1. Home
  2. Automotive Technologies
  3. Does anybody here actually know anything about cars? 7M-GE Supra

Does anybody here actually know anything about cars? 7M-GE Supra

No, not you guys in rec...

1988 Supra, 7M-GE. I got it with ~177,000 (the speedo's busted, SURPRISE!) and have put 10-15,000 miles a year on it for 5 years. So we're looking at ~230,000 miles.

When I got it the oil pressure was on the low side, and it has been getting lower and lower. It's a Canadian model, and when running 35-45 MPH the oil pressure is under 2KG/cm2. I don't know what that equates to in PSI, but it's the bottom 1/3 of the guage. At idle it's about 1KG/cm2.

Oh. 2 k/cm = 28.4 psi (2,500 RPM), 1 k/cm= ~15 PSI (750 RPM)

Seems pretty low. I did buy a sending unit after I bought the car, because they are known to go on the low side as they age, but I CAN'T FIND THE DAMN THING!!!

From this:

formatting link
Measure Oil Pressure:

Oil Pressure: at idle speed: 0.3 kg/cm2 (4.3 PSI) or more At 3,000 RPM: 2.5-5.0 kg/cm2 (36-71PSI)

I think at 3,000 it's just under 2.5, but it seems to be sitting under 2 k/cm most of the time.

I haven't changed the oil this year, since I haven't been driving the car. It needed ball joints, and I just did them 2 weeks ago.

Also, from the same page:

Low Pressure:

Oil Leakage (*) Releif valve Oil Pump Poor quality oil (*) Crankshaft Bearing Connecting rod bearing Oil Filter clogged (*)

Well, I think the engine could use a freshening, but there's no knocking to be heard. The Oil Quality...hmmm...I added a quart or two before I started driving it. Oil Leakage. I did the spark plugs last year, and didn't want to spend $7 each for the Factory Stainless steel screws and bushings from Toyota, so I made some up from the Hardware store. I think I'll have a look at these to see if they're loosening, because I'm also smelling oil burning off something. I replaced the valve cover gaskets when I did the plugs, since they had 1/4" gaps in them and were leaking badly. Oil Filter clogged. Like I said, I did a change before I put it away last November...

I'll check the obvious Saturday and then get back...

Reply to
Hachiroku $B%O%A%m%/(B
Loading thread data ...

No, it runs like a CHAMP! No visible sludge anywhere, and I've had the valve covers off and the plugs out, everything looks cool. It was owned by a lawyer from Toronto who is now a judge here in Mass. I have a lot of records for it.

It's getting an oil change Saturday, and as soon as I finish typing this I'm checking the torque on the valve cover screws.

The engine is in great shape, the transmission *sucks*!

Reply to
Hachiroku $B%O%A%m%/(B

I knew at least one good person would answer! ;)

Um, what am I looking for with thicker oil? I did this with my 'hachiroku' the last 30,000 miles I drove it, upping from 10W40 Dino to 20W50. I did get a response on the guage, but not what I was hoping for (like, readings like when it was *new*!)

Reply to
Hachiroku $B%O%A%m%/(B

I CAN'T FIND THE SENDING UNIT... :(.... I've tried!

I usually do, but the oil was really clean, since I changed it 2 days before I parked it.

I usually change it when I take it out of the garage, and then once in June or July, and then again before parking it.

I think I overestimated the mileage. It may be less than 5,000 miles per year.

Reply to
Hachiroku $B%O%A%m%/(B

I always change the oil before putting it away.

I guess maybe I shouldn't have topped it off with 1.5 qts of 5W30 synthetic last week, eh?

Full oil change Saturday.

Some of the valve cover screws were loose, but it didn't bring the OP up a lot.

Reply to
Hachiroku $B%O%A%m%/(B

At 200K + miles, if the car wasn't kept up, the crankshaft and connecting rod bearings may be worn. The correct way to check would be to drop the oil pan, pull the bearing caps, and plastiguage the bearings. The easy way to check would be to try thicker oil.

Reply to
Ray O

If you are reading an oil pressure gauge built into the car I would check the pressure separately with a good gauge. You could have a bad oil pump or pressure valve as well.

Given that the oil filter is apparently completely clogged up after you changed the oil (and filter?) last November and didn't drive it since then, I would say the engine is probably full of sludge. It sounds like basic maitenance on this engine has been ignored for most of it's life and is well worn out.

Reply to
Radioguy

Oh, boy.

This is the second time you've mentioned this.

You know what that entails on a Supra?

Reply to
Hachiroku $B%O%A%m%/(B

As Radioguy mentioned, it is probably a good idea to measure oil pressure with a gauge. Remove the sender and screw in the fitting for an oil pressure gauge and see what you get.

As for thicker oil, try 20W 50 since it only gets driven in the summer, and change the oil before the engine gets fired up for the first time after hibernating.

Reply to
Ray O

Been there, done that. I usually put oddball parts someplace where I know I'll find it even if I don't remember where I put it, like the glove box.

If you change the oil just before parking it, then you shouldn't have to worry when you fire it up in the spring.

Reply to
Ray O

DAMN! Another "drop the pan" suggestion!

formatting link
formatting link
formatting link

Methinks replacing the engine is easier!!!

Reply to
Hachiroku $B%O%A%m%/(B

A lot more than I want to get into in my back yard with a couple of jackstands!

Reply to
Hachiroku $B%O%A%m%/(B

Valve cover tightness or looseness doesn't affect oil pressure, just oil leaking down the sides of the engine.

If using thicker oil doesn't bring up the oil pressure, you can also check the oil pump with a regular feeler gauge if you have a manual with the specs. Basically, you are measuring the clearances between what looks like a gear and a crescent and the pump body. You should be able to get at the pump if you drop the oil pan.

Although the oil pressure relief valve is a possible cause, I have never seen or heard of one failing on a Toyota.

Cheapo oil pressure gauges (for test purposes) start around $60, with pro sets running about $140 with all of the adapters for all sorts of engines.

Reply to
Ray O

...

Put 4 quarts straight 40 in it and a half quart 50w. (Gear lube). Use synthetic so you never need to change it again. That or replace the oil pump gears. (Drop pan, booo) I think I still have an extra one in the garage.

Remember you can still buy a JDM engine with under 40K and have it shipped for far less than a used motor at a junk yard.

Reply to
Gary L. Burnore

I do. You lift the engine up slightly and drop the rack. That's all. Oh, and the sending unit is near the filter, if I remember correctly.

Reply to
Gary L. Burnore

I still say it's just a warn oil pump. Thick oil will fix that. Synthetic will stick to the parts like oat meal.

As someone else mentioned, the only thing that'll do is stop dripping.

They always go first.

Reply to
Gary L. Burnore

Dropping the pan should be a pretty straightforward job, especially if the pan has a regular gasket instead of FIPG.

Reply to
Ray O

If that's true then how could a new oil filter become so quickly clogged?

Reply to
Radioguy

Not sure if that's it. The car has ~230-250,000 miles. God knows when the speedo cable broke; I sure don't. They usually break between 150-175,000 miles, and this one shows 177,000 on the odometer.

Could be bearings, could be a worn oil pump, bad sending unit, or any number of things I don't want to mess with...

Reply to
Hachiroku $B%O%A%m%/(B

The subframe is right underneath it...

Start here:

formatting link
UGH! Unless you have another method! ;)

Reply to
Hachiroku $B%O%A%m%/(B

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.