Ford Focus ST Forum banner
1 - 12 of 12 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 ·
Car recently turned check engine light on while driving to work one morning. Normally route, freeway driving. Exhibited no other issues. Driving home, code still on and Engine Fault warning comes on. Oil temperature light not climbing past 1/4 when it used to get halfway by end of my trip.

Pull code and it's showing P0128 or engine not reaching proper temperature. Figured, no problem, I'll just change out thermostat on the weekend. Coolant level all good.

Two days later driving around and steam comes from the right side of hood. Pull over and coolant reservoir almost empty and whistling with steam coming out underneath. Figure, OK tank is cracked.

Tonight change out thermostat and coolant tank. Put all new coolant. Test drive and oil temperature still not climbing much. Used to get to halfway and now I can't get it to quarter. Engine light still on and Engine Fault came back. Likely have to take to dealer but was trying to avoid as I'm out of my primary warranty and most cooling parts not covered under warranty.

Help.
 

·
Registered
Joined
·
532 Posts
How did you replace coolant? It's very important to get air pocket evacuation. I know it's a little warm out, but does your heat work?

The overpressure degas port is on the underside of the tank.
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #3 ·
Okay, update time.

Coolant was properly bled as per standard methods. Heat can get very hot if I switch it on. Boiling issues persists. Engine temperature now seems to reach proper temperature so old thermostat may have gone bad but seems to only have solved half my issue.

Took into Ford dealer on Tuesday, they pulled a different code (P26DE - Sound Symposer issue) - another engine fault came on this weekend. They tested everything related to that and nothing was wrong. I think they misunderstood my issue because when I spoke with my service agent she said that he had pressure tested the cooling system and cap but I think he only focused on the sound symposer. Drove for a relatively short while today in 15 degree Celsius (59 F) temperature. Got back to my garage and noticed coolant smell again. Left car on and opened hood. This is what I saw (this was actually it happening again after shutting car off for five minutes but it seemed to build up again):


This is the exact issue I had before changing the thermostat and coolant tank. Perhaps cap is bad? Blocked radiator? Or something else causing excess pressure in the system? At no times does the engine heat or coolant heat go above "normal" or center position while this is happening.

Have emailed the dealership asking for further assistance. Car only has 62,400 kms/38,773 miles. No tunes. No mods. Very well maintained by previous owner and myself.
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #4 ·
Just adding a quick note to the end of this so that everyone knows what my specific problem ended up being. After being in the Ford shop for too long, they finally discovered that the wiring harness recall was never done, despite it being listed as being done at a previous dealership. At first the new dealership wanted to charge me since they couldn't claim the repair on something that was supposed to be done. The service manager took photos and was going to contact the previous dealership and have them pay for it. They never did get back to me so no clue.

What it amounted to was that the fan was not coming in soon enough and the coolant was actually boiling over. The back crimps must not have been allowing the proper electrical signal to hit the fans. I've been many weeks since the repair was done any everything is rock solid now. The coolant level has not moved a mm since being repaired and filled.
 

·
Registered
Joined
·
768 Posts
What's interesting is you really did have an overheating problem, but the oil temp was indicating much cooler than normal. I know it's not a "real" oil temp gauge, but still interesting. What the hell does it actually indicate then??
 

·
Registered
Joined
·
3,629 Posts
What's interesting is you really did have an overheating problem, but the oil temp was indicating much cooler than normal. I know it's not a "real" oil temp gauge, but still interesting. What the hell does it actually indicate then??
The oil temperature is modeled from the engine coolant temperature.

 

·
Registered
Joined
·
768 Posts
So again...what the heck is it actually indicating? Seems like just some made up number. I'd be more concerned about that and what that information is providing to the driver. Oil temp can be a very useful tool if it's a real indication. As an example, I have a real oil temp gauge in my truck (I know cause I installed it). My water temp never ever changes, but oil temps will be all over the place depending on outside air temp and what I'm doing with the truck; towing, cruising, etc. Very useful and informative. Seems like we don't have that here.
 

·
Registered
Joined
·
532 Posts
So again...what the heck is it actually indicating? Seems like just some made up number. I'd be more concerned about that and what that information is providing to the driver. Oil temp can be a very useful tool if it's a real indication. As an example, I have a real oil temp gauge in my truck (I know cause I installed it). My water temp never ever changes, but oil temps will be all over the place depending on outside air temp and what I'm doing with the truck; towing, cruising, etc. Very useful and informative. Seems like we don't have that here.
Not really a made up number. It's a model. And also fairly accurate as long as the system parameters remain in bounds. The oil pressure gauge is the same deal. It's also based on a model.

What if I told you that your coolant temp gauge was useless too? (Outside of shooting to the red when you're overheating, might as well be an idiot light)

Pretty much anything built since the 80s will show middle-range on the gauge all the time. I think the coolant gauge on these cars shows middle-range from something stupid like 100-220*



Manufacturers do this because people freak out when the little needle isn't in the "normal zone" as evidenced by all the threads started on this forum asking if it's normal for the oil pressure to be pegged when you first start your car in the morning. :saint: It saves the dealers from having to constantly deal with stupid questions.

Another reason is cost. They can appease the enthusiasts without having to add extra wiring and sensors.
 

·
Registered
Joined
·
768 Posts
Not really a made up number. It's a model. And also fairly accurate as long as the system parameters remain in bounds. The oil pressure gauge is the same deal. It's also based on a model.

What if I told you that your coolant temp gauge was useless too? (Outside of shooting to the red when you're overheating, might as well be an idiot light)
Oh, I already know that one. On my F150, I think the water temp gauge is in the "normal" position from about 140 to something above 230 (cause I've seen 230 on my real gauge and the dash gauge never moved).
 

·
Registered
Joined
·
625 Posts
What the gauge shows and what can be read directly from the ECU are not remotely the same. Grab an ob2 scanner or ap3/SCT/whatever and look for yourself.

The ecu know exactly what the coolant temp is, it just chooses not to tell you via the gauge.
 

·
Registered
Joined
·
768 Posts
Agreed. And I get the "why". I'd think a potential ST customer would be a bit more of a gearhead than the average customer and they'd give us the real deal; or such would be on my wishlist.
 
1 - 12 of 12 Posts
Top