What could the problem be?
 

Well I just got my 88' supra turbo and now it is eating through oil like nothing, It went from half way to the fill line to not even on the dipstick after about 2 hours of highway driving :frown:

Also it heated up a lot, I haven't had a chance to check if it's missing coolant because I'm still waiting for it to cool down :(

Its also getting very crappy fuel mileage, put 50 bucks in it and after a 2 hour highway drive there was about a fifth of a tank left.

I'm not sure what the farthest right gauge is, I'm pretty sure it's something for the turbo but the gauge is flat lining, nothing is showing up.


Could the problem be that the turbo needs to be redone? Head gasket? Or some other problem. Thanks for any help :help:

EDIT: Checked the coolant levels, they're fine so I'm not loosing any coolant.

did you pull the codes?

is there any smoke? if there is, what color?

is there any oil under the car?

did you use premium gas?

what's the milage on your supra? how long have you had it? what work have you done to it so far?

when you step on the gas does your oil pressure increase?

is there oil in your intercooler?

is there coolant in your overflow?

these all need to be answered.

did you pull the codes? Wouldn't I need a programmer to do that?

is there any smoke? if there is, what color? Yeah theres smoke, its your typical grey smoke as far as I can tell.

is there any oil under the car? If it was it wouldn't be major, I'll put some newspapers under it tonight to check.

did you use premium gas? Not sure what the buddy who I bought it off of was using, likely regular.

what's the milage on your supra? how long have you had it? what work have you done to it so far? 147k km, a day, nothing yet but it looks like this problem is going to open a can of worms.

when you step on the gas does your oil pressure increase? Yes

is there oil in your intercooler? How do I check that?

is there coolant in your overflow? Yes.

Thanks for the help thusfar.

did you pull the codes? Wouldn't I need a programmer to do that?

no you don't just read this, MK3 TSRM On-Line

this is your new bible, so to speak.

is there any smoke? if there is, what color? Yeah theres smoke, its your typical grey smoke as far as I can tell.

there's black, blue, and white/grey smoke, black is fuel, blue is oil, and white is moisture. your grey smoke could mean a blown head gasket BHG or if your turbo oil seal is shot it would be throwing oil into your intercooler which would result in moisture in your intake. this was my problem.

when you step on the gas does your oil pressure increase? Yes

this could be a sign of worn piston rings, which a engine with your mileage wouldn't surprise me. i would do a compression check on your cylinders, read here for that MK3 TSRM On-Line

is there oil in your intercooler? How do I check that?

the ic piping at the bottom of you intercooler. remove that and see if any oil drips out

Thanks alot for the help, I'll do the checks that you said tomorrow and post the results.

How much would a new set of rings run?

Mmmm... well honestly, you probably wont be looking into just new rings, if you are going to take the engine down that far apart then you should do a re-build. Sorry I do not have a price on the rings for you.

Good luck.

chambers is right. when you check your compression, if it is out of spec then a engine re-build is neccassary

what? more info please. specific info, not the TSRM link hehe.

when piston rings are worn it allows the compression from the cylinders past the pistons down around the crank and into the oil pan. this increases the oil pressure. a surefire sign is if you push your oil dipstick all the way in and go around and step on the gas and walk back around to the dipstick and it's pushed out by any degree. this was the problem with my 87 non-turbo that i sold. another sign is low compression in your cylinders. but that could also be just a BHG. my last post i said that if your compression is out of spec it means a engine re-buil is neccassary. I wasn't completely accurate. it could mean just a doing a BHG job. If your piston rings are worn then you must get a engine re-build.

"when piston rings are worn it allows the compression from the cylinders past the pistons down around the crank and into the oil pan. this increases the oil pressure."

This is not true at all. What you said about the dipstick is partially right, but if this is happening, i would be checking to make sure the PCV system is clean and in good working order before assuming anything else. Oil pressure increases with engine rpm, and has nothing to do with the amount of throttle you are applying. Oil pressure is higher than the amount of air pressure the crankcase could hold without blowing something out, so pressure in the crankcase does not change oil pressure at all.

What you need to do is a dry and wet compression test. Doing a regular compression check, and then add a little bit of oil into the cylinder and do another compression check. The oil between the piston rings and cylinder walls create a temporary seal, and if your wet test numbers jump more than about 20psi, its a pretty good indication that your piston rings are not sealing properly.


This doesnt seem to be the biggest concern though. If you are losing that much oil you are either burning it or leaking it. When you say the smoke is the "usual grey", what does that mean? No car should be smokeing. Does it look pure white? or does it have a slight tint of blue to it?


