I was told that it’s good to use synthetic oil from day 1 when you buy you buy your car brand new or with low km’s. My car has about 120000 and I was wondering if it’s safe to switch to synthetic oil. So far 2 mechanics told me not to do it. What do you guys say? Anyone has any suggestions or comments?
I switched over to syn. Had leak near my main seal. And I wonder if
running a thicker viscocity was the cause of my shims popping out :dunno:
Its all a myth! Go nuts switch it over. I did my motor at 115km and another motor at 180km. No worrys. I think marc posted sompthing up hear about a year ago on it.
[quote=“nissan240sx1992”]I was told that it’s good to use synthetic oil from day 1 when you buy you buy your car brand new quote]
this is false, you need to do a proper break in with it befor you can run synthetic.
Na just put it in. Break in how? another myth
[quote=“jjm_240sx”]
Na just put it in. Break in how? another myth[/quote]
I’ve heard of that before. Don’t break in a new motor with synth, since the synth won’t allow the rings to seat properly? or the synth won’t allow enough friction to hone the cylinder walls/rings for good compression…? (Someone who know’s please confirm/deny this information)
You need friction to seat the rings properly. This is why so-called “hard break-ins” are hit and miss. People think that just because their motor didn’t blow up, they didn’t do any harm.
Synthetic is too slippery. The rings won’t wear in at all, cam won’t seat properly etc etc.
Depending on who did your machine work (was the block honed/bored to the pistons or to spec, was it cross hatched, grape bunched, etc)
Synthetic is great, don’t get me wrong. The problem is it’s sometimes too good. You’d be surprised how many gaskets will seal fine for dino oil, then all of a sudden piss like crazy on synth.
Gonad, your shim dropped because your motor was not maintained. Valvetrain must be lashed properly as part of routine maintenance. The longer you leave it, the worse it gets. The shim is there to take up slack. As the slack gets worse, eventually nothing is holding the shim in place. If anything I’d blame the synthetic before the Dino. Too thin, no cushion.
If you want to run synth, go ahead. If after your oil change, your motor spews oil like a sprinkler, switch back to Dino. If not, enjoy.
[quote=“jjm_240sx”]
Na just put it in. Break in how? another myth[/quote]
Exactly, F’ breaking in a day one car, thats what the warrenty is for :twisted: I pitty the dealership that sells me my first new car :twisted: (most likely going to be a G35, Maxima or Altima SE-R)
you guys are off topic. He has 120 000km’s and wants to put in synthetic. Then some one said there is a break in peroid he would have to do… Not ture…
Now you guys are talking about a fresh new built engin. I have read that you need to use normal oil to break it in as well. I am sceptical on that one as well.
You do need to use normal regular oil to break in a motor. When you clean up the cylinder walls, you use a grape bunch hone and cross hatch the walls. This is to keep a nice rough surface.
During the break in period, you are wearing everything into place. Synthetic is too good. It will actually keep this wear from happening, so your motor won’t break in properly. A lot of parts are designed to wear into each other to seat, especially in the valvetrain.
But as for 120,000 km, it sounds fine for Synth. Synthetic is better than dyno, you just have to be careful. It can find its way through gaskets and seals, because it’s so “thin.” I’ve seen it happen a bunch of times. You can go from a perfectly clean no leak motor, swap to synthetic and all of a sudden find new leaks all over. If you switch back to regular oil, the leaks will go away.
You usually want to break a new motor in with garbage oil. Well not garbage oil, but not fresh oil. All the break in lube will contaminate the oil, so there’s no sense in wasting $100 worth of synthetic oil.
“dyno oil”
the first time i read someone posting that, i thought there was some sort of special oil that you use on a dyno. :oops:
Now whats the deal with these “High Mileage Oils”, whats makes them different then regular oil. Do they have special additives mixed in?
Yeah, thats how they advertise the oil. I personally think Castrol GTX or Mobile 1 Synthetic are the best. There is anoteher oil that I have been hearing about Amsoil. I hear honday is using it on their new cars and if you dont’ use it your warranty will be void. They have Amsoil synthetic which suppose to be good. Anyone can comment on that new oil?