Dodge Challenger Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
7,683 Posts
Discussion Starter #1
I guess this topic goes into the irrational fear category for me. I've never experienced it, never knew somebody who experienced it, but only hear about it from time to time in an anonymous web forum discussion. There's never a clear cut reason or consensus for its occurrence...it just sort of "happens". Do you just wake up one day, and your motor oil is a gel, instead of a liquid? Does it happen over time, and you are just none the wiser as the dipstick looks wet the whole time? Is it apparent at all on an oil pressure gauge or even a low oil pressure light? Is it something that some substandard oils happen to "do", or is it something that certain engines have a habit of "doing" to the oil?

What do you guys know about it?
 

·
Registered
Joined
·
1,431 Posts
While oil won't gel on its own, water and antifreeze getting into the oil pan will create an emulsion that looks like a gel. Blown head gaskets will give your oil that nasty chocolate milkshake appearance.

Excessive idling and short duration trips during winter weather can also deposit quite a bit of water into the crankcase, but changing the oil more frequently will prevent most problems. Trying to squeeze 10,000 miles between oil changes on short trip vehicles during the winter may cause "gelling".
 

·
Registered
Joined
·
401 Posts
Ive heard that a lot of engine sludge problems are do to "short" trips where the engine does not warm to full operating temp. BUT just what Ive heard. Not sure.
 

·
Super Moderator
Joined
·
14,543 Posts
the major issue is the engines don't have good drain back from the cylinder head back to the oil sump.

The heads run hot from the combustion chamber and this in turn 'cooks' (burns) the oil which makes it take on the consistency of tar and gets sludgy.

Eventually the passages and drain back holes get plugged, and the the problem worsens.

Toyota and Audi had this problem for years and couple that with an owner than might not follow oil changes as they should, the engines eventually starve of oil and will fail. Often the sludge would clog/restrict the oil pickup in the sump.

Drive at highway speeds and the engines would score or seize from oil starvation, yet the sump was full of oil.

This was especially problematic on V6 engines from Toyota and Audi from the mid 80s through the early 2000s.

The Audi 4cyl turbo engines could get the oil gelling issue as well, due to the additional heat a turbo'd engine creates. Oddly, the VW versions didn't seem to get this very much, or Audi drivers run their cars a lot harder than the typical VW owner...?

Some of this has been resolved by redesigns to the engines.

When there were warranty claims the mfgr tried to push this back onto the owners as negligence with respect to maintenance of their cars, but there was a high frequency of this going on.

Syn oils would help, but if the owner is doing lots of stop and go driving, short distances (not fully warmed up) this can contribute.

So many owners try to cheap out by using lower grades of gas or not spending the $$ for synth oil when the mfgr recommends it - many think 'it runs fine, why spend more $$ on it'.

About 10 years ago a number of makers switched to synth oils with the tighter tolerances and high operating temps today's cars have.
 

·
Registered
Joined
·
6,340 Posts
2.7L........................nuff said.

50K on mobile one.. BANG... Yep and Mopar said it was my fault..

Oil Slude is because of defects in engineering, nothing more, nothing less. Heads cook the oil, even synthetic.

Hal was spot on.
 

·
Registered
Joined
·
7,683 Posts
Discussion Starter #7
So do we have anything to worry about with our Hemi heads cooking the oil or are they pretty invulnerable to that at this point in their design maturity?
 

·
Registered
Joined
·
714 Posts
the major issue is the engines don't have good drain back from the cylinder head back to the oil sump.

The heads run hot from the combustion chamber and this in turn 'cooks' (burns) the oil which makes it take on the consistency of tar and gets sludgy.

Eventually the passages and drain back holes get plugged, and the the problem worsens.

Toyota and Audi had this problem for years and couple that with an owner than might not follow oil changes as they should, the engines eventually starve of oil and will fail. Often the sludge would clog/restrict the oil pickup in the sump.

