I am curious if this applies to all models with this powertrain.

 

It should be an issue for all Hyundai and Kia models that use the engine in Hybrid or Plug-in Hybrid mode. It is worst for the Plug-in Hybrids since in EV mode they run the engine at idle speeds in winter for cabin heat.

 

If the engine doesn't have a 5th injector for port injection, it will dilute the oil at each cold start (winter/summer)
Only solution is short oil change intervals 4000 miles / 6 months

 

"...and add oil heating function based on the driving pattern..."

What is this?

 

Congratulations! You're the first one to ask. You get the golden turd.

Here's what it meant when Jeep updated the firmware on their Wrangler 4xe plug-in hybrid.

The Wrangler 4Xe has a process called 'Fuel Oil Refresh Mode' aka FORM, that is supposed to prevent oil dilution. Jeep engineering put together a pretty good explanation as to how it works:​

​

Fuel and Oil Refresh Mode​

​

In short, the vehicle software monitors your driving and I'm assuming the frequency of cold starts and short run cycles to predict the amount of oil dilution. Based on the model, the Wrangler 4Xe will operate in one of 4 modes:​

​

· Step 0: Normal Operation: Below a bottom threshold, vehicle operation is normal.​

· Step 1: Moderate fuel dilution: Between the bottom and middle thresholds, silent start allows electric operation during a drive until the first ICE start. After that, you'll see the FORM message and the ICE will continue running until you shut the car off.​

· Step 2: More fuel dilution: Between the middle and top thresholds, EV operation is not allowed. The ICE will start when you power up the vehicle and remain running until you shut down, or the bottom threshold is reached, whichever comes first.​

· Step 3: More fuel dilution: Above the top threshold, EV operation is not allowed, and the vehicle will instruct you to perform an oil change.​

If this is what Hyundai did, say bye-bye to most EV operation in cold weather.

 

Congratulations! You're the first one to ask. You get the golden turd.

Here's what it meant when Jeep updated the firmware on their Wrangler 4xe plug-in hybrid.

The Wrangler 4Xe has a process called 'Fuel Oil Refresh Mode' aka FORM, that is supposed to prevent oil dilution. Jeep engineering put together a pretty good explanation as to how it works:​

​

Fuel and Oil Refresh Mode​

​

In short, the vehicle software monitors your driving and I'm assuming the frequency of cold starts and short run cycles to predict the amount of oil dilution. Based on the model, the Wrangler 4Xe will operate in one of 4 modes:​

​

If this is what Hyundai did, say bye-bye to most EV operation in cold weather.

Thanks for the info. I'm skeptical of the "fix". My car fuel dilutes summer and winter (and winters are mild in southern NM). I seldom start my car in temps under 50deg F (10C) even in winter. It's the short trips that are the problem coupled with very slow warm up of the gamma II. The next thing I was going to look at is the exhaust heat recovery system. OEMs are increasingly using these to get engines up to temp quickly and the Tucson HEV is no exception. They supposedly add 3kw of heat to your coolant which is a lot. I don't think there's any electrical connection of the unit to the ECU and thus no warning if it were stuck closed. When I get the ambition, I'm going to crawl up under the car and have a look.

I will wait to see how others fare with the ECU "upgrade". I would hate to have any changes that hurt fuel economy which is great on my blue model.

 

Here you go,, TSB is essentially "if you see this and vehicle under warranty, you is to follow this procedure, otherwise, we may deny claim"

Here is also the Recall, note how all the DTC codes mirror. Just like typical Hyundai way, recall part of them, let the rest come out in the wash. seen this with misfire logic with Elantra, stop light switches, and couple others

 

WTactualF?? Required update for all Santa Fe HEVs. Optional update for Tucson HEVs and PHEVs.........IF you know that the TSB exists........... and IF you can convince your dealer that your vehicle qualifies for the update.

I guess I'll be updating the tip that I sent to Consumer Reports.

 

I feel like I would rather just change my oil every 4k miles for my Santa Fe Hybrid than have them nerf winter EV usage.

 

If you decline the firmware update, I would suggest getting something in writing saying that the warranty will not be effected.

(Your signature says that your car is on order. Note that the TSB is required for all Santa Fe's prior to delivery.)

 

I received it 2 weeks ago. No idea if that got done before the trek started but after the March TSBs. I must have missed where it says prior to delivery, since this isn't a recall. I'll look again. (Edit: right at the top.)

I do notice when the car first turns on, it won't go into EV mode until the car has been on for a certain amount of time (not sure if that was normal before this).

 

Did the oil analysis give you a reading of viscosity at 100 ̊C? Using Valvoline 0w20, it shows a spec. of 8.30 centistokes at this temperature. It is worth noting that the density of the same oil is 0.8465 kg/l. The density of petrol is about 0.730. These measurements are made at 15 ̊C.

