Engine's burning oil - how much longer will it last?

bottgers · July 2005

I have a '93 Tercel with about 125K miles. It had 89K when I bought it back in '02. The engine used a little oil when I bought it (I had to add about 1/2 qt every 750-1000 miles or so), but I believe the consumption has gotten worse. Now it'll go through 1/2 qt about every tank full of gas. It doesn't leak so I know it's burning the oil. The weird thing is that the engine still runs very well, has plenty of power, and still pulls over 40 MPG on the highway. In other words, the engine doesn't act like it's burning oil as badly as it is. Usually when an engine shows signs of wear to where it's burning oil this badly, you usually notice a definite drop in power and/or fuel economy. That's just not my case. I've always used good oil (Havoline) and filters (PureOnes), with frequent change intervals (about every 4K-5K). I guess my questions are these: How much longer before this sucker starts looking like a misqusito fogger going down the highway, and is there anything I can do differently to slow down this wearing out process? Also, I was hoping to get 200K out of this car. Is that no longer a feesable goal?

See Also: Troubleshooting Engine Oil Consumption

Mr_Shiftright · June 2005

I bet it's a fairly simple job...that's just a little SOHC isn't it? You could inspect the cam and possibly re-use it if it was expensive.

andys120 · July 2005

Are you getting less than 500 miles per quart? If so you may have to replace the motor but if you are still in the 600-700 mile range then you might be able to get some more use out of it.

It doesn't sound like you'll get 200k out of the motor but you could get that out of the car if you want to put another motor in it.

Mr_Shiftright · July 2005

It's not uncommon for vehicles to burn oil but still run well. Old Volvos are notorious for this. Your oil rings are probably shot or maybe you are sucking oil through some really bad valve guides or seals.

At any rate, unless you run afoul of emissions testing (which generally doesn't care how much oil you burn) or unless your car's smoke becomes reallly obnoxious, you can keep it running for a long time. Eventually you will burn oil so badly that you'll foul the plugs a lot or destroy your catalytic converter and this will become quite a nuisance for you.

Or you will forget to add oil and then KABOOM.

fintail · July 2005

That happened to my fintail, as it was stored for some time and the guts of the engine deteriorated. The plugs would foul, so I'd get to clean them and run it for 30 mins until they fouled again. The car eneded up getting a valve job AND rings...it was a disastrous job that took me and some others over 2 months to do. But 8 years later, it's running like a top.

The worst it got before I had to break down and fix it was maybe 200 miles/qt on the highway, I could double that in town. Smoke was awful at startup or when going up a steep hill...barely notioceable otherwise.

If you really like the Tercel...just have it looked at. A valve job couldn't cost too much on something like that...surely less than that fintail.

iluvmysephia1 · July 2005

the baby in on a new Scion xA RS 2.0, eh? I owned a '66 Ford Fairlane(without fins!!)that burned oil badly. When the smoke would waft inside the passenger cabin I finally had to get rid of the thing. Yukko. Talk about barbequeing your old car's engine!

fintail, been to Burlington, WA lately? Anything new along the I-5 corridor there?

BTW-take a gander over towards Burlington as you're heading past town on I-5 next time and you should be able to spot Jerry Smith Kia there on old Highway 99. That's the dealer I bought both of my Kia's from. They're a solid and reliable dealer of Kia products there in the beautiful Skagit Valley region of Washington state. Over and out.

bottgers · July 2005

Here's what I'm thinking on the matter. Since the engine's still got good power and it still gets good fuel economy, my guess is the oil burning problem isn't coming from worn cylinders or rings. I would say this indicates the engine still has good compression which means the rings, cylinders, and valves are all sealing properly, which could only mean the valve guides are the cause of the problem. Anyone else agree? If this is the case, I could have the valve guides replace relatively inexpensively and still have plenty of miles left on the car. I really don't want to replace the car just yet if it can be avoided.

Mr_Shiftright · July 2005

You could have worn oil rings but good compression rings however.

Best way to know what's up is to do a cylinder leakdown test, and then all will be revealed.

fintail · July 2005

My fintail had a severe lack of power and poor mileage when it was an oil burner. I was amazed at how competent the car performed when I had it fixed...the mileage isn't shabby either.

iluv - I now live in Bellevue, transferred to a better job. I'll actually be going through that area tomorrow though, to pick up the fintail (it is stored north of Bellingham) and bring it here.

