Coolant smell and loss of coolant; engine running too warm?

[Primalzer]

So I had the car in for some brake system work at the dealer a week or so back. I had them take a look at the cooling system as after a longer drive, I get the distinct smell of coolant. Now the fluid level, when taken to the dealer was on the low side; at the bottom-most acceptable cold level, when warm. They topped it off, but I'm still getting the smell. I've also noticed that the car runs pretty warm, especially in traffic. I have an Ultragauge, and consistently see 220* in traffic, which seems high to me (even though it doesn't register on the dash's idiot gauge.) And it's not like I'm in warm/hot climate, it still Chicago spring, and we're still in the 40's, 50's and 60's.

Dealer did a pressure test, and the system holds pressure. Worthwhile to replace the reservoir cap?

 

[StealBlueSHO]

So I had the car in for some brake system work at the dealer a week or so back. I had them take a look at the cooling system as after a longer drive, I get the distinct smell of coolant. Now the fluid level, when taken to the dealer was on the low side; at the bottom-most acceptable cold level, when warm. They topped it off, but I'm still getting the smell. I've also noticed that the car runs pretty warm, especially in traffic. I have an Ultragauge, and consistently see 220* in traffic, which seems high to me (even though it doesn't register on the dash's idiot gauge.) And it's not like I'm in warm/hot climate, it still Chicago spring, and we're still in the 40's, 50's and 60's.

Dealer did a pressure test, and the system holds pressure. Worthwhile to replace the reservoir cap?

Monitor the fluid level... the smell could be from one of the techs spilling it everywhere... it takes a long time for that smell to go away...

As the motor warms up so does the smell...

Where is the needle on the temp gauge?

 

[ncole]

I will agree with it taking a long time for the smell to go away.  If you are running 220, that is not normal.  Not anything to be overly worried about, but higher than a properly filled and operating system should be from the numbers I see.  Does it ever cool back down all of the sudden and then go back up?  I am wondering about an air pocket in the system.  I had one I believe, but it worked itself out after I replaced the thermostat.

 

[lamrith]

220* is that Cyl head temp or coolant temp?

 

[SHOdded]

I would make sure that coolant looks absolutely clean, because the water pump does tend to let go on these Duratec engines.  Then it is a $2K+ repair bill to fix it, assuming you don't drive it after the engine overheats.

Is there even a separate coolant sensor on these engines?  There isn't on the NA 3.5.  There IS a cylinder head temperature sensor, and the coolant temperature is a derived value, I think.

 

[pmezo33]

If the techs did a pressure test and it's holding, there shouldn't be any leaks.  It's a closed system, so if it holds vacuum, the system is closed.

You said this happens in traffic, right?  Next time it's happening, pull over and check to make sure the fans are going.

This doesn't explain the smell of coolant, but are you 100% sure it's coolant that your smelling?

 

[Primalzer]

Yes, it's definitely a coolant smell, and the smell happened BEFORE it was at the dealer, so I can rule out coolant spill. I've had a few cars that have had various...coolant issues icard: so I'm fairly well versed in the smell of coolant related issues leaking/burning

I'm not sure where the temperature is derived from. All the gauge states that it's coolant temp. I'm not sure where or how it is getting that temp. The idiot gauge on the dash usually sits at about 1/3 to 2/5 the way up the gauge, but when the temp is high, it's at about 2/3. Still way in the normal range, but higher than normal. When the temp hits about 220, it seems like the fan finally will kick on, and the temp will drop to around 200, but then will rise again. Usually don't sit in traffic long enough for it to do that cycle more than once, maybe twice. Once I start moving, the temps generally start falling. Maybe the fans would be something to investigate

 

[SHOdded]

Definitely, confirm fan operation.  I know I have various PIDs available for monitoring on the Edge with Forscan Lite, one of them being fan duty cycle.  That's one easy way to tell.  190F thermostat and 210F fan activation on the Edge.  So it would seem fans should come on the EB at 200F, but I will have to dblcheck.

Thermostat Opening Temperatures 
Starts to open  82°C (180°F) 
Fully open  95°C (203°F)

 

[Primalzer]

Will do, and report back.

I will probably replace the reservoir cap, just for giggles, to rule that out.

 

[pmezo33]

Will do, and report back.

