I posted this in an oil thread in the LT1 section but didn't get any responses.

I am trying to decide what oil I should use in my next oil change.This will be the first time I will be doing it myself (God help me LOL). I bought the car at 75K miles and I *think* it had conventional (dont know what type) its whole life until I payed a lube shop to put Mobile 1 full synthetic 5w-30 in it...without knowing it would mess up seals and gaskets so naturally it started leaking but not enough to drop the oil level on the dipstick.Still don't like seeing those drops on my garage floor though and i'm not skilled enough to fix leaks yet.

Should I stick with it or change oils? Go back to conventional? My dad suggested that I try Valvoline max life synthetic blend 10w-30 or 40.I'd like to stay with some kind of synthetic cause I hear it holds up against heat better,and my LT1 likes to run a little warm in stop and go traffic (210-220ish,i was told that this is a safe temp for the LT1).I don't live in freezing temperatures nor 80+ degree weather in the summer if that matters.

Any advice from the LT1 crowd? Thanks.

 

it wasnt the syntic oil that messed up the seals

 

I see no one answered your question in the LT1 area. As you can see choices in oils and the opinions associated with them can become confusing. lol

Listen to your pop. I went with a M1 5W-30 full synthetic in the LS1 @ 77,000 miles and it was a nightmare. Then I tried the M1 10W-40 and that created more ticks and knocks. Then 10W-50 which worked awesome to get me from CA to PA. But went to the Maxlife 10W-40 and then 10W-30. I change the fluids religiously and will drop a 1/2 can of Sea Foam every 10,000 miles for a quick clean. Again, each engine is as different as how they respond to the oil used.

So, the best you can do is give it a shot and if it gets nosier or your psi reads odd, you can always switch it out for something else and keep doing that until you find a product that works well with your engine.

As for it running "warm" ummmm, could have something to do with it being "stock" down to the original spark plugs. lol No worries, so is mine. Does the engine smell or sound warmer than it used to without the gauge reading? If you are not already, you should become familiar with the smell of overheated coolant and become familiar with the "pinging" sounds the engine makes which will clue you in to potential blocked coolant passages in the block.

EDIT ADD: Fuseone is correct - it is not the synthetic that harmed the seals, the viscosity and flow of the oil is thinner, thereby allowing it to pass and SHOW the already worn seals and gaskets.

Good luck.

 

Jenns,

Well,the M1 I have in it right now isn't noisy or anything.No pinging or knocks.It actually runs pretty good in my engine.Oil pressure is good at 15-20psi warm idle,45 warm cruising @ 2K,60 cold idle.Just don't like how it revealed leaks I guess,lol.I was also thinking about seafoaming my car,but I don't want to risk fouling plug(s) right now.

There is an oily type smell coming from the engine when it runs warm for an extended period.This is only in constant stop and go traffic though,where it runs in the 210ish area.I think that smell is heated up dry oil that has leaked onto my engine somewhere.Cruising non-stop will keep my temp at steady 185,so I don't think my car has an overheating problem right now.I changed the thermostat and flushed/refilled the radiator not too long ago.No new sounds or smells since I got it 10 months ago.

I suppose I'll try the trial and error method until I find the right oil.Thanks for your help.

 

You are very welcome. Sounds like you are taking good care of him.

Sometimes it is best to adhere to the "if it ain't broke - don't fix it" methodology. lol

Take care and be safe.

Jenn

 

If changing oil to synthetic in a car with only 80k miles caused you to "mess up seals and gaskets" then you sir have a bigger problem.

 

I think we have already redirected his understanding that it did not mess up the seals and gaskets, but just allowed bypass.

 

Stick with the Mobil 1. I've used Mobil 1 with each of the 6 F-bodies I've owned, won't use anything else.

 

Not sure what you're trying to suggest, but thanks for the helpful post.

Yeah, apparently that's what technically happened when I switched to a synthetic.

I already bought some Max life 10w-40 and changing it in tomorrow.Hoping it will keep the leaks at bay or stop them if i'm lucky.