Do a leakdown test for sure, as Shifty says. A valve job for that thing has to be well under a grand.

chrisducati · July 2005

My daughter drove for about two years using a quart every five hundred miles. as long as it isn't blowing blue smoke and you keep it topped off it will run for a long time. She just checked the oil every week and added when it reached the Add point. That was a Nissan Sentra that had maybe three oil changes in 100000 miles... I think it would have lasted a few more years had it not been totaled. And a lot longer had she changed the oil.

bottgers · July 2005

So is it possible the problem could be worn valve guides? If that's the case, I'm thinking that couldn't very expensive to get fixed, right? If it's the rings causing the problem, then that would be something I'd just have to live with. I wouldn't spend the money it would take to rebuild the engine. I suppose a valve job would be worth doing if the rest of the engine is still in good shape.

Mr_Shiftright · July 2005

Well doing a valve job on top of an old engine can be tricky business. Now that your internal engine parts are used to chuffing along like a low compression locomotive, to be suddenly subjected to a very tight top end may pound the bearings and rings into submission.

This is why you want to do a leakdown test....you might have both valve guide AND ring wear, in which case strengthening the top end will only cause more oil to escape past the oil rings into the combustion chambers.

Testing for bad valve guides shouldn't be too hard. First of all, if your valve guides are the culprit, usually...usually...you'll get a lot more blue smoke at start up, and it will gradually diminish; also, if you get blue smoke while ACCELERATING, that's usually rings...if you get huge clouds of blue smoke while DECELERATING, that could be guides. So when you get a high vacuum situation (closed throttle plate) you'll tend to suck oil past the guides, but in a low vacuum situation (throttle to floor) you'll tend to pump oil through the oil rings.

Another sign of bad rings is blow-by, which is that chimney smoking effect you get at idle, where you can see puffs of smoke coming through the oil cap on top of the engine---be careful about testing for this on OHC engines, as the camshaft can send a lot of oil through the open oil cap.

chrisducati · July 2005

so isn't it fairly expensive for either of these. Valve guides or rings. We had a toyota that the rings went bad at about 140000 miles, I couldn't get anyone to re ring the car and that engine was not available from a remanufacturer. Seems the thin cylinder walls meant no over bore. I doubt I would put 1500 bucks in an old toyota.If that is all the car is worth to begin with.

bottgers · July 2005

My car has exibited one of the symptoms you listed which is the puff of smoke coming out of the tailpipe during startup. The only other time I've actually seen the engine smoking was the other night. I was leaving a parking lot after a fireworks display and through the headlights behind me I could some smoke coimg out of my tailpipe while the engine was idling. As soon as I brought the engine above idle, the smoking stopped. I haven't seen the engine smoke during acceleration or deceleration, nor have I seen smoke coming out through the fill hole. I guess like you said, probably the next move would be to have a leakdown check done. I have that before about doing a valve job on an old engine and that it can cause problems with the bottom end. I guess at this stage of the game, the only thing I would probably want to do would be to replace the valve guides. Anything else I'll just have to live with until the problem gets so bad it isn't worth dealing with anymore.

bottgers · July 2005

I could be wrong about this, but I would think having the valve guides replaced would be the least expensive thing to fix of all the possible problems. If the rings are bad, that would mean a complete engine overhaul and I wouldn't do that as it would be prohibitively expensive.

Mr_Shiftright · July 2005

If your leakdown test determines most guide wear, I'd just order up a rebuilt cylinder head from a rebuilder and slap it on there rather than rebuild yours.

Lookee here---only $285 bucks. I couldn't buy even the valves alone for my engine for that.

http://www.adccylinderheads.com/site/792044/page/292968

PS: I have NO idea if these are any good---I just googled 'em.

chrisducati · July 2005

that isn't to bad a price. Add the price for the new cam, seals and labor, it might be worth it. Depends on what the rest of the car is like.

geo9 · July 2005

You could have a simple problem............Bad PVC valve or if you have power
brakes...... a bad vaccuum line to/or brake booster check valve !!!!

A cyl. leakdown test as others have posted will tell.......................

bottgers · July 2005

......like valve guides or something even less minor, I'd go ahead and have the work done. If it's going to get into things like replacing the head, valves, canshaft, or bottom end work, then I'll just keep driving it as is. It's probably not worth spending a grand or more to fix the problem. I will have the leakdown test done and see what the verdict is.

geo9 · July 2005

With these OHC engines everyone RAVES about being so modern
and such there is NO minor repair of the valve guides.

