1991 Buick Park Avenue oil and fluid specs and....

[gregk24]

1991 Buick Park Avenue oil and fluid specifications, and recommendations.

We are looking at getting a 1991 Buick Park Avenue. It has 114K original miles interior is in good shape, exterior is in decent shape for its age aside from a few dents here and there. I dont know anything about the fluid specs for this car. I THINK it takes 10w30 engine oil, can anybody confirm this? Also if anyone owns or knows the other fluid specs and what not for this car, please share! As far as oil grade, power steering fluid type, transmission fluid type, coolant type, and brake fluid type. For oil filter I am either going to use a AC Delco PF47, a TG, or Fram Ultra. For oil, I am thinking of using Quaker state 10w30, Pennzoil Yellow Bottle 10w30, or maybe even Rotella T5. What do you think? Any other helpful comments or questions are perfectly fine. Discuss!

 

[redhat]

Trans. Fluid would be Dex III from the factory. Valv. MaxLife Dex/Merc would be a good choice.

Oil should be 10w-30, but I think any 5W would be fine. Even a 0W-30. I'd be partial to 5W-30 QS Defy in this application, but then again, we're splitting hairs. The 3.8 will like just about anything that's in grade and regularly changed. No big need to feed these things synthetic.

Coolant, it's a model before Dexcool so get some Peak Green and flush it out.

Typical DOT 3 brake fluid, nothing special. Key is fresh from an unopened container.

Regular PS fluid at the auto parts store/Walmart.

Fram TG or Ultra would be good. Model number would be 3387A. Purolator would be 10111.

These old girls are great cars.

 

[sciphi]

Any remotely modern Xw-30 will suit the engine just fine. Change it every 5000 miles or so, and it will run for a long time. The transmission takes Dex/Merc ATF. Generic will do, but Maxlife ATF also works quite well. Use the leftovers to flush out the power steering. Coolant is old green, or all-makes, whichever is cheaper. Brake fluid is DOT 3, and any generic will do.

Changing those fluids out with new will matter far more than brand for this old Buick.

 

[Merkava_4]

Originally Posted By: gregk24
I THINK it takes 10w30 engine oil, can anybody confirm this?


Yes it does and there's no reason to use anything else.

 

[gregk24]

Originally Posted By: Merkava_4
Originally Posted By: gregk24
I THINK it takes 10w30 engine oil, can anybody confirm this?


Yes it does and there's no reason to use anything else.


Yep, I plan on using 10w30...thats what was spec'd so I'll probably go with that. What do you all think about Rotella T5 10w30, worth considering? or would Defy or PYB be better suited?

 

[901Memphis]

It was originally specified for 10w30 but there's no reason to use it with modern shear stable 5w30s being available. Defy 5w30 is a solid choice.

I also agree on the Maxlife dex/merc transmission fluid.

I had good luck with Prestone power steering fluid also, locally available at Walmart or auto parts stores.

Fram TG3387A or 3980 would be great filter choices, not sure if it uses the PF47 or 52 but they are interchangeable. The PF52 is longer though so you have to make sure it will clear the frame.

 

[gregk24]

Also, what size wrench does the oil drain plug take? Does it use a crush washer? If so what size?

 

[Nick1994]

If it were mine it'd get Mobil 1 5w30 and a Fram Ultra every 5k and use MaxLife ATF. Any power steering fluid and brake fluid and some good old green coolant.

On my 90's Chevy truck it took a 15mm for the drain plug.

 

[WiskyBadger]

No crush washer. If I had to guess is say 13mm or 15mm for plug. I'd try the shell t5 and give it a shot. Clean that old girl up in no time.

 

[901Memphis]

My Buick didn't have any washer by the time I got it but would weep until I bought a rubber gasket I found on summit racing listed as the correct gasket.

This is what I use.

Fel-Pro Oil Pan Drain Plug Gaskets 70820

 

[Merkava_4]

Originally Posted By: gregk24
Also, what size wrench does the oil drain plug take? Does it use a crush washer? If so what size?


It takes a 15mm wrench and the neoprene seal fits down into a recess in the drain plug. You don't have to change the seal every time; they're reusable. Felpro makes a nice drain plug seal for that; NAPA has them.

 

[gregk24]

Ok, good to know Merk! What do you all think of Next Gen 10w30 and Next Gen Maxlife 10w30? Pep Boys has them for $1.90 per quart, any good?

 

[gregk24]

Does anyone know what the oil capacity is of the 1991 Park Avenue?

 

[SJohnson]

If that has the 3.8 engine, it's the same one I have in my '96 LeSabre. I use mostly 5W30 or 10W30. Mine takes 4 qts. Do you know if the upper and/or lower intake manifold gaskets have been changed? Mine went bad around 140K. Started leaking coolant into the oil. It's a known problem on these engines. It's best to change both when it needs to be done.

 

[gregk24]

Originally Posted By: SJohnson
If that has the 3.8 engine, it's the same one I have in my '96 LeSabre. I use mostly 5W30 or 10W30. Mine takes 4 qts. Do you know if the upper and/or lower intake manifold gaskets have been changed? Mine went bad around 140K. Started leaking coolant into the oil. It's a known problem on these engines. It's best to change both when it needs to be done.


I thought these early 3.8's didnt have that issue?

 

[aquariuscsm]

Use plain ole dino 10W30,PYB,GTX,VWB,QS,etc. Mine held 4.5 quarts w/filter change.

 

[Merkava_4]

My Buick 3800 has always taken 5 quarts to get to the full line.

Valvoline Maxlife would be a good choice if you can find it reasonable.

 

[901Memphis]

The capacity is 4.5 quarts with a full drain and fill including the oem PF47 filter but if you move up to the PF52 or Fram 3980 you can dump a whole 5+ quart jug in and be just a smidgen over full.

I do this on my 3.1 Buick which specifies the same capacity.

 

[Merkava_4]

Run the full 5 quarts. I've even ran 6 quarts without issue, but finally decided it wasn't necessary.

 

[bigt61]

My 94 Pontiac w the 3.8 holds 4.5 quarts w filter. Any 10W-30 or 5W-30 should be fine. I use Maxlife, it slowed down the consumption. I also use the cheapest Purolator filter at Walmart, works fine. Bars Leaks pellets for the coolant. MaxLife ATF for the fluid top off - only change the fluid if it's brown - I've never changed mine. It takes a rubberized drain plug washer - cheap at the dealer - I change mine every 10 years or so.