'97 Camry: Easy for DIY?

[bolink654]

Put a whiteline rear swaybar on the Camry. Best $170 I've ever spent on a car. Does it make it a Corvette? No. But it goes from "this is boring" to "hey I can dig this"

[kpt4321]

Originally Posted by ragtoplvr

The design of the head is such that the oil will turn to sludge. Oil contains additives for that, but they wear out. So changing early helps make sure the additives are at a sufficient level for operation.

Does the head have a sludge generator in it?

What is the "design" of the head that results in sludge?

[Lesharoturbo]

Originally Posted by kpt4321

Does the head have a sludge generator in it?

What is the "design" of the head that results in sludge?

Poor oil return flow due to small oil return passages. It allows the oil to overheat because the oil stays too long in the hottest part of the engine creating sludge that compounds the problem.

[kpt4321]

Oil return flow has to be the same as oil feed flow, otherwise eventually all your oil would be in the head and the pan would go dry. The rate at which oil is going up to the head has to be the same as the rate at which oil is going back to the pan.

Camrys are water cooled, right? What part of the engine is so super hot that it turns the oil to sludge? Why doesn't this happen in air/oil cooled motorcycles and cars, where the oil temps are way hotter?

Just as importantly, what is the actual mechanism by which heat turns oil into sludge?

[bolink654]

I don't really see what we need to explain, personally. Google it, it's well known amongst the Toyota community of the sludge. Toyota even sorta acknowledged it, then reversed their opinion... or something. I don't know full detail, but a quick search finds this -

http://www.toyotanation.com/forum/8-...t-journal.html

From the Wall Street Journal, March 4th.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Toyota Gets Customer-Care Lesson
From Perils of Oil Sludge in Engines

Car companies are huge, impersonal and powerful organizations that often
give unhappy customers a hard way to go. Want to buy a car? We love you.
Got an expensive problem that's not covered by our warranty? Sorry,
can't help you.

But there are signs that the industry is waking up to the reality that
creating legions of unhappy customers is bad business -- and perhaps
more costly than the risk that a few undeserving gripers might get a
break. Consider the case of Toyota and Oil Sludge.

Toyota, which has a deserved and documented reputation for top-notch
quality and reliability, sent ripples throughout the industry last month
by announcing that it would change its usual warranty policies to cover
repairs to motors installed in several 1997-2001 model lines if those
engines turned up damaged by oil sludge. The offer, which runs for a
year, covers engines installed in 1997-2001 Toyota Camrys, Solaras,
Sienna minivans, Avalon sedans, Highlander sport utilities, and Lexus
ES300s and RX300s. These are some of Toyota's best-selling models.
Toyota said about 3 million vehicles are covered by the offer.

The action isn't a recall, Toyota said: Only people whose engines
actually are damaged by oil sludging -- or "gelling," as the company
terms it -- will get the benefit of this deal. Still, the announcement
marks a victory for consumers and a defeat for the industry's
conventional behavior toward customers with complaints.

I also hear (though, that's all, just hearsay) that some people have run oil test on 5,000 mile oil from a Camry and found it should have been changed before 5k. Simplest thing for me to do to mine is just change it at 3-4k...

[troidus]

Originally Posted by kpt4321

Oil return flow has to be the same as oil feed flow, otherwise eventually all your oil would be in the head and the pan would go dry.

Duh. I once serviced a low-mileage (48k, IMS) late-70s Camaro that was smoking and leaking. Popped the rocker covers off and the lower drainback holes were completely clogged and the uppers weren't much better. The whole upper end was coated in 1/4" of thick goo, even the rocker arms. The top of the engine was flooded with oil, because more was going up than could return, overwhelming the valve stem seals and the rocker cover gaskets, and may have been getting sucked into the PCV system. I had to wash out the whole engine.

[troidus]

Originally Posted by kpt4321

Just as importantly, what is the actual mechanism by which heat turns oil into sludge?

Are you aware that engine oil is composed of polymers of different lengths? The shorter ones can either cook off or can link with other ones to create longer chains, which don't flow as well. Sludge is a mix of long-chain polymers and contaminants, created by combustion byproducts and heat. Some engines and oils are more susceptible to sludging than are others.

[kpt4321]

Never mind! :)