Major disassembly is required as well as machine shop work which
is quite spendy. Not to mention the added parts that may be required
since you already have a 100k mile engine. (Timing belt, cam seals,
water pump and on and on)

Run it till it blows up and save yer money !

Mr_Shiftright · July 2005

That is my inclination....however, you could possibly replace the valve stem SEALS without disassembly. You could also run a heavy straight-weight oil and that might help some.

bottgers · July 2005

......I decided to start with the easiest and least expensive things. I replaced the PCV valve. I noticed the old one was showing signs of passing a lot of oil. I could be wrong, but I don't think PCV valves are supposed to pass oil. I also ordered two bottles of Auto RX. I've heard nothing but good things about this stuff and it certainly couldn't hurt to try it. We'll see if this curbs consumption.

Mr_Shiftright · July 2005

Well a bad PCV will certainly cause oil leaks and possibly a little bit of oil burning.

Auto RX is IMO snake oil. Nothing in a bottle will ever cure engine wear. But you can be our own personal guinea pig on the matter and report back after extensive desert and arctic testing. We're counting on you.

lemko · July 2005

...that a lot of those additives are "snake oil." Fortunately, I've never had an oil burning problem, but what is the truth about STP, Motor Honey, etc.? There's a coworker with on older car who has been using straight 50-weight to reduce oil burning. Wouldn't this heavier oil make the car harder to start in the winter?

Mr_Shiftright · July 2005

Well of course one doesn't use 50 weight oil in winter, but generally his decision is scientifically sound

The reason snake oil isn't sound scientifically is pretty simple---IF the engine is burning oil because there is cylinder bore wear or piston ring wear, and that wear is so great as to allow oil to pass through or combustion gasses to pass through, well now really, what liquid goop in a can is going to cure that?

All you end up doing is making the oil thick for a little while and gum things up until the engine reaches operating temperature and breaks it all down again.

If someone is counting on some goo in a can is going to stop 120 psi compression driven by exploding gasoline, well good luck to them.

If the problem is measurable engine wear, then all that stuff is a complete waste of money. But if the piston rings are just stuck or the engine is severly sludged up, then maybe maybe some strong addtives/cleaners and frequent oil changes can help, sure...

But after 100K++ miles, it's not likely to be sticking rings---a rather uncommon occurrence on modern engines.

Anything you can do with "engine magic" in a can I can do with 50 weight oil, because it is the same principle...the heavier and gooey-er it is, the slower it will work into the combustion chamber. But sooner or later it'll burn just the same.

And I've busted down engines that were doped with STP---it's not a pretty sight.

geo9 · July 2005

Any valve stem seal replacement requires removal of camshaft
(if ohc), rocker arms (if not) to get access and remove the keepers
and valve springs.

Removal of spark plugs to put compressed air in the cylinders
to hold the valves in place.

Then ya gotta slip the valve spring compression tool in place to
release the "keepers". Remove valve springs. Replace O ring.
Reassemble......................

LOTS of work......Equals $$$$

There were several posts in the GM threads about high oil
consumption. GM issued a TSB to replace the PVC valve with
one with a smaller orifice...............
Must of worked..............No further complaints seen............

Bott...........Hopefully you will get lucky and a PVC valve will do the
trick!
If you have power brakes...Did you check the Vaccuum line to the
booster for oil residue ?

Lemko is also correct...........The old heavy straight weight oil will cut
oil consumption down. With that many miles it prob. won't make a
difference in the winter..............

Mr_Shiftright · July 2005

PCV problems with brand news cars are a lot different than PCV problems with old beaters.

Nah, popping off a camshaft on a Tercel isn't hard, especially considering the alternatives, which might be engine overhaul or the local government taking your car off the road. Couple hours shop time and that's it. Price it out let us know.

50 weight oil in winter is like jello---not recommended unless you use an engine heater.

oldharry · July 2005

I know very little about STP or other "snake oils", but when I think of STP, I remember the seeing Andy Granatelli on TV with the failed bearing from the trans of his turbine car the first year he ran it at Indy: It looked like lubrication failure to me.

The next year the rules were changed so a turbine car could not win.

