all Corollas between 1983 to 2001 and 1.3L to 1.8L capacity). There are two temperatures, from memory, one 82 °C and the other 89 °C. I've installed the 82 °C and now find that the water and oil temps are steady at 80 °C at 80-110 km/h. Was around 65 and the bike was running rich (see thread: "K100 running temp".

As we are heading for summer I will stay with 82 °C, but may switch to 89 °C when the weather get cold again.

The only difference in dimensions between BMW and the Toyota one is the length. This is not an issue because when the stem closes the by-pass the assembly pushes against the spring which has a lot of give by design.

The cost is $27 as opposed to $75+. Oh, yes, don't forget to get the thermostat gasket and the thermostat cover O ring. It is a common BS (imperial size).

Ned

Tridon TT214-180 fits many, many toyota vehicles including the following: 4runner,  Avante,  Camry,  Celica, Corolla,  Corona,  Dyna, Estima,  Hi-Ace,  Hi-Lux,  Lite-Ace, Mr2,  Rav4,  Soarer,  Starlet,  Supra,  Tarago,  Tercel,  Townace.

For the o-ring you will need see:
http://www.nak.com.au/products/bs1chart.html

see BS 1 Series O-Ring Size Charts

What you want is BS134

Designation   Inside (mm)   Inside (“)   Outside (mm)   Outside (“)   Section (mm)   Section (“)
BS134   47,30   1.7/8" (1.862”)   53   2.1/16"   2.62   3/32” (0.103")

1 7/8” by 3/32” or 47.30mm by 2.62 Grainger #
  • Regards, Robert
Toronto, Ontario

1987 K75 - Build Blog @http://k75retro.blogspot.ca/

Offline foliver

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Re: Toyota Corolla 1600 thermostat replacement for K75
« Reply #5 on: February 03, 2021, 07:26:41 PM »
Hi, thanks for your answers!

Well, I have discovered that the thermostat that was fit into the bike was not an oem, and it differs in dimensions.
I read the post that rum is talked about, and some has posted a picture with the OEM measurements, and the Toyota one ( at least the one I've here) is really close to the OEM measurements.
The thermostat gasket is too wide, and doesn't fit into the diameter tube.
May be I can sand it a bit, or find a substitute, as posted in:

https://www.motobrick.com/index.php/topic,4903.msg92831.html#msg92831

I've boiled the Toyota one, and with a cloth, I've tried it into the position on the bike.
The feeling is that the bypass element, touches the end first, and then I need to push to arrive to the final seated position, when cold, the bypass circle, doesn't touch the end to seal it.

BMW OEM measurements:

85°C, Flange: 48mm, Foot: 27,7mm, Height:30mm (foot to flange) https://www.euromotoelectrics.com/product-p/thermostat-716.htm

Here the rough measurements of the Toyota Corolla 1.6 one: ( Calorstat by Vernet, TH6484.82)

82C, Flange 48mm, Foot: 28mm, Height:33mm

So I'll try to resolve the gasket and try.






  • Montevideo, Uruguay
  • Bmw K75C 86

Offline foliver

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Re: Toyota Corolla 1600 thermostat replacement for K75
« Reply #6 on: February 03, 2021, 10:38:57 PM »
Ok, I sanded the diameter of the rubber gasket, and it fits nice.
But, it's more thick of the oem, so the cap doesn't goes in enough.
I decide it to sand a bit the cap length ( like 2mm) to allow the cap o ring to make contact to the radiator body.
If something goes wrong, I"ll buy a new cap and oem thermostat, and that's it, but I guess it going to be perfect.
I'm preparing it after 6 years without running, so once i assemble the gas tank, and the other parts, I"ll post the results.
  • Montevideo, Uruguay
  • Bmw K75C 86

Offline Laitch

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Re: Toyota Corolla 1600 thermostat replacement for K75
« Reply #7 on: February 03, 2021, 11:11:43 PM »
Good luck with this, follver. Your persistence searching for a remedy could payoff.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles
I wept because I had no radials until I met a man who had no splines.
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Offline foliver

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Re: Toyota Corolla 1600 thermostat replacement for K75
« Reply #8 on: February 03, 2021, 11:20:24 PM »
Good luck with this, follver. Your persistence searching for a remedy could payoff.

