Sierra :: 1991 SLE - Oil Pressure Fluctuates From Around 20 To 80
May 1, 2012
I just purchased a 91 sierra sle with the short bed. I am interested in buying a cap for it because the snap on tonneu cover is falling apart and id like a cap. Would caps from other full size short bed pickups work or does it have to be from a sierra/silverado?
Also i notice the oil pressure fluctuates from around 20 to 80 depending on if I am idle (20) to acceleration at 80, when driving it seems to go up and down to depending on the accelerator position. is this normal??
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I have a 1991 gmc 1/2 ton with 200K on it. Its a 350 engine. The engine has been stumbling for a long time. I've tried many things ...new fuel pump and filter...complete tune up.....checked all vacuum lines..replaced a couple lines...EGR valve.....changed head gasket and intake gasket. Checked the warm up flap inside the air cleaner. I am now very very frustrated.
This stumbling happens often but intermittent also....sometimes worse than other times like the truck is about to stall. The truck seems like its being held back like a loss of power. The truck will begin to stumble so i will pull over and rev it up and it seems to clear itself for a short while then right back to stumbling.
Upon warmup in the morning she seems to run fine until hot. No codes being thrown ...service engine light NOT on. Even while at a stop i will hold the throttle part way and revs at different rpms. I am now at a loss and feel defeated.
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My oil pressure gauge jumps all over the place when I get over 3000 rpms. At lower rpms it is in the normal range and the engine sounds ok. How can I tell if this is the oil pump or the sending unit or the gauge? This is a 1980 CJ5 with a 151ci 4 cylinder.
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This truck has 180km on it and runs fine except as of lately i have developed a surge while at constant speed. When i step on the gas it does not seem to happen.....it only happens when I reach a constant speed. The odd time it will surge at idle and the engine will rev up and down on its own also. When at highway speed it seems to not do this. The truck never dies completely....just surges slightly.
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I'm working on getting my GMC seirra 1500 5.0 L running. Last fall When I was making a trip to another town, it broke down. When it broke down it smelt like plastic was burning, I was unable to figure out what the smell was.
First I though it was a bad battery connection, or that the starter had went.
I changed the Battery, made sure the cables were good. changed the starter and it still doesn't work.
I know the battery is working for sure because There is power to the lights so I can turn on the brights. There is no power to anywhere else on the dash though other then the icon that shows the brights are on.
When I try to turn the engine over, nothing happens at all. Doesn't even make a clicking noise.
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I just bought this nicely used 1991 GMC Sierra 1500 series pickup truck for $650. It started up and ran fine when I gave the seller the money - the few leaks in the break lines.
Easy fix right!
So my son (19 that knows it all) and I went and changed all the brake lines (made everything one size 3/8 line.) Filled it up with break fluid and started the truck. I had my so pumping the breaks and holding them (his first time) I bled the far rear (passenger side) then I had him turn the steering wheel to the right so I could bleed the front driver side.
He turned, and turned and turned until the engine died.
Now the truck only runs when the steering wheel is turned all the way to the right or all the way to the left.
Going to pull the codes to see what the heck is going on....
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2003 f250 6.0 had a no start issue at first which ended up being bad connection/ chaffed wire at ficm.. ive replaced regulator with blue spring, new oil/fuel filter housing, new Motorcraft filters, and a orileys fuel pump.... guage i have reads 55psi at start up. While accelerating it obviously drops down, but it seems to goto 40 to 45psi then back to 50..then at times it goes back down while driving and stays around 40 45psi regardless if accelerating or coasting etc. Then after couple mins when i accelerate it will go back up?
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When it's cold I can floor it and it'll go to 4K RPM.....When it warms up the oil pressure drops and then I can't push the motor over 1500 RPM. I overhauled it and used the old camshaft....I really don't want to get charged 80 bucks an hour for a mechanic to take 2 days to tell me it something I could have fixed myself.
1999 GMC Sierra 4.3 V6 "W"
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I have an 03 Sierra Half Ton when the engine is warm it runs fine but at cold start, half the time it doesn't have the fuel pressure to start, i have to turn the key a couple times to build it up. Idk if the fuel pump is weak for if it would be more the regulator. I started having this problem after i replaced the fuel pump. The fuel pressure gauge shows 50-55 lbs, but every now and then when its cold it will only jump to around 5 lbs (but this is only when the engine is cold... why?) What should i go after first? Regulator, new pump, Replace the fuel filter again?
