Comanche sounds like a diesel -

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post #1 of 7 Old 05-13-2008, 06:07 PM Thread Starter
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1991 MJ Comanche 
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Comanche sounds like a diesel

Somebody please give me any ideal as to why under heavy acceleration my 4.0 inline 6, 1991 comanche sounds like a diesel truck when I punch it. It has 200K+ miles, just replaced the water pump and the belt it good and tight. I'm at a loss to figure this one out, any help is appreciated. Thanks

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post #2 of 7 Old 05-13-2008, 07:25 PM
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1989 MJ Comanche 
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Not sure what you mean by sounds like a diesel. Is it just loud. Head over to Better chance of some help
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post #3 of 7 Old 05-14-2008, 08:12 AM
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Are we talking "clatter"? Could be a sticky lifter.
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post #4 of 7 Old 05-14-2008, 10:29 AM
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My lifters are all really noisy too... sounds like a Mini-Diesel too...

Not much I've done has had any effect... will be rebuilding at some point in the future...
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post #5 of 7 Old 05-14-2008, 12:17 PM
Pete M
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Could be pinging maybe? H.O. engines don't have a knock sensor. Try throwing an octane booster in the tank.
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post #6 of 7 Old 05-15-2008, 06:45 AM Thread Starter
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Thanks to all that replied

Thanks guys, I appreciate your replies, I finally figured it out. I was a little low on oil and the oil light flickered just before shifting at red line, added oil, noise went bye bye. The noise sounded like a diesel sitting at idol the kind of have that metalic rattle I don't know how else to describe it. The noise wouldn't be all the way through exceleration just at the end of a shift point under wide open throttle. During light exceleration it would not do it at all.
Take care!!
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post #7 of 7 Old 05-15-2008, 09:44 AM
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Sounds like you could use a gauge cluster swap so you can monitor you oil with a PSI gauge...

Either way, congrats on getting it figured out.
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