Switching to Synthetic

Due to a previous discussion on this forum, I have been doing a lot of research on Synthetic oils. One thing I have found is the possability of leaks in high milage/older engines. Is there anyone here that switched to synthetic after 100,000 miles and were leaks found or not? Thank you.

At that high mileage, I would forget about switching to syn. Synthetic does not cause leaks, but will find them. ie, A spot in a gasket that is questionable, and would survive with continued used of dino oil, will not survive a switch to synthetic.

I am asking this question as part of my research btw. Thank you to all who reply.

after 100,000 whenever useing patrolium oil I've switched to high milage by Valvoline and that stuff really works great, stopst the little leaks, puts moisture back into the dried out seals and what not, love the stuff

and, if you seen the other post, dont yo uknow by now not to post a question about oil on this page lol

I don't want to start anything and don't want people arguing who is right. Just want replys on people's personal experiences. By the way, have you seen the new Valvoline High Milage synthetic?

and, if you seen the other post, dont yo uknow by now not to post a question about oil on this page lol



I used to have an old 86 1/2 nissan hardbody i put on synthetic it had 130000 on it when i got it and when i sold it it had 280000 on it had no problem with the synthetic in it i have always been told not to put it in older car that have a dry sump oil pump that was told to me buy my uncle that is a GM mechinec and that is what GM had told them in there schools hope i could have been some help

no i havnt, something ill have to look into

Due to a previous discussion on this forum, I have been doing a lot of research on Synthetic oils. One thing I have found is the possability of leaks in high milage/older engines. Is there anyone here that switched to synthetic after 100,000 miles and were leaks found or not? Thank you.



I used to have an old 86 1/2 nissan hardbody i put on synthetic it had 130000 on it when i got it and when i sold it it had 280000 on it had no problem with the synthetic in it i have always been told not to put it in older car that have a dry sump oil pump that was told to me buy my uncle that is a GM mechinec and that is what GM had told them in there schools hope i could have been some help

I had 125,000 miles on mine when I switched to synthetic and no leaks whatsoever.

If your engine does not leak now, it probably won't with the synthetic.

Just remember when you switch to do a flush first and use a good non-fram oil filter.

Also, extend your change interval to 5000-6000 miles.

I have a 95 s-10 with 180000 miles and switched to syn. oil around 120000 and haven't had any leaks.

Smart man, yea, synthetic will not hurt even a higher mileage engine.

I have a 92 S-10 Blazer and i'm almost at 200,000 miles. I started putting Castrol Synthetic in at around 150,000 due to a friends recomendation. I finally just got my first leaky gasket in the manifold. Is it because of synthetic? Who knows. But i'll never go back to any other oil..........gaskets can always be replaced at a fraction of what engine components cost.

Intake gaskets won't be hurt by the synthetic.

Also, just FYI, Castrol Syntec is not a true synthetic.

Go to Mobil 1 with the next oil change for the same price and have even better protection with a true 100% PAO based synthetic oil.

Oh, and don't use a Fram oil filter.

LT,your gonna love this,I cant wait to see your response.

In a previous s-10 4.3 I had 148,000 on it when I bought it. I promptly went to synthetic (Mobil 1).
I drove it until 198,000ish,then I sold it.it ran great,no leaks blah blah.

my current s-10 2.2,5 speed I bought at 10,000(started on Mobil 1) and it has 107,000,runs great.

My Blazer bought with 90,000 has 115,000,at 90,000 started Mobil 1,runs great.

Here's the kicker,LT your chance to cringe..*LOL*.

I change the filter every 5000 miles,add enough oil to top off the dipstick.*less than a quart*
I totally change the oil *Drain it* every 20,000 miles
Maybe two oil changes a year,maybe.

yes you read it right..

no new leaks that werent there before.
thats my story.

comments are welcome.

Well.......

I actually don't mind your situation. I'd rather see oil being used like that then synthetic being dumped at 3000miles.