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Buick LeSabre Engine help



  • khh3khh3 Posts: 1
    I have a 1993 buick lesabre, here's my problem, first of all let me add this, new fuel filter was installed, fuel pressure was checked, and was in parameters. So my problem is, the car starts fine, idles fine. On the highway and on city streets, when stepping of the gas, the car boggs down step down further, and more so, let up slightly and its ok. I was treating the fuel with star tron, and used recommended amounts and it cleared up for sometime, now I am back to the bogging down when stepping on the gas, and the fuel treatment no longer works. Have any Ideas? please help!
  • Just got this Lasabre about a week ago. 1995, 89,000 miles. It has the 3.8 V6. It seems to have been well maintained. Incredible cosmetic condition!

    It starts on 1st turn of the key and runs very smooth.

    I do hear some engine knocking, sounds like it is coming from somewhere on the top end passenger side. The knocking starts when I put it in drive.

    I also have an oil leak from somewhere, it is also on the passenger side. I got underneath and cleaned around the oil pan and oil filter but the leak is coming from somewhere above. I didn't see any leakage around the head covers.

    I am having a hard time locating where the oil is coming from. Any ideas on how to narrow it down?

    Thanks in advance

  • bob252bob252 Posts: 48
    Hi Doug, I just sent my 95 to a new home with 250000 mi on it, For your oil leak, LOOK just above the filter (oil) and you will see the oil pressure sending unit, it costs about $8...and from what you described I'll bet that is it. A very easy job, take off the right front wheel and remove the rubber splash guard (it has little plastic pins that look like a nail head,use diagonal cutters) DIKES gently go under the nail head and pry upward to remove them. They will come out in two pieces, then start the engine and check for the leakwhere the wire connects. Check Autozone for the best price if one is near you, as for the knock well that is pretty much impossible to guage without hearing it. you can e me at rsa2500@hotmail if you need more info. I can only hope that it never ran without any oil in it.But if it only knocks when put in gear then it probably is not the engine..Hope this helps Bob.
  • Bob,

    Thanks for the info I will check out the oil sensor.

    I don't know the history of the engine, but it runs smooth no hitches at any speed and no smell of hot or burning oil coming from anywhere. I got the car for song and have another I drive regularly so I can take my time with the LaSabre. Took it for a small road trip to Fresno (about 800 miles round trip) the ride was so smooth all my passengers abandon me to sleep!

    I will let you know the outcome of the oil sensor

  • dewc3dewc3 Posts: 35
    I am looking for a diagram for the 1997 buick lasabre engine. Also my oil pressure is pretty much nothing and hitting the red line, I was told by several mechanics and including the dealer that oil pumps rarely go out in that buick but they suggested that I take off the oil filter, then remove either 2 bolts or 4 bolts and underneath that is something called a by pass valve or also by the name of oil pressure regulator valve, the dealer calls it a by pass valve, has anyone ever heard this, but most of all I need a diagram of the buick lasabre 3800 engine
  • dewc3dewc3 Posts: 35
    I was just wondering do I have to lift the engine in any way to take off the oil pan to replace the gasket on a 1997 buick lasabre 3.8 engine. The way I can see it is there is like to bolts that come off to get some kind of guard off so I can see the remaining 2 bolts on the backside of the oil pan, otherwise I see the other 18 bolts. Also I have replaced something called the bypass valve or " oil regulator vale" that is located inside the oil filter housing. You take off the oil filter & then there are 4 bolts to take off, the the by pass valve is in there spring loaded. The valve looks like a socket that has been hollowed out best I can describe it, but my question to that is I replaced that valve and oil pressure was great, then I drove around for a little bit then the pressure dropped down to like it was in the red before when I had to stop driving it. But I guess my question to this valve thing is COULD the spring be bad to where it is not pushing the valve back and forth like it should be doing because the valve appears to be jammed again inside the oil filter housing and the spring doesn't appear to be doing its job as well. ALso is it tru the the oil pump either works or it doesnt by the dealer and auto stores as well. I was able to drive 4 miles before the pressure dropped back down since i replaced this bypass valve :cry:
  • bob252bob252 Posts: 48
    Hi No need to lift engine, remove the splash guard from the starter, remove the bolts and twist the pan to remove the oil pick up (2 bolts) and the pan will fall down. The pan gasket from the 95 that I own was reusable and a thick plastic one. You need to remove that splash guard to access the bolts in that area, you do not need to remove the starter....Hope this helps.
  • dewc3dewc3 Posts: 35
    Thankyou for your reply. I am going to replace the spring that goes behing the bypass valve which all that is behind the housing. You take off the oil filter, then remove 4 bolts, then that will come off and there is a little valve that looks somewhat like a socket and a spring goes in behind that. Then I am replacing the oil pickup tube with a new one along with a new gasket. Then I will see if I am able to get oil pressure, if not then any suggestions would be helpful as I would not think the oil pump itself would let a car run 4 miles then drop pressure, oil is not getting somewhere and Im hoping that replacing what im doing will resolve this. So my next question is when a oil pump is bad, will it work intermittingly or just NOT work at all, I was told it would just not work at all.
  • This is probably very simple.
    I have a '97 Regal with Plain Jane Kelly Springfield tires. Great tires, quiet, smooth, and I can drive any where in ice and snow.

