I own a 2002 Corolla with a 1zz-fe engine that burns a quart of oil every 500 miles. It doesn't smoke probably because the catlytic converter is new, nor does it leak....no oil on my garage floor.
I'm convinced the rings are stuck due to excessive varnish build up. I've tried so-called varnish solvents like Lucas, Marvel Mystery Oil, and Sea Foam. The engine is still burning oil.
Years ago before overhead cams I did engine overhauls. What I did was remove the cylinder head, drop the oil pan, shove the pistons out the top of the engine and change the rins and connecting rod bearings. Sometimes I would have a machine shop re-work the cylinder head.
Since I'm not familiar with overhead cam engines, here is my question.
Can I just remove the cylinder head and set it on my shop table and then remove the pistons and replace the rings and then re-install the pistons, cylinder head, etc?
Why do this? Two reasons. Money savings and I'm not convinced the cylinder head needs re-working. Thanks in advance for your kind help.
The 2 methods you describe sound pretty much the same.
But no, if you don't want to do any work to the head, you dont have to.
But I would recommend it be inspected by a machine shop, especially where the valve seals are concerned.
Rebuilding an overhead cam engine is the same... setting up the timing components is really the only big difference. I'd go for it if you have already done this sort of thing. I'd probably at least put some new valve stem seals in the head and have it machined.
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I can see your point in having a machine shop inspect the cyl head valve guides, etc. I have two concerns. One, of late it seems like everyone has a good reason to want me to spend some money and I don't know of a machine shop that would tell me the truth. Two, if I do take the head to a machine shop does that mean I have to remove the two camshafts? This is where I get concerned. I not sure I could put the camshafts and lifters back together correctly because engines have change so much! What say you?
I can see your point in having a machine shop inspect the cyl head valve guides, etc. I have two concerns. One, of late it seems like everyone has a good reason to want me to spend some money and I don't know of a machine shop that would tell me the truth. Two, if I do take the head to a machine shop does that mean I have to remove the two camshafts? This is where I get concerned. I not sure I could put the camshafts and lifters back together correctly because engines have change so much! What say you?
1st, yes, the cams have to be removed.Either you can do it, or the shop can do it. Of course, the more time they spend on it, the more it costs you.
Cams are stamped ex and in. If you decide to take the head apart yourself, just label each valve , lifter, spring and retainer to the corresponding cylinder. They do have to go back in the same spot.
I took a totally stripped down head to the shop. Had it vatted, the valve seats cleaned and polished and he assembled it with my new stainless steel valves, seals, seats, Crower springs , titanium retainers and shimless lifters. It was only $175.00.
If you end up getting a valve job, they will need the cams to set valve clearances.
I marked the cam sprockets and timing chain so that I could keep the timing when I put it back together... It was nothing. Keep track of the lifters, valves, caps like MR2Jedi said... its just a matter of keeping them organized.
I was able to take the main bearings out from below and pull the pistons from above, leaving the block in the car.
I had the head redone, seals, and new rings, my car still burned oil. I should have done the pistons/cylinders while I was at it.
I'm displaying my ignorance by asking this but I have no other choice. You say, "I had the head redone, seals, and new rings, my car still burned oil. I should have done the pistons/cylinders while I was at it." What do you mean about the pistons/cylinders? If you replaced all of the worn and varnished clogged rings, what more should/could you have done? Replace the pistons and re-finish the cylinder walls? Thanks for your help !
I did scuff up the cylinders to help the rings seat, but what I neglected was miking the pistons and the cylinders bores. I should have used this repair manual to check and make sure my cylinder bores were within tolerance, and that my pistons were in tolerance. I believe the pistons in my car were undersized.
I guess what I'm saying is, please just make sure you are within tolerance of the bores and pistons.
Oh BTW, please don't break the VVTI sensor when you remove the head bolt nearest to it. A few of us learned the hard way ack.
There is NO solvent that will dissolve the carbon in the ring groves( not on the engine anyway), but you can pull the pistons , remove the rings and clean the piston ring groves.