 

Viscosity at 100 deg. C was 6.0 centistokes. Definitely out of spec for 0W-20 per the SAE J300 table.

 

Captain, you are right about the warranty claim. Here in Australia, Hyundai battled ferociously over a warranty claim on one of their atrocious DSG dry-clutch gearboxes, despite the obvious flaws. I started to think that they had recruited their warranty staff from Volkswagen.😆

 

I have a 2019 Tucson PHEV which I've had to take to the dealership twice because of heavy white smoking.
They said the oil was contaminated with some water (see photo) and the reason was that I was not driving enough for the engine to get warm enough for the water to evaporate! I live in Iceland where it can be a little cold in the winter (-5 to -10°C) and drive around 11 km in 11 min to work (one way).
What is your opinion, is this normal? My girlfriend has a hybrid Toyota and drives less distance, but nothing like this has happened in her car.

 

FYI:

2022 PHEV Dumping Gas into Oil

Have the 2022 Tucson PHEV version and it is now in the shop with 5400 miles on it. 400 miles after the first oil change. Level on the oil dip stick was above full, color was yellowish, and car is blowing oil smelling smoke out the exhaust. Stopped it and had it towed as soon as I saw the...

www.hyundai-forums.com

This also seemed to several of us to be coolant, but turned out to be oil. It will be interesting to see the results of Mungo544's suggestion.

Be sure to make the dealer aware of the TSB. Since most of us are heading into summer, you might be the first person who could notice the effect of the TSB firmware update.

A PHEV is more susceptible to this issue since as long as the car can run in EV mode the engine just runs at idle as needed for cabin heat.

The Jeep solution (Post #6 above) basically eliminates EV and Hybrid mode driving. We don't yet know what the Hyundai firmware update does.

One thought I've had is to stop charging the car in cold weather and basically run it as a hybrid. That will be a major disappointment, but better than putting the engine at risk. Hybrid Tucsons have reported the issue, but not as severe.

One slight solace is that this issue appears to be somewhat common across various brands and models of Turbocharged Gasoline Direct Injection (TGDI) engines, and not a unique Hyundai defect.

 

Did they drain and refill your engine oil ? If not, don't go back to that dealer. There shouldn't be measureable water in your oil just because you don't get your engine up to temperature. That much water in the oil looks like a head gasket leak to me. Are you having to add coolant periodically? I would drain the oil and put some in a one quart clear glass container to see what percentage of water is in the oil (the oil will separate and float over the water). Anything more than a trace means you likely have a head gasket leak imho. Bring your evidence with you when you return to the dealer.

 

It was a Hyundai official dealership so they changed the oil on both occasions. There is a 7 year warranty so I would assume they needed to fix the engine if it broke down because of the water in the oil? Or perhaps they will blame me for not driving long distances
Have not checked the coolant, thanks for the tip. But I dare not drain the oil, so as not to void/affect the warranty.

I read the TSB and it's good to have that as a reference. It sounded from the dealership as my car and driving was an isolated case! But now I have been driving the car for more than a month as a hybrid car and hope most of the water has evaporated. And yes it's a disappointment not being able to use the PHEV as intended.
Perhaps they need to advertise the car differently

Thank you for the feedback!

 

It is unclear whether mine has the update applied or not, and I won't find out until the first oil change, but perhaps we can determine from evidence before I reach the first oil change. I have noticed when I start the car, it must reach about 1/5 of the temperature max in the bar graph/diagram on the instrument cluster before it allows for EV mode use. Do others with pre-2023 models see the same behavior? If I hooked up an OBD II device to the car, you think it would give me the actual oil temperature or engine temperature, or would I need a Hyundai-specific tablet?

 

Possibly different than my (pre-update) Tucson, but it could also be a confusing dash display. When starting out in cold weather last winter my Tucson would be running in EV mode but would also be running the ICE at a steady 1100 RPM or 1500 RPM depending on the outside or cabin temperature (I'm not sure which). The green EV display symbol would NOT be on while the ICE was idling, but the tachometer clearly showed that the ICE wasn't being used for propulsion, just for cabin heat. If you haven't done so already, turn on the tachometer display to see clearly if the car is in EV mode but not showing the EV display symbol.

If EV mode is being suppressed until the ICE warms up, that does sound like a different behavior.

 

We've driven 550 miles. Almost all of it has been short trips. We've used just 6 gallons of gas. Temps here have been in the 40s most of the days we've driven. I think that counts as exactly the situation where we should expect gas in our oil. We checked the oil yesterday. It was not above max. It sat right in the middle of the "good" zone. The oil looked pristine, a nice, clean yellow. Our car was manufactured early in 2023. Any chance the program for the car has been changed to prevent the gas-in-the-oil issue?

 

I had a phone conversation with Tech Support at Amsoil.

