27th Sep 2010, 17:12

Is your car low on coolant or running hot? 38,000 miles is very low to have this issue. I had a '99 Park Avenue that I traded a few years ago with over 145,000 miles, and I believe it still had the original intake manifold (I bought it used).

15th Dec 2010, 18:39

Same here. Bought a mint 98 LeSabre with 59,000 miles in May of 09, and on the way home the CEL came on. Drove it for about a month with the light on sometimes, and other times not. Brought it in to get checked out, and $900.00 to have the UIM replaced.

It seems besides this being a common problem, it also seems to happen to a lot of people shortly after buying it used.

One thing I'm worried about is it happening again, as I am not sure if they replaced it with an upgraded version or not.

The part number for the new Dorman unit they put in is 15668.

Anyone know if this is an upgraded version?

24th Jan 2011, 17:30

I purchased a 1998 LeSabre for my mom about 5 years ago, now mechanic is telling her she has a leaking plastic manifold, and total repair will be $810 including hose fittings, gasket set, oil change and new anti-freeze. The car has 75,000 miles on it. It has not locked up yet.

So the question is, does she go ahead with the repairs assuming no damage to the engine or cut her losses now?

25th Jan 2011, 15:14

This is a very common failure for the 3.8 Series II. It is very rare that the engine would hydrolock and be destroyed. In fact, the price you quoted is pretty reasonable. I would certainly have it repaired. If you are still driving the car, I would stop as you can make the problem much worse and more expensive. If you try to sell it non-running, it will be pretty much worthless, and you still have a very nice car with relatively low miles. You certainly won't find a comparable car for $800.

27th Jan 2011, 20:11

This is very strange to hear. I know of many who own Buicks, all with the same 3800 series 1 or 2, with over 240 k on series one's and over 500k on series 2's, all with original engine and transmission. I think some of you may be victims of negligence on behalf of previous owners. Engines require maintenance. My Buick received little before I bought it, and it shows, but not catastrophically. The 3800 series ii is considered to be one of the best engines ever created. Wards top engine of the century. I think many of your cars were severely abused before you bought then.

28th Jan 2011, 17:34

Unfortunately this is a very common failure in the Series II 3.8, not the Series I however. My parents bought my grandparents '98 Bonneville, and it developed this problem at about 100,000 miles. My grandpa always had it serviced regularly and never abused it, and this problem originally cropped up while they still had the car, the dealer was able to temporarily fix it for them, but as I stated, it did eventually fail. I also had a boss with a '99 LeSabre that had the same problem. I have personally had 2 Park Avenues with the Series II, and so far I have been fortunate not to have this problem.

30th Jan 2011, 13:58

Yeah,this malfunction is almost a certainty with these cars, since they were poorly engineered from 1995 on. But what I've always wondered was, if the retrofit with the aftermarket intake manifold could make it more or less as good as the old 3.8 liter, or if the retrofitted motor was still a delicate thing?

6th Feb 2011, 13:58

You can add me to the club. I inherited a 98 Buick LeSabre from my mom with 32,000 miles on it. A thousand miles later, coolant just disappearing, and heater quit heating. Added coolant and heater worked, and a week later, same problem. After reading the previous comments, I guess I'd better get it to the mechanic. Hopefully, I will make it to the shop less than a mile away. Good grief, I can't take much more.

7th Feb 2011, 17:17

Good Lord, if you truly inherited the car, you are out $1,500 at the most for a very nice car with 32,000 miles. Granted, this should not be happening on a car with that low of mileage, but it is 13 years old, and you did get it for free. If you can't put up with repair costs, give it to me, I'll gladly put $1,500 into it and have a very nice second car.

2nd Apr 2011, 01:46

You said you replaced the engine and it stalls. That is because they reused your throttle position sensor, which got coolant into it, and is no good. Easy fix.

