Thermostat

[storm]

I had suspected the privious owner had removed the thermostat in order to turn down the heat as the temp gauge stays pinned to the bottom and the plugs are pure black. I decided to pull the entire bike apart (which is what it takes to pull the stat) What I found was the stat was stuck wide open. Rather than run to Honda I figure I would just match it up with a auto stat and if the diameter is the same - a thermostat is a thermostat. Beside Napa is just down the street.
The question is - I can go anywhere from 160 to 195 but am leaning towards 180 as a mid point. Anyone know what the stock temp is?

[georgeorge]

I'm not sure of the answer to your stat temp question, but I just want to say that if you do find a car t-stat that fits and is the right temperature just make sure it's a fail-safe Stat as is the stocker. That means that if it ever fails, it fails open. This will ensure you never overheat due to the T-stat failing.

[Kevin_56]

I just did the thermostat replacement today. I got the Turbo Tom replacement. I just looked at his site and it says the stock stat is 180. Do what you want, I got Tom's.

Kevin

[Highrider]

The ST1300 thermostat should start to open at 180 degrees F and be completely open by 203 degrees F.
I would say a 180 is a good target to start from.

[Fred]

Not an uncommon problem. Apparently there is a high failure rate on the Honda OEM stats. lots of threads if you search. If not, just order one from Turbo City in Anaheim Ca. This guy knows his stuff and has a stat that is the right temp and will last longer than mother hondas.

[Scooterb]

I hope you didn't tear off the throttle body to remove the thermostat like it states in the manual. If you did, you could have saved yourself an enormous amount of time by following the direction in this thread:

Thermostat replacement (http://www.st-owners.com/forums/showthread.php?t=9259)

The thermostat is spec'd at 180 degrees F. You can get one at Turbo Toms here: Turbo Toms thermostat (http://www.turbocity.com/product_info.php?cPath=64&products_id=588) I'm not sure what kind of luck you're going to have finding one at an auto parts store. I don't recall seeing anybody who found one to work in this application.

Good Luck!

[Raven]

When you find a replacement please share the part number and cost. I think you're right and see no reason why a car stat wouldn't work just fine so long as you can find one the right size and temp range.

[BigTom]

I really see no reason why a car stat wouldn't work, if the specs are correct.

ST1100 is stant 13868. 180 degree, works just fine:)

[Big Al]

I have an '05 with 21k that's been sitting for 6 months out in the garage with very cold temps, I noticed a small amount of coolant that leaked into the bottom of the lower cowlings and oil pan but, couldn't tell where it was coming from. After wiping it off, I took the bike out for a ride and didn't see any coolant leaking anywhere. - I did notice that the bike took a lot longer to warm up and hovered at about 2 bars. It was about 40-45 degrees outside at the time.

I suspect my thermostat is starting to go but, what might be causing the coolant leek? Could it be something more sinister?

Any comments would be much appreciated.

[georgeorge]

Al there are several hose clamp on and around the T-stat housing. give them all a little cranking down when your in there. That is prolly the cause of the leak.

[Blrfl]

Al there are several hose clamp on and around the T-stat housing. give them all a little cranking down when your in there. That is prolly the cause of the leak.

That post should be on the front page for the next three months. :D

--Mark

[STeve1300]

That post should be on the front page for the next three months. :D

--Mark
Yep, +1 on that. Last year that happened mto me. It stopped, but I just couldn't get myself to ignore it. When I pulled the radiator, I found more green on the housing. As long as I was that far into it, I went ahead & replaced my non-faulty tstat anyway. (I ordered one earlier as a precaution after reading these threads) I also siphoned all the remaining coolant out of the reservoir. It used to be assumed that small black radiator paint chips were the root cause of the failures. Tightened the clamps last year.... resisted the urge to sneak the bike out on nice days so far this winter.... and no problems!

[storm]

1996 to 1999 Jeep grand cherokee thermo will fit just fine. $3.55 plus tax.
I got the 180 but you can go 160 to 195.

[storm]

The bypass is a 1/8" in hole and the stat opens at 180 it's not that complex. I did have to drill the hole and reduce the diameter a few thousands so it would fit in the recess. It is running now and holding true at mid point.
Do what you will I am just sharing info on this. Saying the thermo will not work is like saying you have to use Honda oil which we all know is not made by or for Honda - it's Valvoline or Penns.
I have done this often over the years with no issue.

I only save $12.00 and a 30 mile trip to the dealer for a stat that is basic in operation. If this seem outragous than don't do it.

