Coolant overflows at reservoir

[b&t88accordlx]

This is what's happening.....

I filled the coolant reservoir up when it's cold to the"max" line just before my 200m trip home. The temp guage read it's normal position all the way to a rest area (an hour or so later) where I got out and it was fine, no spillage. When I came back 5 min. later, the reservoir was leaking at the top. I got underway again without adding any coolant. The temp guage read the same. I stopped to eat (an hour and a half later) and it was no longer overflowing.

I had to replace the tstat 2 weeks ago with one from the parts store. I let it run 45min to make sure the fans came on with no leaks. I noticed the the opening on it is smaller than o.e.m.

Would the opening make any difference? It's a 195d tstat. Should I go back to an o.e.m. tstat?

[OldSchoolSwap]

Keep a very close eye on your temp gauge and make sure the fans are turning on.
The water reservoir cannot be filled to the top, it has a limit mark for filling up. If your limit is passed, over spillage may happen.

How ever, your case is a bit diffrent. Boiling of your reservoir can indicate multiple things such as over heating due to locked or in your case a smaller thermostate than stock specs (id get OEM, its about $12 anyway).
It could be multiple issues like i said, bad fans, water pump not ciculating the water properly, blown head gasket and leaking. But i don't want to alarm you with all these negative "vibes"

i'd say, change the stat for a stock one and see what happens.

[dj99]

You should also get a new radiator cap when you change your t-stat. They are designed to release the radiator's coolant at a certain pressure point into the reservoir, and can wear out over time.

BTW, when I changed my t-stat, I used an aftermarket one rated for 180 degrees. Maybe the 195 one lets your coolant get too hot and create more pressure?

[POS carb]

I second those opinions.
1st change the cap that should solve the overflow prob.
I have a lower temp t-stat in the housing, that's hot enough in my opininon. Oh and lower temp = more HP so technically it's a hp mod (like .2hp lol )

[OldSchoolSwap]

PFFFTTTT at POS "HP" hehe...
but yeah, the radiator cap is a good point. flew right by me.

[b&t88accordlx]

Thanks all....I'll switch out the stat and cap sometime this week and be back w/ info!

[b&t88accordlx]

Well, I changed the stat out to oem and it's back to it's normal self. I haven't changed out the cap, either.

Thanks for all the help!
:super: