Probably diving into the engine coolant thermos soon

About a month ago, my wife's '07 threw a P1116 code. No other codes came up on Techstream. Radiator is topped off and the overflow tank is at the cold line with a cold engine. I reset it and it's been gone since then. Until yesterday. She got a check engine again. After she got home, the light was gone, but the code was in history. AFAIK, it's the original coolant and it has about 127k miles, so it's overdue for a coolant change. Coolant still looks clean and pink, but I'm guessing it's either an intermittent clog at the coolant tank valve or the valve itself is sticking. Does that sound reasonable to those of you who've delved into it more?

 

Thanks for the tips, @JC91006 and @Patrick Wong. I also talked to Todd over at Tampa Hybrids. He agrees, based on my description, that the valve is a likely candidate. I'll know more Friday when I can dive in. It'll be the first time I've explored that part of the car.

When this issue first occurred, there was no place to put more coolant. Everything was full. I check it every couple months and there was one time I added about a half cup. That was the only time. I think it was almost a year ago.

I'll have to double-check. Last I looked there was no sign of leakage at the water pump. I just rotated the tires the other day and checked the boots and looked for anything loose while the wheels were off. Saw no pink stuff when the right front wheel was off. We bought it with 98k miles. There is no record of it having been changed.

I'll know more Friday when I can be at home in the daytime.

Yup. That's what I told my wife when it happened the first time and I read the code. I need to fix it because I'm anal about that stuff, but I don't need to miss work for it when I have 3-day weekends.

 

I do want to change the engine coolant while I'm at it. I did the inverter coolant in Sept. 2017 at about 119k miles. I've been looking for a good video on it, but haven't found the one I remember seeing months ago and liked.

 

Sweet! Thanks my friend. I'll probably just let her drive my car for a few days when i do this and I can use hers and check it at work and at home till it's clear full. It's about 10 miles each way.

 

The engine wouldn't have cooled after 10 hours at work? I was planning to check it right before starting, not right after parking.

 

The deed is basically done. Got it mostly refilled. Drove it a while. No codes yet. Will top it off again in the morning after it cools. I think I still need to add the better part of one quart based on what came out. I hope to do an autopsy on the old valve tomorrow.

 

All I could find was 3rd gen videos. Not much help on an '07. I took @JC91006's advice. It was pretty easy. The only hard part was getting the valve out of there. No place for big hands or for blood thinners. Even with lifting the inverter as far as I could and wearing mechanic's gloves, the back of my hand and my lower arm show lots of evidence of the latter. [Edit to add: glad my hands are fairly small.]

But well worth it to me compared to the prices I've heard about here from dealers. Remember, if you're not bleeding, you're not trying. JK - I'm actually a bit of an industrial safety nut after 23 years of making beverage cans.

 

OUCH!! I know what you mean. Another thing to watch for is when using a wrench or ratchet on a very tight fastener. If you're pushing, don't wrap your fingers around it unless you know they won't slam into something nasty when it breaks loose. I saw several guys go to the ER for stitches that way.