Engine power

MARK PERRAUT

MEMBER
1996 CHEVROLET TAHOE
V8
4WD
AUTOMATIC
134,000 MILES

My 1996 Tahoe is a great vehicle. However, on the highway at say 70 miles per hour when I start to go up a hill. The engine power drops off and if I try to compensate by pushing gas pedal down it will shift and try to speed up but, it drops rpm's and bogs down. Then, the service engine soon light comes on. Eventually, the light will extinuish. Maybe 4 or 5 starts.

Monday, March 28th, 2011 AT 7:34 PM

3 Replies

WRENCHTECH

MECHANIC
20,761 POSTS

The "check engine" light is an indicator for a system that monitors many electronic functions in the system, also called the "malfunction indicator lamp" (MIL). It can come on for any of hundreds of different causes from any of the systems that the computer monitors. Some are very important and can lead to further component or engine damage and some are emissions related not as serious but still a problem and need to be repaired.

Your first step is to have the computer scanned to retrieve the trouble codes that were set when the check engine light came on. Those codes will give you specific information about what the computer saw and will get you pointed in the right direction to find your problem. With a 1996 or newer and some 95 cars and you have an AutoZone or Advanced auto parts in your area, they will read them for free. Once you have these code numbers, we can be a lot more specific about what your problem may be.

Was this

answer

helpful?

Yes

No

Monday, March 28th, 2011 AT 8:05 PM

WOLFPACKMAVERICK

MEMBER
1 POST

I too am having an engine power problem with my 1998 Tahoe with 185,000 miles like you described on the highway going between 65 and 70 and engine power drops. I have felt the engine "shaking" and have to back off and coast because if I try to push the pedal down it will want to shake. I would get a random misfire code when I have check this in the past. I started out changing the spark plugs and that seemed to help for a week or two. Then going back up hill on the highway it would happen again. So I replaced the spark plug wires. That seems to help for a week or two. Then it would start again. I replaced the distributor cap and rotor button and that seemed to help for a few weeks. My last thing I can think of to try is the ignition coil. I have a multimeter and tested the primary and secondary windings of the coil. The primary windings have.7 ohms resistance and the secondary has a 6.4 kohms resistance. When I look online at the specs for a new coil the primary ohms is.2-.4 ohms and the secondary is 6.7kohms. I want to know if I am in range or not.

Was this

answer

helpful?

Yes

No

Tuesday, March 29th, 2011 AT 12:56 PM

WRENCHTECH