Buick LeSabre: Real World MPG

luvjoy

Hello People:
Two months ago, bought used 1995 LeSabre with Dynaride. Everything about the car ride, etc. is perfect, as far as I can tell.
The MPG Are HORRENDOUS!
Around town, like 10 or 11.
Long trip, maybe and I say maybe 15 or 16!
I CAN LITERALLY SEE THE NEEDLE MOVE!
I asked the Dealer I got it from what he thought it might be and he said he doesnt know what is causing it and the warranty has run out. HE DID PUT IT ON THE COMPUTER FOR ME TOO...... UGH

Ok, Im a woman and really dont know what to do next, except maybe trade her in. I dont think its the engine, everything sounds fine. If anyone has any thoughts, please let me know.
Thanks Y'all.
Joyce

53rocket

I think your trouble shooting process is pretty easy. My '95 gets 25 and 26 mpg highway.

Obviously your using fuel. Could be;

Dried out gas line leaking, any smell of gas under the car?

Your fuel pressure regualtor is bad and it is letting too much fuel into the engine. Check your oil level and see if it is overfull or smells like gas. Too much gas could be leaking past your piston rings and into your oil pan.

Is your fuel gauge accurate? Does it accept 12 gallons to fill it when it is registering 1/4 tank?

luvjoy

Hiya,
Sorry I couldnt get back sooner. Been a long time, but Ive been sick and hospitalized a few times. I just last week had a local mechanic do a tune up and he said things were bad, still the same original wires, etc. BTW the car is a 98 LeSabre, not 95! LOL I checked it twice and gas mileage is the same. Not sure what to do next.
Thanks for you help, I just read your post and I will follow thru on those things.
Joyce

cookie98

I have a 2001 Lesabre with 66654 miles on it. My car was cutting off and then if I sit for 15 minutes it would restart. I took it and had them run a diagnostics test. The mechanic tells me that I have an upper intake leak which is going to run me about $700.00 to get fix. The part is only $163.00 without the labor and other things he want to do. Have any one have this problem and if so what is the price range to get it fix?

imidazol97

Did he explain how the "leak" would cause th car to cut off, I assume you mean it died, and then the car would restart later? Did he explain results of his diagnosis?

I'd find a second, qualified, mechanic to evaluate the car. I'd even pay to have a dealer check it--at one with a good reputation.

Upper intake manifolds were redesigned in 1999 when the failures became common. 2000 models on the failures have been rare. Perhaps the mechanic has a boat payment due or is wanting to increase Christmas spending this year.

The upper intake replacement requires removing the injectors and rails and the throttle body. These are quick and easy for mechanics who have done them before. The upper intake manifold comes off with 6-10 bolts and needs to be excamined when off to deetermine what really happened.

Many afficianadoes of 3800s would suggest removing a few more bolts on the lower intake manifold (metal) and replacing the lower intake seal--on 2000 models I don't know if that's necessary or not--on earlier models it's become a necessity. The bolts sometimes are loose and the original gasket has been redesigned by GM for the lower.

To help with self evaluation of his diagnosis:
do you see steam out the tailpipe when the car is first started especially on cool mornings compared to other cars in your area. That could be coolant getting into cylinders from a leaking gasket.

do you have a change in the level of the coolant when the car is parked on the same level after cooling overnight? The coolant has to be dropping if there's a leak letting it go into the motor.

do you have a rough running motor when first started due to coolant affecting the mixture and the plugs?

do you have a milky look to the oil on the dip stick? This is the most dangerous symptom if you have it because that's coolant getting into the oil instead of being burned and the coolants damage the bearings quickly when they are in the oil.

Also--there was a recall for that car to change the gasket where the throttle body bolts to the end of the upper intake manifold AND to change the bolts holding it on for a better seal there. Hot coolant flows through the upper intake manifold and into the throttle body to warm up the air coming into the motor quicker and there were some problems with leakage there--not in other parts of the manifold as in earlier 3800s.

The recall also added pellets of an organic stop leak which used to be added at the factory (factories-probably most makers use it) to seal up tiny seeps. The pellets are ground walnut shells or something like that. I add them to mine each time I drain and refill my Dexcool. I put in two crushed up into the hot coolant and drive the car for 30 minutes to circulate the stuff. This recall was done on 2000-2003 models if I recall correctly.

