Diesel like sound from motor

[KLUTZ]

I have heard a slight , dieseling like sound from my 98 EX, 182,000km 4L, for some time now, but this weekend, after getting gas from an independant station, it seemed worse. I remember seeing somthing on this on another thread, but can't locate it. I still get 480 km on a tank of gas, highway and city combined, or 300 miles, with or without the sound.
Is this a gas problem or what? It had a complete tune-up at 148,000km.
Thanks

 

[Okrazie1]

Is your engine the OHV or SOHC? If it's an OHV it could be piston slap.

 

[32to1]

sounds like a piston slap prone OHV...pretty common with the 4.0's

 

[KLUTZ]

Yes.. OHV. Please, some info. on piston slap!

 

[Okrazie1]

I'm going to quote myself from a post I made way back in 2001:

Originally posted by Okrazie1
My understanding is that the infamous “marbling” sound is piston slap caused by the piston design of the late model 4.0 OHV, and the least bit of carbon buildup aggravates it. From what I’ve seen on some other boards on the net (Ranger sites), getting a remanufactured engine is a crapshoot. You might get a good one, or you might get one that sounds as bad or worse than the one you have now. I have the sound in mine, but after thinking it over, I decided to live with it. It doesn’t do it all of the time, its not extremely loud, and other than the noise the engine runs like a champ.

According to what I've read, the piston slap is not supposed to affect the longevity of the engine. Mine still does it from time to time, but it hasn't gotten any worse.

 

[KLUTZ]

Thanks for the re-post. I did find some other posts after looking, and the question of synthetic oil vs. regular oil was mentioned. I have used synthetic since 28,000km. Could a thicker oil lesson the noise? Like I said, I still get reasonable milage, 480 km / tank, and the engine runs like new.