Happened to check last week and found coolant on top of my transmission, have ordered parts to redo most of the cooling system. Today the thermostat housing arrived and when I was looking at it I noticed that the thermostat is not quite 100 percent centered. Wanted to confirm my suspicion I grabbed a flashlight and was able to see a sliver of light. Is this okay or is the housing design made to have a perfect seal?

 

Just guessing what you mean by a "sliver of light".

In order for the cooling system to function correctly, T-stats never seal 100%, some coolant always needs to bypass the radiator and return. Otherwise no heat reaches the T-stat, T-stat never opens, engine burns up.

 

While I appreciate that you have taken the time to reply, that is not an accurate statement. The purpose of a t-stat is to block off the coolant from the radiator until the engine is warming up. This is why for some vehicles and t-stat models you will find a recommendation to drill a tiny hole to allow for air bubbles to pass through and escape.

 

Did you purchase you TS housing from Amazon? I replaced one with their part and it was one week before I was replacing the coolant temp sensor (not a big deal). However a month later I was replacing the housing because the sensor that is part of the housing went out. What a pain in the butt. I went back with OEM because I had heard others say g the same thing about some of the Chinese knock offs. You should consider changing the water bypass tube while you're there.

 

Suggest you buy from known vendors such as Pelican, ECS, FCP and others known to offer parts from established makers. While that approach is not a guarantee you won't ever get a bum part, it will increase the odds in your favor.

 

Looking at yesterdays post, I can see why you would say that. I was unclear.

What I was trying to convey to the OP is that T-stats are not simple on-off valves, instead, they modulate the flow between the radiator and the bypass path to maintain the design temperature. Thus, a T-stat never seals flow completely as the OP seemed to believe.

 

Yeah, do NOT buy thermostat housing off Amazon. You'll have no clue what you're actually receiving. Same with HPFP and any other major component... I have a strong personal policy against buying essential components for my vehicles from places like Amazon. Buy from a reputable shop, whether on-line or in person.

If you purchased the thermostat housing from a reputable shop, and are not satisfied with the quality, return it. Sometimes the cheapest isn't always the best option...

 

Amazon can be the wild west of car parts. They don't have the fitment down nor the knowledge of MINIs like people here on the forums and us.

 

thanks, I went with the motorad brand off rockauto. I did end up doing the water pump, water tube and the reservoir as well.

 

and as the OP I replied. You are still putting out a half truth. A t-stat will completely cut off flow, to the radiator. It shuts off the path to the radiator and only allows coolant circulation within the engine block while everything warms up.

 

thank you, I agree whole heartedly. In the end I was just wondering as to what exactly one should expect out of these parts, and really just wanting to avoid more time without a car if possible. I can only get by on my motorcycle or borrowing the wife’s Subaru for so long.

 

I second this and what njaremka said.