[RickKlem]

Looking at buying a 2017 XT5, luxury. The check engine light is on with a temp sensor out of range code. The needle on the temp gauge doesn't move off of cold. The warning that the assisted steering is reduced. And the auto off shows off all the time.

It does come with a third party warranty and they are going to tell me tomorrow if this is covered.
The weird thing is on the way home today. The air started blowing ice cold, then I looked down and the temp gauge is reading just below middle and the steering warning is gone. I didn't think to check the auto off but I will tommorow.

So is this the thermostat or sensor?

Is this a huge deal, because I have until Monday night to return the car , because I got it from. Carvana and they give you 7 days to cancel the deal.

Question: When I start it up there is 6 bright red LED's on the dash that's shines up on the front windshield then it goes out after the engine starts. Is this HUD, and if so how do I get it to display speed.

Thanks for any input.
Rick

Another question, on some of the displays on the dash it will have a V6 in a green box. Does this mean that this engine reduces to 4 cylinder when conditions are correct

 

[mzbk2l]

Hi Rick. The red lights are the collision warning, you are correct about V6 and 4 cylinder (although I don't know if I've ever noticed our 2019 XT5 doing that), and yes, the other symptoms indicate the failed thermostat. Any chance you're still under the powertrain warranty, which is longer than the bumper-to-bumper?

 

[njacobsen]

It does come with a third party warranty and they are going to tell me tomorrow if this is covered.
The weird thing is on the way home today. The air started blowing ice cold, then I looked down and the temp gauge is reading just below middle and the steering warning is gone. I didn't think to check the auto off but I will tommorow.

If the third party warranty does not cover thermostat replacement, it will cost you $1000-$1500 at a dealer. There may be a backorder situation for that thermostat. The thermostat would have been covered under the Powertrain Warranty which was 6 years or 60,000 miles from the date the car was first titled. If you can squeak in under that warranty which is transferrable, Cadillac will pay for the repair.

As @mzbk2l said, the red lights are the collision warning which means you do not have HUD.

Another question, on some of the displays on the dash it will have a V6 in a green box. Does this mean that this engine reduces to 4 cylinder when conditions are correct

Yes, that is AFM which was implemented on the 2017 XT5s and continues on current models. You can find many opinions about AFM on this Forum which comes down to personal preference. Personally, it does not bother me and the engagement was completely silent and went unnoticed on my 2017. I did not realize how often it switched to V4 until I drove with that V6 symbol visible and could see when the switches took place.

i want get lemon for my car - 18 days under repair and continue

i want get lemon for my car - 18 days under repair and continue

Last summer my dealer had to order front and rear driver side lower control arms for my 19 CT6-V . The bushings were defective on the control arms and are non replaceable so both control arms had to be replaced . They were on national back order and coming from China. It took 90 days for the parts to arrive !

 

[UberCaddy]

If I'm looking at a car with those problems, I'd walk away, as fast as possible.

 

[ALPAN]

yes, it's bad idea buy Cadillac

 

[golfermack]

If I'm looking at a car with those problems, I'd walk away, as fast as possible.

yes, it's bad idea buy Cadillac

I believe there’s only one problem, the thermostat/sensor issue which might still be covered under the power train warranty. If not, I’d require Carvana to cover the cost of repair, or return the car.

IMO, one issue is not unusual when buying a 6 year old car. Get it fixed at no cost to you and keep the car.

FWIW, I love my 2017 XT5.

 

[RickKlem]

It concerns me that it started working. If a T-Stat fails it normally stays broken and same for a faulty sensor. Am I correct?

 

[mzbk2l]

If I'm looking at a car with those problems, I'd walk away, as fast as possible.

One problem - the thermostat? Doesn't seem to be an uncommon issue, and if you can get it fixed in the first week of ownership at no cost, you can probably expect a reasonable amount of trouble-free drive time after that. I'd say it's a pretty safe bet to pick that one up, especially if the price was decent.

 

[njacobsen]

It concerns me that it started working. If a T-Stat fails it normally stays broken and same for a faulty sensor. Am I correct?

It has not been uncommon for the temperature to rise for a short period of time. You have reported the issue to the seller and now is the time to fix it before it recurs and it will.

 

[EJCarter]

It concerns me that it started working. If a T-Stat fails it normally stays broken and same for a faulty sensor. Am I correct?

We had a similar issue last week on our CT6. The wife pulled in the garage after a long trip and the fan was running. I wondered why? Outside temp in the 50's. She turned the vehicle off and fan stayed on for about 5 minutes. No CEL on dash. Coolant was full (midline in overflow tank). I started the car and temp gauge was cold. Figured thermostat failed open, but wondered why the fans were running. Did some research that night. The next morning, I started it. The fans immediately came on. Drove it for a few miles and the temp gauge did go back to normal - and fans shutoff. Figured it could be a fan relay. Or, maybe it's an intermittent thermostat failure or its starting to fail. I stopped by the dealer to see if they had an fan relays in stock. Figured I'd replace the low cost part first as normally it takes a week to get an appt. Luckily, they were able to squeeze me in if I could leave it. It's still under warranty...
It ended up being the thermostat. A soft code was pulled...
P0128 - Engine Coolant Below Threshold
*Engine coolant temp gauge defaults to cold
*The A/C is commanded to off and inoperative
*The cooling fans are commanded to ON
Replacing the thermostat also required pulling the intake, thus replacing numerous gaskets and O-Rings. They had everything in stock. Had the vehicle back by 4:00 that afternoon.

 

[RickKlem]

So this issue isn't limited to the XT5 but to any Cad that uses that engine. Was there a certain year range that this was a problem? I'm still interested in the XT5. Other than any dealer or owner records of this being replaced, is there a way to tell if it has been replaced by looking at it? I'm assuming they ( dealer) replaced with an identical tube.

Rick

 

[EJCarter]

Our dealer stated it's not a super common issue with the 3.6 Liter motors, but they have replaced quite a few over the years. I'm not sure you can tell by looking if the thermostat assembly has been replaced. If it has been, and it was done at a dealer, it would be with OEM parts. It's a small cast aluminum housing with the thermostat...that just so happens to reside partially under the intake plenum. From the front of the engine, look towards the left - mid side where the upper radiator connects and you should see it...
Definately not our old 5.7 liter 350's where it sat right on top and took about 5 minutes to replace...

 

[ALPAN]

..that just so happens to reside partially under the intake plenum.

so replacement requires many hours of labor and is expensive and dealers refuse to change

 

[njacobsen]

so replacement requires many hours of labor and is expensive and dealers refuse to change

Statement taken out of context...entirely false...

 

[ALPAN]

Statement taken out of context...entirely false...

my car with thermostat problem under repair from 04 Jan.

 

[njacobsen]

my car with thermostat problem under repair from 04 Jan.

Sorry to hear your car is not repaired yet. Is it you who left the car at the dealer and refused to drive until repaired while waiting for a Thermostat? Have you insisted upon courtesy transportation while your car is in the shop? Going on 3 weeks without a vehicle, perhaps you need to look into the Lemon Law in your state.

 

[Grady_In_Texas]

In our case, the replacement took about 2.5-3 hours (9;30 to a little after noon) at our dealer including describing the problem (again), 50 questions, 100 point inspection (with no sales pitch!), a post-work test drive, exterior wash and interior vacuum and wipe down (mini-detail). It doesn't look very complicated but there are a lot of o-rings (with different part numbers) to replace. Our dealer had the new kit in stock and said it was a reasonably common problem. No pushback b/c we are still under warrant. (2019 with 35K miles) Grady