Leaks after synthetic

I understand that there are many posts bout will leaks after switching to synthetic but I have not seen an answer to my question, its possible that nobody knows and I just have to give it a try.

I'm working on a 98 tacoma with my 15yo son that he saved up to buy. We replaced the CV joints, rack and pinion bushing did an oil change to synthetic.

As others have discussed we now have at least one source of an oil leak.

My question is has anyone had the leak stop after switching back to regular oil? I understand that it would be better to just replace all leaking seals, gaskets etc but we have already spent most of his money.

Thanks in advance. If no one has prior experience I will just give it a try and report the results. Of bite the bullet and hunt the leaks down.

 

Have you inspected it to determine what is the source of the leak(s)? That's a 25+ year old truck, so some leaks are to be expected and I'm personally highly doubtful it has little to anything to do with your choice of oil. Most oil leaks on these motors can be fixed for very little money, assuming you do the grunt work (labor) yourself.

 

I would fix the leak and party on. Probably something simple. Use the good oil.

 

As hard as it is to believe, the leak definitely started after oil change (not from drain plug or filter) as I park in on an epoxy garage floor with cardboard under to look for leaks. I'll try to chase it down. Probably a good project for him anyway

 

Most common leaks, to my knowledge, are the valve cover gaskets or the adjacent half-moons and cam seals.
Pretty simple replacements, and a good intro to engine work as you only have to pull the valve covers. If its any of those 3 you should replace and reseal all of them. Cheap fix which should only take a few hours for a first timer.

 

Yep, probably valve covers and the moons, they leak. Easy fix. Look to change the EGR valve and it's gasket if you end up pulling the valve cover. At least the EGR gasket, they get super hard over time.

 

Not hard to believe. The new oil probably has a better detergent quality that removed some gunk that was masking a failed gasket or seal somewhere. Did you check the oil filter to make sure it's totally seated? Just a thought.

 

I know it sounds too simple, and it's not a scientific term, but synthetic oil is just more "slippery". It will get past seals that conventional oil won't. If things are tight with respect to money, try changing back to conventional oil and see what happens. You have nothing to lose but a $15 jug of oil from Walmart and you will quickly know the scoop. I personally don't believe synthetic oil can clean out the sludge that fast to cause leaks, but my opinion only.

My sons 2005 2.7 4 cyl with 260,000 was a mess until he replaced all of the seals mentioned here. We cleaned it and it's dry as a bone since. No more drips on the driveway. Ready for another 250k.

 

I switched to a synthetic in my '96 a few years back because I had a bunch of Mobil 1 left over from a car we no longer had. I did have a slight leak in subsequent years but don't recall it happening right after the switch. I replaced the valve cover gasket last year and no more drip (Still using synthetic) Things happen on an old motor.

 

Synthetic oil is fine, find the leak and fix it.

 

There are two 2.7L 1st gens in my family. Both will leak oil from the oil pan gasket when completely full. If they are .5 qts below full, they pretty much stop leaking. Is it possible the truck was a bit low on oil before you changed it and now it's full? If it's a 2.7 and that is the case, likely the pan gasket.

If it is the pan gasket and it's 4x4, you need to either lower the front diff or raise the engine to change the gasket. We just run ours 1/2 qt low.

 

I would get a uv dye kit and find the leak(s)

most likely the valve cover gasket.....

On mine if you fill oil too quickly the half moons will seep....

 

IMO
i never use thin synthetic in any older vehicle......(which is everyone of my vehicles)

in fact i move up to a thicker grade 40w

buy what ever is on sale

this is my method, however i check oil lvl and change oil on regular basis

on Subaru forums (those boxer engines burn oil by design) owners NEVER use synthetic
unless the want to run a Mobile One sticker on purpose

 

that oil dye
will nvr nvr nvr use again
after i found leak bc of dye(was the exact spot i thought it would be after degreasing engine)
took 3 additional oil changes to get that dye out
was a freakin headache

 

I like the house brands.....which is most likely relabeled Valvoline syn blend...

Frequency is more important than some fancy label.....

 

It would have leaked sooner or later regardless of what you put in it for oil. I'd wait until it's dark out and grab a bright flashlight and start at the bottom and work your way to the top of where you can see fresh oil. Not a whole lot of places it can be leaking from. V6 or 4 banger?

 

2.7l
Valve cover gasket- easy
Distributor o ring- easy
Timing chain tensioner gasket- easy
Oil filter housing o rings- easy
Oil pump cover and seal- moderate challenge

That’s what it took to fix oil leaks on my 96 and where I had leaks.

 

yeah the oil pump cover gasket is like the valve cover gasket....
they're not very tough and get cooked to death eventually

and its not the synthetic......its the advanced detergents in it.

 

Hey OS
Since I got u
What is your opinion as far as half moons

I replaced mine while back….but the were aluminum….I installed the rubber ones bc they came with kit/and I was a newbie

rubber or metal half moons?
Prefrence?
Downfalls?

 

Yeah saved them