91 Nav. upper noise passanger side | Ford Explorer Forums - Serious Explorations

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91 Nav. upper noise passanger side


August 22, 2005
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City, State
Bethleham, PA
Year, Model & Trim Level
'91 Navajo
'91 Navajo with roughly 120K on this engine and 20K on trans & clutch. OK here's whats happening. Been noticing when I go up a hill or step on gas I hear an upper engine noise coming from the passanger side, kinda like a knock or trrrrrrrrrrr that disappears when I'm on level ground or when the engine isn't under alot of work. Changed the oil and it became worse and happened more often, when I put in some motor honey it settled it down a bit. But when I've been driving for a while & the engines hot & I get on the gas or go up a steep hill, then I hear it again til I take my foot off the gas. I heard it's the lifters. Don't get any smoke and nothing else seems wrong.. Anyone know what it is and whats the best way to resolve it, perhaps a bolt on kit or something I can do myself?... I mean I just redid the whole truck see--> http://www.cardomain.com/ride/2262259/1 any help or opinions is greatly appreciated..

Sounds like dirty mass air flow sensor. either clean or replace the part and it might go away. Try some 91 octane gass and see if it goes away, if it does it is more than likly that sensor. I would also get that "motor honey" out of there and just put in a good quality oil such as mobil 1 5w30 synthetic blend. If you like the synthetic blend go to full synth at next oil change.

I have the same problem with my 1992 explorer with 150,000 miles on it... I have tried all of the above and it still does not fix the problem... I did try the "steam cleaning" mention in another article here. It worked for about a day then came back... if you find out what works, please let me know

I didn't think the MAF could make a metallic knock & why would a thicker oil lessen it? I was thinking more along the lines of lifters, anyone have anything????