The fact that you are overheating is something you need to look into. You say the overflow tank has coolant in it to the full line. Does is your radiator full? Does the overflow tank spit out coolant ever?

Yes the rad is full and I've never noticed coolant coming out of the overflow tank.

I agree with the previous post that questioned the amount of blow-by to oil pressure fluctuations. My oil pressure drops at idle, and picks-up at driving, but this has to do with worn bearings, not excessive blow-by. I don't have excessive blow-by. And yes, I tested it.

As far as the cooling system problems, you may want to flush and fill the cooling system, and make sure you pull the radiator out and flush it completely. Crap, gunk and rusty scale could be blocking some of the tubes in the radiator, cutting it's efficiency. Replace the cap and thermostat. Fill with 50/50 coolant. Toyota red is best. Anything good for aluminum protection is OK. I use distilled water. Tap water can contain chemicals that may shorten the life of the anti-rust and water pump lubricating additives in the coolant.

Of course, this is if you rule out a need to re-build. That should be the first focus. If the turbo is leaking oil, it will get sucked through the intercooler on it's way to the engine. You should see oil in the piping. If that is OK, a leak-down test will reveal the condition of the valves and rings. Any shop should be able to do this. If it is out of spec, a rebuild will be required.

i stand corrected, thanks, however you mentioned that i was only partially right on the dipstick info. could you elaborate? on my 87 non-turbo when i stepped on the gas my dipstick would shoot out 2 inches and it was the piston rings and i had to do a re-build. as far as oil pressure rise when you step on the gas. i have the normal rise on my 91 turbo now with just normal operation. on my 87 non-turbo it was riduculous. my pressure would peg out. that is the differance i was talking about.

Well i say that because if the dipstick was being pushed out, piston rings would not be the first thing to assume bad. There is a pcv system that evacuates excess pressure in the crankcase via the intake, and if this system is clogged, the pressure will have nowhere to go, and will push out the dipstick. Although if you have excessive blowby and the amount of blow by exceeds the amount of air the pcv system can flow, you will also push out the dipstick. Basically im trying to say don't assume the worst right off the bat, and start off easy.

You must have also had a clog in the PVC system or a MAJOR ring failure. I had a friend's old GM V8 blowing the hose off the breather system for the same reasons. But, an oil pressure spike is not a real good diagnosis of a ring problem, but a symptom of a major problem.

cool, thanks guys

No oil under the car. And I wot'ed it down the road for half a kilometer or so; its got boost so te turbo is working.

What's the best way to get at the intercooler?

mine drops to about 5 at idle, and picks up to around 20-35 ish while driving around.

so now its not the rings, its the bearings. wooo :yum:

yes, use distilled water for those reasons. only use regular water if you DESPERATELY need to, and afterwards do a flush of your system. itll bite you in the ass in the long run.

Sidewinder, you can survive for a bit if you switch to 20W/50 oil, and use a bottle of STP with every change. This bumped my idle pressure to 10-15 psi, and has been holding there for a year. I'm planning on an engine rebuild. It will probably happen this winter or next spring.

I've been driving this way since i owned the car, which was a little over a year ago. No problems yet, so i dont wanna throw to 20w50 in there too soon lol :x: It might even be something else, hopefully.

Regardless, its getting a rebuild down the road.

Please dont do this.... Putting thicker oil in your car is not the answer....

please read the oil link in my signature Busted Knuckles before you advise someone else....

The Following is from jdub over at supramania. Knows alot about oils


A 20W-50 will increase oil pressure and keep the bearings from touching the crank journal/rod end - False
A thicker oil will increase oil pressure in the 7M, but only to a point. The design of the 7M has the oil relief valve set at 63-71 psi...over this oil is simply routed back to the pan. More importantly, the oil cooler valve on the stock filter head operates at 40 psi and you have a controlled "leak" from the oil squirters on a turbo motor. Pressure is resistance to flow...a 20W-50's increase in pressure means that it does not flow as well through the bearings or to the top of the motor. Considering a 20W-50 oil is 3-4 times thicker cold than a 5W-30, it's significant. This means a couple of things:
- On a cold start, you will have restricted oil flow where you need it the most.
- The oil relief valve will cut the flow further by opening at the higher pressure and dumping oil back into the pan.
- It will take longer for the oil to get to the cam shafts...the small diameter hole in the middle does not facilitate flowing high viscosity oil. Since the oil flows from front to rear on the cam shafts, it is going to take the #6 cylinder valves the longest to get the oil flow needed.
- The oil squirters spray pattern on the cylinder walls will degrade with a high viscosity oil...especially cold. It's simple...higher viscosity, lower velocity.
Oil pressure has little to do with the way an open bearing (like rod & main bearings) works. Like I said, these bearings depend on hydrodynamic lubrication to function...saying increased pressure will improve this is a very basic misunderstanding of how the bearings really work. The ONLY time I could see using a 20W-50 from a bearing standpoint is if you've built the motor for it by opening up the bearing clearances to get the flow...you will see some very experienced engine builders do this, mostly on race cars that get re-built every season anyway.

mkiiisupra, I beg to differ on a few points.

