Automobile / Chevy / Tahoe

Chevy Tahoe Repair Questions and Answers

Question: 1999 Chevrolet Tahoe mileage: 76,000.  Last July I was talking to my brother about improving my fuel mileage in my Tahoe. He suggested replacing the spark plugs, wires, cap and rotor. At the time I was getting about 15 miles per gallon. I replaced the cap and rotor, the wires and the spark plugs, using Bosch platinum Plus 4 type plugs. A few weeks later I noticed a slight decrease in fuel economy so I checked the spark plug wires, found one not quite in place over the plug and pushed it on. I checked my mileage again but noticed no improvement. I then removed the fuel filter (it had been replaced only a few months before) and found the fuel in the filter quite dirty, which had me wondering if I had dirt in my fuel tank. I replaced the fuel filter and again checked my fuel economy a week or two later but it had not improved. I again removed the fuel filter to see if it was full of dirty fuel but the fuel was clean so I reinstalled it. I checked for leaks on the fuel filter before I had removed it as well as looking for leaks elsewhere, as good as I could lying under the truck in the driveway. I didn't find any leaks. A few weeks later my fuel economy was down to 11 miles per gallon, so I checked for causes on the internet and I found oxygen sensors as a possible cause. I then went to my mechanic and asked him if oxygen sensors could be the cause. He ran a diagnostic check and told me the 2 upstream oxygen sensors were bad. This was the only thing he found. He said they weren't reacting quickly enough and when the truck was at idle they were actually telling the engine to add fuel. So I had him replace the 2 upstream oxygen sensors and clean and service the throttle body, idle air control passages and P.C.V. So after spending $705 Canadian to do this I was hopeful the problem was fixed, it was not. Then I decided to clean the air filter. It is a K & N type and under normal conditions doesn't have to be cleaned and re oiled for 50000 miles. I had only driven about 30000 miles so I didn't consider this at first. I cleaned the air filter and re oiled it with K & N's filter cleaning kit. Then I checked my fuel economy and it had dropped to 9 m.p.g. This had me thinking that perhaps I had sprayed too much oil on the filter so I re-cleaned it and sprayed a light coat of oil on it. That is where I am now. I have been using the trip odometer to check my mileage so I thought maybe the trip odometer was not accurate. I am comparing the trip odometer to the odometer and so far they match. What I did notice is that from the full mark on the fuel gauge to the 3/4 mark the fuel gauge seems to drop more rapidly then from 3/4 on down (I think!) So now I'm wondering if I have a fuel leak on the top portion of my fuel tank, although I don't smell any gas fumes or see any liquid. My fuel economy seemed to go up a bit and then down more. I'm running out of things to check and I'm really hoping not to spend too much more money on repairs but with gasoline costing about $3.65 Canadian a gallon I need to get this fixed. My mechanic suggested that I get rid of the Platinum Plus 4 spark plugs and go back to the original equipment plugs. Do you have any suggestions for me?

Answer: Going back to the original equipment sparkplugs is a good idea.  Also, very carefully check the fuel pressure regulator as it might have a slight internal leak which is causing your poor mileage.    

Question: 1998 Chevy Tahoe 4x4 truck Mileage: 106,200. My question is pertaining to a noise that my truck has recently started making an interesting "squealing" noise. The noise seems to be louder and longer lasting at various times. Basically, it sounds like a belt or something when it's wet -- like I said, it sounds like a squealing noise. I've opened the hood to see if I could pinpoint a distinct location but still wasn't quite sure as it's quite loud and the sound fills the engine compartment. Also, the noise eventually stops after I've been driving for about 10 minutes or so -- the duration being a little longer during colder/wetter days. I commute about 30 miles every day to and from work, but the sound was happening previous to my new job so I don't attribute the trips to the cause. Also, the noise returns after the vehicle has been turned off for approximately an hour to an hour and a half. It's been suggested that it's perhaps the fuel pump and not a belt at all -- me not being a mechanic; I'm unable to assess this theory. Patrick

Answer: It sounds like that the noise is caused by the drive belt. With 116,000 miles, if the belt and belt tensioner have not been replaced recently, it would be in order now anyway.

Question: 1998 Chevrolet Tahoe mileage: 88,200. About a month ago when coming to a stop from a slow speed, it feels as though the ABS kicks in. Six months ago I had the same problem and the mechanic replaced the rear speed sensor, left front hub and bearing assembly and the right rear emergency cable. That was about $800. Could the same thing be happening again after six months and 7,000 miles?

