Some comments on a previous question.
Question: A GMC Likes To Whine
Hey Vince, It has been a while since I contacted you for anything, (by the way, thanks). I was just looking over your Q&A section on another site and this one (copied below) jumped out at me. You may want to add some more info.
I had the exact same problem and my fuel pump went out after a while. I didn't know what it was when I bought it. It had about 85,000 miles on it and was whining when I got it. Apparently the fuel filter was stopped up and it had burned out the pump. I wound up replacing the filter after owning the truck for a few months when a friend heard it and told me I better replace the filter, or I would be buying a pump for about $400. I replaced it and the noise went to a much lower level.
Unfortunately, the damage was done and about 6 months later the pump went toes up too. Amazing how much money a filter can save you. By the way, the 1998 GMC owner's manual says you should change the filter every 7,500 miles. I think it may be a typo and it should be 75,000. I currently change mine every 50,000. I figure I would rather throw away $50.00 on a filter change than another $400 + inflation.
Keep up the good work,
Lee
Questions and Answers:
A GMC Likes To Whine
Q. I have a 1998 GMC K-2500 pick-up truck. Lately (past 3-4 months) the fuel pump constantly whines while the truck is running. Normally it would just whine for about 3 seconds when I turned the key on. Now it's all the time.
Please help.
A. Actually this may not be more of a problem than an annoyance. Some fuel pumps just get noisy over time. There is a fuel dampener attached to the pump and this may be what has gone bad. At this point if the noise doesn't bother you, let it go. Otherwise the only other option is to replace the fuel pump.
The fuel pump lives inside the fuel tank and will require the removal of the tank to replace it. Not a particularly difficult job, but one I would do with the utmost caution. I have seen a car explode and the shop burn to the ground while such a job was being done. The 2 technicians who were taking the gas tank out were killed instantly.
If you do decide to drop the tank and replace the pump yourself, please, use the utmost caution. The fuel is under high pressure so be sure to remove the fuel pump fuse and crank the engine for a minute or 2 to relieve the pressure.
An empty gas tank is more likely to explode than a full one. Don't just disconnect the battery, take it out completely and put it somewhere away from the vehicle. Do not smoke around an open gas tank and do not use an incandescent drop light. I can not stress enough the dangers involved in this kind of job. But, some common sense and safe work practices will make it go smoothly.
Answer:
Thank you for relating your experience with this problem. I'm always glad to get feedback, good or bad, on any of my articles. As for this particular question, and in this venue, I can't be sure of what the problem may be. I can offer the most likely causes but I can rarely say for sure. I have found a lot of bad fuel dampeners in these fuel pumps so I feel this is the most likely cause of the noise he was hearing. I have heard fuel pumps whine for years without giving it up.
But the extra added information you supplied will help those in similar situations make a better, more informed diagnosis.
