Old Buick 3800 with slight oil leak

Yes I would try the Valvoline MaxLife High Mileage 10W30 syn-blend next time. The MaxLife synblend has a good reputation for fixing leaks.

If that doesn't work, try the Pennzoil conventional 10W30 HM. A fine oil for a Buick a V6.
I agree with this.

We had a 2002 LeSabre w/3800 in the family from new and all our cars at the time got Havoline conventional 10w30. At some point my dad thought he'd try Mobil 1, and it proceeded to leak. He went back to the conventional and the leak stopped. Car was sold with ~160k mi and no further problems with oil leaks. We also had a 92 LeSabre before that and it went ~225k mi on conventional before it was sold. No oil leaks.

Some may parrot that synthetic oil will only clean out a preexisting leak, and I don't totally disagree. However, I suspect seals in some older cars are not very compatible with synthetics. For your sake, I hope you're dealing with the latter and can reverse the leak.
 
It’s a 28 year old car, the seals are likely tired. You’ll likely get all kinds of opinions on what to do but I think it makes sense to switch back to syn blend and see what happens.
 
Barrs Leak Oil Stop Leak works wonders. One of the engineers who helped develop it used to post on a diesel forum, it's not a seal sweller, just a conditioner. It's in just about every car I own, been using it for years.
 
You should replace the valve if it has never been done before. Monitor the engine for signs of improvement afterwards.


Sorry to sidetrack but question to anyone that knows the design: how does that PCV function when the MAP is sitting on top of it? What/how is providing a source of vacuum flow when the entire valve is under vacuum?
 
Sorry to sidetrack but question to anyone that knows the design: how does that PCV function when the MAP is sitting on top of it? What/how is providing a source of vacuum flow when the entire valve is under vacuum?

Well after searching more online, I seemed to have found the answer to my own question,
Which sorta-kinda explains it. Without a vacuum diagram, its still kinda a mystery but anyhoo, back to the thread at hand...
 
If you’re having an issue finding the leak, Amazon has engine oil leak detection dye kits for around $20 or so. Add the dye and run a bit. The kit comes with yellow safety glasses and a black light.
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I had an 03 Lesabre with the Gen II 3800. Much as you describe, it would drip and mess mainly from the valve covers all over the garage floor. I had the best success with Quaker State High Mileage 10W30 which pretty much worked to stop all leaks. I'm not even sure if the particular oil is still made as I believe they have now gone full syn on this oil, and I don't believe it was at the time. I also had weeping beginning around the rear main. I put a can of Blue Devil Rear Main Sealer in as well. Long story short between the QSHM and the Blue Devil, the car stopped leaking and was dry when I sold it in 2022.
 
Years ago, I had a 1995 Buick Park Avenue with the Series II 3800 V6. They are "okay" engines, not as bulletproof as the 1988-'91 3800. At 150,000 miles, mine was weeping oil from the valve covers pretty bad and my mechanic said it was weeping at the rear main seal as well. Mine wasn't anywhere close to dripping on the floor. So, check the valve cover gaskets and rear main seal. If you want to keep this car forever, it is ESSENTIAL that you monitor the upper intake area for coolant leakage and keep a close eye on the overflow tank. The 3800 Series I and Series II have plastic upper and lower intake manifolds that like to crack due to years of heat cycling. The EGR tube is routed through the plastic on the Series II, not sure about Series I. If you are lucky (as was I), the coolant will leak externally and you will smell it and see it in the intake valleys. If you are unlucky and it leaks internally, the engine will hydrolock in no time and she's a goner. Just keep an eye on fluid levels and address any shortages and you should be fine for a long time. Just cross your fingers that parts will still be available down the road.
 
Agreed.. what you say us correct. I should have prefaced what I said to obviously make sure the leak isn't a danger. I do get sick of storing cardboard to replace with fresh ones after it gets saturated, but the 800.00 could well be saved to fix something that really needs fixing. In my situation anyway.
Same with me, but I am going to try a potentially cheap fix. Tomorrow my cousin is going to replace my PCV valve with a new $7.50 AC Delco PCV valve from Oreilly, and a new PCV hose too. There is a chance that might stop or reduce my oil leak.

You might consider doing the same, but I assume your mechanic would have already thought of that?
 
