I have a 2001 Suburban, 5.3 liter, 2 wheel drive, automatic transmission. I often take 250 to 600 mile trips and track my MPG between gas fill ups/rest stops about every 2-3 hours. I use cruise control and maintain the same speed as much as possible on each trip.What happens is my MPG varies from 16.8 to an all time best, 24 MPG between fill ups. What could be causing this?
View 13 RepliesI am suddenly getting 8 mpg decrease both long and short trips. Rotated tires, checked psi and did an alignment but couldn't find cause. I remember my old car had an engine thermostat and when that was stuck open or close the mpg decreased a lot too.
View 19 RepliesCan't fill the tank in my 1981 Chevy 1500 Truck; pump cuts off after 7 gallons. I took the vent tube and the fill hose off and there are no blockages.
View 8 RepliesI have a 2001 Chevy 2wheel drive 4.3 V6 Pickup with a long lasting engine knock. I use it only to haul trash and building materials, maybe once every other week. The knock is sporadic. If I take a long trip and drive on an interstate highway the following morning upon start-up the truck will knock heavily and continue to do so as long as it is running. If I take the truck for a short local trip, the following morning it will start with no knock and only start knocking after driving maybe 10 miles. If I drive only short trips, the truck will almost always start without knocking and only knock once it is fully warmed up. I purchased this vehicle from my brother who drove it this way ever since he purchased it at a salvage auction (full of dents and some damage) who put over 20,000 miles on it with this same engine knock.
Other than the dents, the truck is in great shape, no rust, and has 118,000 miles on it. I would like to keep this thing because it was very cheap and I only use it sporadically. So, I'd like to know if I'm going to eventually have to put a motor in it or if there is some small fix I could make to stop this knocking sound. The sound: It is heavy. It sounds bad. It knocks along with the rpm of the motor. My brother, who is also a great mechanic, thinks it may be piston slap or something in the valve system. I've also had a mechanic listen to it. He thinks it's a rod bearing or wrist pin. What I don't understand is how could it be any of those things when it makes a difference how I drive it the last time it was used? Could it be something simple like a vacuum issue, knock sensor or crank sensor?
While driving my 1998 Chevy Prizm, my car lost the ability to accelerate but the car never lost power. I managed to pull over and let the car run for a bit before trying to accelerate again..the car only got up to 30 mph and wouldn't go any faster.....after a couple of hours the car run okay. What could be going on? I got new spark plugs, oil change, and an idle air control valve........
View 18 Replies07 Chrysler Town & Country with 86K. It's been happening off and on for about a year now. On long highway trips when I'm driving fast (maybe more when it's cold), a whirring noise will build up. It starts quiet and can get really loud. When I get off the highway, the engine noise goes down and the whirring noise is really obvious. I take my foot off the accelerator and the whirring noise continues for about 10 seconds. When I hit the gas again (this time at city speeds, 30 mph or so), the whirring noise instantly comes back and can get high pitched and LOUD, almost like an old police siren.
Last time it happened, I popped the hood to track down the source. It seemed to be coming from the engine block. When you're looking down at it, it's coming from the left side, directly under the drive belt (but not the belt).
2007 Chrysler Town & Country, 72k. It's happened twice now. On long interstate trips, over 50 miles, the engine starts to make a loud whirring/humming sound. The temp and RPM gauge looks fine. The first time it happened, I checked the dipstick and it was very low (I was overdue for an oil change). I topped it off and it went away for a few weeks but then it came back, after about 100 miles running it 75 mph or so. Then the oil was fine. Pulled off and let it cool for 30 minutes and it was fine but I drove slower. It seems to come on while I'm on the interstate and the engine noise covers it until I get off and then it's very loud. Maybe it seems to get louder when I take my foot off the gas.
View 4 RepliesA few weeks ago i had a surging idle issue very intermittently, and it went away for a while so i stopped thinking about it. Just got back from a weekend in vermont, about 130 miles each way, and i noticed as soon as i got to vermont and came to a stop sign it was surging, and when i just got home it was surging again. Why would this have picked back up after long stretches of running for a while? Runs great as far as i know, just have this surging idle for some reason.
View 14 RepliesMy car is standard 5 speed transmission, when my car is running my idle varys between 800ish to 1500 intermittently within seconds and if I don't drive it after starting the car it will stall on me (in neutral) after the rpms go up and down about 9 times.
The thing I found is if I disconnect my idle air control valve attached to my throttle body it stops the jumps in rpm. I have tried replacing the valve with one of my friends control valve Hyundai accent 2004 that works and fits perfectly on his doesn't work on mine. Right now I have my idle air control valve disconnected at the moment but i want to fix this issue because my rpms are at 1300 at idle.
I have a 2.0l Jetta that has been giving me problems for about a year now.
First, the car started dying out on me after long trips at en excessive rate where it would shut off and have trouble starting multiple times consistently. So I got the fuel lines cleaned, a new fuel filter, the fuel pump checked, and did a basic tune up by changing the sparks and oil.
Still the same problem. after some troubleshooting i gave up and decided to take it to the stealer dealer. after a $130 diagnostic fee and a $300 repair fee they told me that they had fixed it by replacing a speed sensor in the transmission. the car was noticeably running better and did not stall during the short driving i did. I am a student so not much driving was done initially. A couple of months later i took a ~150 mile trip and upon stopping at a red light and trying to go once the light turned green the car stalled.
I took it back to the dealer that told me they would check if the speed sensor was faulty. it was not and they could not refund me my money. i paid for another diagnostic for another $130 and this time they said it was a bad coil pack, a $400 repair fee that i was not going to pay. i went out and got myself a coil pack and installed it myself. still the same problem.
