Engine Coolant Trouble Light

[Chuck W]

The connectors are VERY prone to corrosion, even if the sensor itself is good.

It also sounds like there is a leak somewhere, if it's regularly low on coolant. I could also see that if it was low enough on coolant, it may be possible that you had an air pocket in the cooling system and the sensors don't work well when "dry". Adding the coolant and letting the system circulate and "burp" any air pockets may explain the better running after adding coolant and letting it run for a bit.

[MrAl]

Thanks for the comments.

Well yesterday i had trouble starting it again. I finally got it started, and decided to try resetting the OBDII error codes.
I reset them all which really was mainly for resetting the 116 code, and the car ran very good.
So i drove off to ShopRite to get some food before the storm hits again. IT went very well all the way there, and then when i pulled into the parking space the Check Engine light came back on again and the car started to idle really rought for a few seconds i thought it was going to stall. It recovered though and kept running which sounded ok.
When i shut the engine off, the fan kept running again too. I could hear it was not running full speed but somewhat slower.
So i went in and quickly grabbed a few things then went back out to the car, it started right up no problem.
I drove home no problem. I parked in the driverway as usual, turned off the engine, and the fan did NOT run this time.
Doesnt make any sense, unless as you guys are saying a bad connection making an intermittent contact or else an air pocket in the cooling line somewhere. IT would have to be a big air pocket though i think to have it act up like that i would think it would get pushed right past the sensor pretty quick but of course it is too hard to tell for sure.

So i guess i have to check the connections next. Maybe tomorrow or the next day. I hope it is that only i kind of fear buying the wrong sensor (one that doesnt work well that is).

Thanks much.

[Chuck W]

The fan continuing to run is a sign of a bad ECT sensor signal, either due to a bad sensor or a bad connection.

Be gentile with the connector, because it could just come apart in your hands, if there is excessive corrosion or it hasn't been serviced in a while.

[MrAl]

The fan continuing to run is a sign of a bad ECT sensor signal, either due to a bad sensor or a bad connection.

Be gentile with the connector, because it could just come apart in your hands, if there is excessive corrosion or it hasn't been serviced in a while.

Hi,

Thanks for the reply.

This car is more modern than any of hte cars i had owned in the past and thus i am still learning to deal with the OBDII and effects the errors have on the car.

This problem really does puzzle me. Why would the car suddently idle bad once it detects a bad ECT sensor. That doesnt make sense at all. I could just imagine the little guy inside the computer module exclaiming one day, "Oh wow he's got a bad ECT sensor, we better make the car run bad now!". (ha ha).


But really this is so intermittent that maybe it really is the connector. It only does it sometimes but of course the error code does not reset itself when it goes away.

I had a similar problem a long while back but never figured out what it was. It stalled one day at a traffic light during a rain and ran really really rough once i restarted it. I had to pull over, turn the headlights off, and wait for it to smooth out. That was strange and it happened again several months ago also during a slight rain coming back from a dollar store not to ofar away.
I am thinking that this is one car that really needs to be warmed up good before driving. I think that may have had something to do with it because both times i did not let it warm up before going on the short trip. By the time i got there, it was probably still not too warmmed up, so when i left, that's when it happened both times about 60 seconds after leaving the parking lot when leaving to head home.

I didnt get to check the connector yet we had some more snow. I meant to get out there but wanted to wait till the snow cleared up a bit more.

Any ideas no matter how far fetched would be great to hear except for ancient aliens caused this problem
"Ancient Alien Theorists say YES!"

Someone suggested making a Tee shirt that says this.

[abscate]

Ultimately the ECU tells the injectors how long to fire, something like 100 times a second, and calculates that each time based on throttle position, air flow , air temperature, engine temperature, timing, etc. If the sensors that input fall outside the correct ranges the injected fuel won’t be right. Under load you might just notice some smoke or reduced power but at idle it will be rough.

Cars got a bit smarter in the early 2000s; I have a VW T4 with a bad sensor that the ECU is cold starting by guessing the engine temperature from startup time. It works quite well, even at 10 F

In 1999, we got a much better ECT connector with a high end Volvo sealed snap, and all those connector troubles go away. Still on my original from 10/1998

[MrAl]

Ultimately the ECU tells the injectors how long to fire, something like 100 times a second, and calculates that each time based on throttle position, air flow , air temperature, engine temperature, timing, etc. If the sensors that input fall outside the correct ranges the injected fuel won’t be right. Under load you might just notice some smoke or reduced power but at idle it will be rough.

Cars got a bit smarter in the early 2000s; I have a VW T4 with a bad sensor that the ECU is cold starting by guessing the engine temperature from startup time. It works quite well, even at 10 F

In 1999, we got a much better ECT connector with a high end Volvo sealed snap, and all those connector troubles go away. Still on my original from 10/1998

Well that explains a lot thanks.

I went out to check that conenctor yesterday but th sun was too bright so i could not see into the engine compartment well enough to examine the connector. The car started up ok though no problsm and seemed to run smooth.
I'll have to go out there at night with a good flashlight in order ot see it properly.

[abscate]

So i drove off to ShopRite to get some food before the storm hits again.

There’s your problem. You should be shopping at Uncle Giuseppe’s

Caitlin chooses some Olives......

[MrAl]

So i drove off to ShopRite to get some food before the storm hits again.

There’s your problem. You should be shopping at Uncle Giuseppe’s

Caitlin chooses some Olives......

Hi,

Just curious, is that a real place? The photo looks like they have a lot of stuff there.
Shop Rite is one of the better stores around here but their prices have gone up quite a bit in recent years and their stock variety went down quite a bit. Plastic bags for food went up from 1.79 per 75 to 2.79 for 75 over about 1 or so years and they got rid of the 150 count box because that was cheaper overall if you really needed two boxes of 75.

We also had a 'new' mexican store about a mile from here that opened with a great grand opening. They had good food including meats and you name it. A few months later a union came in. The meats turned ransid, icould not buy meats there anymore they were disgusting, worst i have ever seen. They closed up a couple months later. In total, a full sized supermarket opened and closed 6 months later in total. I've never seen anything like that before. There was such clamor around the opening and it lasted all of 6 months.

There is another mexican store in the area but they have been open for years. The difference could be location.

[abscate]

Its on NJ Route 17, East side about 5-10 miles from Ramapo/NY border. Caitlin and I got to a Volvo pickup point early so made a $150 diversion for Italian eats. Great food and decent pricing, fantastic service.

You can pickup your Volvo parts from Ramsay Volvo your food from the Uncle G.

Its right at Lake Street Jughandle so you can get there travelling either N/S on NJ 17

[MrAl]

Its on NJ Route 17, East side about 5-10 miles from Ramapo/NY border. Caitlin and I got to a Volvo pickup point early so made a $150 diversion for Italian eats. Great food and decent pricing, fantastic service.

You can pickup your Volvo parts from Ramsay Volvo your food from the Uncle G.

Its right at Lake Street Jughandle so you can get there travelling either N/S on NJ 17

Hey thanks for the info. Dont know if i want to go that far but that's still good to know.

I've also used Uber Eats a bunch of times
Not too bad i guess.

Now what we really need is a Uber Volvo Parts
Any startup company takers out there?