No matter what you do, its always a can of worms, ha ha .
How many miles on the engine? Has it ever been run out of oil?
Rebuilds in the car are always hard.
The reason I asked how many miles, is that if the car has alot of miles ( worn cylinders ) just re-ringing and honing probably wont fix the oil burning. You wont be burning oil just from stuck rings anymore , but will be, from large clearances between the new rings and old worn cylinders.
In this area, it is $300 just to adjust the valves AFTER the valve job on a 1ZZ head. If you have close to 200,000 miles you will be needing a valve job. You can check this your self by doing a leakdown test before you tear down the engine or roughly afterwards by filling each combustion chamber in the head with light oil or even gasoline and seeing if it holds it without leaks( unlikely with high milage),you can also submerge the head in water and blow compressed air into the intake and exhaust ports and look for air leaks ( bubbles)around the valve seats .
After the valve job you can adjust the valves your self by swapping around the buckets and then whatever valves dont make the cut you can take them to an auto machine shop and have them remove how ever many .001's you need off the valve stems.
I own a 2002 Corolla with a 1zz-fe engine that burns a quart of oil every 500 miles. It doesn't smoke probably because the catlytic converter is new, nor does it leak....no oil on my garage floor.
I'm convinced the rings are stuck due to excessive varnish build up. I've tried so-called varnish solvents like Lucas, Marvel Mystery Oil, and Sea Foam. The engine is still burning oil.
Years ago before overhead cams I did engine overhauls. What I did was remove the cylinder head, drop the oil pan, shove the pistons out the top of the engine and change the rins and connecting rod bearings. Sometimes I would have a machine shop re-work the cylinder head.
Since I'm not familiar with overhead cam engines, here is my question.
Can I just remove the cylinder head and set it on my shop table and then remove the pistons and replace the rings and then re-install the pistons, cylinder head, etc?
Why do this? Two reasons. Money savings and I'm not convinced the cylinder head needs re-working. Thanks in advance for your kind help.
I've done this a couple times. Here is a quick list of what I would recommend.
REPLACE: piston rings, head bolts, head gasket, valve cover gasket, valve seals, ehaust manifold/downpipe doughnut.
INSPECT FOR WEAR: cylinder walls, rod bearings. Both should be good unless it has been run low on oil or there has been a major part failure.
REMOVE AND CLEAN: valves (they get carbon buildup), pistons (carbon buildup) take you time, clean out ring groves and oil drain holes. This is where your problem is in the first place.
Hone the cylinders.
TIPS: You do not have to remove the timing cover. You will have to remove a stud (E6 I believe) that the belt tensioner is mounted with and there is a 10MM bolt holding a cam chain guide on that is a bit if a pain to get loose.
The cams have to come off to remove the head bolts. They are tripple square, cant remember the size.
When I tear down the head I just set everything on the workbench in the position I took it out from.
The lifters have a number engraved underneith. You can cross reference the numbers in a repair manual if anything is out of clearance and needs to be "adjusted". They will wear tighter so I usually set them up on the loose end of tolerance. This is especially important with the ehaust valves.
I like to use a couple zip ties and tie the timing chain to the cam sprockets (just go through the sprocket and around the chain). When you are putting everything back together rotate the crank pulley so the timing mark is at 0* and line up the cam sprocket marks to each other like is shows in the repair manuals. You will want all chain slack in the back where the chain tensioner goes.
I pull the cylinder head with the ehaust manifold still bolted to it. You will have to remove the o2 sensor to get the to downpipe bolts loose and done forget to remove the bolt that bolts the manifold to the bracket (it's kind of hidden under the manifold).
I have a lot of miles on my car. The engine wears GREAT! it just gets some carbon buildup on rings and valves. I can't imagine the cylinder walls will need anything more than a hone unless it's had a rough life.
I think that's about as short as I can make the list. I probably missed something.....
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'98 Prizm 4spd 272K bought @ 221K for $300 Oil consumption fixed @ 265K for $247
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Ring Replacement
I probably missed something.....
Linear Mode