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I have an '89 GMC Sierra which has the standard rear wheel anti-lock brakes offered that year and a vacuum booster. It has about 180,000 mi. on it. I have a problem with the brake pedal fading to where it goes completely to the floor. This happens whether the engine is running or not. The brake warning light is not on (but is operable), there is no air in the lines, and their are no external leaks. The resevoir has stayed at full level. I rebuilt the master cylinder and the bore looked great as did the seals, but I installed the rebuild kit anyway.
There has been no change in performance. Can this be a problem with the isolation/dump valve assembly leaking internally. I would think that would cause the warning light to come on. The i/d valve is a costly part to replace and I hate to experiment on such a solution without some confidence in the source of the problem. The GM Service Manual troublshooting indicates air or internal master cylinder leakage is the culprit, and indicates the light would come on for any i/d valve problems.
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I have the code P0453 set and believe I need to replace the fuel tank pressure sensor. I have the part and want to know if this part can be replaced without removing the fuel tank. There is a video on youtube that shows replacing the part by lowering the tank with a transmission jack after the straps have been removed. Replacing the sensor by touch and feel maybe using mirrors to see what you are doing? It might be possible to cut a hole in the bed and patch it later but that seems pretty time consuming too.
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1991 Celica ST 4A-FE automatic, 238,000 miles, son's car, has been running great, until he says his oil light occasionally flickers on him. Car is in Wisconsin, driven maybe 2 miles one way to work every day, hasn't been on the highway is a couple months. Has synthetic 5W-30 oil with about 2,000 miles since last change.
Brought the car into the garage. Sure enough, after engine warmed up and idle got below 1,000 RPM, oil pressure warning lamp would come on. Engine sounded normal at idle and fast idle. Tough to put a mechanical pressure gauge on this engine (after to remove the alternator and A/C compressor and bracket, per the service manual, to access the oil pressure switch). I drove it on the highway, put about 40 miles on it, ran great, until I exited the highway. Anything below 1200 RPM, oil pressure warning light would come on.
Came home, removed the oil filter with intent to change it (to make sure it wasn't plugged). Smelled of gas. Oh-Oh. Drained the oil (oil level was at full mark, unusual for this vehicle, normally would be 1/2-quart low after 2,000 miles - 2 months of winter driving). Oil came out with consistency of water. Smelled of gas, and could see water droplets as I switch the drained oil from a collection pan into a jug. Thought was many short trips caused oil to never get hot enough to burn off unburned fuel blow-up or accumulated moisture, so oil was diluted, much too low viscosity.
Changed oil & filter with synthetic 5W-30 & Purolator PureOne oil filter. Took it back on the highway for 40 miles again. Highway drive was fine. Upon exiting, oil pressure warning light came on at 1,600 RPM or below. Oh-Oh. Had another 40 miles on the highway to get home. Highway drive was good again. Upon existing, oil pressure warning light came on again at 1,800 RPM or lower. Oh-Oh.
Worrying that the oil pump for pressure by-pass valve or of bearing spin-out or extreme wear (although engine sounded fine all the time), decided to order an OEM oil pressure switch. Had to take some of the bolt-ons off to access the oil pressure switch, but not all the service manual said had to come off. Took the old oil pressure switch out - looked just fine. Installed the new one, put everything back together. Checked to make sure the oil pressure warning light still came on with key in the ON position (it did), so I knew the wiring connections were good. Startup was fine (cold engine). Took it on the highway for 40 miles, after exiting highway, no more oil pressure warning light. Even tested the situation with the automatic in drive, brake applied, lights on high-beam, heater fan on high, rear window defroster on (got the engine down to 600 RPM), still not oil pressure warning light. Turned engine off, then turned ignition key to ON, oil pressure warning light comes on like it should.
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A friend of mine has had this 2000 Sierra since new. It has just over 100K and never had any cooling issues before. Last week when it was about 10 below zero she drove it home and it overheated and pumped a couple quarts of antifreeze overboard.
She refilled it the next day and it was fine but got it looked at by a local independent mechanic. I had told her that it was likely a sticky thermostat and it ought to be changed out anyways due to its age. The mechanic thought I was wrong and that she had driven it off to quickly in the super cold weather.
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Lately, I have noticed the idle on the R to be a little lower than normal and it is fluctuating with the AC on. The plugs were done about a year and 10,000 miles ago with OEM NGK iridium, along with the rest of the 80,000 mile maintenance items. I have no engine faults and religiously use Shell 93. The engine has the UM ECU/DSG [spark cut] tune with Milltek engine-back exhaust [no cats/resonator]. Is there something that I am missing that may be the culprit? I need to pull the plugs and check them because with any idle issue I usually suspect plugs but have never had an issue with plugs failing this soon.
