oil pressure light on 1994 Camry 4 cyl

[Pablo]

I didn't want to mention the "sludge" word, due mainly to previous oils used and history. The gummy oil pump pressure relief spring did cross my mind, and I suppose this is a real possibility if the filter was clogging, but still - how gummy could this engine be????

 

[unDummy]

Maintenance history seems reasonable, except for your last several exteneded runs. Driving style, not mileage, is also important.

UOA the oil coming out of the car now. If the oil looks like someone was mining for metals, then damage did occur. If not, I wouldn't worry about it. Yes, if the filter is defective, and UOA is scary, file a claim.

All it takes is short trips, defective thermostat, low oil levels, PCV failure, and insides can get dirty quick. Winter would exaggerate the fuel/moisture seriously.
Moisture/fuel dilution can be hidden simply by taking a long ride prior to an oil change or UOA sample.

This is why visual inspection of the engine is important.

I also looked at your UOAs, which I believe were giving you a false sense of security concerning running the oil until it was completely spent. Reread Teedubs 1st comments on your Dec UOA.

There is a problem that is being compounded be excessively long OCI!

 

[Pablo]

Indeed undummy past posts are interesting:

EGR going

ASL with 15K miles

Related hesitation?

Oil light acting up in 2006

 

[Donald]

So if the engine was all sludged up and that clogged the oil filter the pressure relief in the filter should have kicked in and bypassed the filter and my oil pressure would have still been fine?

The old filter is on its way to Amsoil. Guess I should plan on doing an oil analysis and dumping this oil?

 

[Pablo]

Well the best thing you did was to not continue driving the car. I'm thinking it's not damaged at all, but I certainly would do an oil and filter change (do a UOA if you are worried), order up some AutoRx and do the clean thing. 2X.

 

[unDummy]

What you need to do is change the oil/filter now. UOA it if you worry about damage.

Concerning the filter, if it sludged up, then its possible to sludge up the filter bypass too. Or, the resistance to oil flow caused the pump bypass to stick or hang open.

You should practice frequent ~5k OCIs until can rule out sludge. Sorry, but without an engine inspection, you should seriously consider the 3-5k/3mo routine.

In this situation, UOAs gave you a false sense of security. I also don't know why anyone would want to run an oil until it is completely spent.

Just because an engine has been using synthetic oil, doesn't mean it is clean. Sorry, with your extended OCIs, unknown driving style, questionable engine state of tune, engines life long OCI history, oil consumption, low levels, short trips,.... I would think that the synthetic is the reason why your engine is still running.

I don't see the synthetic oil as an excuse for eternal OCIs, as an excuse to run low on oil, as an excuse to have an engine not in a proper state of tune, or as an excuse for anything. With every issue that was found, OCI should've been adjusted accordingly and immediately.

I also would like to ask, what is the reasoning for your extended oil change intervals?

And, did I mention that you should pull of a valve cover for sludge/crud inspection?

Pablo, thanks for the link. I was pretty much ready to slam a certain product. But, the only thing I find wrong with Amsoil is their blind marketing/advertising. I truly don't see their oil or filter to blame here.

 

[Donald]

OK, Amsoil has the filter and is examining it now and an oil sample is on the way to them. I expect an update early next week. I changed the oil and now have some non synthetic oil so I can do AutoRx.

 

[Donald]

Amsoil said the oil analysis indicates boron and 12% water. That seems like a lot and guess I would expect the oil to look milky. Does this sound like a head gasket?

 

[Donald]

Now that I have seen the actual report rather than an email, the water was only 0.12% rather than 12%. But the Boron was 324. Still I am not sure how the tiny amount of water in the oil contributed to the oil pressure problems and/or clogged oil filter.

 

[Pablo]

The only thing I can add is that sometimes sludge , or rather random chunks of sludge may not be detected in a $25 UOA. So - Amsoil said the filter was OK?