Spark knock,pre-ignion,pinging???

[Buckshot_1]

While driving my Explorer to work, when going
up hills or passing I hear rattling noise in
the engine. On highway speed alls ok until
I start up hill. I also notice while towing
a small trailer,(not in O/D at this time)
but it's worse.
Can timing be out?
The engine pulls stong and runs great!


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Ken P.
1992 Explorer XLT 4Dr
Kenwood sound system
K&N filter,modified airbox
thats it 4 now!!Well Maybe!!

 

[AgExplorer]

Buckshot,

It could be one or more of several things. A lot of the guys have reported that cleaning the MAF sensor has corrected the problem. If this doesn't do it, you may want to try to clean the upper air intake system and throttle body to remove build up and deposits. Carbon build up can cause pre-ignition which leads to the "rattling" or valve clatter you are hearing. Others have done a tune-up (new spark plugs and wires) and this has eliminated the problem. Give them a try and let us know how it works out for you.

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AgExplorer
95 XLT 4X2 4.0L OHV
AMSOIL Synthetic Lubricants & Filters
NGK Platinum Plugs
Jacobs Electronics Wires
Info and Ordering for AMSOIL Synthetic Lubricants - Dead Link Removed

 

[rockylaurence]

Buckshot; True it could be a lot of different things. I chased this problem for sometime. I replaced plugs, O2 sensors, cleaned the MAS, used LOTS of injector cleaned to no-avail. It ended up being Carbon build up that I burned off by driving to and from work in 2nd gear (to get the RPMs up to 3500-4000). During my normal routine I never get above 2300 RPM for an extended period of time which allowed the carbon to build up. Also, I used some of that stuff(its called HOT-I think) sold in AUTO ZONE to "Beat" emissions testing.