Oil/Fuel Dilution Concerns...

[Miqie]

Those with suspected gas on dipstick...............if you briefly hold a lighter under it, does it ignite?

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[izzy]

I don't have loosey goosey rings lol

Bro I wasn't trying to attack your rig, all these trucks have low tension rings that allow for some blowby, loosey goosey rings is a fact for modern gas engines.

 

[TimC.]

Why can't you sample test your oil? Speed uses FedEx. Is international samples not allowed?

 

[MustardTiger]

Why can't you sample test your oil? Speed uses FedEx. Is international samples not allowed?

Speed doesn't take samples outside of the 50 states. Blackstone is not really an option either, from what I've read. If anyone knows a place in Canada that does it, leave a comment!

 

[32spoke]

The T24A has a thermal efficiency rating of around 38%...which is pretty high for a mainstream modern engine. Not many engines surpass 41-42%. I want to make it clear, my truck ONLY dilutes during extreme cold conditions....which is -25c and below (-13f). The colder it is from there, the worse it seems to dilute (and probably condensate too). Except for the fringe areas of the northern states...many Tacoma's in the mainland US are not going to be exposed to these type of extreme cold operating conditions, or very briefly if they are. Those who are in the northernmost border states, the prairies of Canada, northern Canada, and parts of Alaska...will be operated, at times, during extreme cold, and need to watch carefully for oil dilution. Otherwise, in normal temperatures...this is NOT an issue. I don't have loosey goosey rings lol, and the engine is not failing. Also to note...this is an issue I've read about at length (i.e. oil level increasing on the dipstick), over on comparable Rav4 forums, regarding the A25 engine. I've also read about this issue with the new Land Cruiser...and I'm sure we'll soon see some 6th gen 4Runner owners in the north bring the issue forward as well.

I truly believe the issue is compounded by several factors:

-intake air temperature low (-20f and below during extreme conditions)
-ambient air temperature low (-20f and below in extreme conditions)
-oil temperature low (180-185f)
-minimum threshold achieved for engine coolant temperature (175-180f)
-direct fuel injection experiencing less atomization of the gas, due to all these extreme cold metrics (especially the low intake air temperature)
-extreme cold temperatures will naturally yield less efficiency, thus higher engine load (i.e. burning more gas)
-E10 gasoline that contains/attracts more water, and is less efficient (thus a need for increased engine load, more boost, and resulting higher concentration of condensation)
-0W20 oil and low tension piston rings
-minimal shielding on the front of the vehicle, other than the grill shutters that (should be closing). However that is a relatively small section of the radiator/condenser area anyways

I think the best thing someone can do is monitor the oil level during cold operating conditions (say -13f and below). If it gets too high (say 1/2 inch above full mark) and you're nowhere near due for an oil change, you need to vacuum the oil down to the add mark, and top it off with fresh oil. Keep in mind, if you are choosing to stick with the Toyota recommended 0w20 grade oil...when it gets 1/2 inch above the full mark...you are approaching near 5% fuel diluted oil and that 20 weight oil is now sheared down to a 15 or 10. It is simply not ok to keep running it like this, especially if it keeps increasing during extreme cold conditions. I have moved to a 5w30 grade, and will run that all year/all seasons. My reasoning is that there is always going to be a certain % of fuel in the oil, higher in the winter, lower to almost none in the summer. The 30 weight grade will more than likely shear down to a 20 weight grade anyways. I'd rather have that, then a 0w20 shearing down to a 15 or 10 weight grade and causing actual engine wear/damage while I cluelessly zoom around in my Tacoma. This is the best compromise I can come up with, with my next action to block off sections of the front of the truck. I just don't want it to look stupid. As a diesel truck owner, one winter I got lazy and didn't put my winter front on the truck. On a 5 hour road trip in -30f temps with a nasty wind...the diesel fuel started to gel up and the engine cut out. Luckily I had a jug of Diesel 911, dumped that in, and a pair of Carhartt work pants in the back seat. Those work pants got strapped across the grill, and I was able to make it home. So...I definitely know cold. Just never had any "winter" issues before with a gas vehicle.

I would get an oil sample analysis done, however there is absolutely no place convenient or cheap in my area of western Canada. Blackstone or Speed is not an option.

Anyways, feel free to roast me for what I've wrote above, as you see fit

E10 will burn, and though it attracts moisture, it will pass through your direct and indirect fuel injectors and atomize and burn- not pass into the crankcase in any extreme volume…. Get some after market block and coolant heaters, and please have you oils samples tested. You might correct- fuel contamination… but condensation is going to be a bigger issue in cold weather- the oil test will verify what is occurring and allow you to address the concern accurately. Good luck!

