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73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: txtj79 on December 09, 2007, 07:47:37 pm
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I have a 1980 Chevy with a 350. The oil pressure seems really low. If 12 o'clock is 30, then mine is reading 15-17psi while cruising and only about 10-12 when idling? Does that seem low to anyone else?
thanks,
T.J.
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on the guage in my 87, the 12 o'clock position is the 30 mark. my truck has a new motor and stays around the 45 to 60 psi mark all the time. my monte carlo has a well worn 350 and at idle only makes around 30 psi and goes up to 45 or 60 while driving. as the engine wears, oil pressure will drop. one of my motor manuals says that average oil pressure for a 1980 350 motor is 45 psi.
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recheck the numbers on your guage. 60 should be max--all the way right.
Your pressure, when driving, should be at or above 45. When at idle, it will go down 10-15 lbs.
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Sorry, I messed that description up. I meant to say that 12 o'clock was 30psi. My truck is barely showing 15-17 psi when cruising and 10-12 psi when idling. Should I be alarmed? The truck runs good otherwise but it is burning a lot of oil.
Thanks,
T.J.
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For idle that isn't low, that is normal. General rule of thumb for a stock motor is 7-10lbs at idle and a additional pound for every 1000 rpms. When cruising, what speed are you talking about? 60mph or 30mph.
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I'm talking 65-70 mph when I say cruising. Even when I floor it getting on the freeway, it still doesn't go above 30-32. What do you think, Chris?
-T.J.
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Means whe is getting loose on you. I reringed and rolled new bearings in mine and a pump and I get 75 on startup, 27-35 at hot park idle, 24-25 at in gear hot idle, and 50-80 at speed, depending onWhat speed. and a happy 85-100 floored.
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Sorry, I messed that description up. I meant to say that 12 o'clock was 30psi. My truck is barely showing 15-17 psi when cruising and 10-12 psi when idling. Should I be alarmed? The truck runs good otherwise but it is burning a lot of oil.
Sounds like its time for a rebuild if its burning a lot of oil. You can just keep driving it till she goes. It could take a while but you will spend alot of money on oil.If it were me , I'd be dumping the cheapest discount oil I could find in there.
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I think it is getting on in age if it is below 30 at 60mph. Dump some thicker oil in there. What are you running in it now?
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Anyone remember STP engine honey? Marvels mystery oil. How fast can you sludge up a motor?
Snake oil for engines.....
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Yeah, I'm running 10w-30 in it. I'm thinkin of going with some Rotella for diesels. My dad seems to think it will help. What do you think?
I came to the conclusion that its burning oil because the right side tail pipe spits out a lot of black soot at start up. Is that a logical conclusion?
Thanks,
T.J.
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Thicker oil is just a bandaid (in my opinion). It would work in the short turn. Sounds like a rebuild to me. :'(
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I would be a bandaid, but it would keep it running long enough to get a replacement.
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TRY USUNIG 20-50W OIL ;)
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I came to the conclusion that its burning oil because the right side tail pipe spits out a lot of black soot at start up. Is that a logical conclusion?
Thanks,
T.J.
No, oil burning would be bluish grey smoke. Black smoke is unburned fuel.
I agree just put 20w50 until you are ready to rebuild...
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wow, my 24 year old 305 must be a lot better than i thought! i sit NO LOWER than 30 psi at idle (in gear, normal operating temp) and AT LEAST 45 psi (normally 60 or really close) at cruise...not bad for never having any major work on 'er, huh?
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okay, un-burned fuel. What would cause that? Could it be plugs or could it be running too rich? If it is only black smoke on the right side, could one assume it may be the plugs or something like that and probably not the fuel mixture? Right now, I'm just hoping to get through to tax refund time. Then get the engine rebuilt.
Thanks,
T.J.
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Do you have a quadrajet? They are notorious for draining the contents of the fuel bowl from the well plugs into the intake. When you go to start it you get a nice poof of black smoke.
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you might want to intall some replacement(aftermarket) gauges.
on my truck it used to read some low psi on the oil gage.......when i replace it - i got a
30 psi idle and a 45-60 psi at crusing 30 mph.
i always blamed the unacurrate original gage.
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You'll have to check the plugs for fouling. Should be grey at the tip. But the unburned gas might be a sign that they're not hot enough.
You're not smelling any gas when you check the oil dipstick are you?
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no, no gas smell when I check or chnage the oil. I'll check the plugs.
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Did you read my post?
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Yes, I thought I replied...YES I have a q-jet and I have a puff of black smoke when I start it up, both tail pipes smoke at start up, but teh right one is much worse. Is this something that can be fixed or does the carb need to be rebuilt?
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Sounds like what I described then. No you don't have to rebuild the carb but you have to take it off to epoxy the plugs and let it set up over night to cure that problem.