Service Schedule on Serpentine Belt

[Patrick Wong]

Originally Posted by CharlesJ

Thanks. Is it possible to replace the belt without undoing the underside and going under the car? Or, just not enough room from the top to place the new belt around the necessary wheels?

Hi Charles,

Yes, it would be difficult to get the serpentine belt around the crankshaft pulley without being able to reach the pulley from below the car.

Originally Posted by jayman

... Not sure if I posted the results of a teardown of a Tacoma 4.0 v6 with 158,000 miles on it. That cylinder head already had pretty bad deposits.

The owner wanted performance parts installed, and since it was starting to lose compression, he agreed to an overhaul. The piston ring land is pretty nasty too

Thanks for your comments, Jay. Do you know the history of that particular Tacoma, regarding fuel brand used and the oil change frequency?

[jayman]

Originally Posted by Patrick Wong

Do you know the history of that particular Tacoma, regarding fuel brand used and the oil change frequency?

AFAIK the owner claims whatever was cheapest wrt fuel and oil. Oil changes usually every 6 months or 6,000-7,000 miles

NJ isn't Winnipeg, but in winter is cold enough to cause problems with condensation, causing oil breakdown. I have to admit I was surprised at the deposits on the piston, the intake valves also have deposits. I thought all gasolines were supposed to have additives to prevent that? See attached photos of the intake valves and head

You can tell it's an area with salt in winter. Check out the rust on the studs

The teardown convinced the Tacoma owner to change his ways. His project wasn't cheap, around $9,000 by the time the rebuild and performance upgrades were done. Would have been cheaper to just bolt on a TRD supercharger, at least until the motor finally went

[jayman]

Oops, no more attachments for me. I've just reached my 50 MB limit

[andyprius]

Great phots and description! Thanks Pat.

[richard schumacher]

What alloys are used for the block, head, and cams?

[Patrick Wong]

Originally Posted by jayman

AFAIK the owner claims whatever was cheapest wrt fuel and oil. Oil changes usually every 6 months or 6,000-7,000 miles

NJ isn't Winnipeg, but in winter is cold enough to cause problems with condensation, causing oil breakdown. I have to admit I was surprised at the deposits on the piston, the intake valves also have deposits. I thought all gasolines were supposed to have additives to prevent that? See attached photos of the intake valves and head

You can tell it's an area with salt in winter. Check out the rust on the studs

The teardown convinced the Tacoma owner to change his ways. His project wasn't cheap, around $9,000 by the time the rebuild and performance upgrades were done. Would have been cheaper to just bolt on a TRD supercharger, at least until the motor finally went

Hi Jay,

Your photos serve as good advertising for Shell, Chevron, and the other major gasoline brands that claim top-tier affiliation. The photos also should encourage owners in cold areas to change their engine oil frequently (or use synthetic oil). I've noticed a few recent posters reporting visible sludge at the bottom of the engine oil cap, which is not a happy sight.

Originally Posted by richard schumacher

What alloys are used for the block, head, and cams?

Hi Richard,

The block and head are aluminum, while the camshafts, crankshaft and bearings are steel.

[jayman]

Originally Posted by Patrick Wong

I've noticed a few recent posters reporting visible sludge at the bottom of the engine oil cap, which is not a happy sight.

If you have visible "latte" underneath the oil filler cap, you have sludge buildup in the motor itself

Remember that bare minimum spec API oil dropped the requirement to prevent cold black sludge. I'm sure if you changed the oil often enough, you would be ok on cheap oil.

But how often is often enough? 5,000 miles? 3,000 miles?

An uncle of mine was a mechanic at the Alcoa plant in Port Lavaca, TX. He used to tell the family members living up here to never put more than two months or 2,000 miles on the oil and filter, in winter. That probably helped, the family members who listened to him got long life out of their cars

[patsparks]

Jay, the cam follower buckets look buggered in your picture, are they that pitted really or is that something on the top? Those pistons look to how I would expect them to look in a car with 300,000km on it, at least like ones I have pulled apart.

I noticed in another post where you had a picture of the underside of a cylinder head, one cylinder looked washed like it had a head gasket leak while the other 2 had carbon build-up. I'd rather see a little carbon than none. Carbon is a byproduct of combustion and the cylinder head and piston crown are cooler than the combustion gases so there will be condensation of hot vapour on them.

[jayman]

Originally Posted by patsparks

Jay, the cam follower buckets look buggered in your picture, are they that pitted really or is that something on the top?

The guy claims they really are that buggered. The motor wasn't running very well when he had the work done

Originally Posted by patsparks

Those pistons look to how I would expect them to look in a car with 300,000km on it, at least like ones I have pulled apart.

Apparently, the compression was already below the bottom spec

Originally Posted by patsparks

I noticed in another post where you had a picture of the underside of a cylinder head, one cylinder looked washed like it had a head gasket leak while the other 2 had carbon build-up.

Not sure, had to look at the photo again to determine what you saw. Sure looks like a coolant leak, doesn't it

[jayman]

I should note - again - this Tacoma received very indifferent maintenance from the owner. If it wasn't cheap, on sale, it didn't go in. Apparently he never changed the gear oil either