I met a guy that worked for the dealer and had the same tech as the dealers so i took the car to him. he had it for 2 days and drove it for over 80 miles to test run it. he could no replicate the problem and just charged me 80 dollars just for his time.
I decided to take matters into my own hands and I read on these forums a couple of common solutions to the problem such as changing cam,crank,speed sensors etc etc and i started out with the crank..then speed...etc etc.
2 days ago my water pump had been leaking and i believe the antifreeze caused the timing belt to slip about 3 teeth in the middle of driving. luckily no bent valves or any damage to the engine but i did have the push the car about half a mile. After a 5 hour job i replaced the pump and the timing belt along with the cam sensor. I drove it around 70 miles and everything seemed fine. just yesterday i drove around 120 miles and the car had a small stall about 50 miles in when i was at a red light. The rest of the trip it ran fine. As i got to my apartments I decided to see if i could replicate the stall since the engine was hot. I stopped and waited around 10 seconds and then stepped on the gas, the car did almost stall but it stayed on since i let go of the gas. I tried it again and it would no longer do it.
Does a 1990 chevy truck have a fuel regulator, 5.7 efi? if so where is it located?
View 1 RepliesMy plan to clean the fuel injectors on my 2008 Silverado LS 4.8L V8 came to an abrupt halt when I was unable to disable the fuel pump relay because it is missing from the spot where it should be located according to the schematic in the owner's manual. Would removing the "fuel system control module" (fuse #21) instead of the fuel pump relay work?
View 7 RepliesSeveral years ago I had to replace the fuel pump - truck had about 100,000 miles. Within the last 4 - 5 months I have replaced the fuel pump twice and just today (about two months since the last replacement), the fuel pump has failed again. That has been the pattern now for the last several months. I have had the work done by one of the reputable car repair shops in town - they have also done work on my 2004 Impala with no issues with the repair. There must be something else going on besides just the fuel pump going bad. What would cause so many fuel pump failures.
View 16 RepliesMy 95 chevy 1500 pickup is having fuel pump issues. Somewhere between the relay and the sending unit. Pulled the tank, and put power directly to both the pump and the sending unit. They both run. Put in new relay, still not turning on the pump. Do not know if this is related, but the switch to turn on the interior light when you open the door does not work on the drivers side door. If I pull on the switch the light will come on.
View 3 RepliesI have a 2001 Chevy Silverado with the 4.8L V-8 engine. It acts like it is running out of gas ( the gas tank is over half full). The truck has sat for about 6 months in this condition without being started here in Sacramento, CA. I then replaced the fuel filter and for a few minutes it started and the engine ran fine (without actually driving it). A few days later I started it again and it now again acts like it has fuel starvation, it will rev up briefly then act like it is running out of fuel. I know the fuel pumps are the Achilles Heel of these trucks, but before I try changing it I was wondering if there might perhaps be another problem such as the new fuel filter plugging up quickly or possibly an electrical problem. I've always heard these fuel pumps either work or they don't work, nothing in between. This problem is intermittent but big enough the truck is not driveable. Is there any way to get a good take on the problem before diving into the fuel pump replacement and hoping that solves the problem ?
View 5 RepliesHave a 2007 Chevrolet Suburban. The voltmeter reading varies from 13 to 16 volts, no obvious reasons for changes in the reading. Chevy says there are a number of different inputs that determine what the reading should be, such as battery temp, etc. On older cars you could use the voltage to determine when something was going wrong with the electrical system. Other that a complete loss of alternator output, can you use the reading to diagnose electrical problems, such as a bad or dying battery?
View 4 RepliesEvery time I turn the car on, the "from start" fuel economy reading resets to 15l/100k. After driving for a while it goes down to 4l/100k but then resets back to 15 once the car is turned off. Is there any way to get it to stay at what it finished at?
View 11 RepliesWhile most of the emphasis I've seen on improving fuel economy seems to focus on warming the car up quickly in cool/cold weather, I seem to be experiencing significant mpg drops at the other end of the spectrum.
View 8 RepliesI have a 2008 prius. Usually it gets me around 52-55mpg, I've had it since January. Since a couple of days ago its not giving me anything above 49. I know thats a normal number, but considering the fact that its usually quite a bit higher I'm wondering what the cause of the drop is. Also around the same time, when I pull out of my driveway I notice what appears to be a bit of water leakage. Its under the vehicle in the front center, and it only happens when I start the car for the day and pull out of my driveway (its on an incline).
View 4 RepliesI am wondering about how fast to accelerate for maximizing fuel economy. I understand with the P&G approach that you don't want to get up to speed too slowly. The question is whether it really is more efficient to go ahead and get up to speed or stay within the ECO guidelines? In particular, I find that getting up to highway speed especially that it can take quite a while to get up to 70 mph without having it going into the power range. It seems like it is better to get up to speed and then back off to go to the high efficiency mode.
View 16 RepliesI've got a 2001 GMC Sierra 1500 with about 80,000 miles and with a gas gauge that is possessed. It sometimes appears to be working normally, but is just as likely to do very weird things, like: When I fill up the car with gas, it will always register empty. And it will stay there until it sees fit to move to full. BUT: if, as I'm traveling down the road, I move the transmission from drive to neutral, the gas gauge will move to full. This also happens arbitrarily between fill-ups, with the gauge sometimes registering empty and sometimes finding some random place around where it should be. Once again, if I put the car in neutral, the gauge will move to its correct position (at least I think it's the correct position!). I was told my one mechanic that the problem is that the fuel pump is wearing out, and that this problem is not uncommon for the Chevy/GMC trucks. The fuel pump is in the gas tank, I'm told, so to replace the fuel pump is rather expensive.
View 16 Replies