31st Aug 2011, 14:41

I replaced the plenum and intake manifold gaskets on my 1999 LeSabre, and had no further problems after that. I'd say go ahead with the repair, as that seems to take care of it for the long run. In fact, I'm buying a 1998 low-mileage LeSabre, and though I'm preparing myself for the fact I'll probably have to go through with it again, it's a bargain in all! Great car!!

7th Sep 2011, 15:26

I am in the process of purchasing a 98 LeSabre from a neighbor. It has 44,000 miles on it. I am making payments on it for the total price of 2,800 dollars. Deal? And this is my first car, so what should I expect and prepare for?

8th Sep 2011, 16:56

Sounds like a very good deal to me. I would keep an eye on your coolant level though. As you may know, the intake manifolds in these cars are notorious for leaking and causing serious engine problems.

19th Sep 2011, 15:42

I had a broken valve spring.

27th Sep 2011, 13:17

I just had the same thing happen to me with my 98 Buick LeSabre, that was purchased in May for 4,000 dollars. Rolling down the highway when the temp gauge comes on. Pull over, put more antifreeze in, then the check engine light comes on. I thought I was getting a sweet deal, 4 grand for a car with only 60000 miles. Looks like we've all been taken to the cleaners on these lemons.

13th Oct 2011, 10:34

I have the same problem with my 98 Buick. The water leaked in the starter, and the starter exploded. Did anyone get reimbursed for this? If so, give me the information. gerald_hpkns@yahoo.com

30th Oct 2011, 22:54

I also had a Buick. I say had, because the same thing happened to me. The repair service wanted 3000.00 for a rebuilt engine.

As a result, we ended up getting a new car. Very expensive for us.

29th Apr 2013, 02:23

98 Buick Regal LS 3.8L Series II (Non-Turbo)

Inherited from my mother after she passed away still in the living trust... I am the trustee. 78,000 miles on it. This car always runs great, a lot of long highway miles at 65 mph to 75 mph in AZ, but it has used lots of Dexcool coolant 50/50 mix (not leaking it though anywhere).

But it did have a previous problem with the ignition switch harness (shut off when turning, all dash lights on sporadically, much other stuff)... These are famous for that too. Tough job, but worth it, replaced the key switch & VATS II keys too while in there.

Back to the plastic upper manifold (plenum) problem though... I had just returned from 525 mile round trip to PHX, AZ and it ran just fine. The next night my wife called me as our youngest son was driving a short stint on the interstate, 2 miles, and off at the next exit. When they reached the bottom of the exit, the car started missing, they parked at their destination a few blocks away, the car was still missing, and they shut it off.

Later (2 hours or so), they go to start it, it won't crank, click, click, click only. Called me for rescue. Sounded exactly like the starter failed (battery tested very good with a load tester & fully charged). Got a rebuilt starter from Auto Zone, then pulled the old one out, replaced it, same click with no spin/crank. Took the old starter to Auto Zone, tests good. Uh oh! Ordered another ignition switch harness, thinking the VATS II was shutting off the crank portion of the starter (it can), installed it and checked all under hood fuses... Same problem.

Pulled off the accessory belt, engine will crank by hand with 1" socket and long bar counter clockwise 340 degrees or so, then back clockwise the same distance, but locks up tight at each end (1 cylinder seems to be hydrolocked???). Time to research. I saw this problem mentioned once before elsewhere, concerning this issue having to do with the EGR tube in the upper manifold/plenum.

I start to pull the spark plugs. The front 3 look OK, but can tell it has had coolant hit each plug occasionally. Each look like they are burning OK though, all three front holes are dry as a bone. Started to pull the backs (these are a nightmare with those aluminum plug wire guards on the ends), passenger side out, hole dry, look the same as the fronts, middle still isn't out yet, but as soon as I got the rear driver's side plug out, about a cup and a half of Dexcool coolant flows onto the floor (the thing was hydrolocked on combustion chamber #6).

Now it will hand crank 360 degrees and more. So I put the battery back in and it spins free, even with #4 plug still in, though it is hitting the compression stroke there.