Harry

bottgers · July 2005

The principle behind my use of Auto RX isn't to try to apply a band-aid to worn engine parts, but rather to clean the engine internally and recondition seals. What you said is true about worn engines and using addititves on them is nothing more than prolonging the inevitable. However, the way my engine has been using oil doesn't necessarily point to worn engine parts, but rather some type of a sealing problem. If that's the case, Auto RX could very well cure the problem. At any rate, it isn't like it's a huge investment which makes it well worth giving it a try. I will let you know how it works.

Mr_Shiftright · July 2005

Well I hope it DOES work for you!

My point which might have been muddy is that without a cylinder leakdown test we really don't know if your problem is engine wear or not, and so if I were in your shoes (I wear an 11) I would test first then try the remedy most likely to work.

Also I'm pretty adamant on the idea that reconditioning seals never works--now THAT part is voodoo. The engine cleaning part as a benefit I could buy that in some cases, certainly, but once a seal has lost its vibrancy, swelling it up like a raisin through chemicals is a short-term solution at best. Once you soften it, it loses its ability to remain resilient under all conditions.

bottgers · July 2005

I can tell you it wasn't the PCV valve causing the problem. I just changed my oil today and added the Auto RX. Hopefully, this stuff will do something to help.

geo9 · July 2005

What weight oil did ya use............. Straight 40 or 50?

Just nurse it along or spend big $$ to repair...................

bottgers · July 2005

I use 10-30. I have noticed a substantial reduction in the puff of smoke the engine lets out during cold starts since adding the Auto RX. Maybe this stuff will help. There are quite a few people in the bobistheoilguy.com forum who said this stuff worked for them. I am still scepticle as I've never had any success using oil additives in the past.

bottgers · July 2005

.....so far it appears that either Auto RX is nothing but snake oil or my engine's suffering from some type of mechanical wear that this stuff can't cure because I'm about 300 miles from dumping my first ARX application and the engine's still using just as much oil as it was before I started the treatment. I'm sure if this stuff was going to make a difference, I would've seen a change by now.

geo9 · July 2005

Snake oil......................

Go with straight 40 weight and keep running it !
I do it with my ancient "winter rats". My 87 Escort never complains...LOL!

iluvmysephia1 · July 2005

ran with the motor burning oil at about a quart to every 250-300 miles IIRC. As a goofy young lad of 18 I failed to keep it topped off constantly and one day running down the Mukilteo Speedway north of Seattle it just...ummm...sputtered and froze up.

Yep, I kept it alive and had a rebuilt 6 cyl 200 c.i. engine thrown in the nice looking Stang. The next major failure was the transmission and the car was gone, making way for a 1970 Chevrolet Suburban. Ya wanna talk about beasts to drive. Probably achieved 8 miles to the gallon in that people mover!

210delray · July 2005

How in the world could you go from a Mustang to a Suburban?

Reminds me of the guy at work who seemed to be genuinely intrigued by the Ford Excursion when it first came out. Maybe he thought he could carry his Ford (Kia) Festiva inside it!

iluvmysephia1 · July 2005

and was willing to trade a '65 Mustang with a borken tranny for a good running rig. It was between a '73 AMC Gremlin and a 1970 Chevrolet Suburban and I chose the Suburban. The sub-10mpg forced another choice, though, within a few more months. Sometimes wish I would've chose the Gremlin but it seemed a little small for us. Ended up with a '66 Ford Fairlane I quickly dubbed old Smokey. :surprise:

bottgers · August 2005

.....is where it belongs.

vorlon1 · October 2005

Hello out there. I've searched the forum to find just this problem. I have a 2001 BMW, 330i. I run this car hard (all highway miles) and have $117K. The car has been a dream to drive, but now is burning oil at what I believe to me an unacceptable rate. Every 1000 miles (sometimes less / sometimes more) I have to put a quart of oil.

I have taken the car to the dealership on multiple occasion. There is no leaking, the underside is dry as a bone. There is no discernable smoke on start-up or in motion. Power and gas mileage is great. The compression is within norms.

The dealer conducted some form of test and removed / replace valve in the crankcase - they said it was out of spec and sucking up to much oil. This did not solve the problem. The dealership now has me using 10-60 M3 High Performance Motor Oil. They are trying to go the cheap route and not teardown the Engine.

I think I have a problem within the Engine -i.e. rings , valve guides, etc.

If what i believe is right - what can be fixed first without too much fuss and money, Or should I just have them tear the Engine down and put in new valve guides, rings, etc.