There have been a variety of good suggestions in this thread. I'm going to try a combination of suggestions. Will install new PCV valve and hose, switch to a conventional 5W30 if I can find a good one, otherwise a good 5W30 synblend, if still leaking will add some stop leak, if still leaking I'll take it to a mechanic for a full going over.

I can't let this car die because I'm very handicapped and this car is comfortable for me. The passenger seat has been customized for my body and the car is roomy enough for me. Also, the huge trunk is perfect for my cousin to store my mobility scooter.

I can't get into modern cars because the new safety regulations require a signifigant gap between edge of seat and door for side impact safety. I'm physically unable to get into a car with that gap. I can't get into any modern cars. Also, modern cars trunks are to small for my mobility scooter. A modern SUV or van would have enough room, but be too high for me to get in and modern vehicles all have that extra gap that I can't get across to enter vehicle.

So I must keep my Park Ave in good running order longterm.
 
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my dad had a 97 la saber, with a leak, check or have someone crawl under car and tighten the oil pan bolts as the gasket material shrinks,my dad was the same way,he liked his car and drove it till he was 100 years old,it actually burned very little oil,he used peak 5w-30 synthetic.
 
I had an 03 Lesabre with the Gen II 3800. Much as you describe, it would drip and mess mainly from the valve covers all over the garage floor. I had the best success with Quaker State High Mileage 10W30 which pretty much worked to stop all leaks. I'm not even sure if the particular oil is still made as I believe they have now gone full syn on this oil, and I don't believe it was at the time. I also had weeping beginning around the rear main. I put a can of Blue Devil Rear Main Sealer in as well. Long story short between the QSHM and the Blue Devil, the car stopped leaking and was dry when I sold it in 2022.
I had also found that the old QS HM oil was easily the best at slowing leaks. In my use it was 10w40 blend. Only a one vehicle experience, but it did far better than the HM's from Valvoline and Castrol. That QS HM seems to be gone for sometime and was replaced by QS "all mileage". I haven't tried that and it seems to be conventional.
 
I had also found that the old QS HM oil was easily the best at slowing leaks. In my use it was 10w40 blend. Only a one vehicle experience, but it did far better than the HM's from Valvoline and Castrol. That QS HM seems to be gone for sometime and was replaced by QS "all mileage". I haven't tried that and it seems to be conventional.
I see Walmart still carries Quaker State Synthetic Blend High Mileage -- $18.82 5 quart container.
 
I see Walmart still carries Quaker State Synthetic Blend High Mileage -- $18.82 5 quart container.
I just checked and you are correct! Priced correctly as well. That had disappeared from Walmart (as vendor) online listings for quite a while. It appears that they've dropped the syn-blend statement form the container. They evidently also have a full syn HM listed now as well.
 
I just checked and you are correct! Priced correctly as well. That had disappeared from Walmart (as vendor) online listings for quite a while. It appears that they've dropped the syn-blend statement form the container. They evidently also have a full syn HM listed now as well.
I was down at my local Walmart yesterday. Quaker State on the shelf besides the HM FS was jus the All Mileage. Assuming, you would have to order the QS HM Synthetic Blend offline?
 
Agreed.. what you say us correct. I should have prefaced what I said to obviously make sure the leak isn't a danger. I do get sick of storing cardboard to replace with fresh ones after it gets saturated, but the 800.00 could well be saved to fix something that really needs fixing. In my situation anyway.
I'm going to try Blue Devil Oil Stop Leak as recommended by someone earlier. My cousin replaced my PCV as recommended by someone earlier. He thinks my old one was fine (he tested it), but I'd already bought the new one. Those are 2 cheap easy things you might try.

Another thing I'm going to try is switching from Syn HM to Conv or Blend HM. Conventional HM if I can easily find it. Otherwise Blend HM. Any brand.

If none of the above resolves it. Then replace valve cover seals and dipstick O-ring will be next. If it's my rear main seal, it's not worth the cost/hassle and I'll just live with the drip.
 
ATP AT-205 has been mentioned many times on BITOG and other forums at being excellent for stopping some leaks.

Do search on that here and other places for some videos and reviews.
 
ATP AT-205 has been mentioned many times on BITOG and other forums at being excellent for stopping some leaks.

Do search on that here and other places for some videos and reviews.
Do you think ATP-205 is better than Blue Devil Oil Stop Leak, or equivalent?
 
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