Thanks!, I hope so
  • Montevideo, Uruguay
  • Bmw K75C 86

Offline blackie1

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Re: Toyota Corolla 1600 thermostat replacement for K75
« Reply #9 on: February 03, 2021, 11:26:21 PM »
well you could keep sanding bits of the toyota one
or......... go wild
and take out a 2nd mortgage for the OEM one  112350
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Offline foliver

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Re: Toyota Corolla 1600 thermostat replacement for K75
« Reply #10 on: February 04, 2021, 06:04:10 AM »
well you could keep sanding bits of the toyota one
or......... go wild
and take out a 2nd mortgage for the OEM one  112350

Hi, the oem one, is at 5300 miles away (8500 km), two weeks and a half from home, and 130 uss cost ( including usa-uruguay shipping and customs)
The Toyota one is at home, now, cost me 9 U$s, and it's fun, easy to try and I learn things in the way.

I've spent more than 500$ in fuel pump kit, filters, tank gasket,orings, washers, etc.
I need to change the brake lines, oil from forks, battery and tires, repaint.........

So if doesn't works, I go for the mortgage!
  • Montevideo, Uruguay
  • Bmw K75C 86

Offline blackie1

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  • christchurch nz
Re: Toyota Corolla 1600 thermostat replacement for K75
« Reply #11 on: February 04, 2021, 05:05:36 PM »
fair enough,
i was just being a little facetious.

 112350
  • christchurch, new zealand , where else would u want to live, really
  • 1991 K75RT naked 67,000kms

Offline foliver

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Re: Toyota Corolla 1600 thermostat replacement for K75
« Reply #12 on: April 09, 2022, 10:39:27 PM »
Hi all, as Laitch suggest me, here i'am posting how the termostat is working.

I runned the bike in summer, after some tests at home.

I've not had any affraid about, i mean the swap seemed ok for me.

It works fine.
it do the job.

The termostat opens as it should, and lets the water runs as it should, the bike doesn't overheat.
Hoses and radiator are hot, once the water circulate.

The cap is well sealed, no water goes out.
So, all in all, this problem is solved.

It was a good solution.
The bike has 1000km since it was installed, along with new fuel pump kit and shaft, and water hoses

This termostat is an Vernet 6484  K2720 , 82 degrees, i bought it as a Toyota Corolla replacement

this page shows a Vernet one with cross reference to cars

https://www.autodoc.es/calorstat-by-vernet/7278110

  • Montevideo, Uruguay
  • Bmw K75C 86

Offline The Mighty Gryphon

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Re: Toyota Corolla 1600 thermostat replacement for K75
« Reply #13 on: April 09, 2022, 11:13:17 PM »
Thanks for the update!  Good that it's working well for you!
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline foliver

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Re: Toyota Corolla 1600 thermostat replacement for K75
« Reply #14 on: September 19, 2023, 12:11:49 AM »
Hello again.
reporting one year later.
Here we are in winter now, so I'm not using the bike, just I turn it on times to times.
The last days of the summer, I've had some water drips from the thermostat cover. It seems bendt a bit, cause seems the the fir was not perfect, and the 2 bolts are making too much force, so the thermostat cover bends a bit, and one year later, the material seems to show fatigue.
May be it needed a more aggressive polish of the o ring to achieve a good fir of the cover? May be.
The thermostat keeps working fine.
Opens and closes ok. Bike is ok, despite the water drips.
Now, I'll come back to original one with new cover, to be safe prior to a trip.
At the distance, It was a good solution, but after my experience, be sure the cover seats well, at full close position.

A hug from the south!
  • Montevideo, Uruguay
  • Bmw K75C 86

Offline Laitch

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Re: Toyota Corolla 1600 thermostat replacement for K75
« Reply #15 on: September 19, 2023, 10:13:13 AM »
Thanks for this cautionary update, foliver.  112350
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider
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