View Full Version : High Oil Consumption

Mike Farish
06-22-2002, 11:08 PM
I was introduced to your club today at Maple Grove Raceway in Reading, Pa. Met some super guys and asked some questions about the dilema with my Coupe. I am currently consuming a qt of oil every 500 miles!! It's a 95 auto with 45K miles. I bought it new. At 23K miles I sold it to my 26 year old son who needed a late model car to replace his. I never used oil up until I sold it to him and always changed it at 3K miles (Castrol). He owned it for 15 months and put 20K miles on it. He had it serviced at a local Goodyear shop. When I bought it back (he wanted a 4 door vehicle and I knew he'd take a beating if he traded it in) I noticed black oil barely on the stick. He said he had it changed 800 miles ago?? I obviously decided to change the oil and much to my surprise the drain plug was on so tight I couldn't get it off and the plug was mostly rounded off. I ended up taking the car to this Goodyear shop and talked to the Mgr. He said the last time it was in, my son told him to just add some oil. I had him change my oil and filter and replace the drain plug. He said the car uses oil and he has been putting 20W50 in it to see if it would help??? I couldn't believe he did this. Anyway my son to this day claims he never knew it used oil and anytime he took it to this place it was just to replace the oil and always around 3K miles. To date I have had a Bilstein oil engine flush done at dealership, replaced the PVC valve and changed the oil every 1500 miles. The tailpipe has oily residue, don't see anything around the engine block but of course it's tight in there. Occasionally I smell oil under moderate acceleration with the a/c or heat on after initial start-up.

What's most likely my problem and where do you suggest I have it fixed? I just don't know if I trust turning this over to just anybody at a dealership.

I'm looking forward to responses from anyone who is real confident of what my problem is and how it may have happened.

Thanks in advance..


06-23-2002, 01:43 AM
Hello. I see there are currently no responses so I will be the first, even if not the most knowledgeable. By the symptoms you describe it seems to me the oil was completley neglected after selling the car. I would say it was never changed after selling, and probably wasn't thought of until the oil light either turned on or someone smelled burning oil. Now I have seen engines go 30,000 miles w/o an oil change and not burn, but these engines are supercharged and therefore under very heavy load. Most likely the piston rings are damaged, and oil slips past into combustion. This explains why the mechanic used 20/50; he tried to reduce the amount of oil slipping past the rings by using a thicker oil. It usually helps, by the time its burning a lot it usually doesnt matter anyway. It is possible the oil shop never changed it properly, but you probably won't know. Basically, the engine can continue to run and burn oil for quite some time, but to repair it, you'll probably end up rebuilding it. An unfortunate problem that happens to many cars, from neglecting such a simple task as changing the oil. A little lengthy; others will offer alternative possibilities if there are any.

06-23-2002, 01:49 AM

Mike Farish
06-27-2002, 08:16 PM
Thanks Digitalchaos for your reply. I suppose a compression check is in order. My local Ford Dealership wants $169 because all the plugs are tough to get to. If I was younger I would attempt this myself. The dealership told me up to $2K to go into the engine, cheaper if it's valves. What's the downside of adding oil every 500 miles?

I also welcome anyone else's suggestions.

06-28-2002, 01:25 AM
Well theoretically other than the obvious expense, it should run almost forever. I have seen engines burn oil for 100,000 miles. Eventually, it will affect the exhaust, namely the catalytic converter. I can't really say how long, but it would probably take a while. It will also foul the spark plugs eventually, necessitating more tuneups. Undoubtebly it will also reduce your mpgs and performance some. Like I say though, it should run for a very long time. I am suprised to hear the dealer say up to $2000 for a rebuild, assuming that is total cost. That seems cheap to me, considering the labor of removing the engine, replacing parts inc piston rings, and reassembling.

06-28-2002, 05:10 AM
If the oil stayed clean after an oil change when you had it and now you can't keep the oil clean after a change, this leads me to believe that your sone never changed oil in the last 20,000 miles. Why would any shop not change the oil when it was brought to them. And even the cheapest oil would do the job if it was really changed every 3000 miles. I think your son needs a good talking to. If oil is going pst the rings I would say you would have blue smoke all of the time. If it was going past the vavle guides usually only on initial acceleration after idling.


06-28-2002, 03:08 PM
I have an interesting story to tell. You may think that your son changed the oil and he probably did...once.

I suspect that someone torqued the drain plug on so tight, that instead of changing oil, they just kept on adding oil.

