Engine light came on and the code reader (I forget the number) said it wasn't warming up fast enough. Now it's needing antifreeze every few days. Just looking at other threads here I see pressure leaks are somewhat common, my car does not leave any antifreeze on the ground so I was thinking head gasket, but my exhaust pipe looks exactly like it always did. So where do we start the investigation?

 

The gaskets on the thermostat can start to leak as they age... If you are getting a code for the thermostat, might want to look into changing it out anyway.

 

Where is the leak coming from? If you don’t know, you can pressurize the system, from the coolant tank, to 15 psi and start looking for the leaks. My first coolant leak was the coolant tank itself, second one was the water pipe on the back side of the engine.

 

When I saw the code I got out my book (service manual) and read something about the thermostat being heated by electric. Reading that made me think I should sell the car, sounded crazy & I decided to forget about it - until this came up. Guess I'll do a pressure test, but what's the deal with an electric thermostat??

 

just wait till you look up what the thermostat looks like. It’s one big piece of plastic.

 

Looks like the t-stat housing itself is the leak, NAPA says they have one so this afternoon I'll find out forsure if it's the leak, after I have the right new part in my hands~

 

Do replace the water pipe to the pump

 

I already got back from NAPA before I saw this! The t-stat housing is now in (twice) had trouble with the so called water pipe not going all the way together. It's so hard to see and work with I thought I had it right only to have a bad leak. Second time, after complete removal to check for damage, I got it right. I now have a short test ride done and it seems ok, will know better after some longer rides~ Thanks for the help, that's a nasty job!!!

 

For future reference, always lube o-rings. You only need a greasy film, no goobers! That might have made it a bit easier.

In a cooling system either o-ring grease or silicone grease will do. I guess you could use Syl-Glide in a pinch and it should be compatible with coolant and the o-ring material.

I'm grateful your tstat failed as it made me realize that my 2013 is far past due for water pipe / tstat preventative replacement after 8 years of service!

Likely totally unnecessary, but it won't hurt to double check that all the air is out of the system.

 

Second test ride made the water in the canister disappear, when I started to remove the cap, it all came back, so I'm thinking I have trapped air. Just glad the old 3.0CS is running good, but I better renew the reg. The Mini book doesn't have much on purging the system. They say to turn on the heat, strangely also the seat heater which I thought was electric, and to remove the cap and run it. Then if that doesn't work to use some kind of vacuum tool (not their wording). So, the basic question, is there some trick to get the air out?

 

I had my bleeder open till I saw water then let the temp get up to 220 keeping the reservoir at the full level. My heater was on but wasn’t hot enough, so I kept the bleeder open till it got got and topped off reservoir. Project mini has a good one for bleeding coolant on you tube. I think it’s in the how to section as well.

 

Checked out that video just now, but I see no "bleeder screw" on my engine which looks different than his~

 

The vacuum tool is awesome for filling the coolant. A little expensive, but totally worth it.
https://www.ecstuning.com/b-schwaben...l/003466sch01/

 

This tstat housing might be a bit different than yours, however the bleed screw is the same. Which is the big Philips screw on top. It can be a bit hard to locate as it is down a crevice in between the vac pump and HPFP.

 

OK, I see it this morning - One more cup of coffee & I'll try it~

 

I've had a coolant leak going on for a while now. I've been monitoring it until I got up the courage to change out the thermostat housing. Today's the day. Not as awful a job
as I thought it would be. I'm hoping for no more leaks. Time will tell.

 

Don't put a lot of torque on the bleed screw. It has an o-ring and that is what makes the seal.

 

I want to thank everyone here for the input, water level is staying put & I see no sign of leaks & no new engine lights on the dash so I believe it's fixed~