They use gas chromatography to measure fuel dilution of oil, which is more accurate than the Flash Point method used by Blackstone.

Measuring Fuel Dilution in Lubricating Oil

Severe engine damage can occur due to fuel dilution in lubricating oil, as high fuel levels (>2%) in a lubricant can lead to decreased viscosity, loss of dispersancy, oil degradation, and loss of oxidation stability.

www.azom.com

The viscosity of my oil had dropped to 6.0 centistokes at 100 deg. C., which is a little lower than 16. The oil started out as 0W-20.

They are seeing increasing instances of fuel dilution with the increased numbers of direct injection engines in use.

The technician said that modern oils can handle some degree of dilution while retaining their ability to lubricate. He said that the most important measurements to keep an eye on are wear metals, watching for changes over time or the exceeding of thresholds in a given sample. Amsoil measures iron, chromium, nickel, aluminum, copper, lead, tin, cadmium, silver and vanadium. Unfortunately they do not publish the thresholds on their test report unless a particular contaminant exceeds the threshold.

Interpreting wear metal trends needs to take into account how long the oil has been in service when it is sampled. ("Normalizing" the test results.) Without a measure of operating hours mileage has to be that measure, but in PHEVs and HEVs this is complicated because some proportion of those miles are in EV mode.

I was able to find an Amsoil training publication that does a good job of explaining their methodologies and how to interpret their results.

http://www.syntheticwarehouse.com/brochures/oil_analysis_study_guide_g2780.pdf

Be sure to read the footnotes.

Side note - Amsoil sells a sampling device that allows taking oil samples without having to drain the oil.

 

Well, my OBDII device does not read the coolant temperature. I'm not sure if that's Hyundai's fault or the manufacturer, but I'm looking into it. I can see all the other standard stuff, but no coolant temperature (or oil temperature) means no baseline for how the car behaves with oil temperatures and EV modes.

 

Does your OBDII device report engine hours? With HEVs and, especially, PHEVs that is a more meaningful measure of engine usage than mileage when normalizing wear metal trends in oil samples.

 

OK, I found an app that has a PID that works with the Hyundai vehicles! I will attempt to see if there is a set temperature at which EV will work again or if it's a set time.

 

Generally when it’s cold outside, engine needs to heat to about 50C before it will go back into EV mode and the engine will always run to maintain at least this temperature. I use the Lufi X1 OBDII gauge in my HEV.

 

My first run indicates about 130F for EV mode access, which is only slightly above that number. A quick Google search indicates that gasoline starts to vaporize at 140F for what it's worth. Presumably yours doesn't have the TSB update, though, correct? If so, that would imply, albeit with the one data point caveat, that either something else was done than simply requiring the engine to run more, or my car doesn't have the TSB update, either.

 

This is a bad news….

It means that fix is not effective…

 

Reading below articles, one issue can come from fuel pump leakage:

 

That does not apply to our cars, i.e. MY 2022+ Tucsons.

 

Hopefully they have fixed this with the newer SmartStream 1.6L turbo engines. I know they have completely redone the PCV system, now using a Pressure Regulation Valve that is built into the rocker cover like some VW/AUDI and Volvo's. If anyone has more info on this I would love to hear about it. They may even have a built-in oil separator. Anyone know?

 

Hi, I have a 2022 Tucson 1.6 hybrid 2wd auto with 15k km based in sunny Costa Blanca Spain. Recently I noticed the oil level had increased in the engine and the oil was noticeable dirtier. I got the car to my dealer where they diagnosed a faulty high pressure fuel pump! They changed the pump, oil and filter and have assured me this will fix the problem, but having seen your thread and not able to understand how the pump could influence the oil level. Will keep an eye on the levels even more now. Have you heard of this “fix” before? ( This is my first post so apologies for any errors)

 

The pump is run by a cam on the top of the engine. If it develops a leak while it is providing fuel pressure of up to 5,000 PSI! it will leak directly into the top of the engine where it will flow right into the oil passages, diluting the oil. It really is simple and easy for this to happen and has been a known issue for some time now.

 

Unfortunately makes sense now, surely this should be an easy fix by now for Hyundai! Think I will run the car for a week then get the oil changed again 👍 thanks for your reply.

 

This is a common problem with this type of engine for all manufacturers. Not an easy fix unless you want to sacrifice mileage on the HEV and PHEV vehicles.

 

@Captain Blight Have you considered what premium fuel might do to our GDI engines? I know premium fuel is not required, but several other forums on Bob is the Oil guy have some reasoning why higher octane may lead to less fuel being injected, and subsequently less fuel dilution. Not a panacea but apparently will reduce the dilution.

I'm running a few tanks of 93 Costco Top Tier gas, and will see. Obviously, this doesn't replace shorter OCIs and moving up in oil weight (going to switch to 5W-30 instead of OW-20).