Answer: We have worked on Chevy trucks with symptoms similar to yours. Replacing the rear brake shoes with brand new OEM brake shoes fixed the problem.

Question: 1999 Chevy Tahoe  mileage: 105,000. Recently, it started idling rough and the Service Engine Soon light blinks at idle, but once you start driving at runs fine but the SES light stays on. A tech ran the codes and told me that my #5 cylinder was misfiring. After numerous pieces of advice, I have replaced fuel filter, spark plugs, plug wires, distributor cap, rotor, one of the oxygen sensors and the problem still persists. The tech had tested the compression in my #5 cylinder and it was actually high according to him possibly due to some carbon buildup. Also the new #5 plug has some residue on it only after 2 weeks. So far I feel that I have ruled out an ignition issue and the compression issue. I am thinking a fuel injector may just be dripping at idle (which may explain the deposits on the plug) and fine under throttle. What do you think?

Answer: We think you have done a really good job of diagnosing your problem. It does sound like a faulty fuel injector. You may also want to check the EGR valve to make sure it is closed fully at idle. The EGR valve in your type of engine has a tendency to hang open slightly due to carbon buildup.

Question: 1999 Chevy Tahoe , mileage: 36,123. We experienced pulsating front rotors. The dealership replaced them only to have to do it again at 22,000 and again at 33,300. We do not tow anything and drive normally. Now the Warranty is out and I am faced with having to do it again. We have tried changing wheels and hardware. When it starts it doesn't take long to get really bad, maybe 1000 miles and it shakes so badly it wants to break traction on the front tires (at a Hard Stop). Very annoying!

Answer: In order to answer your question we will assume the dealer replaced your rotors with new ones (not your old rotors re-machined)  Now, check to see if the front brake calipers might be hanging up slightly during the time you are driving, causing excessive heat on the rotors. In addition, check to see that the rear brakes are functioning properly so as not to overload the front brakes.

Question: 1995 Chevrolet Tahoe 4X4 mileage: 75,000. I am an ASE CMAT for 20 years and I just bought a used but cherry 1995 Chevy Tahoe 4X4, 5.7 litre. I completely serviced the vehicle but was puzzled by the strange plastic plugs on the drive shaft u-joints. Three U-joints have strange plastic inserts on one side of each bearing. How are these lubed? Do I take the plastic inserts out or use an injector tip over them? If removal is necessary, is there a procedure? I am unable to find any reference to these strange plastic inserts in GM TSBs. I am not a GM brand tech but appreciate its strength and many design and construction methods. Thanks very much for your help.

Answer: Assuming we are talking about the same plastic plugs on the u-joints, they were used by the factory to assemble the u-joint by injecting epoxy to hold the u-joints together. You will notice there are no snap rings on the u-joint cups. The u-joints do not require lubing.

Question: 1997 Chevrolet Tahoe, AWD 1997. ABS Kelsey-Hayes 4WAL. During deceleration when the car reaches 6 mph both front sensor values drop to zero at the same time and ABS activated (Brake pedal pulses and deceleration become wrong). During acceleration, the rear sensor works well but both front sensors value zero. When the car reaches 6 mph, both front sensors value OK. (Same as rear and remains the same during the trip). We checked the resistance of the sensors and we find 1050 ohm for both. Unfortunately, we have documentation for older Tahoe's only. In these documentations, we find that the resistance of the front sensors should be around 2.5 - 3.0 k ohms for AWD and around 1.0 k ohms for RWD vehicles. We checked P/N of the sensor and it was OK. We ordered new ones but the resistance of the new sensors were 1.0 k ohms so we doesn't fit them. Have you any idea to solve this problem? Charlie, Budapest

Answer: Check the front brake rotors. There should be a reluctor that is part of the rotor that the sensor reads. If the brake rotors have been replaced in the past, there is a chance that the wrong ones were installed without the reluctor. Also, check the voltage generated by the sensor when the rotor is turned at low speeds. The voltage will be AC current, not DC current. At low speeds you should get somewhere between 1 and 5 volts.

Question: 1998 Chevrolet Tahoe 4X4 mileage: 49,000. A couple days ago I noticed that my coolant level was low...I filled the overflow container and then went for a drive. When I stopped, I noticed a leak under my engine; when I got under the truck to see where it was coming from, it looked like it was coming from the water pump. I looked under the hood and I noticed that the front of the water pump where the fan connects was wet. I took it to a mechanic and he said that the water pump needed to be replaced. He said the coolant would start to run out the hole in the bottom of the water pump when the bearing go bad...then it will start making a noise when it gets worse. He said that it would be $60.00 for a new (Lifetime) pump, $125.00 for labor and then coolant and tax, total of $207.00 out the door. Does this sound like it's the problem and if it is, is this a fair price for repairs? Is it normal for a water pump to go out at 49,000 miles? Thank you for your help.