Drive at highway speeds and the engines would score or seize from oil starvation, yet the sump was full of oil.

This was especially problematic on V6 engines from Toyota and Audi from the mid 80s through the early 2000s.

The Audi 4cyl turbo engines could get the oil gelling issue as well, due to the additional heat a turbo'd engine creates. Oddly, the VW versions didn't seem to get this very much, or Audi drivers run their cars a lot harder than the typical VW owner...?

Some of this has been resolved by redesigns to the engines.

When there were warranty claims the mfgr tried to push this back onto the owners as negligence with respect to maintenance of their cars, but there was a high frequency of this going on.

Syn oils would help, but if the owner is doing lots of stop and go driving, short distances (not fully warmed up) this can contribute.

So many owners try to cheap out by using lower grades of gas or not spending the $$ for synth oil when the mfgr recommends it - many think 'it runs fine, why spend more $$ on it'.

About 10 years ago a number of makers switched to synth oils with the tighter tolerances and high operating temps today's cars have.
Oh the VW turbo 4-cyl (eg Passat) that is same as Audi has the problem just as much. I think perhaps it is more an issue of newer engine being more resilliant

I think the issue is really one of inadequate PCV system more than anything else, exacerbated by poor-quality oil and extended drain intervals.

I wouldn't worry about it on any engine that didn't already make itself a "history" of sludge (eg. VW 1.8 Turbo).

I might suspect hard driving would actually be better for it. On some Saab cars I am familiar with, the sludge usually happens to the lower-power engines and automatic transmission, while high-ouput turbo version and 5-speed manuals are less likely. Is it because of the arrangement, or perhaps because the manual driver is an enthusiast who changes oil regularly?
 

·
Registered
Joined
·
1,738 Posts
I haven't heard of these problems with our cars. Change your oil per the mfg. recommendations, using the recommended weight and grade of oil, and I think you'll be fine.

Enjoy your car. The 5.7L has been in vehicles for many years. It's a good engine. Don't worry about this, just do your maintenance.
 

·
Registered
Joined
·
714 Posts
How do the Hemis hold up to high milages anyway? My 318 Magnum from my 98 Ram burns a ton of oil at 150k ish miles, no smoke ever but I need a careful eye on the dipstick (rings I figure).
 

·
Banned
Joined
·
1,844 Posts
today i was cleaning my guns , and noticed that some of my gun oil had gelled into little white pearls. its been a while since i used it last . guess there is some kind of seperation that caused it to gell.
 

·
Super Moderator
Joined
·
14,543 Posts
How do the Hemis hold up to high milages anyway? My 318 Magnum from my 98 Ram burns a ton of oil at 150k ish miles, no smoke ever but I need a careful eye on the dipstick (rings I figure).
Your 318 probably lets some oil past the rings (or valve guide, valve stem seals) - with cat converters, slight amounts of oil consumption can get burned up within the cat and you may not see the (slight) amount of smoke, as it dissapates quickly that you can't see it from the rearview mirror like older, pre-cat vehicles might show.

On a lot of (not diligently maintained) newer cars, I noticed slight oil smoke on decel (worn valve guides, valve stem seals) or some smoke when the accelerator is depressed (worn rings, upper cylinder walls) under load, but its only noticeable by someone driving behind the car, since its a small amount.

On an engine with significant wear or oil consumption issues, unburnt oil will make it past the cats and then the tell-tale blue smoke appears.

In the NW area, [esp. with automatics] I notice a lot of drivers will fire up a cold engine, throw it into gear even before fast idle settles down (injected engines only need 15-30 seconds to drop down from high idle) and tear off at 25-35mph and you can hear the upper end of the engine being noisy as the cold oil is flowing as thoroughly through the valvetrain.

Couple that with our winter temps in the 20s-30s and I see a lot of fairly newer (3-5 years old) cars that smoke and exhibit valvetrain noise of some noise from the bottom end of the engines relatively early on.

