Topic: Does Synthetic Blend Leak?

[blackdiamond]

Does anyone have any experience with Synthetic Blend oils?  I tried Full Synthetic Oil in my 22R and the seals couldn't contain it so I switched back to Conventional and it the leaking stopped.  I have been told that Blend oils won't leak like the full synthetics, has anybody experienced this?

[silver_truck]

I haven't had any leaking with synthetic blends...I also didn't see any leaks with full synthetic though. Sometimes you can pick up Castrol Synth blend for pretty cheap, I got mine at Wally world for like $2 a quart

[Salvo]

synthetics tend to leak a bit more than conventional oil. the stuff is so slick that it will find any little spot and seep out... I never noticed more leaking with synth oild than i do with conventionals... Of course my engine stops leaking when i was it for months so i may be the exeption to the rule

[trollbum]

i think he discovered this so he asks about the blend which i'm lead to believe is a mix or "Blend" of the two ;-)

[mr4x42u]

at work when we switched to full syn we had to go on seal changing trends along with the oil..Older oil seals seem to have a problem with the syn..The leaking stopped after the seals were changed out so it olny seems to be a peoblem with older seals..

[guywithuglyyota]

I heard a rumor that the blended syns (I used valvoline durablend) are nothing more than very very pure Dino oils. And they dont actually contain synthetics at all. But this is only someting I heard around the campfire. I know that I switched from Durablend to Mobile 1 and the engine had the same leak as it did before. Its the older engine oils, and the seals that are conditioned by them that have the leakage problem. My 85 accord went 185,000 on regular oil before I switched over to mobile 1 and it had zero leaks before, and after the change.     

[shiftless89]

ok my 
synthetics do not cause leaks or create leaks.
I have found that when you switch to syn lubes, it cleans out all the crap around the old seals revealing leaks that were already there that were pluged by trash in the dino oil.   therefor the syn lube is doing its detergent job of lubricating and flushing crap.


unfortunately you have to reseal to stop leaks

[blackdiamond [OP]]

I am in complete agreement that synthetics "find" leaks rather than "creating" leaks; however I have heard that the blend oils don't have the same issues.  I now have Mobile 7,500 blend in my 85 that developed a massive leak when I tried Castrol Syntec so I will report if it leaks.

As a side note, the Castrol Syntec is a group 3 base oil and is 100% purified dyno oil.  Mobil 1 is made in the lab (PAO base oil).  I don't know if blends are a mix of conventional and synthetic or just a purified dyno, I suspect it varies with the manufacturer.

[midwestmud]

I run full syn and never had any leaks  pep boys has a  $15 rebate going on for Quaker state full syn you end up paying around a buck 5 a quart

[blackdiamond [OP]]

 

Quaker State, Castrol Syntec, Valvoline, Pennzoil and several others are only Group 3 synthetics (Carbon Based with Parafin)

AMSoil, Redline, Royal Purple and Mobil 1 are Group 4 synthetics (PAO based created in the lab)

I think that Redline is actually Group 5.

Group 3 oils are good quality, but not the same level as the Group 4 oils.

 

I am running Mobil 1 in the 04 Tundra because it is easy to get.

Full Synthetic and Blend leak in my 85     

[Cheesemaker]

I just stick to castrol gtx it's cheap, works good, and I can't see the reason to go to a $$ synthetic when I don't put alot of miles on our rigs!  And the whole will it leak issue!  I've got enough leaks, the last thing I want to do is possibly create more!  And I change my filter/oil every 2500 to 3000 miles religiously!  So, hoping to get a little better gas mileage to save money, to which in turn to spend what you saved in gas on synthetic oil just has me baffled!  My wife and I drive less than 5 miles to and from work, and town.  So we aren't getting good gas mileage anyway! 

I can see running synthetic in a newly built motor, or one that is in really good condition with no leaks, and rock crawling.  Only because while rock crawling or off-roading in general your actually putting more hours on your motor than if you were to drive on the hwy!  That's why when I get my truck set up I'm going to install a hour meter so I can change my oil at the same time in theory!  But this is my opinion!


But, I know the debate on the synth vs. conventional oils have been debated to the death here on this board and around every grease monkey garage/campfire/break room table!  And it always boils down to what you believe in and what you want to run!  I used to get for running Pennzoil in my el camino, but at about 200,000 on the engine with nothing but pennz in and I sold it with zero oil loss, no sludge build up, and compression equal to a new engine!  So, it's what you believe in!  That's the good thing of this site, we value everbody's opinions!   8)