Routine oil change - very little oil drained but dipstick shows full

[AaronB]

Hey guy, ok so I've been long time lurker and finally need the advice of the pros.

So recently I bought my first Supra, (an 89 turbo targa) and today came time for the first oil change in my possession. This is my first oil change by myself but i've done other car work so I felt fairly competent.

First the car's history - a little over 234,000 miles, original engine, two previous owners, both did religious oil changes at 3,000 miles with Castrol GTX 10w-30 (at least that's what the second owner used).

Anyway, so i put the car on ramps, making sure it was level, as some Supra owners pointed out, and removed the drain plug gasket. The oil came in a slow thin stream, barely more than a drip, as if the faucet was left on. It drained like this for a few minutes than went to a drip, after 30 minutes I checked and only about a quart had drained out. I check the dipstick (remove, wipe, insert and remove again) and it still showed almost full. I also never had any low oil lights on the dash or any knocking from the engine. The car has a small oil leak, but over a course of 12 hours it would show about a 2.5" wide spot on the driveway.

Now when the car was on ramps the passenger side was higher, and since that's the side the drain hole is, i put the drain bolt back on, rolled the car off the ramps and pushed it to another part of the driveway where the passenger side is lower and the front is pointing down, and removed the bolt again. Still very little oil came out. So it's either i lost 4 or so quarts of oil from the leak, or there's a huge amount of sludge, but the oil that came out is not completely black and the dipstick still shows about 80% full.

I thought maybe i drained the trans but I double checked and i'm sure it's the oil pan. I'm, well confused to say the least.

Any ideas to check?

 

[super51fan]

What size was the drain plug ? Should be 19mm.

 

[AaronB]

Yup, it's the stock 19mm plug. The washer looked to be aluminum, but it doesn't seem to have dented the oil pan. I will be using an OEM toyota gasket once this is all done.

 

[super51fan]

Did you poke a screwdriver into drain hole. I have seen super sludged engines that won't drain oil because of sludge. I have found our dipsticks to be tricky to read. I have upgraded to 92' dipstick. They are easier to read. IMO

With plug out you could always pour in some oil and see if it runs out right away. If it does it means you are not reading dipstick correctly.

The 7m engine does not have oil level or pressure light. I wish they had a oil level sensor. Good luck.

Glad to hear you getting new Toyota drain plug gasket.

If you are 4 quarts low it is going out the tail pipe. IE burning oil. If you would pour 1 quart of oil on garage floor it would be about 10 foot circle.

 

[suprahero]

If you're four quarts low, you'd have heard about it.

 

[AaronB]

Great, thanks for all the ideas! I was thinking to pour in more oil to see if it comes out, but it got dark early. Tomorrow hopefully i will be able to try these and update my progress.

If it helps, on a cold start and for a minute or two I get some white smoke coming from the exhaust. It's not enough to signify a bhg (unless it's the super early stage of it) but only the amount you would see on a cold start. I do not recall smelling burnt oil but of course that does not mean it is not burning. Regardless I will be checking all of these things.

 

[Silver MK3]

If you get smoke on a cold start, and only then it is most likely valve stem seals, its a fairly common issue with the cars considering their age now. Something seems off here with the 4 missing quarts. Did you have the filler cap open to aid the draining process as well? Not that this would cause the issue most likely, i just don't see how you are missing 4 quarts of oil...

 

[AaronB]

Could be the valve stem seals, i'll have to check. I did remove the filler cap, didn't seem to make a difference. After some other searching on other car forums i'm leaning towards the sludge build up in the oil pan. Won't be able to check till tomorrow but it seems like the most logical solution.

 

[atmperformance]

i think we need pictures of this "level" car on ramps

 

[AaronB]

Ahh yes I realize how ridiculous that sounds ...let me specify. My driveway has a point where the concrete ends and there is thick dirt/clay going downhill. It's in just a way that if I put the ramps on the dirt and the rear tires are on the concrete the car is almost level front to back. No pictures as the car is back on the driveway, but hopefully this clears it up haha.

 

[super51fan]

If the car is burning lots of oil the oil control rings are stuck. Valve stem seals failing causing blue smoke on start up is way less than a thimble full at most.

I would change oil and make sure it is on the full mark. Then drive till you use a quart of oil. Not unusual to use a quart in 700 to 1000 miles in older engines. If you drive and keep it full you can get a lot more enjoyment out of car. IMO

 

[AaronB]

Unfortunately I won't be able to check anything until tomorrow, got called into work early.

Super51fan, that's a good thought on the oil control rings, however the smoke i get is pure white, not blue, so I don't believe it is burning oil (at least a lot of oil). Still thinking it may be sludge as that seems to make the most sense. Tomorrow i'm going to get a good look under there.

On a side note, is it bad to leave the drain plug out? I have plenty of plastic and a large oil drain pan to catch/secure any oil that leaks out, since it is dripping a little bit still. Would this pose any danger to the engine internals?

 

[AaronB]

Ok tried some things today and here's what I found:

I stuck a plastic stick into the drain hole and moved it around..no sludge at all. Plastic came out mostly clean. Next I poured about a quart of oil in the fill hole and it started draining normally after about 8-10 seconds.

So there's no sludge blocking the drain hole..which as much as I don't want to believe it means I must have been running on 1-1.5 quarts. I don't see any blue smoke but as stated I do have a small leak. Maybe the small leak over weeks is bigger than i thought. Regardless now I need to find where the leak is, which is the easier (since I know I have a problem and i'm not just crazy). I will be replacing the gasket on the drain plug, using an OEM toyota oil filter (i bought the car with an aftermarket filter) and will try and source a '92 dipstick as super51fan suggested. Will also check valve seals and whatnot later down the line, but I'm ok with adding a quart every 1000 miles or so, i'm just trying to isolate the issue as much as I can for now.

Does anyone know where to source a '92 dipstick? I did some searching on the webbernets with no luck, and I dount someone parting out a car would part out just the dipstick.

 

[hvyman]

I always found the early dip sticks easier to read. The early dipsticks are not unreliable either.

 

[super51fan]

Toyota Dealer for dip stick.

 

[AaronB]

Hey guys just an update - so after a few days struggling with a stuck oil filter (a whole 'nother issue haha) I finally got it off and could complete the oil change. After using a real toyota gasket and filter it seems the leak has stopped! Still may be burning oil but that's for another day. Thanks guys for all your input on getting my poopra back on the road.

 

[Amtrack]

The 7m engine does not have oil level or pressure light. I wish they had a oil level sensor. Good luck.

Are you sure with the oil level light / sensor?
The later euro MA70s (from end 90s up) all have an oil level sensor with a warning light in the dash.

I am extremely sure on that because my second supra (92) has the sensor and light.
Just curious if all of the U.S spec MA70 are without the sensor.

Not 100% sure if all euro Specs are fitted with it or only the german ones as they died quite often back in their time (BHG, Rod Knock from low oil level - the Autobahnen taking their tributes...).