Man! Ask a question about OIL and you get some slick answers
I am going to - run at least 10w30 for now and check my bearings.
I am not going to bring it back to the DOCTOR because they just never felt right. I have a couple of shade-tree mechanics here so maybe we'll get under there together. I have never done anything of this magnitude and please don't bother telling me how "easy" it is cause (for me anyway) it ain't. Listening to other real car guys talk about this always made me feel this was a critical last step to be avoided unless absolutely necessary. Is it absolutely necessary to pull the engine and the crank in order to do this job?

 

I have had very bad luck & experiences in the past with 20w50 motor oils Dave.

Sure it was my experiences only.

I learned Pontiac crankshafts don't deflect unlike SBC & BBC singing away at 7 - 8K.

I run less than .002" running oil clearance on the mains & rods of a Pontiac 455.
I keep the exact(in 1/10,000ths of an inch) clearances a secret to myself.
Blew around 10 455's in a row trying to build them up like a Chevy.........

Chevy machinists had them all prior.
Setting the mains & rods up to .003-.004" with 3.25" diameter mains.

Vandervell bearings when I found them were like A GODSEND TOO.

I ran 10w30 like my late friend advised.

No problems even after 10,000 miles of hard driving, high speed street racing, drag strip action, 2- 3 am street racing.

And I love TOP end speed, foot on the floor for 2-3 miles flat out.

i only lost to Big Girl.
I held her off to 160 mph on the 70 TA speedo.
Big girl blew past me at when 2nd 4bbl carb kicked in.

I had the speedo past 2 inches in the 70 TA running on I 80.
Big Girl was gone.

Summer of 1998.

3 AM.

People at trucks stops said they could hear the "Maniac" & Big Girl " coming flat out WOT from 5 miles away.





Big Girl runs on 10w30 motor oil too.

Castrol GTX to be specific.

My beat up ford Ranger has 410,000 miles on it.
Always ran on Castrol GTX 10w30.
was my late buds.
He bought it new in late 1986.

Castrol GTX is "just crap oil like others had told me in the past here on C4".

"Whatever I say"

They drive like sissies on the street anyways.

I can & will show them how to run & drive a Corvette.

 

4 hrs to pull a C4 motor, your a better man than I. No thanks!!
Would take me that long to find the wrenches that were thrown out of frustration of all the tight spots on those cars lol.

If your oil light is coming on doubt an oil change at this point will help things unfortunately.

 

Lol, I like your style.

 

It is not necessary to pull the motor to check a bearing. however i'd much rather be checking all of these clearances with the motor 3ft in the air on a stand vs me on my back with the car 18" off the ground and me sandwiched underneath it. makes for very not fun times.

yes a motor can be yanked in 4hrs or less depending on if you have help and how quick you move. i had all of the accessories off the CFI in an hour or 2 and the rest of the top end just after that. Once the intake is off (and you don't even need to pull the intake) it's a TON easier to get those back top bellhousing bolts. there's those 6, your torque converter/clutch, 2 motor mounts, front Y pipe, and it's out.

It also helps when you have access to this:



i don't throw tools. i just smash things. throwing tools creates more headache when you gotta find them. i'm usually on a limited time budget and more time spent hunting for tools is less time i have for beer.

 

I guess for you its a Snap - on...

 

i see what you did there...haha

what is worrying all of us here is the fact the indicator light and low oil pressure come on. this is not normal. I'd almost first get a real mechanical gauge hooked up just to eliminate the sending unit/wiring. if it verifies a low pressure condition then it's time to get serious.

 

The pressure comes up normaly but after the temperature approaches 200 or so, the pressure decreases until that red indicator comes on. It is not immediate which, i would think, means the reading is accurate.

 

It does sound like you've got a "rebuild" coming up in your near future.
Sounds like you just need to figure out how to keep the coolant/oil temp under 200 F all the time then....

I'd drain the existing oil in the engine and refill with new stuff - 10w 30 or 40 would be fine to run this time of year but it will not make that much of a pressure difference once it is up to temperature.

Might want to change the oil pressure sensor/switch to ensure it is not part of the problem.

You need a minimum of 10 psi of oil pressure for every 1000 RPM.

 

Would changing the thermostat help with the temperature? If so, what thermostat should I get?

 

Sorry - I was just kidding about that - my bad - and no a simple cooler T stat swap will basically do nothing since there are several other factors (computer programmed "fan ON" setting, ambiant air temp...etc.) working in conjunction which contribute/control the overall temperature of things.

again - you might get lucky by just changing the oil and oil pressure sensor....considering the alternative I'd say that this is worth a shot for less than $100.

 

pROBABLY JUST A GOOD STEP. wHERE IS THE OIL PRESSURE SENSOR?

 

If youre standing on the drivers side of the car look where the distributor is....its just below that at the rear of the block and in about 2 in(??)
Brass piece I believe with a wire attached

 

I run 5-30 in my C4's 355 but then again its what the machinist recommendeds for my build....Its easy to remove the engine from my 95 in four hours (working alone) with a little help its quicker...


Mike

 

You guys are quick wrenches....or im getting old. Probably both lol.

 

The first time i doing something it seems to take forever,after that it takes a lot less because i know what tools I need the what to do first,but 4 hrs seems a bit ambitous to me.JMHO

 

I am not exactly sure where to mount the guage?

 

If you are running dino, this is good advice. My advice, step up to something like Valvoline Maxlife 10W40.

There was good information in the above thread on the quality of oil with no specifics of how to find the best oil. On your oil bottle, look for ACEA (European) A3 spec.


I use GM 10W40 SL rated (and ACEA A3) semi synthetic blend oil in my 89 COrvette, and in the hot days of summer in traffic, oil pressure is too low for my comfort, and my car has 30,000 easy miles....

10W40 Maxlife and Durablend are the only semi synthetic which is ACEA A3 rated oil on the market, Maxlife also happens to have seal conditioners. 10W40 can be used down to -20F, and should be much better at colder temperatures. Mobil 1 is made from Group III base stock, not really full synthetic chemistry so synthetic vs non synthetic are more marketing terms. Stick to standards like ACEA A3. Only the best oils will have ACEA A3 certification, only a few grades of Mobil 1 are advertised to satisfy the spec just like Valvoline Maxlife 10W30 or 5W30 do not satisfy ACEA A3.

If I were you, I would try different grades oils for the winter and summer, but if you want to use an oil year round, Maxlife 10W40 would be a good choice. This is the oil grade of choice for most cars in Europe and none comes SM rated, all the oil is SL rated (older spec).

Even Mobil S syntetic blend (available as factory fill in Europe for our Opel with the Ecotec engine, also used in Chevrolet Aveo in the US, guess what oil they use in the US for the same engine) 10W40 is superior to Mobil 1 in wear tests. There are some good synthetic oils like Quaker State/ Pennzoil distributed by Shell in the US. Quaker state challenged Mobil last Spring which went unanswered so XOM accepts competitors are better at least in the 5W30 grade.

http://www.animegame.com/cars/Oil%20Tests.pdf

C4ZF6nut

 

it lasted this long on the oil that was being used all along.

 

Everyone picks their own poison mine is 20-50 on engines with more than 60k miles and temps over freezing. It has worked for decades with no problems..
Dave