[UNTMatt]

Be sure to do a through flush of the radiator and take a good look at the fill, intake, and outlet pipes for loose paint or overspray.

Paul

+1

Plenty of overspray in the radiator inlets.

Also, the flush does not add all that much time to the operation. Using the crushed ice trick cleans out the reservoir quite easily and very well.

For the flush we used a 50/50 mix of distilled water and vinager. I plan on doing the flush at every coolant change since I'm alreay in that far and it's not much extra effort.

[storm]

That's fine - I forgot to mention it's an 1100 which has a bypass hole and a single plunger.

Other than that - never mind.:)

[Big Al]

Al there are several hose clamp on and around the T-stat housing. give them all a little cranking down when your in there. That is prolly the cause of the leak.Thank you Brian. - My bike is due for a service soon anyway. Maybe I'll have the dealership install Turbo Tom's stat while they look into it for me.

[storm]

I just got back after a 350 mile run with the new stat - works fine however the temps were in the high 40's so it never did get past the 1/4 mark. Much better than before however as now it actually warms to the point where it will idle at 1100 rpm. Sure wish I would have gotten some more of that engine heat as it was fairly cool out there. As soon a I pulled into the shop the temp went up to the half mark and pretty soon the fan kicked in - only for 20 seconds or so. So far it seem to be working well.

[rider13]

I have a 06 with 10K and I leave in CA.

How do I know if the thermostat is workin or not?

Since I got the bike I have always 3 bars on the temperature gauge.

[storm]

Mine was stuck wide open so the gage never moved - it just stayed pinned the end.
I guess the other way is worse - where it goes to the top and fire shoots out.

[dteel]

Ok, I am not addressing this to you, just everyone else. WFT does oil brand have to do with this?

The "bypass" I was referring to is not the tiny jiggle pin hole at the top of the thermostat to burp the air.

Both ends of the OEM thermostat have large diameter valves. That's why it's referred to as a compound thermostat. When the engine is cold, the bypass valve opens and lets coolant through the bypass circuit in the water pump. When the engine heats, that whole bypass circuit is shut off by the second (rear) valve on the thermostat. So the dimensional and force characteristics for that second valve must be consistent with Honda's system.

The pics here show the second valve at the rear of the tstat (the large disc) and the channels in the back of the thermostat housing for the bypass circuit.

http://www.**********.com/stf//showthread.php?t=11

I was unable to view the picture you were referring to. Is there another location you could site? (one that doesn't require me to register to another site)

[rider13]

Mine was stuck wide open so the gage never moved - it just stayed pinned the end.
I guess the other way is worse - where it goes to the top and fire shoots out.

I had in the summer (110) the gage going to 4 bars but no fire or coolant shooting out.

[bobsblu]

I got the turbotom thermostat and I swear it is a ford product

[bobsblu]

I was unable to view the picture you were referring to. Is there another location you could site? (one that doesn't require me to register to another site)


You really want to join this forum. It is run by the guy who put all the stuff on the service thread here. Leo7/24 and it's free and simple. Dedicated to only techincal issues.

[rider13]

Would be wise to add to this tread how a rider can know if the thermostat is working or not.

[UNTMatt]

If you are seeing less than 3 bars on the temp gauge and the bike would have been up to temp normally your thermostat has gone bad.
If your fuel mileage drops suddenly and you are seeing less than three bars your thermostat has gone bad.

Paul

If the temps he's been riding in are not getting cool enough, then he might not see less than three bars. I did not notice an issue until well into the cooler weather here.

I might get flamed for this but this seems to be a common enough issue to recommend that, even if you are getting three bars and at the 16k service, replace the t-stat. Flush the system and fill with fresh coolant.

[UNTMatt]

I think we need to make it VERY clear if we are talking about a 1100 or a 1300.
This Jeep thermostat is in what at 1100 or 1300. The gauge pegged. The 1300 has bars, how many bars are showing?

The 1300 owners tend to forget there are quite a few 1100 owners on this site.

Lets make it very clear what were talking about here.

Paul

+100

This is important.

[Blrfl]

I might get flamed for this but this seems to be a common enough issue to recommend that, even if you are getting three bars and at the 16k service, replace the t-stat. Flush the system and fill with fresh coolant.

That's not a bad idea at all. If you're already disassembling the rest of the cooling system to clean it out, 10 extra minutes to pull and inspect the thermostat can't hurt.

--Mark