FAQs—GMC C5000 Topkick
What causes my transmission to slip?
The transmission should engage smoothly and firmly when you shift into drive, but instead, it slips? Oh there's definitely something wrong with it. Transmission slipping may be caused by various things like you are running low on automatic fluid, there's low internal fluid pressure, or your pressure regulation is faulty.
Running low on automatic transmission fluid (ATF) is one of the most common causes of slipping transmission. Transmission fluid is required for the torque converter to be able to transmit engine torque to the transmission. There should also be enough ATF for the transmission to generate internal pressure needed to engage the various gears. If you have low fluid level in your transmission, it may hesitate to engage for a few seconds causing a delay when you shift into drive or reverse. This problem is an easy-fix. All you need to do is to top up with ATF!
For the automatic transmission to work properly, it must be able to generate a certain amount of internal pressure. If the transmission cannot create enough pressure that is needed to engage and shift normally, it could mean that you have a worn-out pump or the pickup tube or fluid filter is blocked. If it is a worn-out pump that is causing it, you are going to have to replace your transmission. On the other hand, if it is a clogged fluid filter or pickup tube, it can be fixed by removing the transmission, then draining out the fluid, and then replacing the filter with a new one. Before you remount the pan, make sure that it has been thoroughly cleaned.
If the transmission is slipping because of a faulty pressure regulation is faulty, you have to replace the pressure regulator valve or control solenoid. If that fixes the problem, consider yourself lucky because normally, when the pressure regulation goes bad, you are going to have to rebuild your transmission, and that can be really expensive.
Why does my engine stall when I'm driving my GMC C5000 Topkick?
For your engine to run smoothly, it needs a good spark, the right fuel and air mixture and an adequate idle speed for the idle load. If you lack one of these, your engine will stall.
There are several causes for engine stalling and it includes dirty fuel injectors, vacuum leaks, faulty airflow sensors, bad throttle position or oxygen sensors, or low fuel pressure to the injectors because of a weak fuel pump, clogged fuel filter or bad fuel pressure regulator.
If your engine stalls intermittently, it can be quite tricky to find out where the problem is coming from. Most of the time, you are going to find out what is causing the problem if an engine components already fails. Using a scan tool will help a lot. But more often than not, you are going to have to seek professional help when it comes to this kind of problem, because if you have little knowledge about this, you are more likely to do more harm than good.
It seems that my fuel gauge is giving me inaccurate readings. What could be causing it?
There are three possible causes of this problem: a faulty wiring, a malfunctioning instrument voltage regulator, a defective sending unit, and a bad ground connection. If you're not too familiar with these components, you'd better take your vehicle to your trusted mechanic for proper diagnosis.