[pawski]

I have 5.2L 98D with 93K miles. I got concerned about engine sludge a few months ago, so I switched to Penzoil high mileage synthetic. Before I used the standard dino oil at the oil change place. I noticed an oil leak last week. I took it to the oil change place to see if it was just a loose oil filter (don't own a filter wrench anymore.) They thought it was the gasket on the oil pan. I haven't had a chance to get under it myself to check it out. Since it's 4x4 they said the front axel must be lowered to get at the oil pan ($360 if they fixed it).

So I'm wondering if I made a big (expensive) mistake by switching to synthetic oil after 90K miles of regular oil. I have read on the internet about how synthetic is thinner and that's can find its way out of old engine. Does anyone have experience with this? I'm also wondering if I should switch back to the regular oil to prevent any further problems from developing.

Thanks in advance for your help. I have to say over the 9 years I have had the truck this board has been a great help for me.

George

 

[IndyDurango]

You can never switch to early. A hole is a hole, so it'd leak sooner or later anyway. Just get it fixed and stick with Synth. I'd suggest Mobil1 instead of Penz.

IndyDurango

 

[MWeed]

If your D is serviced at the proper intervals, there's no real chance of getting sludge problems (depending on how it's driven.) This engine has been run in industrial situations for over 40 years with no problems of that nature at all. The engine is basically bullitproof.

 

[FSTDANGO3]

I don't believe the synthetic caused the leak
My guess they caused the leak.
Clean it up under there tighten everything up and recheck
Steve
DOC Pres

 

[tomk]

a long long time ago, when synthetic oils first came out, there were some seal incompatibility issues that would cause some seals to shrink and leak. This hasn't been a problem for decades, but the old stories take on a life of their own.

As Steve says, you gotta get the underside of the engine all cleaned up and then figure out where the leak really is.

?tom

 

[Silver Ghost]

There are two things (among others) that synthetic oils do better than dino oils when in contact with gasketing materials:
The gaskets don't take as much of a compression set (the gasket will rebound closer to original thickness when compression is released) and gaskets don't swell as much.
In oil pan service, these two properties can often offset each other - high compression set offsets swelling and the net effect is "zero". But each gasket material has different characteristics and one effect could overwhelm the other. So, switching to synthetic could cause a gasket or seal to loosen up and cause a leak. This is more likely to occur with older/higher mileage vehicles like yours - gasket age and newer gasket technologies are more oil resistant.
Try and isolate the leak, re-tighten all the bolts and see what happens.
Properly maintained, even with dino oils, you shouldn't have slugde issues, but switching to synthetic wasn't a bad move - in the long run it'll be a positive for your engine, but some folks have had leak issues and others haven't.

Joe

 

[pawski]

Everyone, thanks for the advise. I feel a bit better. I plan to check under it tonight and try tighting things up. I'll post what I find.

Thanks again,

George

 

[FSTDANGO3]

I'm betting that the filter is leaking and or the drain Plug. Believe it or not if the Drain Plug is leaking the oil will cling all over the bottom of the pan
Steve
DOC Pres

 

[pawski]

I crawled under the D yesterday evening to see if I could tell where the oil was leaking. There was some dark residue on the edge of the pan next to the filter, but I beleive this is likely from the many oild changes over the years. I was able to tighten the filter some by hand so I was hopeful this might be it. I checked again this evening and there's fresh oil so I don't think it's the filter. Anyway, the fresh oil appears to be coming from the back of the pan like the oil change place said. I can't really see the back edge because of the transmission. There doesn't seem to be any bolts across the back of the pan, so I don't think anyone could have loosen anything up. I did try tightening up the bolts I could get to. Didn't help.

I'm halfway considering switching back to regular oil to see if the leak would go away. Not likely I suppose :?. I guess I'll have to take it in and get the gasket changed.

George

 

[FSTDANGO3]

Before you go to a shop do yourself a favor and look on the top of the motor towards the firewall. Make sure the oil isn't running down the back of the motor from the intake.
Oil leaks are hard to pinpoint exactly as the oil migrates everywhere.
keep it full of oil and keep wiping areas off to see if you can pinpoint it otherwise you could start chasing your tail with repairs that just don't stop the leak
Steve
DOC Pres

 

[pawski]

I'll check it, but I don't think so.

I guy at work suggested it could be the main seal between engine and transmission. I suppose this would really cost some money to replace.

Thanks,

Steve

 

[Durangutan]

Joe thanks for the clarification on the leaking seals. I always wondered why the synth was rumored to cause leaks in higher mileage engines.

At my last oil change I switched from the assumed dino that was used for the first 72k miles (assumed because there was a Jiffy Squirt reminder sticker on it when I bought it) to a semi-synth, with the intention of switching again to full synth at the next change. If I'd noticed any leaking I'd have called off the synth swap, but so far nothing's leaked or burned in 3k miles. So I'm going to either Castrol full synth or Mobil-1. Same price.

So it brings to mind a question that I know some of you can answer? Are high-mileage full synths better than regular full synths? And is 72k miles considered high?

 

[FSTDANGO3]

72 K isn't that high for a D
The High Mileage oils have additives to swell seals on older engines
Steve
DOC Pres

 

[Neil]

Leaking down behind the pan can be coming from any number of places. Anything leaking up top will run down back there. (I've had so many leaks, I don't care anymore. A little dop every once in a while is no big deal) Valve cover gaskes are a possible source. If you can't see where it's coming from and really want to know, the best way is to have UV dye added to the system Then you hit everything with a black light and it'll be very clear where's is coming from. Pep Boys or or most shop can do it or I saw a kit in Autozone not to long ago.