BWZ_2k2Z28

Bought my Z28 in late May last year. Changed my oil and put 5w30 Mobil 1 in it. Car ate a little over a quart in 3000 miles on the first change. Then it ate about 2 quarts in the next 3000 miles. I switched to AMSoil cuz of all the good things I heard about it. 2 weeks after I did that I got a rear main seal leak So I fixed that and put Castrol GTX 10w30 conventional oil in it. Car didn't use a single drop of it. Bout a month ago I tried the Castrol part synthetic oil 10w30. In 600 miles my car was 2 quarts low with no apparent oil leak. So it seems like my car just hates synthetic oil. Just curious if anybody else has had any problems with synthetic?

decipha

i have a bone stock 98 ss with 96k miles, the oil was changed with castrol 5w30 synthetic at 94k miles according to the sticker and it hasn't lost a drop

i just bought the car though so i can't say with any real certainty, however i have driven about 600 miles since i've bought it and its still at the same level

MRMonster

iTrader: (3)

My car has Mobil one 5W30 synthetic and it will go through a quart about every month and a half or so. The car doesn't leak at all. I just have kinda excepted it and keep a quart in my car at all times and top it off when the light comes on. I think its something to do with the crappy PCV system the motor has.

JakeFusion

iTrader: (7)

Get a PCV catch-can since you already have the LS6 PCV system.

If you take your TB off and look down into your intake manifold, you'll see it coated in oil. Great job, GM.

...

BWZ_2k2Z28

When I ran it with Mobil 1 I just blamed the pcv system on the loss of oil. But how exactly do you explain the fact that it didn't suck up any of the conventional oil? That's the part I can't seem to understand.

Paul57

I am not sure how to explain this but I'll give it a shot. Synthetic oil flows easier. A friend of mine use to show the difference between conventional and synthetic by putting both of them in the freezer. After pulling them from the freezer he would tip the bottles upside down. The conventional was almost gel-like while the synthetic flowed easily with minimal difference, from the temp. The synthetic may be finding its way around loose clearances whether it is in rings or seals. Amsoil has acknowledged that a high mileage motor that was experiencing no oil consumption "could" "possibly" see oil consumption with synthetic. Hope this helps.

BWZ_2k2Z28

yea that makes sense Paul. I just would've thought that the conventional oil would break down more than synthetic at operating temps, therefore if anything the conventional oil would get sucked u and leak through seals and that kind of thing. But thats not the case apparently.

FormulaTA327

Mine eats it up also and I run Mobil 1 5w30 and constantly is ticking

mannyman84

iTrader: (2)

How many miles? Check your PCV system for sure. Also synthetic oil is thinner by nature and will thin out even more when it gets hot. Do you go WOT a lot? Also make sure you aren't getting that morning puff of Smoke out the pipe when first starting it up or after It sits for a long time. If so, most likely valve seals are taking a crap or already did. Also curious to know why change from 5w to 10w, I see you live in VA which it's pretty cold in the morning if I'm not mistaken. You should keep your 5w because 10w is for hotter weather.

Austinma62

I always thought it was the detergents that are in synthetic oils that find there way better through old seals and cause them to leak somewhat... I maybe wrong though.

mannyman84

iTrader: (2)

You are right. Synthetic oil has detergents and slowly clean out sludge that may be clogging potential leaks

RockinWs6

Synthetic oils are very thin, conventional oils are much heavier. I use high mileage oils in mine which is a heavier mix of synthetic and conventional oils. Works nice, If use all synthetic WOw is it noisy.

ZouMechE

iTrader: (1)

I've put about 2000 on my first change since buying this car with Castrol Syntec 5w-30. Haven't seen any noticeable oil consumption by looking at the dipstick. I've never been a fan of Mobil1, and synthetic blends are a waste of money. Try a full synthetic Castrol..

badazz81z28

iTrader: (6)

How can it be even possible that 5w-30 synthetic is "Thinner" than 5W-30 conventional? I think that is an urban legend...If you car consumes oil...period, you have a mechanical problem (PVC, valve seals, ring seal etc). Don't blame the oil.

Paul57

From my previous post...

AmDWs6

my brother's ls1 is one piece off work, we changed oil same time, his oil is black and almost gone while mine was fairly fine & still oilly colored not black

"MAC"

iTrader: (1)

I had this same issue, my PVC system was all screwed up and was leaking oil into my intake and was burning my oil inside my valve covers if I was you id check there first to see if it is doing this and if it is just delete it. I believe my mechanic did or he just fixed the problem entirely. I was also advise not to run a synthetic run what the manufacture says and mix in a little 90W with it and you will be fine.

"MAC"

iTrader: (1)

Synthetic oil ( I hope I am explaining this right) yes it flows easier, because it is a lighter base and thinner what could be happening is that the oil is getting above your cylinders and burning when the spark ignites the fuel. this did happen to me because the person who had my car last built the motor and sprayed it. when he put it back together to stock form to sell it he didnt set the rings right and it scratch my cylinder walls up pretty bad my cylinder heads where black as can be from the carbon but the groves allowed the synthetic oil to move above the cylinder head. Hope this helps and sometimes it isnt just a mechanical problem sometimes it is just that you are using the wrong oil.

spicebird98

iTrader: (10)

throw some Shell Rotella T in it and you wont have to worry. Valvetrain is dead quiet.

RockinWs6

LOL open the bottle and pour......OR go to the oil companies web sites and look at the thickness ratings at different temps.

Pennzoil platinum 10-30 pours like melted butter compared to Pennzoil conventional 10-30.