Synthetic Oil in Possible High Mileage AMC 360

Synthetic will make it past the rings just as easily as dino. The real advantage to synthetic is it lasts longer between changes. Apart from that it's basically the same. The only real benefit I have ever received from running synthetic (Mobile 1) was in sub zero weather the ZJ would turn over easily when other cars were dragging to start. Now to be fair I was running 5W30.

Personally, I would go with a synthetic blend like Castrol Syntec.

The only down side is that synthetics do tend to get out from holes that regular dino doesn't. I've got a front main that keeps dribbling a bit. Just too lazy to do seals on it.

Remember that a "synthetic blend" is nothing more than synthetic mixed with dino. Add a couple bottles of synthetic to your dino oil and you get the same thing. That's how I use up any leftover synthetic or dino.

Hi Randall, The puff of smoke at start up, is are bad valve seals. That are easily replaced using an air compressor to hold the valve in place during the exchange. I've never been sold on "synthetic oil" as I know it's the same oil pumped out of the ground, with another refinery step. I have been happy with Pennz 20/50 for my Bronco 351M with over 350 thousand miles, zero slug, and never had the heads off. Bought a new Cherokee in '02 and switch it from

Well said Bill!

That being the case then, perhaps the prudent thing to do is just keep using what I've been using for years (Delo 400) and forget about the synthetic. I have had such good results with Mobil 1 and Rotella over the years in other engines, that I thought I would want to go there again with this one, but I can see now that it is not worth the risk that it will start the seals leaking. It's dry now, so why tempt fate?

If in fact, this engine has 183K on it, i.e., it is the original engine and was never overhauled, I may have an engine rebuild in my future and I can decide on the switch then, after a break-in interval with petroleum oil.

Many thanks, again Doug.

Bill:

Thanks. I think a valve seal replacement would be in order, and not too expensive. It may be beyond my capability now that I am using a carport and not a shop. It has been hovering around 0F here of late. It sounds like a good early spring job, after I don't need the Jeep for the snow and before I can get into the lake back country.

If you would like to ease into the process, try a hybrid oil first. I havent had a bit of leakage since converting clear to full synth a couple years ago, but mine is a 95 wih only about 130K miles.

I think after reading all of the posts in answer to my question that I will stick with Delo 400, which I have used successfully for many years, instead of switching. One of the motives for doing so was to standardize oils with my Mercedes 300D, which just underwent a rebuild and will eventually be serviced with Rotella-T after the break-in is done in a couple months. But running Delo 400 in the Jeep is no problem, and in fact that is what I have used in three Wagoneers now, and I would certainly not want to bring on leaking, etc., when there is now no problems. As someone her has said, if it's not broke, don't fix it.

Thanks again.

Not unlike the threats of death and physical violence you have posted?

PKB

Randall, you can safely killfile both cujo and square, they never contribute more than noise to this group.

Go F*ck yourself finally Jewjo... You have something to say about spamming, but you are no better yourself ass f*ck. Every breath you take is a waste of oxygen for real people!

Doug,

Thanks. I suspected as much. I am not going to glorify their posts with any further replies. If it is not Jeep related, I will ignore it. I just wanted to make the point that the infantile posts can be ignored until they start replying and interfering in the normal course of dialog.

Doug, don't add fuel to the fire. It only emboldens the Ass Clowns. Ignore them. Better yet, killfile/filter them. It's like they never existed.

Better yet, killfile/filter them. It's like they

True, but sometimes poking the trolls is just irresistible. I only see "them" when someone quotes a post.