Answer: If it is the water pump, the price sounds fair, although you may want to price compare with other reputable mechanics. It is not uncommon for a water pump to fail at 49000 miles despite the fact that we have seen them last much longer.

Question: 1996 Chevy Tahoe mileage: 87,000. I have water dumping out of the bottom of my truck. It is coming out of the back part of the engine as I can tell. I thought the water pump was located at the front. I had someone tell me that it was an intake gasket. But, I was told that those don't leak very much water out. As soon as I stop it pours out. I know this will be hard to diagnose over the email but your advice will be greatly appreciated.

Answer: We have experienced similar coolant leaks coming from a heater fitting on the back of the motor.

Question: 2000 Tahoe Z71  mileage: 68,260. I have had the Tahoe for about 4 months now. Everything has been fine up until a trip to the lake towing our trailer. About an hour into the drive, a smell came into the cab of the truck. (A mix of propane and rotten eggs) It was actually quite strong and persisted for the rest of the drive (1 hour). Since that day the smell comes and goes. Sometimes when the truck is cold and sometimes after it has warmed up. I just had it to the service guys to check it out. They said it may be the catalytic converter but everything checked out OK. They said that they smelled a "faint" odor and it didn't last.

Answer: The smell is probably from the catalytic converter. When you were towing the trailer, you required more power from your engine and consequently, more fuel through the converter. We can only guess that the trailer disturbed the airflow from the back of the truck, which allowed some exhaust to invade the cab of your truck. The catalytic converter may have been overheated with the extra weight of the trailer thereby causing it to work at less than 100 percent efficiency now.

Question: 1995 Chevy Tahoe mileage: 61,556. We bought this vehicle new in 1996 with 88 miles on it. It is a 4-wheel drive, four door, with the towing package. Every 10 to 12,000 miles we have to replace the fuel pump. We also had the fuel injectors changed once. We have followed up with the maintenance with GM. We also had the gas filter changed 4 times. We are still facing the same problem. Please help us.

Answer: Sounds like you have contamination in your gas tank that is plugging your fuel filters and fuel injectors, shortening the life of your fuel pump. Using major oil company gasoline provides good protection against reoccurrence.

Question: 1999 Chevy Tahoe mileage: 106,000.  I put some cheap gas in my truck and the next day it started spark knocking.  So I put a knew fuel filter on it.  It still was kicking back.  The next morning it would not crank.  Therefore, I put new spark plugs in it.  It still would not crank.  I checked the plug wires and the distributor cap and it was good.  What could it be?

Answer: Your car may be ready for a major tune-up including spark plugs, plug wires, distributor cap, rotor, fuel filter and air filter.  Also, perform a fuel pump pressure test.  Clean fuel injection system including throttle bore, idle speed control motor and passages.  If problem still exists, scan computer for trouble codes.

Question: 1997 Chevy Tahoe mileage: 48,000.  I’m getting squeaking sound from my brakes and would like know the price of a good brake job

Answer: Parts and labor for front and rear brakes should be approximately $300.00.  If a brake rotor or wheel bearing needs replacing, it will cost more.

Question: 1998 Chevy Tahoe blazer 350 mileage: 110,000.  I need to change my battery.  However, the positive cable bolt head is stripped completely round.  Can you advise me of what type of wrench to use to loosen it so I can remove it without replacing my cable and bolt.

Answer: Try a pair of channel lock pliers.  Remove the negative battery cable first.

Question: 2002 Chevrolet Tahoe mileage: 19,000.  A clunking noise is frequently heard coming from the rear of my Tahoe when accelerating from a stop.  The noise can be quite loud from inside the vehicle.  When I questioned the dealer service writer he explained by telling me the noise is normal.   He said that Chevrolet used to adjust the rears to eliminate this noise but the remedy was found to cause more problems in premature wear in the rear.  I shudder when I hear the noise!  Is this correct or do I have a problem developing?  Thanks for your assistance.

Answer: Try removing the drive shaft and lubing the splines on the “U” joint yoke that goes into the transmission.  The transmission fluid normally lubes this yoke but a good heavy-duty grease lightly applied works better.

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