From M1 HM to PU for Cleaning?

[lukejo]

I just acquired a 1995 Camry 4cyl with 170k. Previous one-owner used PYB for the first 120k, then switched to M1 HM for the last 50k. Under the oil fill cap I see some sludge. Not just varnish, but a thin coating of black sludge.
I assume it is due to one or possibly two things: while maintenance records are good (OCI every 4k since new), driving was almost always short-trip, in-town, sometimes months and months without getting on the highway. In combination, I'm not sure if PYB was any good 15-20 years ago under these short-trips driving habits.
Runs great. Burns no oil. Very, very small leak (maybe 2 drops per day and imperceptible on the stick).
Question--if it has had M1 HM for several years and I still see some sludge should I switch to PU for a while and see if clean-up occurs? Running as good as it does, I don't want to try an auto rx or similar treatment...but rather just try gentle cleaning through good oil. I guess my only hesitations in trying the PU....is why change if it won't clean any better, and concern over the seals if I leave the HM on this 20 year old engine. (only 10w30 since new) Thanks in advance for your thoughts..

 

[geeman789]

20 year old car... how many years left...?

I would use any brand name oil, keep it fresh, and not worry too much about the small amount of sludge.

Loosen it up too fast, and you may cause a real problem.

If you are bored, remove the valve cover, and the oil pan, and see how much sludge is really present. If the oil pick up is clear, I would leave it alone.

 

[CapitalTruck]

If the vehicle has had high mileage oil used for a significant amount of time I believe the seals become expanded because of the seal sweller that HM oils use. After the use of these products is discontinued oil consumption can go up. That would be my worry for you. I probably would just keep up with the HM oil.

 

[lukejo]

Thanks, that might be good advice..just to leave well enough alone. My driving habits are totally opposite than the previous owner, daily commutes to work at 60 mph, 40 miles each way. So, maybe the sludge will improve with M1 HM being driven like this. Or, if not improve, maybe it will not cause any problems.
It just bugs me to look in my 322k Camry and see absolutely no black and then look in this car (which seems to be in better shape in every other way) and see all this gunk.

 

[lukejo]

Originally Posted By: geeman789
20 year old car... how many years left...?


Haha...I know, maybe a good point. But, this car is just my work commute car. I don't put the family in it. Just a good commuter for me to rack up miles on. I still drive the 322k Camry every day, so if I switch to this one, which is almost a cream puff, I'm thinking years and years left.

 

[benjy]

back in the 70's i tore down a small block chevy for a rebuild, never seen owner before. i filled a pound coffee can with sludge, when the owner asked how'd it look i said you run pennzoil!!! he said how did you know!!! that typical was pennzoil of old!!!

 

[901Memphis]

Sometimes the fill caps can get sludged but its isolated. Without pulling the valve covers i would venture to guess it's not nearly as bad on the rest of the engine. Some engines just throw oil up there and it gets sludged.

 

[SrDriver]

A new PCV valve would not hurt anything either and they are inexpensive.

 

[Tabor]

I de-sludged a 1991 Honda Accord with 3k mile changes of Castrol GTX. If I had to do it again I would probably use Mobil 5000 only because it's the cheapest name brand Dino that I have access to.

 

[geeman789]

You could run a hdeo (diesel) oil for a change or two... a little more cleaning power...but I would keep the intervals shortish.

Rotella T-triple makes a 10w30 conventional that would probably work well in summer.

 

[Alex38]

I'd stick with the M1 HM. Your longer highway drives should help the M1 to clean up that engine, if it does in fact need it.

 

[zuluplus30]

M1 HM is a seriously good oil with a high dose of detergents. Changing to PU won't "clean" any more than the M1 has done over the last 50k. Just keep using a HM oil since it's had a steady diet of that and change it at reasonable intervals. Even with some light deposits that engine should have another 100K+ left in it.

 

[Jameson]

When I purchased my truck I had no idea how long the orange can of death or oil was in there. All other fluids looked great however.

I ran mobil 1 5w20 full syn (which my v-8 consumed/weeped 1qt per 1000 miles) for the 4000 miles or so to "clean" things.
When drained it, it "appeared" surprisingly thin.

Did the same thing for 3000 miles with 5w20 pennzoil yellow bottle. Consumed/weeped 1.75 qt over the 3000 miles.

Now since running four 5000k intervals (one 7500) of mobil hm syn blend, checking every fill up, the oil does not turn brown until the 4000 mile mark or so. It consumes/weeps about 1 qt per 3000 miles. The pyb and mobil one were dark brown around 1000 miles.

I am contemplating switching to mobil 1 HM and stretching the intervals to 7500-8000 miles. The type of use I have would be considered severe duty.

 

[Nick1994]

Do your Camry's have the 2.2L or 3.0L?

My 2.2L Camry has a baffle (or whatever you call it) under the valve cover and you can't see what's going on in there just from the oil cap. If it's the 2.2L change the valve cover gasket just for the heck of it, it's super easy and get a good look.

 

[Boss302fan]

Originally Posted By: SrDriver
A new PCV valve would not hurt anything either and they are inexpensive.


I agree and would also stay with Mobil 1 HM. Just shorten the OCI to 3-5K miles for a few OCI's...

 

[lukejo]

Originally Posted By: SrDriver
A new PCV valve would not hurt anything either and they are inexpensive.


Thanks, I picked one up today.

 

[lukejo]

Originally Posted By: Nick1994
Do your Camry's have the 2.2L or 3.0L?

My 2.2L Camry has a baffle (or whatever you call it) under the valve cover and you can't see what's going on in there just from the oil cap. If it's the 2.2L change the valve cover gasket just for the heck of it, it's super easy and get a good look.



2.2L --- Yep, my '97 has that baffle, but I can still see with a light and head at the right angle. This car, the "new" '95 has no baffle..easy to see.

 

[lukejo]

Originally Posted By: geeman789
You could run a hdeo (diesel) oil for a change or two... a little more cleaning power...but I would keep the intervals shortish.

Rotella T-triple makes a 10w30 conventional that would probably work well in summer.


Hmmm. Never thought of that. No down-side to trying if I keep the OCI short?

 

[Nick1994]

Originally Posted By: lukejo
Originally Posted By: Nick1994
Do your Camry's have the 2.2L or 3.0L?

My 2.2L Camry has a baffle (or whatever you call it) under the valve cover and you can't see what's going on in there just from the oil cap. If it's the 2.2L change the valve cover gasket just for the heck of it, it's super easy and get a good look.



2.2L --- Yep, my '97 has that baffle, but I can still see with a light and head at the right angle. This car, the "new" '95 has no baffle..easy to see.


Those 2.2L's sure are power houses aren't they?

 

[lukejo]

Originally Posted By: Nick1994
Originally Posted By: lukejo
Originally Posted By: Nick1994
Do your Camry's have the 2.2L or 3.0L?

My 2.2L Camry has a baffle (or whatever you call it) under the valve cover and you can't see what's going on in there just from the oil cap. If it's the 2.2L change the valve cover gasket just for the heck of it, it's super easy and get a good look.



2.2L --- Yep, my '97 has that baffle, but I can still see with a light and head at the right angle. This car, the "new" '95 has no baffle..easy to see.


Those 2.2L's sure are power houses aren't they?

I tell you, with as many miles as I drive for work, that's probably the big reason I don't have more tickets. But then again, you get over 300k on the suspension/etc. and you get a little uptight hurdling down the road over 65 mph.