 

Hey Formula Freak - let us know if the leaking slows/ceases after you run the blended for a couple days.

 

Will do.

 

Best thing for you to do IMO is switch to a thicker oil. "Made in Germany" Castrol Syntec 0W-30 would leak less than the amber-colored water that is Mobil 1 5W-30. IMO, M1 5W-30 is one of the worst synthetics you can put into an LS1, and oil analyses have backed me up on this one. GC 0W-30 has better cold-flow properties to protect better on startup, better viscosity and a better additive package to protect better while driving, will deliver better oil pressure in almost every case and will protect against leaking better since it's thicker.

That's my $0.02. You can get GC 0W-30 at most Autozone's. Make SURE it says "Made in Germany" in the back.

 

Yeah I thought about that oil too cause it seems to be pretty popular on this site.I saw some Castrol Syntec 0w-30 at Carquest today but I don't think it was the German stuff.Thanks for your input Choco.

 

ive been using castrol syntec 5w-40 and love this stuff!! mobil 1 is a good oil.. try using maybe 10w-30 synthetic next time!

 

Choco you are correct. M1 is poop. lol

As a lurking LS1 owner since 02-07 I have read some exceptional posts you have made concerning the German Blend of the CS. However, not all of us have the cash to spend on it. Now, I know you will probably answer "pay now or pay later" and you, again, would be right. But, here is my question. With your research and UOAs which ten oils would you list as acceptable for the LT and LS1 in order from best to worst?

If you have already done this, just linkie-link. lol

Thanks

Jenn

 

No problem. Most Castrol 0W-30 is German stuff, but a handful of it is USA made. The USA stuff isn't nearly as good. Check the label. Odds are it's German.
It's not "poop." I'd rather have it in my motor than any conventional oil. However, Mobil 1 is GROSSLY OVERRATED. People think it's the best stuff out there - and it was damn close to that 10 years ago before Exxon bought Mobil and trashed the product line. They turned a high quality oil into a "reformulated" oil. What does that mean? Well, they cheapened the additive package, turned it into a Group III non-full synthetic and jacked the price

Not all Mobil 1 sucks. The 0W-40 and, particularly the 5W-40, is good stuff. I had good results with 5W-40, though I did consume quite a bit more M1 5W-40 than I do GC 0W-30.

I actually have USA made Syntec 5W-30 in my crankcase right now (long story, don't ask). I gotta check my oil level...I don't trust the USA stuff, I hope I didn't consume a lot...
Autozone puts it on sale for $4.49/quart several times a year. When it's on sale, I go out and buy 12-18 quarts of oil. I probably have ~24 quarts of oil in storage right now.

Considering I run the synthetic for twice as long as conventional, I'm really paying $2.25/quart for oil. It's not expensive at all when you look at the cost over the long run.

I really don't know. I can't answer that. I can only tell you I've had great results with GC 0W-30. The time I couldn't get my hands on any, I ran Mobil 1 5W-40. If a day ever came where it become impossible to get GC 0W-30, I'd probably just use Mobil 1 5W-40 or Castrol Syntec 5W-30.

None of it's "bad oil" per say. Some is just better than others. It's all going to protect better than conventional. Running GC 0W-30 just helps me sleep easier at night. I got enough stuff to worry about

 

Fair enough and well said. I appreciate the response. I guess my engine just has not responded well to it. God knows I tried.

Take care and sleep well.

 

Changed the max life in today.Man getting the car up high enough for me was a PITA,but the actual oil change was pretty straight forward .Will post back in a few days to report leakage status.

 

Mobil 1 10W-30 is thinner than Mobil 1 5W-30. If he's having problems with 5W-30 leaking, 10W-30 will be worse.
It's decent oil, just too thin for the LS1 IMO. It may work a lot better in smaller 4 cylinder motors, but not for a larger V8. It produces way too much valvetrain chatter and oil consumption for most users.

Nighty-night

 

Well,it seems like it slowed down the larger spots where it leaked,but a couple more very small ones popped up on the cardboard. Oh well.