I’ve had what I feel like are an unusual amount of oil leaks over the past 15,000 miles, and they are very annoying. Valve cover gasket, pushrod cover gasket, possible oil cooler/main seal, and something that I haven’t looked in to yet. It seems to be a popular thought that Mobil1’s full synthetic oil (that I’ve been using… 10W-30 and 5W-30) will encourage oil leaks with the detergents in it. If that’s the case, I’d like to try something else… Valvoline, Rotella, Castrol? I’d like to stick with Full Synthetic and usually go with the high mileage flavor, but I don’t want to switch to something else and have similar problems to what I have with Mobil1 because i didn’t do my research. Should I think about a different weight as well? Haven’t ever looked in to it. What are your guys’ thoughts? TIA
New oil leak… Mobil1? (1 Viewer)
- Thread starter Demonic92
- Start date
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Try Rotella 5w-40.
Dude, if your truck leaks then replace the seals. It's not the oils fault.
Lol my seals were replaced at the dealer in 2014 and somehow they’re already leaking again
That's 7 years ago.
How many miles since then?
Was it a Toyota Dealer? Did they use OEM Toyota parts?
I found when I accidentally put in 10W-30 in my truck instead of the 5W-30 that I have been using, it started leaking all over the place. I put the 5W-30 back in and the leaks stopped. Higher oil pressure can lead to more leaks.
I found the records on the Toyota dealer portal after inputting the VIN. I assume they used OEM since it was the dealer. Since then they'd only put 20,000 miles on it, so I suppose it must have been sitting a fair bit.
According to the records, they replaced: VALVE COVER GASKET, DISRTIBUTOR O-RING, OIL PUMP ORING, & CRANK SEAL
It still seems early for them to be leaking again though. Maybe it's the other seals they didn't replace that are now doing most of the leaking .. rear main, oil pan gasket, etc.?
I don't see spark plug tube seals.
Also, not uncommon for them to strip the bolts on the Valve Cover. That seal is just under slight compression (there are stops so the bolts don't smash it) and if the bolts are stripped, there is no compression on the seal and it will leak. The bolts back by #6 are regularly stripped on these.
I did mine in 2014, I have put over 100K on it, and I feel like I'm about due to repeat all of them again, as I am seeing leaks crop up again. Prior to that they hade been done at 145K in 2006.
So:
145K in 2006
196K in 2014
321K in 2021
That's about every 7 years.
I
I just replaced the VCG along with tube seals and the PCV. The dizzy o ring looked ok. I’m a little wary of the front and rear main seal jobs. They don’t seem very noob-friendly.
Easy when you pull the engine!!!
Ask me how I know
Most of the external oil leak locations involve no added pressure from the oil pump. Oil viscosity may impact pressure, but once the engine is at operating temperature the leaking gaskets "O" rings and seals are not significantly impacted by the viscosity. Seals leak because of wear and to a larger degree loss of elasticity, i.e., they get hard. Some "O" rings will almost resemble plastic. Time spares nothing. This is why lubricant companies sell "high mileage" oils, they attempt to soften some of the seals and gaskets to buy some time in their life... Sooner or later though
Not to be too technical/picky - 1fz-fe doesn't have pushrods or rocker arms
I assumed he was talking about a 3FENot to be too technical/picky - 1fz-fe doesn't have pushrods or rocker arms
You
Never use synthetic on older engines. Causes leaks. Conventional is all you need
77mustard40
SILVER Star
3FE… 15/40 all the time, that’s what’s in my 40.
WarDamnEagle
SILVER Star
I use synthetic in everything.
- Thread starter
- #16
What's the benefit to 15/40 over 5/40? I drive in below-freezing weather often in the winter, so the 15 seems like it'd be pretty thick at low temps.
77mustard40
SILVER Star
I’m in a warmer climate, makes sense to run 5/40
Application specific. If you wanted to run a 40 weight, you’d go with 5w rather than 15. I run 5/40 in southeast AK a bit north of you, with good cold starts & blackstone results.
And the old wife's tale perpetuates...
Oil does not cause leaks.
Lack of maintenance causes leaks.
I've been using synthetic fluids in everything in both my old 91 and 97. My 3FE had leaks until I replaced the old and crusty seals and gaskets. It's amazing how that works.
seals get less pliable because of age and heat. Oil is largely irrelevant. Does viscosity and oil quality and type make a difference to moving parts? ah huh, not the same subject as leaky seals and gaskets
conflating leaks and lubrication is kinda like "if I wear a diaper will that fix my aching knee?"