The car runs great otherwise - it's very annoying to put oil in the car every 1000 miles. If it was every 3000-5000 miles then I would have no problems, but this is a BMW - it's supposedly engineered to go 300K - having this happen at 117K is bothersome to say the least.

Looking forward to your help.

Regards

Manny Mateus :confuse:

Mr_Shiftright · October 2005

Well GEESH, someone has to do a cylinder leakdown test and then you'll have good quantitative data and some data for making the right decision.

isellhondas · October 2005

Sure, you could have someone tear down that engine, hone the cylinders, put in new rings etc. You could easilly spend 4000.00 and turn your 1000 mile per quart BMW into a 3000 mile per quart oil burner.

Do you really think it's worth the expense?

For me, simply adding a quart of 1.50 oil once a month isn't a big deal.

And I don't like their reccomendation of using a heavyweight oil to mask the problem. 10-60?? Never heard of the stuff?

wtd44 · October 2005

And why would 10W-60 oil significantly slow the burning? The designator indicates the basic oil is 10 weight, and has elastomers added to cause it to simulate 60 weight during full high temperature running. To top it off, I've read that some manufacturers consider 1 quart per 1000 miles to be acceptable oil consumption.

isellhondas · October 2005

All cars use SOME oil. They have to. To me, 1000 miles isn't a big deal at all.

Just check it often to make sure it doesn't get worse.

I remember I once had a Chevy that used a quart every 700-1000 miles like clockwork. I kept that Chevy five years and it never changed. Ran like a top too!

wtd44 · October 2005

Back in the Dark Ages, I had a '55 Chevy V8 that deteriorated down to 50 miles per quart as I crippled in to my folks house on a college Christmas break. I spent most of my available time that two weeks rebuilding the engine in their garage, under my father's tutelage. We got it together and I drove it the 900 miles back to school.

isellhondas · October 2005

The Chevy I had was a '62 Impala SS with a 300 HP 327.

Beautiful car that just liked a quart of oil once in awhile.

wtd44 · November 2005

I never had an Impala of any year. My '55 Belair needed a bench bore, but there was neither time or inclination to remove the block from the frame. I sat on the fenders and ran a hone seemingly forever (after ridge reaming, of course) to ready the cylinders for used pistons I bought at a junk yard, fitted with brand new extra-wide land area rings to take up the space. I hand fit the rings for each cylinder, as you would expect. I left the crank journals alone and replaced the babbitt in the big ends of the rods. This "parts exchange" did me good for another 25K miles, at which time the ol' engine got skunky again. I sold/junked the car to an old friend whose family owned a repair garage business.

isellhondas · November 2005

When I was a kid I was once so broke I had to buy brake shoes at a junkyard!

upriverjoe · January 2007

can you use a analog voltmeter to do diagnostics on a 96' 2.4 stratus? if so, how?? my stratus just stopped running!!! no no engine trouble light comes on, it turns over and sounds like it wants to start but won't?????????replaced timing belt about 500 miles ago and just replaced coil. my tach seemed to quit working just before it stalled???? any and all help will be appreciated :

squeekusa · January 2007

10W-60 is a 60 weight oil, with polymers to simulate a 10 weight in cold temperatures.

W does not stand for weight, it stands for winter, meaning that an oil with a W is suitable for use in winter.

shipo · January 2007

"10W-60 is a 60 weight oil, with polymers to simulate a 10 weight in cold temperatures.

W does not stand for weight, it stands for winter, meaning that an oil with a W is suitable for use in winter."

Ummm, no. You have it exactly backwards. 10W-60 oil is a 10 weight oil ("W" does NOT stand for winter) that is stable enough that when hot it only thins out to the viscosity of a straight 60 weight oil. There are two methods of stabilizing thin oils (take your pick, 0W-30, 0W-40, 15W-50, 10W-60... it doesn't matter). The first is to add what are generally termed "Viscosity Improvers" (VIs), and the second is to produce an oil from a fully synthetic base. Most middle of the road oils (Motorcraft 5W-20 for instance) use some synthetic PAO and some VIs to achieve the desired result.

FWIW, while formulations are a tightly kept secret by all manufacturers, it is believed that some oils, Mobil 1 0W-40 for instance, are formulated with such a high quality PAO base that they need no VIs to achieve their classification.

Best Regards,
Shipo

Engine's burning oil - how much longer will it last?

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