Auto Zone has the entire upper manifold kit $129.99 in stock with limited lifetime warranty. I pulled it off, replaced the spark plugs, Doorman manifold kit Part #615-180, includes everything for the job including the new injector o-rings, upper and lower, PVC valve, all other o-rings needed, and all gaskets and other parts for senders/vacuum ports, & full instructions including torque values and procedure, etc. (takes about an hour to prep the kit to even go on).

And it includes a new, smaller around, steel riser for the EGR, that you grab a hold of your old larger aluminum riser with vise grips, twist and pull out of the lower intake manifold, then just tap in the new riser into the lower manifold (the kit came with 2 different diameter risers, same height; mine needed the larger around of the 2).

Only special tools needed are a 3/8" inch pound torque wrench that reads 20 inch lbs. - 200 inch lbs.

After cleaning out the lower manifold, this was loaded/flooded with coolant, soaked it all up with paper towels, bagged and disposed of properly, cleaned & scraped properly all the gasket surfaces including the throttle body, started installing the upper manifold/plenum... Hand screw in all upper manifold bolts using an 8mm & a 10mm socket (driver's side rear corner is a long stud with a 10mm nut... I stacked 3 of the 10mm nuts here as I did not have a very deep socket, then backed the lower nut with a 10mm wrench once all torqued properly, and removed the other 2 nuts that were for the throttle body actually), and a 1/4" drive socket extension only, no ratchet or wrench. Then, torque all in the required sequence to 22" lbs, then 44" lbs. again in sequence, then 89" lbs., again in sequence. **See Torque Sequence below. ***SPECIAL NOTE: Torque carefully in INCH POUNDS... Not FOOT LBS.

Standing in front of engine-radiator/bumper/grille area... Torque sequence (clean all bolts first, then install hand tight & torque. All are 8mm bolts, except #7 which is 10mm nut on long stud), sequence is center rear #1, center front #2, driver's rear #3, driver's front #4, passenger rear #5, passenger front #6, driver's inlet rear #7 (this is the long bolt stud with 10mm nut... stack 3 10mm nuts... use 2 from throttle body, then remove to install rear EGR bracket), driver's inlet front #8, passenger end middle #9, passenger front end #10.

Then re-install the throttle body and injectors with new o-rings provided, and fuel rails as a unit, coat those injector o-rings with Vaseline lightly and they will slide right in when you tighten down the fuel rails. Re-install the rest in reverse order of removal.

Auto Zone will loan you the 20" lb.- 200" lb. 3/8" drive torque wrench for a $50.00 deposit (90 days use, no return, they take your deposit and you can keep it). I had a 120" lb. to 300" lb. one, but that wouldn't work here.

The area where the EGR riser goes through the plastic upper intake on the new kit does not any longer contact the riser as ours did before (it has an air space all the way around of about 1/4", and it is sleeved with metal so it will not melt the plastic again, which causes the original problem of cracking/melting the plastic intake). They also changed the coolant inlet/outlet to the throttle body area and seals, materials, etc. to help alleviate the issue, so this is a much improved kit, so they now lifetime warranty the Doorman Manifold kit at Auto Zone.

Still installing the rest, will add a comment again when I fire this repaired bad boy back up tomorrow. Going to flush the radiator, install the new plugs after I spin it a bit to dry out all chambers, and coat everything with oil properly before the initial start up.

I would also like to run into the GM engineer some fine day that designed this plastic intake too. It should have been a factory recall with a redesigned aluminum part replacement, period.

With the tow home to my garage $40.00, the rebuilt starter $147.00, the 6 plugs $20.00, upper intake manifold kit $130.00, coolant $12.00, new ignition switch harness $47.00, I'm at $400.00 + my labor so far. But I have a good used starter spare and an ignition switch with harness spare for the trunk. I travel a bunch.

Sorry about the book, but some may need the info here... Many I think. If it starts using coolant for some unknown reason, stop immediately, & replace that upper manifold before it hydrolocks a cylinder or cylinders, as liquid cannot compress when those valves are closed on the compression stroke. It will flat destroy that 3.8L engine.