I had a buddy of mine that was doing that for about 50.000miles. He bought a grand am new and instead of changing the oil, he just kept on adding a quart of oil anytime the engine got low. When the engine ground itself to a halt, it still had the original oil filter on. The filter was so clogged with sludge that it was affecting oil flow. The pan had somethng like 3" of sludge at the bottom of it. All of the oil gallies were clogged up with either sludge or coked oil.

OIl has four functions

It Lubricates to reduce friction on metal to metal contacts

It cools the engine parts

It cushions engine parts from shock

And lastly it cleans the engine parts.

Adding a quart of oil when it gets low like that just means that it cannot clean the parts properly.

overall, I would have to agree with the above posts, Since you had the crankcase flushed out, I would say that is fairly clean, also keep in mind that oil mist does gather in the intercooler and intercooler tubes. You might be burning some of that oil too. It is normal for the oil mist to collect in the intercooler tubes beacuse of the PCV valve, but since you now have a blow by condition in your engine, I would expect the collection of oil in the intercooler to be excaserbated.

Also check to make sure you aren't leaking oil anywhere as well. Common culprits are the rear main seal and valve cover gaskets. The valve cover gaskets are rubber and usually respond well to proper retorqeing.

Mike Farish
07-09-2002, 07:30 PM
To: Digitalchaos, Shockwave and Deep6

Thanks guys for you feedback. Yes, I discussed this whole situation with my son and he claims no knowledge of the rounded off drain plug or using any oil. He is married and works at a high profile Body Repair Shop. They send a lot of their mechanical work to this GoodYear Shop.

I read some threads tonight where some guys are using Valvoline Max Life or adding this Lucas stuff?? One claim was the Max Life swells the gaskets? Anyway I've always used Castrol 5W30. Don't know what was used for the 15 months my son had it. He always told the shop to use 5W30. Anyway I suppose I will just run a while since there is absolutely no performance issues so far and gas mileage hasn't changed. Any thoughts as to me using a different oil that may help reduce the consumption? I have never believed in additive either but I'm open for suggestions. Also should I change the oil more frequently than 3K or does it matter? Every time I talk about this I get sick because the car looks like I just drove it off the Showroom floor. Noone can believe it's 7 years old.

Thanks in advance for any feedback....Mike

07-09-2002, 07:49 PM
Hmm. Well first I would walk into your locale Autozone and ask them about some aditives with a good reputation to add to your oil. I believe slick50 might be ok, but don't take my word. Normally I do not condone these, but the damage is probably done. As far as what to use, most oils have additives to renew the seals and make them more pliable. Synthetics are probably better for this.. but with high mileage there could be a catch: if a car has always used non-synthetic, and is switched to syn after many miles, the syn can actually clean out deposits from the engine components which were previously caught in between seals and other sources of leaks. Now obviously special conditions will exist for this to happen, and most times I would guess the additives will counter this affect. Try using Mobil one Synthetic. That, along with the proper additive, could reduce it. One more thing.. I notice you said it is more apparent on startup.. this implies it could be valve seals, or the valve train itself. That is much more practical and cheaper than engine rebuild, and is worth an inspection to see from a good mechanic.

07-10-2002, 04:25 AM
Oil turning black is normally due to combustion byproducts blowing by the piston rings. Smoke on startup is normally (but not always) due to valve seals. Puddled oil in the intake tubes can cause this smoky startup too. Oil in the intake tubes is normally caused by leakage and blowby through the PCV valve, which again is normally from excess piston ring leakage.

Age and heat are usually what causes valve guide seals to leak. They harden with time, usually lasting a minimum of 10-12 years or more. Poor oil and overheating could ruin them but they are tough.

Piston rings can be damaged by running no filter, rusting, over-reving, over-heating, and carbon fouling from dirty old oil. Frequent oil changes, perhaps an oil flush, or squirting penetrating oils down the sparkplug holes may cure a rare set of fouled rings but usually the problem is wear from abrasion or loss of tension from over heating and the damage is permenent.

Steve Best

Mike Farish
07-11-2002, 11:01 PM
To: Digitalchaos and Steve Best...

Really appreciate your feedback on my oil consuming bird. I put approx 5-6k miles/yr mostly driving to and from work. It's a 10 mile ride and 7 of it is at 60-70 mph. I never race it as my racing days ended 30 years ago. I used Castrol 5W30 for the 1st ~20K miles and it never used any oil. My son had it for the next 22K miles and he told the shop to use 5W30 but when I talked to this shop after buying the car back they said they were putting 20W50 in it to cut down on the oil consumption. I've been using 5W30 since I bought it back and it's been using a qt every 500 miles. Do you guys think I would reduce my oil consumption by switching to Mobil 5W30 synthetic? Or something a little heavier? Or just stay with what I'm using currently.

