Pinging Under LOad

[larkvalley]

My 1994 4.0 ,auto explorer pings like hell when warm and under load, check engine light goes on, oil pressure drops a little, timing ?, bumped up the gas i put in it to 93 octane,helped quite a bit ,but still problems, any help would be appreciated, thanks !

 

[Anime]

Probably the worn rocker arm issue. The factory rocker arms were made from metal that was a little too soft and they get indentations from the valves, leaving a lot of space that the lifters eventually can't compensate for and you get valve clatter under load.

The only fix is new rocker arms. Not super expensive, not hard to do, but you do have to pull the rocker arm covers. It's a good chance to replace the upper and lower intake gaskets while you're at it, and of course the valve cover gaskets as well.

http://www.explorer4x4.com/lifters/lifters.htm

 

[mcfearin]

I deffinitly have the problem, any one have a guide yet for this repair? Know of any place selling a kit with all the needed parts togeather?

 

[Roadrunner777]

Pinging is a sign of a too lean mixture.

In addition, I might look at fuel pressure. I might looks for leaks after the MAF sensor, through to the lower intake manifold.

Most importantly, you have a check engine light (CEL). You can get more information before you make major decisions. Read the codes... there are more than a few articles here to do it, or you can get at code reader from Orielly's or many other sources. Tell them what your vehicle is, so you get the right reader. Or, read the blinking light on the dashboard, as described in those other articles. The numeric codes lead to diagnostic indications of where to look for issues. Post the codes here, and plenty of ppl here will be glad to help.

Edit: Apparently some auto parts stores will read your codes for free in the parking lot. That's another option.

 

[wood1]

Mine knocked quite badly when I bought it. Did some research and found my lower intake manifold bolts were loose, plug #5 seems to be an indicator and is usually oil fouled. I retourqued the LIM bolts and it stopped. Just another idea, something to check.

 

[mcfearin]

Thanks for the other ideas, my 1992 Explorer XLT is at 365K miles so thats why I was going with warn rockers as the main idea, I figure at this point they have to have some bad wear into them, the car has been a daily driver sence brand new with the only major repair being a rebuilt transmission, at 180K and its in need of another now. I also need to replace engine mounts and just finished replacing every inch of hose as they had started to take turns at failing. I was looking for some good guides and parts lists as I live so far out from any parts shop, I would hate to start breaking her down and find out I forgot a gasket or bolt, its normally the story of my life.
I do get a check engine light every now and then, I have a great OBD2 reader that plugs right into my laptop but have been having a horible time finding an OBD1 adaptor or reader. The paperclip or wire trick is fine but I am just stuck in the idea of the right tool for the right job. Thanks for all the help and input guys, this is a great site.

 

[exhaustoboy]

Run super unleaded. It will cure the problem. Cheap easy fix.