Thallarsen
Well-Known Member
- Joined
- February 21, 2000
- Messages
- 126
- Reaction score
- 8
- City, State
- Potomac, Maryland
- Year, Model & Trim Level
- '99 5.0 Limited AWD
I have a '99 5.0 LTD with 135k on it. Startup, cold starts, hot starts, idle, acceleration from a start are all fine. Even my mileage is good for a V8 AWD.
But I have this nagging pinging & lack of power when going up hills at highway speeds. Minivans passing me with soccer moms driving them, okay, but yesterday, an ambulance passed me....not on a call. My '91 4.0 with 165k would have smoked my '99 going up hills @ highway speeds.
I run regular Exxon or Shell gas, and I have done the following:
What is left?
One thing that I'm thinking, is some kind of EGR problem. Although I haven't seen the CEL in two years, it did come on shortly after I bought the truck (two years ago). The P.O. offered to make good on the transaction, and took it to a Precision Tune. They ran the codes, and "Insufficient Air Flow - EGR" came up. They replaced the EGR valve, reset the CEL, but the light came on about 300 +/- miles later. It turned out to be the DPFE, which I replaced. No more CEL since then.
My question at this point:
Could there be some sort of corrosion/deposits in the EGR passages that is creating this pinging & loss of power? How would I find out? Are there EGR-related problems that wouldn't throw a code? Do '99 5.0's have knock sensors? How do you test a knock sensor?
Thanks for any help.
J.P.
But I have this nagging pinging & lack of power when going up hills at highway speeds. Minivans passing me with soccer moms driving them, okay, but yesterday, an ambulance passed me....not on a call. My '91 4.0 with 165k would have smoked my '99 going up hills @ highway speeds.
I run regular Exxon or Shell gas, and I have done the following:
- Installed new plugs & high quality wires
- Replaced the air cleaner with a K&N
- Replaced the fuel filter
- Replaced the thermostat
- Run a few tanks with Chevron System Cleaner
- Cleaned the MAF
- Reset the PCM
- Run 1/2 pint of Seafoam through the system
What is left?
One thing that I'm thinking, is some kind of EGR problem. Although I haven't seen the CEL in two years, it did come on shortly after I bought the truck (two years ago). The P.O. offered to make good on the transaction, and took it to a Precision Tune. They ran the codes, and "Insufficient Air Flow - EGR" came up. They replaced the EGR valve, reset the CEL, but the light came on about 300 +/- miles later. It turned out to be the DPFE, which I replaced. No more CEL since then.
My question at this point:
Could there be some sort of corrosion/deposits in the EGR passages that is creating this pinging & loss of power? How would I find out? Are there EGR-related problems that wouldn't throw a code? Do '99 5.0's have knock sensors? How do you test a knock sensor?
Thanks for any help.
J.P.