Point 1: 20W50 is a recommended oil for the 7M-GE and 7M-GTE for ambient temperatures above 40 deg F, according to the owner's manual. So, the oil journals, including the cam journals, are sufficient for this viscosity. I live in Atlanta, and we only see temps below 40 for a couple of weeks in the dead of winter.

Point 2: Oil is pushed through the engine by pressure. The higher the pressure, the more oil is being delivered to all parts of the engine, especially to the top of the cylinder head. At idle pressures of 5 psi, less oil makes it to the cams, and more is running through the main bearings due to widened clearances due to wear. A heavier oil will push less through the mains, and force more towards the cams, as monitored by increased oil pressure.

Point 3: Since 20W50 is a recommended oil, you do not have problems within the oil delivery journals of 'choke points' where the oil delivery hole prevents the oil pressure from being delivered. Thus, the oil pressure is the same at the cam bearings as it is at the main bearings.

Point 4: Bearings get most of their protection from film thickness. Higher viscosity oils provide higher film thicknesses than lighter oils. Pure and simple. And as the bearings wear, and clearances widen, that film thickness may prevent a bearing from getting smoked.

I've read link after link from sites like Bob Is The Oil Guy and discussions that link to studies, like Technical Journal: R&D Review of Toyota CRDL

that specifically links light viscosity oils to increased wear in piston rings over higher weight oil specifically because of the lighter oil running off the cylinder walls faster. They also show increased wear in connecting rod bearings, cam bearings, and main journals.

Again the following from jdub over at supramania.

Note that 20W-50 is listed for a 10 to 100+ F temp range...so is a 15W-40 and 20W-40. On the 2nd line a 10W-30, 10W-40, and 10W-50 are listed for 0 to 100+ F temps...a wider temperature range. Also, if you look at the verbiage at the top, the manual shows API grades SF, SF/CC, and SG...all are obsolete API grades...you cannot even buy these oils anymore. The current API grades are SL and SM...these oils represent a quantum leap in formulation improvements over the oils available when the Supra manual was published. Modern oil's at SAE viscosity 0W-20, 5W-20, 0W-30 and 5W-30 easily cover the temp ranges (especially in cold climates) most of us operate the motor at...oils have simply improved that much over the last 20 years. Bottom line: Take the Supra manual oil chart with a grain of salt.


The manual recommends it - False
See above. The manual does not specifically recommend a 20W-50...it's just one of the oils listed that are "approved". It also recommends a 10W-30...an oil that covers a wider temp range. Completely ignores that API SF and SG grades are obsolete.

In addition you do not need oil additives if you buy good oil in the first place...

The supra is a low oil pressure vehicle and you can only increase that so much at a certain point (mentioned above) it kicks the oil back into the pan allowin less to flow into the engine.

Pressure is resistance to flow...a 20W-50's increase in pressure means that it does not flow as well through the bearings or to the top of the motor.

If you would take a moment and read through Motor Oil I think you will have a better understanding

Ok then after all the arguing back and fourth is said and done what is the correct oil to use for summer driving? I looked through the maintenance receipts the previous owner had and he was running 5w30.

5w30 or 0w30 would be a good bet.

German castrol 0w30 is good oil can usally be found at autozone

There was no arguement... Just dont like to see people give out innacurate information

But if you yourself had taken the time to read above you would of had a good idea of what oil to use and not have to have it handed to you

My dad seems to think that it isn't the rings but a seal in the turbo which is leaking oil and burning it? What do you guys think?

I figure I'm gonna hand it over to Toyota for a day sometime and find out for sure whats going on. No sense buying another turbo or having to do a rebuild if it isn't necessary eh?

Toyota probably wont be much help they dont know anything about turbos and can only tell you to replace it. Need to find a specialty shop in your area that has done work on this car before otherwise you wont get very far

So they wouldn't be able to even pinpoint the problem if it is with the turbo? The only turbo shop around my place is two hours away.

