burning oil

[tnmk]

Hey,
New here.
Just bought a very clean '93 GEO Prizm (1.6 L) which is pretty much a Corolla.

It only has 55,000 miles on it and so far in the first 2000 or so miles I've gone through about 2.5 qts of oil.

I'm assuming that the inside of the engine is probably built up with a lot of sludge and needs a good flush. Number 4 (left to right) plug has a lot of white ash on it. So I will assume it's leaking through the valve guides.

My plan is to order up some Amsoil engine flush and change the oil w/ Amsoil which I'm hoping will re-condition the bad seal.

If that doesn't work then I assume I would need to pull the head and replace some valve guides.

The question:
It appears that this should be a relatively simple job by the looks of it. Or are looks deceiving?

Any other input would be greatly appreciated.

[tashirosgt]

Are you wanting to replace valve seals or valve guides? The valve seals aren't a big deal (since your are the kind that thinks taking the head off isn't a big deal!) . But to change the valve guides, you have to heat the head in a tank (of water, I assume) and then pound out the old guides and pound in the new ones. That's something I've never tried.

I notice the service manual has the "hint" that the intake valve seals are one color and the exhast seals are another. When I got a rebuild kit, the rubber part of both types of seal was brown. I went to the trouble to get OEM seals and, just like the old ones, the two types are different colors, brown for one and black for the other. Did it really make a difference? Who knows.

[tnmk]

thanks, I guess seals is what I'm looking to do. Sorry I said guides. I'm sure after 55,000 miles they should be fine.

So then as you say no big deal I'm assuming the head comes off with relative ease and there's not much in the way . It looks like everything is pretty accessable.

[94_Rolla_Guy]

i hate to be the bearer of bad news but its more than likely the oil rings, they are a common issue with the 7A-FE 1.8L less common with the 4A-FE. the design of the cylinder head doesn't wear the guides especially with 55k.

trying to clean the rings out with flush? this is a iffy thing you might end up burning more oil and creating a problem. i would tend to (considering NO leaks) start short OCI's (2-3k) with conventional oil or move to a 4-5K oci with synthetic, basically run the oil until it dirties up then change it, slowly you will see progress

[Piloter]

Is there a good way to determine whether it's the seals or the rings? I've been told by a reputable performance shop to, after getting up to a decent highway cruising speed, take your foot off and let it coast down in speed by about 20 mph or so, then give the car a little more gas. If there's a bit of a smokescreen in your rear view mirror, supposedly that indicates your seals are bad.

Worn oil rings would affect the compression, wouldn't they?

[Flashmn]

if its the rings it'll smoke through the PCV valve and pretty much constantly. If its the valve seals, it mostly burns when you start up.
Valve seals can be changed wihtout taking the head off if you're good :-) theres few tricks to do it. Using air to hold the valves up or putting rope inside the cyl to hold them up.

[freakinbox]

I get it when I start up, I assumed it was the valve seals like you said.

[diver9000]

Originally Posted by Flashmn

if its the rings it'll smoke through the PCV valve and pretty much constantly. If its the valve seals, it mostly burns when you start up.
Valve seals can be changed wihtout taking the head off if you're good :-) theres few tricks to do it. Using air to hold the valves up or putting rope inside the cyl to hold them up.

Flashmn is right and its the easiest way to tell. Crank it up in the morning. If it does it only briefly when you first start it or for the first little while during the idle then thats all it is. You could drive it like that forever, without a whole lot of problem except for the oil loss. But you seem to be losing a little more oil than I am comfortable with (actually any oil loss in uncomfortable), so I would definitely start looking for where your oil is going to. Check the obvious spots: inside the valve covers, check the oil in the pan, see if you exhuast is wet coming out the pipe etc....... then if you are not mechanically inclined have a shop check it out. Even if you have to have the head work done, its not too bad on a 4 cylinder engine. Did you buy your car with a warranty? It should still be covered if so.

[tnmk]

[quote=94_Rolla_Guy]i hate to be the bearer of bad news but its more than likely the oil rings, they are a common issue with the 7A-FE 1.8L less common with the 4A-FE. the design of the cylinder head doesn't wear the guides especially with 55k.

1st It's not a 1.8, it's a 1.6, does the problem still exist with that engine?

2nd I've learned a lot, a whole lot, about synthetics recently because I recently became an Amsoil dealer. (no I'm not trying to sell to anyone here.)

Synthetic oil will clean the engine thoroughly and get rid of the sludge deposits which could very well be the cause of the leak. With only 55,000 miles on it I reall doubt a wear problem with guides or rings. Possible, but I doubt it. Once the sludge is gone the synthetic oils will condition and expand seals where regular petrolium actually shrinks seals.

I just got off the phone with my sponsor (been selling Amsoil since 1983) and he told me of an individual that he sold product to that had a 1 year old Suburban with 30,000 miles on it and he was using 2 qts oil a week. Switched to Amsoil and never burned another drop.

Now I'm not saying this will happen to me. In fact I'm only hoping it will. But hopefully now you all understand where I'm coming from and why I want to try that first.

Oh yea, I didn't think of the PCV at first. I'll cahnge that out right away.

A lot of great input though. It's greatly appreciated

[toyomoho]

On the seal color issue, the exhaust seals operate in a higher temperature environment then the intake seals. To save money, auto manufactures use different materials for intake and exhaust seals. The seals are slightly differant to tell them apart. You can use an exhaust seal on an intake valve stem but not visa versa.

[94_Rolla_Guy]

its not so much a wear problem with the rings they sludge up get stuck and the drain holes in the ring grove plug, and the oil cant be controlled by the rings (stuck) and has no where to go thus it blows by the compression rings.

the compression will most likely come out perfect even above perfect my 202km engine was doing 215psi but after taken apart and looked at the compression rings were completely free and minimally worn BUT the oil rings were hopelessly stuck level with the skirt but surpriseingly not badly worn. i put the pistons in varsol, acetone, clean oil and it took weeks for anything to happen. that motor was hopeless burning 1liter every 250-500km now my supposed "low miler" is burning 1Liter every 1250-2000k so i have been messing around trying to desludge it before im replacing bits.

From being around the corolla's a bit ive seen alot of the 93-95's (7A-FE) that burn oil but i do know and see a few people with the 4A-FE and oil issues later in 95-97 OBD2 and some minor changes seem to address and correct the issues a bit?!?!?! as the problems seem to be less.

If you want somemore reading try www.bobistheoilguy.com and check out the forum

[tnmk]

I'll try using the Amsoil flush and synthetic and then I'll let you know what happens. Maybe it will free up that sludge and get things working right again

[xrated3345]

flush fill and i.m.o lucas ownes all!

[TRDwasiq]

i have 1995 corolla (155miles)man its burning oil and whenevr i punch smoke comes out frm muffler so wht can i do to stop it( next question)should i buy head gasket or buy headers with gasket???

[tnmk]

You can try what I'm trying first. It's the easiest thing you can do. Flush using the cheapest new filter you can buy (I prefer Amsoil al the way. most years inthe business most up to date facility, most products, always on the leading edge, etc. etc) then fill with synthetic. What it does is removes all the sludge built up in your engine. Then the synthetic will expand your seals. Also synthetic sticks to the walls better than conventional oil so your rings should seal better too. I would think the only way this won't help is if things are to far gone.

In that case I have used "Restore" with conventional oil with each oil change and that works good. So does the "high mileage" oils.

If your willing to wait for my results I'm ordering the product as soon as finish typing this. I'll post as soon as I see if it makes a difference, good or bad.