Related topic; what spark plugs are people having good luck with the UM combo tune?
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This is weird. SOmetimes my gas gauge fluctuates from low to high. I don't know how to explain it but it just bothers me thinking there might be a problem I'm not aware of. This also shows LCD display saying 190km left then after I start driving for a while it'll show 210km. [IMG] [URL] ....
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So i decided to be a man and finish my 3.6vr in my gti project. Filled the coolant system with g13 and let the car run for a good half hour but the temperature only went to 130 degrees and would go back down to 120 and back to 130 and back and forth. With the heat turned on it was only slightly warm. Top hose was slightly hot and the bottom hose was just warm. So i tried massaging the hoses some more to let any air out and saw no bubbles. So i decided to go for a drive around the block and temps still stayed the same. So i'm leaning towards a thermostat but the motor was pulled out of a running passat with no problems.
Also its a brand new oem temp sensor
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Well, for the past few weeks the weather in Los Angeles had been a little on the cool side. I didn't notice the cooler weather, but I noticed that the computer says I was getting around 51 MPG for almost the entire tank (the warning was blinking so I think I used about 10 gallons).
Then today, the temperature rose to around 90 degrees. I noticed the heat. All of a sudden, my computer MPG rose to slightly above 52. I think that would be difficult to do as it must average out the entire tank an extra 1 MPG. And correct me if I'm wrong, but if I got 51 MPG over 10 gallons of gas, in order to raise the gas mileage by 1 MPG in the next gallon, I must get around 62 MPG for that last gallon.
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A few months ago maybe more my wife told me that her car (2004 Santa Fe 3.5L) seems like it is going to stall when sitting sill at idle, in gear with AC on. I finally got around to looking at it. Ran a diagnostics and no codes were found. Ran a little rough but not really bad. Had her run some fuel injector cleaner through a tank of gas. I hadn't heard anything more from her about it. We decide to drive one night to a concert with friends and I was driving. The surging was very evident and by the time we got home that evening I had an engine light.
The next morning I ran a diagnostics and had a code for a #1 plug misfire. Checked the plugs and sure enough the #1 plug was toast. I went ahead and changed all plug, checked all vacuum hoses. Even changed air filter. Took it for a long drive in the mountains for a couple hours. No codes and everything seemed to be working as advertised. That was last week. Today it started happening again just not as bad.
Again, the problem only occurs when in gear and AC on. If AC is on engine is fine no fluctuation. Steady RPM at about 780-795. So I figured hey she is probably due for some new belts so I will check the AC clutch thinking that if the clutch was seizing it could cause some issues. Not so lucky. Everything was fine. The belts did need to be changed so not a total loss. The idler to the power steering is a little off but not too bad (have one coming to replace any way). I put everything back together ran another diagnostics and again nothing.
So I was wondering could a faulty alternator cause this. I started the car put it in gear and loaded it with lights, high beams, rear defroster, radio, hazards etc.. everything accept AC and the problem started again. I turned everything off and left it in gear and the problem went away. I placed it in park loaded it up again, including AC and the problem came back.
Any other possibilities. While I loaded everything I had a meter hooked to the battery and voltage dropped from 13.97 to about 12.5. Once I turned everything off voltage went back up.
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Something strange started happening to my '04 Prius yesterday and it happened again today. We are experiencing unseasonably warm temperatures here in Western Oregon for October and when I left my house this morning at 6:30 am, it was about 55 degrees. I have a half hour drive to work on a mixture of expressway, freeway, expressway again and then the two-lane highway.
Anyway, yesterday (and today) when I'm almost to work, my temp. gauge drops down to 37 degrees. This causes that yellow light to start blinking indicating that the engine will not shut off because of cold temps. It will warm back up to 45 degrees a minute or two later. Why is this happening? It for sure is not 37 degrees outside. Is my temperature sensor going bad? Is this exhibiting the behavior of a sensor going bad?
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In the morning when I start the car it idles rough, revving up and down from stable to almost dies from no gas but after 10 minutes of driving car runs fine ... BMW 530i 5 speed with 150K miles ....
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My fuel gauge fluctuates once I turn the key to Acc, once I fire it up it goes back to empty and climb back to the correct position,
Also once this happens, my MFD starts to act crazy, sometimes it shows nothing, and times gets stuck on the door open screen and my steering wheel controls go dead, if I turn off the car and then on its gets stuck "Volkswagen information" screen.
I disconnected/reconnect the battery everything went fine for a couple of days and then happened again,
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