NO. They won't pinpoint the problem.
They aren't in the business of telling you what's wrong with your car dude.
They just tell you how much it will cost if you want them to fix it.

If you try and corner them about what the problems are. They will most likely clam up. While handing you an estimate and shouting....,NEXT.

The owner of the dealership is a close friend of my grandfathers and his neighbor on top of that. I don't think being jacked needs to be worried about I just want to know if they'd have the potential to pinpoint the problem.

To pinpoint the problem, you need to find someone willing to turn a wrench on your car, hopefully you. If the turbo is the source of the smoking, you can remove the lower air hose on the intercooler, and check it for traces of liquid oil going into the intake. If this is clear, you'll need to remove the elbow for the downpipe at the exhaust side of the turbo, and check that for liquid oil traces. If this pipe is also clear, the problem is probably not the turbo.


of course mkiiisupra probably has issues with this advise as well, and will follow up by flooding this topic.........

I'd dump that 5-30 real fast. Go to at least a 15-40 or 20-50. 20 wt. is pretty thin at room temp. I'd only use a 15-40 in winter. These oils aren't thick enough to cause problems, but a too thin oil sure will.

A new, tight bearing clearance engine may be OK with 0-30 wt synthetic, but your clearances are probably pretty loose by now.

Well got it back from Toyota, they said that the valve cover gasket was screwed and that was doing it. There is no way in hell that that could be just it, yes I know its screwed and its leaking some oil, but not that much and it certainly wouldn't make it burn the oil.

At this point I figure it's likely the valve seals.

So I take it that you're saying lighter weight oils are better for engines in their prime but heavier oils are better for higher mileage engines?

I thought you and the owner had an understanding :x:.

Do you think it was him under the bonnet??? Or a tech guy that gets paid salary no matter how much work he gets done?

That's the cat you need as a neighbor. Not the owner.

Aw well, at least it only took them an hour to do that and take out the radar detector the previous owner had in it; wasn't going to be messing with his sketchy ass wiring job myself. And the valve cover did need to be fixed but a monkey could have seen that, live and learn I guess.

What am I looking at for a price on replacing the valve seals?

Before you order this work, I just went back and re-read the original post and previous replies. I think your barking up the wrong tree by now focussing on the valve seals. The valves are not on the pressurized oil circuit, and get most of their lubrication from the gasoline. Even if the valve seals are leaking, you will not get enough oil past the valve stem to account for the oil losses your claiming. A typical valve stem seal leak will be a puff of smoke at start-up, but it clears up. If the smoke is continuous, I'd be focussing on rings or BHG.

I noticed you have not posted results from a leak-down test yet. Any good shop can do this, and it gives a real good indication of the condition of the rings and valves. Do this before anything else. It will help determine the next move. And, it is much cheaper than valve seal replacement.

The reason I say this is because it would be almost as expensive to replace the valve stem seals as it would to do a BHG. Not quite, but it would be cheap to do if the head must come off, rather than spend all that money to do it, and then find out the head will have to come off later.

Hm, good point. I was thinking about doing the BHG kit from the suprastore anyway just to be safe and so I don't have to tear it apart down the road after shoehorning all the mods onto it.

Is a leak down test the same thing as a pressure test?

And I've been having to drive the thing back and fourth to work every other day and I check the oil every time I get to my destination and I didn't lose near as much as that long trip making me think that the high temp of the engine was effecting the amount of oil it burned drastically somehow. I think the dummy who had it before me had his antifreeze to water ratio screwed up and probably just used a garden hose too, I'll do a coolant system flush possibly an upgrade too just to be safe.

And there's something a little odd with starting it too, sometimes to start it I need to have just the parking brake on and not the normal brakes, other times I need to have the normal brakes on and not the parking brakes and sometimes it wont start if I have either brakes on. Whats up with that, there isn't even any order to it it's just random?

I think the brake thing is a red herring. There is nothing connecting the starter circuit to the brake circuit. There is a known issue with the otherwise bullet-proof Denso gear reduction starters. The contacts in the built-in solenoid tend to get beaten out of shape, and can cause intermittent failure of the starter. You can replace these contacts, or just replace the starter to avoid any other starter-related issues.

A leak-down test is slightly different from a compression test. It tests how well the cylinders MAINTAIN pressure using a gauge and shop air. A compression test shows how well the cylinders built compression. Did you have a compression test done? Please post those results. If the compression is good, at least 120 psi with all 6 within 10%, then we need to look even further.