    I cannnot drive my 2003 LeSabre in ice and snow. Tires.....Used Car "salesman" tells me they are new. They LOOK like good tread, etc. BUT the LeSabre is a heavier car (?) than my Regal and the LeSabre is useless in snow or ice. Dangerous is a better description.

    Would I be safe in buying new or similar tires for my LeSabre?
    Any thoughts would be appreciated.
  • dewc3dewc3 Posts: 35
    Can someone tell me the necessary steps to replacing an oil pump in a 1997 buick lasabre limited with a 3800 series 2 engine, for example what tools needed and if timing chaing has to come off, so if there is someone that is 100% sure of the steps I need to take please respond as I dont have 700 bucks to take it to a garage and yes im mechanically inclined, just need the steps :sick:
  • I replaced the Fuel Pressure regulator my engine still runs the same to better!
  • niceride3niceride3 Posts: 17
    The garage or you, did not replace the wires?? Spark plug wires need replacing too at that interval.

  • I've changed wires's , new plugs double checked gap.060. Today the buick barely made it home from work! I used some fuel injector cleaner last week on a full tank that made it run better!
  • this buick is going to the shop!
  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 21,319
    Post back what they find is the problem please.

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • orangeuporangeup Posts: 23
    I had my oil changed at one of those places (short on time) and they overfilled the oil by 1 1/4 inch (30 mm) on my 97 Buick LaSabre. I drove for 430 miles before I found out this was the case and now I have no oil pressure. I bought the book on this car and it literally says that the lack of oil pressure will cut of the fuel supply". I checked the fuel pressure and I have 46 Lbs on the rail at the Schrader valve which is 6 lbs over the mininum, but the car won't start but does turn over. I checked the ICM/coil/plugs, and the alternator and they all passed their tests. I now suspect the lack of oil pressure shuts down the fuel injectors through the ECM (the brain). Can anybody confirm this?
  • bob252bob252 Posts: 48
    Hey Mike, you're on the right track, the oil pressure switch is right near the oil filter, and is not an expensive part, in fact it may be the problem. You did not state about engine noise (rod/bearing knock) so if there is no noise you either have a bad fuel pump or the switch is bad. I had to change mine in my '95 due to it leaking (weeping) at 202,000 then at 220,000 in the middle of January (0f course) the fuel pump decided to quit, not fun in Mass. and 15 degrees out Try this when it is very quiet out, close the door and just turn the ignition on but don't crank it, listen for the whirr of the pump, they usualy get louder when they are tired. This will give you a start. My guess about the overfill has nothing to do with your situation as it may be the person used an even number of quarts, look at the specs in your owners manual, I believe it is 4 1/2 qts. not 5. Other things that can cause this problem are the crank sensor/cam positioning sensor as well. Start with the pressure switch an easy job.
  • orangeuporangeup Posts: 23
    Well, after I drained quart of oil the oil pressure came back but it still won't start. So much for the oil pressure theory blocking the operation of the fuel injectors. In fact I tried spaying some starting fluid into the manifold and got an ignition that scorched the hair off my forearm. Please everybody don't do this. Thank God me and the garage I am in survived. I was trying to test if the absense of fuel was the problem. Lets just say never mind trying to find it out that way. So, now what. It's got fuel pressure, it's got oil pressure, it's got spark, it's got Air, and it cranks over but it won't start. Anybody care to guess. I'll have to try that new crank sensor and its the timing but I'm not hopeful. Thanks for your time and thoughts on this.
  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 21,319
    You should be going through the basics.

    Take off a spark plug wire. Use an old plug or remove one of yours from the front. Put the plug on the metal part of the motor and have someone crank while you look for a hot blue spark.

    Check for injector pulsing by using a 197 running light bulb. The little ones about the size of a pencil with two wires on the side of the glass for contacts. Straighten the wires and put them into the injector connector for one of the inejctors. Have someone crank. Does the bulb flicker with the pulses.

    Check for camshaft rotation by looking into the oil filler opening while someone cranks the motor. Do you see the lifters rocking indicating the cam is turning.

    Get a fuel pressure gauge and connect it. Crank the motor and see what the pressure does.

    You say that you have spark. You didn't say how you verified it--I guess I see that the flashback was due to ignition... But if you have spark, your problem is not failure of the crankshaft position sensor.