I recommend any one buying a recent model car to have compression tests and cylinder leak-down testing done...the above scenario is pretty common, younger drivers and automatics don't understand the concept of allowing the oil to flow for 30 seconds or so after startup and not getting on the throttle so heavy from a cold startup.
 

·
Super Moderator
Joined
·
14,543 Posts
So do we have anything to worry about with our Hemi heads cooking the oil or are they pretty invulnerable to that at this point in their design maturity?
Since the 5.7 has been in production since '03 with relatively little issues and by now there's some high mileage ones on the road it seems to be a pretty durable design.

Coupled with 7-qt sump and a conservative 6K change interval, these seem to be pretty robust engines.
(the old Slant 6, and V8's had 4-qt sumps and the hi-po verions got 5qt sumps - so the more oil you have, the better cooling of internals and more oil to take up combustion contaminants. Plus modern FI systems don't have oil dilution from the greater amounts of fuel that carbed systems tended to contaminate the oil with or wash down cylinder walls...)

The 'standard' sump in MB engines is 8.5qt (late 90s on up) and the really hi-po versions run 11qt in some models...the old 6.3 and 6.9 engines from the 70s ran 11qt dry sump systems FYI.

These MB engines can run full-out for hours on end on the Autobahn w/o issues, since there's plenty of lubrication and internal cooling capacity with their oiling systems.
Couple with required full-syn oils and the large oil sumps, these MB engines run 10-13k oil change intervals and fleece oil filter media (not paper) without issues. The large quantity of oil in the sumps provides a lot of media to absorb combustion by product for those longer intervals.
 

·
Premium Member
Joined
·
362 Posts
How do the Hemis hold up to high milages anyway? My 318 Magnum from my 98 Ram burns a ton of oil at 150k ish miles, no smoke ever but I need a careful eye on the dipstick (rings I figure).
you need pull the intake and replace the intake gaskets. very common problem on the magnum engines. it's pulling oil from the lifter valley. i'm getting ready to do mine when i get some motivation.
 

·
Registered
Joined
·
7,683 Posts
Discussion Starter #16
Since the 5.7 has been in production since '03 with relatively little issues and by now there's some high mileage ones on the road it seems to be a pretty durable design.

Coupled with 7-qt sump and a conservative 6K change interval, these seem to be pretty robust engines.
(the old Slant 6, and V8's had 4-qt sumps and the hi-po verions got 5qt sumps - so the more oil you have, the better cooling of internals and more oil to take up combustion contaminants. Plus modern FI systems don't have oil dilution from the greater amounts of fuel that carbed systems tended to contaminate the oil with or wash down cylinder walls...)

The 'standard' sump in MB engines is 8.5qt (late 90s on up) and the really hi-po versions run 11qt in some models...the old 6.3 and 6.9 engines from the 70s ran 11qt dry sump systems FYI.

These MB engines can run full-out for hours on end on the Autobahn w/o issues, since there's plenty of lubrication and internal cooling capacity with their oiling systems.
Couple with required full-syn oils and the large oil sumps, these MB engines run 10-13k oil change intervals and fleece oil filter media (not paper) without issues. The large quantity of oil in the sumps provides a lot of media to absorb combustion by product for those longer intervals.
WOW!...11 qt of oil?...and I always thought our 7 qt engines were pretty hefty. Great info, Hal H!
 

·
Super Moderator
Joined
·
14,543 Posts
WOW!...11 qt of oil?...and I always thought our 7 qt engines were pretty hefty. Great info, Hal H!
There's some Porsches out there (911 models) that had big sumps too.

Imagine buying 3 gallon size containers of full syn just for one vehicle's oil change...!

The cashiers @ Wally World are always surprised that I'm buying 2 gallons a time time for each of my cars when its oil change time. At least they have pretty good prices there.

Not the typical quantity most mini-van driving customers probably are buying at Wally World for their oil changes.
 
1 - 17 of 17 Posts
Top