PH98I30

I have a 98 I30 with 160K on the clock. I want it to run past 300,000 miles. I am thinking of switching to using synthetic oil. No problems. The car runs great. I plan on keeping this car until it dies. It is the best car I have ever had. I own a 2014 Rav4 and I still prefer to drive my I30. I have been running TCW3 in it for 5 years and it is smooth as silk. Has anyone encountered problems switching to synthetic oil. I drive it about 8,000 miles a year, mostly to work.

CS_AR

Do you have any leaks around the front or rear of the engine today? I switched all of my used 4th gens to a high mileage synthetic to get the seal conditioners.

PH98I30

I have the common upper oil pan leak. It is not very bad. I don't have to add oil in between changes. It leaves a small spot on the ground.

JvG

I have installed synthetic oil on several of my cars over the years. No problem if the engine does not leak.

I have read stories about existing leaks becoming worse. High mileager synthetic makes a lot of sense.

I got my maxima with 100k on it in 2006. Now it has over 200k on it. I run either Mobile One, or O'reillys.
Oil changes at 7 to 8k. Mostly freeway miles.

The Wizard

iTrader: (43)

Not Maxima related, but once I switched to synthetic on my 92 camaro back in 1995 and instantly had an oil leak. Switched back to dino oil and the leak went away.

PH98I30

Why would synthetic oil cause leaks? I do know the molecules are more uniform, but all oil is slippery.

carlem9

Synthetic oil won't cause leaks. Due to its cleaning properties, it can remove the build ups that are sealing existing leaks.

wdornbach

What he said.

I had 1990 Dodge Ram w250 4x4 cummins turbo diesel. About 200 k miles. I switched to synthetic and it started leaking oil from front and rear main seals. Switched back to conventional dinosaur oil and the leaks stopped after a while (but not right away).
Was told this (and he showed me an example journal too) by a cummins engine tech guy (employed by cummins) that this occurs because long term use of dino oil causes a carbonized-ish gummy ring that forms on the seal journal right where the seal rides the journal. This ring is not a necessarily a bad thing but Synthetic oil dissolves this ring = leaks.
Typically I've heard if you are going to run synthetic, you should start from day one when the engine is new.

I have a 99 Beetle TDI diesel, running synthetic 4w40 since day one. It has 350k miles now, no leaks.

PH98I30

Thanks. They didn't have common synthetics when this car was new. Maybe I will run a synthetic blend.

The Wizard

iTrader: (43)

Today's story of syn vs regular oil

https://www.msn.com/en-us/autos/owne...-in/ar-BBEs0Bw

CS_AR

One of my vehicles is a Honda 3.5L V6 with the chronic rear main seal leak problem. Basically, rear main seals start leaking just over 60,000 miles. So when the last seal started leaking, and Honda didn't want to help with replacement, I tried using Valvoline Max Life Syn-blend. It slowed the leak to a level that I can live with. I no longer leave an oil slick in someone's driveway when I visit.

One of my friends is a fleet tech for a HCAV company with roughly 16 trucks. So he was having to add a quart of oil each week to most all of the trucks. They were purchasing approximately 4 gallons of oil each week to keep the trucks in oil. He switched Valvoline Max-Life Syn-Blend and that cut the oil usage in 1/4.

If you have a leaking main seal, half moon, or o-ring, this product will not completely stop it. However, the seal conditioners have been found to slow an existing leak to a manageable level.



My 98 and 99 models have new front main seals. The 99's rear main seal is just over 4 years old. I recently replaced the half moons when I had the upper oil pan off on the 99 model. For those cars, I switched to Mobil 1 high mileage 10w40 when I replaced the tensioners a few weeks ago. So far those engines seem to like that oil.

Turbobink

iTrader: (2)

For one ... and with all due respect to the Wiz, the AAA information is missing a ton of critical information (i.e. data). None of the links provided in any of the articles available (linked or otherwise) provide that information or it certainly isn’t apparent where one can find that data.

Second, the AAA article(s) seem to discuss the advantages of using synthetics when conventional is used in just the same manner. Meaning, the OCI observed when running synthetics is the same as that observed when running conventional.

Here’s the “big picture” reason why I’m saying all of this:

If you’re a relatively normal driver (with perhaps with a good run b/t stop lights and a few WOT kick-downs now and again); you don’t regularly race; you haven’t made significant modifications to your engine and; if you change your oil regularly and religiously, you will gain no performance or protection benefits from the use of synthetic oil over conventional.

But, here’s a qualifier ... where conventional is concerned “change your oil regularly and religiously” means observing the old-school every 3,000 miles OCI (which I do and always have).

In that scenario, you will gain no performance or protection benefits from the use of synthetic oil over conventional.

Synthetic, no doubt, has some qualities and characteristics that conventional oil doesn’t. However, those qualities and characteristics only become an advantage in extreme use cases and in extended OCI situations.

Don’t get me wrong, you want to use synthetic because you feel you need it? Do it. But if you meet the criteria I’ve outlined above, don’t feel falsely secure in thinking you’re making your motor any happier or that it’s gonna last any longer ... I’ve got a 23 year old, 293,000 mile Ford 351 Windsor that’ll support me on that.

And on the leaks thing? If you really want to use synthetics but are skittish on account of the leaks potential … just continue to use the synthetic, the leaks will go away over time.

PH98I30

Thanks for all the input. I read the article that Wizard posted a few months ago. My oil change is due in November. I drive the car to work only, about 70 miles a week. The leak I have is the usual UOP. I don't think the RMS is leaking. I think it is the pan on the RMS side.... actually on both sides. The PO changed oil religiously as do I. I don't have to add oil in between changes. I was going to repair the UOP leak, but my garage opportunity disappeared. I am in the process of looking to buy a home in the near future. Then I will tackle the job as long as the leak is manageable. You guys are a great help. Craig, I wish I had all your experience working on these cars. I'm getting older, but at 63 y/o, I still enjoy working on cars when I have the time. I started back when points and condensers were the main automobile problems. If you got your car to 100k miles you were happy. I want my Infiniti to get past 300k. I haven't had to get a front end alignment in the past 7 years. The front end is solid.

CS_AR

Ahh the good old days. I'm with ya buddy.. I started out working on one of these engines in the picture below. It was an aluminum block V8, with manual transmission, in a little car about the size of a Corvair. It was often misunderstood and a real sleeper like the 4th gens.




In 1962 it was offered in a turbo charged version.

JvG

Looks like a pontiac tempest, or the oldsmobile version. F-85 as I recall. Corvair based transmission on the rear axle. Rope drive in a tube.

GM tried a lot of innovative things back then.