I know this has been discussed plenty on here. I know the issues with this engine, the 3800 Series I and II. So no need to give a long explanation on these issues for this thread.

I have 11 classic cars, some of them are newer cars. In my collection I have a 1989 Buick Reatta (37,000 miles at purchase), 1991 Oldsmobile Toronado (43,000 miles), and a 1996 Oldsmobile 98 Regency Elite II (9450 miles yes that is correct). I had also bought as my first new car in 1987 a Buick Lesabre coupe with a T-package that eventually ran to 253,000 miles and only was junked because of rust. I owned it for 17 years and 104,000 miles and the next guy whom I sold it to ran it 8 years and another 150,000 miles. My 1991 Oldsmobile developed a small coolant leak on the intake gaskets and I had those replaced. No big deal.

So here are my cars

https://www.youtube.com/channel/UC3O...ACOGg-A/videos

Now the real question I have is on the 3800 Series II. I fully expect to have to eventually replace the upper intake manifold with a new one along with the gaskets. I will use the improved one with the metal sleeve in the EGR pipe area along with the new improved gaskets for the lower intake manifold. I plan on doing the valve cover gaskets, tensioner heater pipes with aluminum ones, along with a new thermostat and gasket. With that explanation out of the way I think I have a good handle on what needs to be done someday. Even on my 1996 Oldsmobile 98 with now 10,000 miles. All I have done on that for now is exchange the coolant with fresh dexcool. When I got it it had the original stuff in it but still looked a clear orange color and the car went 175 miles in 23 years! As I drove it about 500 miles it started to turn a but darker due to age so I had it totally exchanged with fresh dexcool. I plan on watching it but this is a collector quality car that will only be driven in the summer and about 500 miles a year.

I also have a driver that I just got a month ago. A 1999 Buick LeSabre with 61,000 miles. I drove it 500 miles home on purchase, since then I have changed all fluids and drained and filled the radiator with new dexcool. While the reservoir was orange but still close to full and not low, the radiator fluid was a more darker color and greenish. No sludge but I deduced that it had been refilled with some sort of universal coolant since there was no sludge in the system or in the pan when I drained it. I have also replaced the thermostat and gasket.

I also have examined the top of the intake numerous times and now have driven the car about 1500 miles. Runs great, no smoke, mileage on highway is 32 MPG. A nice car. However when I have checked it I am getting the slightest pooling and I mean slight. About a thumble full of coolant in one cavity on the front RH side and also rear which is hard to see. We are talking practically nothing.Also you can notice a minimal lower level in the reservoir, maybe a 1/16" after a week or so.

So my question is not am I going to have to do a repair, but generally will this failure more quickly or gradually get worse? I plan on watching it.The car is well worth fixing and I love it. I hope to put off the repair until the summer or spring.

Coolant is coming from the lower intake manifold gasket. While you are replacing the upper plenum gasket, replace the lower manifold gaskets and the coolant elbow. Change the coolant elbow to the metal style. You might as well incorporate an oil change due to accidentally getting coolant into your crankcase while changing the lower gasket.

Thanks for the reply I know it is leaking, I think from the upper plenum since I can see it pooling right below the upper plenum in one spot right below the upper black intake manifold.

I checked the oil looks fine. The question was how soon do these fail? How quickly, I would guess it depends on the car. So if I watch it for a while what are the odds I make it for 3-4 months until spring? Really want to put it off for a short while.

Failure is dependent on climate, mileage, abuse, heat etc.

Once it starts leaking, it can and will get worse. Some have noticed nothing until the engine hydro-locks. Once the coolant mixes with the oil, it eats away at your main bearings, next thing you know, knock knock knock knock. Been there, done that.

IMO, the sooner the better. You're watching a ticking time bomb with no hands.

Noted, but I look at it 3 times a week so I will monitor it. If it speeds up any I will do it.

If they all did that they would have all blown up on most people, since most people never check anything and abuse cars.

If if blows up it blows up. I paid very little for it. Cosmetically a very nice car so worth it to fix it.

That'* not really a good way to look at it. I was giving you worst case scenario of what could happen. If you want to toy with the unknown, have at it. Don't waste our time asking for advice, and when we give it to you, don't shrug it off.

**** YOU AND YOUR BOARD YOU POMPOUS ASSWIPE

I GOT 13 CARS and so shove your board up you ***!! Now delete this and my account.

Your attitude really stinks. First you try to tell me what needs to fix while I clearly stated I knew in the post. So first you do not read like a know it all and then you say do not waste your time. Well I noted your response, Obviously you know it all.

Hate to see your work another know it all.

He requested to have his account deleted after he was given 3 infractions for his rudeness. I choose not to delete his account because I want his pompous behavior to be in public view FOREVER!

And now after threatening me with his attorney, his account is now banned.