Pinging, or chain tensioner rattling?

[andypinto]

Sorry for this thread, might be dumb, but I honestly have this doubt.

When my Ex. engine start to make this strange rattling sound, right away I though: that's pinging¡.

However, after make three times the full cleaning procedure of the combustion chamber, clean the MAF, retight the intake manifold bolts, etc. and nothing happens, I'm really pissed off.

I'm just wondering, but a loose chain tensioner make the same rattle noise than the pinging?

The rattling sound on my Ex. didn't happen when the engine is cold, just when reach the normal operation temp, and with load, I mean, with third, fourth os fifth gear engaged.

By the way, my Ex. is a 1992 4x4 XLT, with 160.000 miles.

Any advice will be appreciated

Thanks

Andy

 

[dogfriend]

If you have a bad timing chain tensioner, the noise would probably happen all of the time, not just when warmed up.

I had a bad timing chain on a 4cyl engine and it sounded like a diesel engine, even when it was at idle. The noise was the chain slapping the inside of the timing chain cover.

 

[TPLYNCH]

Your OHV engine does not have Timing Chain Tensioners I don't think..... That's a SOHC part. Someone please correct me if I'm wrong.

 

[andypinto]

TPLYNCH, according to my Haynes Manual, the 4.0 OHV engine has a timing chain tensioner.

Andy

 

[DaHeinah]

Andy- I had/have the same problem. I fixed it momentarily by putting on a Granatelli MAF but it eventually came back . What type of mods do you have on your truck? My dad thought it might be valve shudder but my "tappit" noise is nearly gone so I don't think that's it. As much as I hate to say this, to truly get rid of the pinging it may be necessary to have our ECU's reprogrammed by a Ford dealer to alter our "timing". That's what one of my four-wheeling buddies did at UNR and he said it worked...just thinking.
Greg

 

[andypinto]

Greg, thanks for your post.
My Ex. is mostly stock, and no mods are in the engine at all.

Checking about the pinging issue, I found that not only the carbon deposits in the combustion chamber can cause the pinging. Also a worn valve could be the origin. When the valve is older (my Ex. has 160.000 miles on it) the edge becomes thin and is not capable to dissipate the heat, so the edge of the valve, as the engine temp increases, turns incandescent and creates a "hot spot" that ingite the fuel mixture before the piston reach the proper position.

Anyway, I believe that my Ex. will must pay a visit to the shop and probably need a major repair in the engine.
Oh, my poor wallet!

Andy.

 

[DaHeinah]

Andy, great informative post. I wish I could borrow you my granatelli just to see how much it helps... maybe get one (about $300) and see if it helps. It permanently helped my brother's 92 X. Hope everything works out.
Greg

 

[andypinto]

Greg, thanks for your very kind post.
I hope that everything works out, also.

Andy