Your Dexcool should be flushed and drained every two years just like every other coolant. I do my own in the driveway.

Your car is about to the point where plugs need to be changed and wires also. They're supposed to go 100k but I replace anywhere from 60-80K. The mechanic may be wanting to change those and the water pump or some other things while he has the car.

cookie98

His explain that this is common in 2001 buick.
I have to check my records because I think I remember taking my vehicle back for that recall.
No I don't see any more steam coming out of the tail pipe on cold mornings then any other cars.
I will have to check my coolant level after I park the car and in the morning.
No my motor do not run rough starting first thing in the morning.
Just had my oil change last month and no milky look was on the stick.
I am going to have another mechanic look at it and get the wires and plugs change. Will post if this helps.

jorgec

Last August my wife, my son and myself took her car a 2004 Buick Le Sabre to Virginia Beach, Va, we live in Northern NJ so this trip is more than 400 miles we filled the tank the night before now remember the Le Sabre takes about 18 Gallons of fuel, it was my son my wife and myself plus luggage the same day we were leaving I had to go to my job to leave a key that is a distance of about 15 miles then turn around go back home because we forgot something that is 30 miles in total, then we couldn't find the turnpike right away when we finally did my speed did not go below 85 miles and hour at any time when we got to Virginia Beach we still enough fuel left to drive the car around the city and sight see so our car is extremely fuel efficient

imidazol97

>His explain that this is common in 2001 buick.

If he claimed that Upper Intake Manifold seeping or leaks area common in 2001 3800s, run don't walk to a real mechanic who's not trying to sell something.

The recall involving UIM was actually the throttle body where it is pressed onto the end of the UIM by 4 bolts/screws and they replaced those with larger washers under the screw to spread the pressure out more and they changed the gasket around the contact and they put antileak pellets that have ground up pepper or walnut shells or something organic into the coolant.

The hot coolant comes up through the UIM and goes into the throttle body assembly to heat it for better performance quickly when the car is started. Apparently because they quit putting sealant into the motors at the factory, a few gaskets had seeped. That's an exterior seep in most cases. And it was rare.

The UIM leaks on the prior version of the manifolds up to 99 were caused by seeps around the UIM gasket to the outside or from the part next to the EGR internal HOT tube deteriorates the plastic and allows seepage from the coolant passages to the throttle body.

tkcolorado

Right now we are using gas with ethanol in it.

85 Octane 18mpg City, 29 Hwy (Foothills) 31 (Flat) Car does NOT like this gas, it runs really rough on cold mornings with this fuel.
88 Octane 21mpg City, 31 Hwy (Foothills) 34(Flat). Car runs much smoother with this octane gas, and cold morning starts aren't as harsh.

drmrmn

Any pointers on replacing these before I begin? I just purchased this car and it's in very nice condition but I can hear and feel the rear shoes. They don't sound like metal to metal yet so I figure I can get by this time with just pads.
Thanks

rudwil

We live in North Jersey and travel to Raleigh, NC regularly, a distance of 512 miles to visit our oldest daughter. Our 95 Le Sabre just turned over 100K miles and consistantly gets 34 mpg on this trip. Unless we get hung up in traffic around Washington DC. I thought my car was the only one that did so well but now I see others who are also fortunate. Why did they have to change things.

andreasewa

I have a 92 Lesabre with the 3800 series (before the series II with the coolant problem), with 155k+ mi on the odometer.

I get at least 20mpg around town, and 28 - 30 mpg highway. (30mpg was the most ever doing 75mph on I-84 between Pendleton, OR and Portland, OR.) Who says you have to have a brand new subcompact to get decent gas mileage?

Oh, and with a tranny cooler and brake controller I can tow 3000 lbs, too.

Maintenance is pretty much just oil changes, tranny fluid changes and brakes.