 

[32spoke]

Speed doesn't take samples outside of the 50 states. Blackstone is not really an option either, from what I've read. If anyone knows a place in Canada that does it, leave a comment!

Google engine oil testing laboratories in Canada. Whatever results you have, email them to Speed and offer him some cash.. since he has one of these trucks, I am almost certain he would love to help and would like to help you solve the mystery.. we all want to help and we all come at this from different directions. For me, the oil test is empirical..

 

[Franko Manini]

The T24A has a thermal efficiency rating of around 38%...which is pretty high for a mainstream modern engine. Not many engines surpass 41-42%. I want to make it clear, my truck ONLY dilutes during extreme cold conditions....which is -25c and below (-13f). The colder it is from there, the worse it seems to dilute (and probably condensate too). Except for the fringe areas of the northern states...many Tacoma's in the mainland US are not going to be exposed to these type of extreme cold operating conditions, or very briefly if they are. Those who are in the northernmost border states, the prairies of Canada, northern Canada, and parts of Alaska...will be operated, at times, during extreme cold, and need to watch carefully for oil dilution. Otherwise, in normal temperatures...this is NOT an issue. I don't have loosey goosey rings lol, and the engine is not failing. Also to note...this is an issue I've read about at length (i.e. oil level increasing on the dipstick), over on comparable Rav4 forums, regarding the A25 engine. I've also read about this issue with the new Land Cruiser...and I'm sure we'll soon see some 6th gen 4Runner owners in the north bring the issue forward as well.

I truly believe the issue is compounded by several factors:

-intake air temperature low (-20f and below during extreme conditions)
-ambient air temperature low (-20f and below in extreme conditions)
-oil temperature low (180-185f)
-minimum threshold achieved for engine coolant temperature (175-180f)
-direct fuel injection experiencing less atomization of the gas, due to all these extreme cold metrics (especially the low intake air temperature)
-extreme cold temperatures will naturally yield less efficiency, thus higher engine load (i.e. burning more gas)
-E10 gasoline that contains/attracts more water, and is less efficient (thus a need for increased engine load, more boost, and resulting higher concentration of condensation)
-0W20 oil and low tension piston rings
-minimal shielding on the front of the vehicle, other than the grill shutters that (should be closing). However that is a relatively small section of the radiator/condenser area anyways

I think the best thing someone can do is monitor the oil level during cold operating conditions (say -13f and below). If it gets too high (say 1/2 inch above full mark) and you're nowhere near due for an oil change, you need to vacuum the oil down to the add mark, and top it off with fresh oil. Keep in mind, if you are choosing to stick with the Toyota recommended 0w20 grade oil...when it gets 1/2 inch above the full mark...you are approaching near 5% fuel diluted oil and that 20 weight oil is now sheared down to a 15 or 10. It is simply not ok to keep running it like this, especially if it keeps increasing during extreme cold conditions. I have moved to a 5w30 grade, and will run that all year/all seasons. My reasoning is that there is always going to be a certain % of fuel in the oil, higher in the winter, lower to almost none in the summer. The 30 weight grade will more than likely shear down to a 20 weight grade anyways. I'd rather have that, then a 0w20 shearing down to a 15 or 10 weight grade and causing actual engine wear/damage while I cluelessly zoom around in my Tacoma. This is the best compromise I can come up with, with my next action to block off sections of the front of the truck. I just don't want it to look stupid. As a diesel truck owner, one winter I got lazy and didn't put my winter front on the truck. On a 5 hour road trip in -30f temps with a nasty wind...the diesel fuel started to gel up and the engine cut out. Luckily I had a jug of Diesel 911, dumped that in, and a pair of Carhartt work pants in the back seat. Those work pants got strapped across the grill, and I was able to make it home. So...I definitely know cold. Just never had any "winter" issues before with a gas vehicle.

I would get an oil sample analysis done, however there is absolutely no place convenient or cheap in my area of western Canada. Blackstone or Speed is not an option.

Anyways, feel free to roast me for what I've wrote above, as you see fit

Send me a DM - I’m having similar issues with oil dilution and I use an oil analysis lab in Edmonton. I live in BC.

Bro I wasn't trying to attack your rig, all these trucks have low tension rings that allow for some blowby, loosey goosey rings is a fact for modern gas engines.

just FYI - there are several reasonable paths for fuel to dilute the crankcase oil besides ring blow-by.