Thanks again for exchanging your thoughts...


07-12-2002, 02:24 AM
Yes I would try a switch to Mobil, just to find out. First try 5w 30, then 10w30. If this doesn't work though, I'd probably switch back. Its expensive. Also, try the oil additive I mentioned. Specifically try Slick Synchron 50, Synthetic engine additive. I was suprised to read on the container last night that they warrant engines for up to 100,000miles if its used w/certain conds. It couldn't hurt at this point. I would also try what sbest said, squirt some penetrating oil, maybe WD40, into the spark plug holes. This could be one of those rare cases, as it was perfect 20k ago.

06-30-2003, 08:01 AM
Well theoretically other than the obvious expense, it should run almost forever. I have seen engines burn oil for 100,000 miles. Eventually, it will affect the exhaust, namely the catalytic converter. I can't really say how long, but it would probably take a while. It will also foul the spark plugs eventually, necessitating more tuneups. Undoubtebly it will also reduce your mpgs and performance some. Like I say though, it should run for a very long time. I am suprised to hear the dealer say up to $2000 for a rebuild, assuming that is total cost. That seems cheap to me, considering the labor of removing the engine, replacing parts inc piston rings, and reassembling.
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I'm far from an expert, but I have a similar problem, so maybe exploring my car's condition we'll learn something that might help us both......hope you don't mind.

I recently got a 91 SC that foules my number 1 spark plug.......


1. My Cat on that side was bad and failed inspection (I swapped out the cats from my dad's 90, a parts car) and it passed perfectly

2. My spark plug gets fouled after driving 100 miles tops, that cylinder stops firing correctly, and the engine runs rough, loss of power. I take that spark plug out, clean it, stick it back in, and she runs like a champ till it foules again.

3. My exhaust looks completely normal

4. after fouling, I notice that my oil pressure guage falls below normal and steadily gets worse.

5. My oil level is good, which tells me that it isn't burning that much.

6. My oil is relatively clean and has stayed that way for some time.

7. The compression is 135 in every cylinder (dry start check)

the previous owner bought a spark plug fouler thingy that's supposed to protect the spark plug from getting clogged. It's completley worthless in correcting the problem

In my case, the oil fouling is an impending problem that needs to be fixed right away, since I can't seem to keep a spark plug clean in there. I'm thinking maybe that oil foul protection plug the spark plug screws into sucks and just put the spark plug in as is might do better, or I'm leaking a lot of oil and that'll just be worse. I'll prob'ly wind up taking the heads off and doing a valve job on that side since the compression test tells me its not the rings (whew!....) - although to do it myself, I gotta get those *($&( INTERCOOLER tubes off there - and that bottom tube is a real bisnatch to get off due to that (*&^ bolt down in there you can't hardly get at.....grrr, anyways

If your spark plugs aren't gettin fouled that much, perhaps they are in a better position in the cylinder on a 95 over a 91 although I have no idea :)

In any case, I guess if anything, be aware your cats WILL go bad if you're fouling a cylinder......I can get around this next year by registering my car in Hood county, where they don't require a smog inspection yet......or I guess I could put new cats on every year :(

If anyone thinks I may be fouling the plug because of carbon and not oil, speak up! I'm just not positive that my oil is getting burned up....

It's curious to me that this guy isn't fouling plugs as fast as me, but is burning up so much oil.....hmmrgggh, any ideas?



06-30-2003, 12:35 PM
AFTER READING ALL THE POSTS..................WHICH HAD SOME GOOD INFO............ TRY 15/40 W BY " ROYAL PURPLE "..........OR ADD A CAN OF " STP "....................... GO WITH A HOTTER PLUGS ALSO...........CHECK FOR OTHER OIL LEAKS......VALVE COVER GASKETS ETC..........AS LONG AS IT RUNS GOOD AND PERFORMACE DOESN,T DROP OFF ...OR SMOKES BADLY.........YOU SHOULD BE OK....................ALSO YOU COULD BE PULLING IT THRU YOUR PVC HOOK UP.......................................... IS YOUR INTAKE HOSE LOADED WITH OIL.................CHECK IT OUT..................FAST FREDDIE:cool: :cool: :rolleyes: :rolleyes: :rolleyes: :D :D