    There is a jumper in the engine compartment for connecting battery voltage to the fuel pump to bypass the other relay for fuel pressure.

    Air. Fire. Fuel.

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • Does anybody have a good deal on the head lights and signal lights part,grill ,sub grill, front bumper,and right fender for a 1996 Buick LeSabre dark cherry.
  • I have a 96 Buick LeSabre and I had the same problem.I took it to the mech. and he chage the ignition control mod. and the first coil to spark-plugs was burn out,it was also replace and everything is working fine
  • orangeuporangeup Posts: 23
    OK, Orangeup here. Here's what's transpired. I physically pulled the plugs and they looked shot but they were not because the replacement iridium plugs look the same. However, in hindsight I saw they looked wet!!! So I drained off a quart and a half of oil and with the new DRY plugs and wires and it started, at least for a minutes or two. Oil pressure came back, but now lots of smoke was rolling out of the exhaust. White smoke, i.e. liquid antifreeze. So I shut if off at first not realizing it was liquid (remember hindsight). Tried to start it again (don't ask why) and it "fluid locked" the pistons. The motor would not turn again. After lots of conversations at the parts store I found out that the 97 Buick LaSabre's has a chronic tendency to blow the gasket between the upper intake plenum/manifold (looks like a black plastic breadbox between the valve covers) and the bottom manifold. (Vin K engine, not all models have a two part intake manifold.) This gasket is made of thick plastic ($52) at Autozone and rubber track on both sides of the gasket and come with a smaller rubber gasket for the throttle body. There are two antifreeze ports that go up through the plenum to the throttle body. The final torque setting on the 10 plenum bolts is suppose to be 89 in-lbs but I am not entirely convinced the throttle body's 3 bolts are suppose to be 24 in-lbs like the Autozone instructions said. Anyway, you have to remove the alternator, the coil pack, plugs and wires, the engine wiring harness, connections to about 5 sensors and three vacuum lines, the throttle body, the fuel rail and the injectors (use new o-rings). to get to the upper intake manifold/plenum and behold the fuel ports. The entire area between the ports was standing full of antifreeze. I used a sponge to soak it all up, 2 cups worth. I had serious nagging doubt this was going to be solved by a new gasket but alas I had no other information to tell me any different. So all good and well I got it all put back together, after several days of heavy drinking (it was 90-105 degrees in the garage) and I started the car after adding oil, antifreeze and bleeding the fuel line. Good pressure (46-50 lbs) on the rail. Two minutes later again thick smoke rolling out the tail pipe.

    I now suspect those throttle body bolts aren't tight enough but think something else is going on. After some serious violation of certain a commandment (Hell must be run on starting fluid) I am now pondering the next steps. Do a quick compression test provided it starts, smoking and all. Tighten those throttle body bolts to 89 in-lbs and plugging the recirclation pipe from the exhaust to the throttle body, because I don't wish to recirculate smoke like that back into the throttle body. So by now you're all suspecting me to find a blown head gasket, right? However, I have to tell you that my oil level did not increase as a result of the engine running, by leaking antifreeze back into the block. Oh yes I did lose another 1/2 gallon of it this time but where did it go. All out the tail pipe? I doubt that but where? Anybody have an idea how else antifreeze is getting into the intake valves. Is it the gasket underneath the bottom intake manifold? I am at my wits end here and ready to call the wrecker but what is holding me back is that it's still such a nice looking car. Any suggestion?
  • orangeuporangeup Posts: 23
    A friend of my suggested on a long shot guess that maybe the antifreeze pressure is too high due to a broken thermostat. Does that make sense to anybody. The thinking here is that the engine gets too hot and the antifreeze boils providing high pressure to whatever point is weakest this time, i.e. like the throttle body gasket.???
  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 21,319
    edited August 2010
    You wrote the description well.

    I don't see mention of something really important. Did you change the LOWER intake gasket while you were in there?

    The upper plenum has gaskets under it between it and the lower aluminum intake and a gasket between it and the metal throttle body.

    The lower metal intake manifold has gaskets between it and the two heads that seal around the water openings that circulate to cool. IT also has strip gaskets at the ends and corners to seal the oil inside the gallery below it. The lower also has an elbow made of plastic that has o-rings around its ends that seal it into the lower intake and into the bracket for the idle tensioner. The elbow usually breaks when you try to remove the parts. Dorman makes replacements available for few dollars at Advance, etc. The are on the HELP rack that's in many of stores sometimes.

    The lower gaskets may be leaking. The white smoke after the car starts is usually from coolant that got moved into the exhaust system. IT will smoke for a few minutes until the parts and pipes are all up to full temperature and have boiled away the oily coolant.

    Your dilemma is to determine if you still have a leak in the lower intake gaskets against the heads. The parts store should have recommended you change everything.