High pressure fuel pump leak: the HPFP has a rod that rides on a cam lobe to pressurize the fuel to around 4000 PSI before it enters the rail. HPFPs have seals that can leak pressurized fuel from the rail back into the crankcase.

2) Leaky injectors that seep liquid fuel into the combustion chamber. Note that liquid fuel does not combust.

3) Dirty injectors that don’t atomize fuel effectively, releasing liquid fuel into the combustion chamber.

Those are just three other ways fuel can get into the oil. There may be other pathways that I’m not aware of. I think that HPFP leaks are highly likely candidates.

 

[Franko Manini]

Why can't you sample test your oil? Speed uses FedEx. Is international samples not allowed?

I reached out to Speed Diagnostix and Lake Speed Jr. replied saying he doesn’t have a way to service Canadian clients at this time.

Google engine oil testing laboratories in Canada. Whatever results you have, email them to Speed and offer him some cash.. since he has one of these trucks, I am almost certain he would love to help and would like to help you solve the mystery.. we all want to help and we all come at this from different directions. For me, the oil test is empirical..

I have lots of UOA data for my truck. I contacted Lake Speed and offered to pay him a consulting fee but he very politely declined. I think he is a pretty busy guy with his day job and getting Speed Diagnostix up and running to its full potential.

 

[izzy]

just FYI - there are several reasonable paths for fuel to dilute the crankcase oil besides ring blow-by.

Yeah of course, I'm just criticizing the brain-dead march towards impossible to maintain, unreliable, and overly complex gas cars in an attempt to scavenge minimal MPG gain while also providing race-car like performance.

Low tension rings is part of that.

Also needing DI is part of that...

 

[Franko Manini]

Yeah of course, I'm just criticizing the brain-dead march towards impossible to maintain, unreliable, and overly complex gas cars in an attempt to scavenge minimal MPG gain while also providing race-car like performance.

Low tension rings is part of that.

Also needing DI is part of that...

100%

It’s the pursuit of marginal gains in efficiency that is killing these engines. GDI is one thing, but add on thin, low tension rings, lower operating temperatures, and lightweight alloys for major castings and it’s a shirt show.

 

[scythanith]

Speed doesn't take samples outside of the 50 states. Blackstone is not really an option either, from what I've read. If anyone knows a place in Canada that does it, leave a comment!

Just ship Canada Post and call it an engine sample. All good. That's what I do.

 

[izzy]

100%

It’s the pursuit of marginal gains in efficiency that is killing these engines. GDI is one thing, but add on thin, low tension rings, lower operating temperatures, and lightweight alloys for major castings and it’s a shirt show.

I have realtime MPG from my Scan Gauge and under load the T24A is getting sub 10mpg anyways, so it's all kinda moot if you are in it 24/7. The injectors are going ham wild in open loop.

They could have gone port injection only, twin scroll still, 2.7L and just made everything as stout as possible and it would still get ~15-25mpg at best depending on driver/rig, which is fine...

Ford/GM/Dodge have been eating the CAFE fees so that their V8 trucks could exist. Toyota could have missed their target EPA MPG by a hair and ended up with a far more simple and stout T24A FTS, but they refuse to pay the CAFE fees and got bit hard (V35A failures).

Instead we honestly got a downgrade from the 1GR. The 1GR isn't perfect, but a relatively large displacement (for a V6) and simple design that can probably run on vodka is honestly a better truck engine.

 

[shackley]

I think this might be a case of it just being hard to read the dipstick, I usually flip my dipstick over and check, it looks overfilled on one side and fine on the other

Yeah, confusing. Which side is correct?

 

[24tacoman]

I have the same issue. I live in Northern Central Canada, and I frequently short trip my truck (less than 15 min drives) in -30C and below to get to work. I have noticed that my oil level is about 1/4" above the full line when cold after driving it for a few weeks. I change my oil every 5000km (every 2 months for me). I also regularly do 8+ hour drives and I am hoping that this warms up the oil enough to evaporate any fuel or moisture that makes its way into the crankcase. I will get my next oil sampled at Blackstone next week and see what the results for fuel dilution are.

 

[izzy]

Something you guys could also try is doing your freeway drives in S7. I tried that out as an MPG experiment and as a side effect of higher cruising RPMs the oil temp (as per Scan Gauge) sat around 220F the entire drive home instead of usial 200-208.

MPG was not affected by using S7 instead of letting the truck shift to 8th, but I kept it below 65.

Or 5th for MT guys

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