AutoRx, Cherokee 160K Miles?

[Dominic]

My friend has a Jeep Cherokee and while I know a lot about oil he knows nothing. His dad ran RP 10w30 in it and changed it every 10K miles

without any sort of analysis.

He asked me to change his oil and I did, and man the whole top of the engine from what I could see was sludge city. It runs alright, but has 160,000 miles and a very slight rear main seal leak (This is the 4.0 Inline 6). I ended up putting Mobil 1 10w30 in it, at his request, and now I'm wondering what AutoRx could do for this engine.

Could I get the sludge out? Would it fix the rear main seal any to run AutoRx? I've never used it, I did recommend it based upon what I've heard from this board, but I'm just curious. It seems like a good application but I don't want to harm the engine since its so old.

 

[47HO]

I used it in my 1990 Jeep Cherokee when it was at about 145k miles. It did stop the rear main seepage.

Those engines are bad to "coke up" the valve train up top. Are you sure that it isn't this, instead of sludge? I don't think anything will remove the coking.

Anyway, you can't hurt it by using Auto-Rx.

 

[Dominic]

Amazing, Thats precisely what I saw. If it stopped your leak, perhaps it will stop his, since his isn't bad at all.

I'll see if he wants to try it

Can't hurt, beats paying for a rear main and might help it live a lot longer.

If the coking up top is *normal* (ahem) then I'll accept it, but I don't have to like it.

 

[Eiron]

Hi Dominic,

Based on all the info Frank's provided (both here & on his website), I don't think there's anything in Auto-Rx which can "hurt" an engine. As you've pointed out, it's a lot cheaper than replacing the seal, but even if they cost the same, replacing the seal wouldn't remove all the crud or improve operating performance.

And if he notices an improvement with his engine, it might be good for him to use it in his aging transmission & power steering systems as well. All the dosages are different for the different systems, so be sure to refer to the Auto-Rx website for the various applications.