Automobile / GMC / Motor Home

Question:  1998 GM Motor home mileage: 50,000.  I am having a pinging problem while driving down the highway at 55 to 60 mph, flat road, also when I put my foot into it to pass, sometimes. Also when starting out whether the engine is warm or cold driving back on the freeway it's as if there is lack of power, sputtering as if it just doesn't want to go and then after a minute it will start to speed up fine. This is an intermittent problem as it doesn't always happen. Have taken it to the dealer twice. First time they changed the fuel pressure regulator. They dead headed the fuel pump, reading was 70 psi. Engine has never set a code so they are also at a loss. Sometimes it does it sometimes not. The engine seemed to work for a few hours after they changed the fuel regulator, but on a trip the problem returned again. Have tried different levels of octane fuel, changed fuel filters, air intake is fine. When it starts to ping it will do it when the engine reads cool or warm, I just climbed through Mt. Shasta and had no problem with pinging, though sometimes when I tried to pass it once again seemed to lack power and then just take off and run fine. I'm at a loss and the dealer has no ideas. Any suggestions on what I could trouble shoot to solve this. Dealers answer has been to drive it till it gets worse, which will probably happen when I'm on a trip. Thanks for any help. 

Answer:  If we could put test equipment on the engine while you are driving and experiencing lack of power, we could obviously pinpoint your problem.  However, from what you have described, it appears you are having intermittent fuel pump failure.  Replacing the fuel pump on a vehicle with 50,000 miles would be a good idea in any event.

Question:  2001 GMC Motorhome mileage: 42,000. My Jimmy has automatic climate control. AC works great, but the heater only heats when the setting is 82 degrees, if I lower it to let's say 76 - 78 it's cold air. The Dealer can't find anything, but I know this not a unique problem. Any ideas?  Thanks, Joe 

Answer:  The temperature sensor for the climate control or the control module itself may be faulty. 

Question: 1997 GMC Motor Home mileage: 150,000. Motorhome will cold start fine...will not hot start. Replaced the starter, etc. after testing showed bad. But, still did not start and made horrible grinding type noise when the key was turned to start it. Finally got it to start and immediately took it home. After sitting about 1 - 1 1/2 hours it did start but made same noise!

Answer: You may have a faulty starter solenoid or possibly some stripped teeth on the flywheel. In addition, load test the battery to verify that it is in good condition.

Automobile / GMC / Motor Home

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