3800 and Synthetic Oil

[ol' yeller]

Any reason not to use a full synthetic motor oil in the 3800? My newest has 87K on it and it appears to have been run on dino oil so far. As I drive about 6,000 miles a year I'd like to switch to full synthetic and then change it once a year. Tried to search here but didn't come up with much. Also I will be changing the ABS fluid and tranny fluid. What is preferred to use in the tranny? Thanks and sorry to be dominating on these boards the last few days. It isn't all about Ol' Yeller but I do have lots of questions.

[handmedownreatta]

thats all i use.

[gkhashem]

On further thought I know to careful when using jack stands, but when using my floor jack where can I lift the Reatta on the front end? Its easy on a full frame car which I have done, but where is it OK to jack up the Reatta and where would you place the jack stands.

[SeanR]

Any reason not to use a full synthetic motor oil in the 3800? My newest has 87K on it and it appears to have been run on dino oil so far. As I drive about 6' date='000 miles a year I'd like to switch to full synthetic and then change it once a year. Tried to search here but didn't come up with much. Also I will be changing the ABS fluid and tranny fluid. What is preferred to use in the tranny? Thanks and sorry to be dominating on these boards the last few days. It isn't all about Ol' Yeller but I do have lots of questions.[/quote']

be cautious with using synthetics in a mid-high mileage GM engine. Every GM engine I've ever tried putting Mobil1 or Pennzoil high mileage oil, it leaked out of every gasket and seal on the engine INCLUDING new distributor gasket seal that was not leaking for many months prior to choosing the synthetic. Others on here claim theirs never leaked so just be warned.

[padgett]

Think leaks are more because many synthetics are 15 weight. If you run the engine over 200F a lot then it is probably a good idea. My cars are tuned to run cool (180-185) so I just use conventional 10W-30s & change every 3k. Lately have been paying a little extra for "high milage" but not sure if worth it.

ps jackstands, I generally use the A-arms as close to the tire as possible but usually am taking a tire off.

Edited August 1, 2012 by padgett (see edit history)

[Bushwack]

I have read of problems w/ cars going full synthetic with miles behind them. Mostly leaky gaskets/seals.

My mechanic of 30+ years feels if you haven't started with synthetic, at most go with a synthetic blend (which I use in all my cars but for the Lexus and Cadillac).

Quaker State says... Motor Oil, Transmission Fluids & Synthetic Oil | Quaker State

[Guest Richard D]

I put about 4-5,000 miles on the Reatta and 1,000 a year on the Skylark. I still change the oil on both at least every six months, I use dino oil. I figure that by six months the oil has enough moisture and contaminents in it to change it. The Reatta gets up to operating temp every couple of days and the Skylark about twice a month. Neither car shows any leaks or oil use.

My 2 cents

Richard

Edited August 2, 2012 by Richard D (see edit history)

[Barney Eaton]

Over the years, I have owned 11+ Reattas and none were new. I switched to synthetic and have had no problems. My 1991 convertible has only been driven 1,100 miles in the last 5 years, but I try to change it annually. On my drivers, I change the filter every 3,000 and a complete old change every year (which is usually about the same as the oil filter) We drove the 1991 coupe to Charlotte 2571 miles round trip, I changed the oil before leaving and changed the filter when we returned.

When I first started using Mobil 1 about 20 year back....they said to change every 25,000 miles. I think as they sold more oil, marketing realised that if they changed the mileage number they could sell even more oil. Now the number is more like 15,000 between changes.

[harry yarnell]

Nope; I use dino for ALL my used cars. Change it at 4,000.

Oil chemistry has come a long way from the 'old days'.

I tear down engines enough to see the difference from then and now. Rarely, even an unkept car, do you see sludge. Bearing and ring failure (wear) are rare.

Now, I'll use synth in any NEW car I buy; probably does my head better than the engine.

[Guest Corvanti]

i used a synth-blend when i got my reatta. (castrol 5W/30, high mileage). the main reason was it was on sale at my local flaps with a free oil filter that was less expensive than dino oil & filter. i used a full-synth when i had newer cars, and will probably go that way on the reatta's next oil change.

i'm fairly "religious" on changing the oil in my drivers every 3 to 4 months or 3 to 4K miles. on lesser driven vehicles, at least every 6 months - usually spring and fall.

as far as oil starting to leak around to gaskets: unless i have maintenance records on a used car purchase, i have no idea how often or what kind of oil was used at changes. with modern synth & dino oils having a higher detergent content, it's possible after a little time it may clean out some sludge/pieces of gasket material, etc. thus causing a leak.

one maintenance item i usually do on any new-to-me vehicle, is check/tighten valve covers, oil pan, etc. to recommended torque specifications while performing the first oil change - which is usually in the first couple days after purchase.

just my $0.02

[burntOfferingOfRubber]

On 8/1/2012 at 5:31 PM, SeanR said:

ol said:

Any reason not to use a full synthetic motor oil in the 3800? My newest has 87K on it and it appears to have been run on dino oil so far. As I drive about 6' date='000 miles a year I'd like to switch to full synthetic and then change it once a year. Tried to search here but didn't come up with much. Also I will be changing the ABS fluid and tranny fluid. What is preferred to use in the tranny? Thanks and sorry to be dominating on these boards the last few days. It isn't all about Ol' Yeller but I do have lots of questions.[/quote']

be cautious with using synthetics in a mid-high mileage GM engine. Every GM engine I've ever tried putting Mobil1 or Pennzoil high mileage oil, it leaked out of every gasket and seal on the engine INCLUDING new distributor gasket seal that was not leaking for many months prior to choosing the synthetic. Others on here claim theirs never leaked so just be warned.

SeanR, has this situation changed for you?  Is it possible that those experiences were due to older formulations of synthetic that aren't relevant to what's available today?  i got a 2007 Grand Prix with the base 3800 and i'm considering the move to full synthetic.

[padgett]

I've been using Mobil 1 10w-30 high milage for years in most of my cars. Probably more than I need but usually jugs are on sale at Walmart. Also live in a warm climate.

[Ronnie]

1 minute ago, padgett said:

I've been using Mobil 1 10w-30 high milage for years in most of my cars. Probably more than I need but usually jugs are on sale at Walmart. Also live in a warm climate.

Do you have any problems with more oil leakage on older cars?  Also do you go more miles between oil changes with Mobile 1 high mileage?

[dship]

I use Mobile 1 full synthetic 10W-30 in my '00 Eldorado and '91 Reatta (regular, not the high mileage) ever since I bought them (Eldo in '07, Reatta in '13).  The Eldo has 79K miles and the Reatta has 109K.  I have never witnessed any oil leakage in either car.  I change the oil w/ filters once a year (regardless of mileage) each April when they get their MA annual safety inspections.  I probably have the change done way too often as this type of oil really doesn't need to be changed but around 7500 miles...or so I'm told.  I don't come anywhere near that kind of mileage in either car, yearly.  I do stick with ACDelco filters, though....just something I've always done. 

Edited February 24, 2021 by dship (see edit history)

[padgett]

Yup, no leakage or burning, rarely add oil between changes (for 50 years been changing the oil when the hot idle drops 1-2 psi, was abut every 3,000 miles). Takes longer now so usually about once a year unless less than 1K miles. (ps SBCs always used some).

[burntOfferingOfRubber]

On 2/24/2021 at 4:13 PM, padgett said:

been changing the oil when the hot idle drops 1-2 psi

 you mean vacuum at the intake port?  what is the meaning of that metric?

[padgett]

Meant when oil pressure drops 1-2 psi at hot idle.