I will probably replace the reservoir cap, just for giggles, to rule that out.

2/3's up on the gauge is definitely overheating.  It should sit right around the middle, maybe slightly below middle.  Anything over that is overheating.

If this were my car, I'd rent a pressure test kit from the auto parts store and do the test myself.  This way I know for sure there's no leak.  You're usually able to test the reservoir cap with those kits as well, so that will save you from having to buy one of those if you don't need one.  That would be the first thing I do.

Once you're 100% sure your system is holding pressure and your cap is fine, I'd focus on that fan.  I've had cars where they're good and then they just intermittently stop working.  Some times it's working and other times it's not. 

Are you having to add coolant to the system at all?  At least anymore than you initially have?  Is it holding it's level? 

 

[Primalzer]

Will do, and report back.

I will probably replace the reservoir cap, just for giggles, to rule that out.

2/3's up on the gauge is definitely overheating.  It should sit right around the middle, maybe slightly below middle.  Anything over that is overheating.

If this were my car, I'd rent a pressure test kit from the auto parts store and do the test myself.  This way I know for sure there's no leak.  You're usually able to test the reservoir cap with those kits as well, so that will save you from having to buy one of those if you don't need one.  That would be the first thing I do.

Once you're 100% sure your system is holding pressure and your cap is fine, I'd focus on that fan.  I've had cars where they're good and then they just intermittently stop working.  Some times it's working and other times it's not. 

Are you having to add coolant to the system at all?  At least anymore than you initially have?  Is it holding it's level?

No, I haven't added any. It was low when I brought it to the dealer, and they topped it off. It's only been a couple weeks, so I'll keep checking cold levels and see where it goes from there.

If I get some time this weekend, I'll throw on a pressure gauge. I bought a new cap already (hey it was $8, not the end of the world, and some nice peace of mind).

I have to start figuring out how to test fan functionality. Any of you guys have ideas, aside from stopping when the car is getting too warm to see if it's running?

 

[Primalzer]

Just incase the fans do end up being the issue, it looks like the fan type/style changed from pre-2012 to 2012-now. The pre-2012 fans are dual's...as pictured, and the 2013+ are also dual's, but are they any better? I know, like the front brakes, there is some cross compatibility.

 

[pmezo33]

I've always just looked at the fans. They're either working or they're not.  One will always turn on when the ac is on, but the other one may not turn on, so make sure they're both going with the ac on. Just something to keep in mind when looking.

And just as a comparison, I just got off the highway and my car has been idling for about 10 minutes. Torque pro is telling me my coolant temp is a steady 192 degrees.

 

[Primalzer]

I've always just looked at the fans. They're either working or they're not.  One will always turn on when the ac is on, but the other one may not turn on, so make sure they're both going with the ac on. Just something to keep in mind when looking.

And just as a comparison, I just got off the highway and my car has been idling for about 10 minutes. Torque pro is telling me my coolant temp is a steady 192 degrees.

I'm sure the Torque app is getting the temp reading the same place as the Ultragauge is.

I'll try to get stuck in traffic and see what I can see/find.

 

[SHOdded]

No way to get stuck in traffic in the Windy City.  LOL.  Looking forward to discoveries ...

 

[Primalzer]

LOL oh I definitely can find a place to get stuck...my route home just doesn't always have tons of traffic, I may have to go out of my way to get stuck

 

[Primalzer]

Ok got myself stuck in some traffic, didn't even need to go out of my way!

For the first half, temps stayed strong, sub-185*. Then about halfway through (15 minutes) temps started to rise. Turned off the AC, and temps continued to climb, topping out at about 210. Parked the car and let it idle and got it up to 215. Jumped out of the car, and neither fan was running at all. Huh, turned on the AC, and both fans came on...

Thoughts?

 

[pmezo33]

Get a new radiator fan. 

 

[SHOdded]

Odd.  Check the fan module connectors and the connectors at the PCM.  Might be a clue there.

 

[pmezo33]

Odd.  Check the fan module connectors and the connectors at the PCM.  Might be a clue there.

I've had the same exact thing happen with my last MKZ before this MKS.  Fans work sometimes and they don't others.  They work with the a/c, but the temps would sometimes go up in traffic.  I eventually just replaced the fan and it solved the problem.