    Note. The upper intake had a reduced size EGR pipe to put into the lower intake, I hope. Did you put that in to lengthen the life of the upper?

    Next. Change the oil. You have gotten coolant into your oil and probably a good amount. Drain the oil. Replace with cheap stuff while you try to troubleshoot, because you'll want to change again soon to get coolant out of the oil before it hurts the bearings more.

    If you do go ahead to replace the lower gaskets, GM has an aluminum gasket set that replaces the soft earlier ones. That's what you want. I was told FelPro also sells that type gasket.

    I think the 1/2 gallon loss may have been an air bubble from the heater and engine getting out. Check your radiator level again. To purge the heater, when the engine is thoroughly hot after driving, rev it to 2500 for 15 seconds at a time. Do this 5 times. That should move water into the heater and force all the air out.

    Be aware of the coolant level as you start driving, especially after the motor has come up to temperature and operated under pressure.

    You have an option of removing the new intake and replacing the lower gaskets and then reinstalling the new upper with the same gaskets. Note, when doing the lower gaskets and sealing with the sealer at the corners meeting the strips on the ends of the gallery, let that dry overnight before putting the metal lower back on.

    Or you can drive the car to see if you are getting leaks.

    Lots of cars have been damaged from the bearing corrosion due to the coolant in the oil. So flush that old oil and filter and put in clean, cheap stuff. Then I'd repeat every 1000 miles until I was sure there was no additional leak from the lower.

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • orangeuporangeup Posts: 23
    A big THANK YOU for your reply. I will take all of your knowledge to heart and proceed again.

    I did not replace the bottom gasket. I didn't thnink I needed to. Me bad....There is indeed a bent plastic pipe in the intake plenum that slides into the hole on to the bottom of the MAP sensor on one end and hooks on the two gasket clips, but I have one mysterious part left over that fell on the floor as I took off the plenum the first time. It is a small 3 to 4 inche black steel straw (pipe). I could for the life of me not figure out where it came from. Is that perhaps what you refer to as a reduced size EGR pipe, or is that the plastic bent pipe to the bottom of the MAP.

    So could you please expand a bit about the reduced size EGR pipe, I'd would greatly appreciate that.

    ... and do you think the torques setting of 24 in-lbs on the trottle body are correct? That sure seems rather loose to me. The documentation seems rather vague. I saw too many statements depending on model and engine Vin. The Autozone documentation at least had something while the manual was clearly wrong because it had a much older manifold with hoses in the figure. Anyway, thanks again for your reply.
  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 21,319
    edited August 2010
    Motormite heater hose fitting $3.50

    The tube that comes out of the bottom of the PCV valve (MAP is on top on cover) sucks air from the engine internals to the incoming air to be mixed and taken into the cylinders.

    I don't know what the black straw is that you found.

    this is the reduced size EGR tube that sticks up out of the lower intake into the plastic intake you had off. The smaller size keeps the hot metal away from the plastic of the intake manifold to keep it cooler.

    Notice the two different sizes of reduced EGRs in this kit: - - - 06.html

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 21,319
    >... and do you think the torques setting of 24 in-lbs on the trottle body are correct?

    Contact the store where you bought the upper intake.

    Or call a dealer.

    I know they have had problems with sealing on later cars with the upper to the throttle body. I believe I tightened mine on the 98 on a Dorman to about the same as the upper to the lower, 89 ft. lbs.

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • orangeuporangeup Posts: 23
    I am much obliged to you for all your insight. It might take some time but I will report back to you how it all comes out. Looks like those parts are the better engineered ones. On my EGR pipe I believe whatever was around it had melted away over 13 years of service and 175,000 miles

    Thanks, OrangeUp.

    p.s. on the last note I'm sure you meant say 89 in-lbs (just so nobody else tries 89 ft-lbs and cracks the intake plenum)
  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 21,319
    Yes, thank you for pointing out my typing error.

    89 IN-POUNDS just like the other screws on the upper intake is what I meant to type.

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • orangeuporangeup Posts: 23
    Progress report:

    Changed oil, drained radiator, did a compression test. All cylinders between 115 and 125 psi, which is good news because it appears the head gaskets are intact.

    So, I took the throttle body off first, to take a look in the intake plenum and indeed coolant all over again. Nice trick here, was to siphon out all the coolant with a small clear plastic hose into a steel can that's on the floor out of both sink holes that hold the 2 hidden bolt to the lower intake plenum, it prevents a mess when I take the plenum back off. From the looks of it the coolant came up past that EGR pipe and/or past the plenum and throttle body gasket that I think I under tightened last time. I can now take the rest off including the bottom intake manifold while I am waiting for those parts to come in.

    Note: I also siphoned the gas out of the fuel rail through the Schrader valve, to prevent spilling gas when I take off the fuel rail.
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