I had to replace the driver side seat belt latch and the power antenna recently. Both were cheap at a u-pull-it. My A/C compressor went out last year, but with the help of a local A/C tech I am able to fix the A/C and convert it to R134a for less than $200.

jmac251990

can i run premium gas in my engine without it causing any trouble, I'm guessing i can cause all the octane rating is, is resistance to pre ignition so i dont think it should damage it

partsman

2001 Lesabre 19 in town 34 w/cruise on freeway, 0-40 mobile 1 oil. tires inflated to max on tire

01taurussel

Hi folks new to the board,

I don't drive fast, or crazy and I only get 20mpg on a 17 mile commute to work (one way). I am not pleased at all with 20mpg, and got 19 on my previous tank.
Car only has 58k, new a new air filter and tires are ok. I know it takes a couple miles for the engine to warm up in 9 or even 25 degree weather. The OD takes a couple miles to shift into OD just like my 01 Taurus did - that happens on cars.

Does anybody else have this problem in the winter? Please advise!

tkcolorado

What kind of road conditions (wet, icy, snow packed, dry)? What kind of traffic (stop and go, slow and go, or just go)? Does your state add ethanol to the gas during the colder months? What do you consider "not crazy" or "fast"?

imidazol97

Is this a commute with stoplights every quarter mile and stop and go traffic? Or is it a commute with 45 mph on the expressway.

In short trip driving of a couple miles on errands with few stoplights our car tends toward 22 -24.5 mpg. We drive gently. The car is parked in a warm garage for cold starting.

If your car is outside at 10 degrees, it takes a long time for the transmission to warm up. I can see the mileage go up on our car for the first 10 miles on a cold day when I get on the interstate for a longer drive.

Try a different brand of gasoline to try to minimize the alcohol you're buying.

And different tires have different rolling resistance. Keep them 2-3 pounds above the recommended which is probably 30 psi. Remember to recheck them after the temps drop; tires at 50 deg. have 4 more psi than tires at 10 degrees. Check the tires cold.

If your commute is like the first I described, you may be doing okay.

01taurussel

Yes, we add ethanol to our gas (10%). Most of the driving is in dry, non snow packed highway driving at 60-65mph. I keep my tires inflated above 32psi, and just put in a new air filter within the last 500 miles.

I never have had a car that gets mileage this low in the winter (ie Taurus 24v, Ford 500, etc)..........Could an O2 sensor be dying?

niceride3

There's hope! I had low mileage also this past Winter. About 20. probably from the severe cold and 10 min warmup in the mornings. 0 degrees F is not goodness. Spring has arrived and avg MPH was struggling to get to 22. No more warm ups for the last 6 weeks. Read somewhere on Edmunds that disconnecting battery for 24 hrs will erase memory of driving habits from computer. I wanted to add a sub to the audio and got to the battery to see a hole in the floor and white powder. Bought new batt and patched floor, cleaned acid powder, neutralized with baking soda. RE-connect battery and after two days of the auto trans shifting really creepy, the shifts got better and AVG MPH is 25 now. I drive 33 mi one way, 60-70MPH and some minor town driving. If I have to get crazy to pass someone asleep in the passing lane......I let her rip......love that 3.8L power!!!! :surprise:

fpsdean

I had a 2000 Lesabre and I'd get upper 30s if I used cruise on the highway and 33-35 if I used my foot and didn't abuse the gas too much, and doing city driving in the winter I'd get 23mpg.

I drove to Baltimore and back during spring break. I didn't clock mileage on the way there, but on the way home I got outside of the city, stopped for gas and coffee, got back on the freeway and put it in cruise and didn't hit the brakes until I got to Albany NY and drove the rest of the way home to Williamstown MA. I averaged 40mpg with 90,000ish miles and original everything (spark plugs, etc.) in the car.

These cars were great on gas. It now has 160,000 and my girlfriend is driving it and STILL averages 28mpg doing mostly city driving with her lead foot, and other than window regulators failing* and occasional oil changes, that's all either of us have ever done to the car and it still runs strong -- yes original everything minus tires, brakes and rotors!

* To those with window regulator problems, the AC Delco part costs nearly $200, but you can buy third party parts that probably last longer for $40-50 and install them yourself and save a lot of money.

My girlfriend did have a '97 Lesabre and the back end and fuel line completely rusted out, and that never got nearly as good mileage even before it started leaking gas. So they did something to the 2000 and newer engines and transmission gearing that greatly improved mileage.