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sh0rtlife
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oil presure 2.5

Post by sh0rtlife »

just wondering whats "normal" and whats not..i did a 400+ mile road trip yesterday and the oil presure gauge kinda bothered me and got me thinking..at idle the car shows next to no oil presure (20-50wt) and it was a 100+ deg yesterday thru the washington desert..of course the guage "could" be inacurate as well....what does a "normal" correctly working guage read at any given rpm on a gtv6?..at 70mph in 5th gear it reads straight up ?55psi?...just kinda wondering if im needing to replace the oil pump
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mjr
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Post by mjr »

Shortlife.

I have a perfectly healthy 2.5, with correctly calibrated oil pressure switch. My oil pressure sits steady and dead in the middle of the gauge ( 55psi is it? cant remember the values) at idle, with the revs the pressure increases, and sits at 75% at near full revs. Highway driving at 70mph gives me 75% gauge deflection. try to replace your pressure sender before the pump. if its bad you will get very strange readings, normally very low.


MJR
benski105
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oil pressure

Post by benski105 »

as i understand it.
you need 10psi per 1000rpm.
from past experience a hot engine will show next to no oil pressure at idle.
from memory the low pressure oil light is set to go off at 20psi and i have always used this more religeously than the guage, particularly at idle!

i have had a few dodgy senders, iv also seen senders mixed with guages that dont match, ie from a different car!
hope this helps.

ben
1962 Giulia Ti Race-car
1969 Giulia Super
1987 GTV6- new race project.
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x-rad
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Post by x-rad »

Low guage reading is normal once oil is hot. Would check with accurate guage if you are unsure. Oil pressure sensor is located center rear of block in the worst possible spot. Luckily, it's a standard sensor. I replaced mine with an Autometer for 25$ after checking pressure with the Autometer guage. Use teflon tape if u replace it. I think it ran about ~20 @ 1000 and 65-75 @ 6000rpm. Can't find my records....here somewhere. I use Castrol 10/40.


Shortlife: the answer to this and many more future questions are in this web site and Alfabb. I suggest reading all the posts you can before doing anything mechanical to the Alfa. Thats what I did and it saved me much time and aggravation. Our search function works well ,too.
Peter A
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Post by Peter A »

I've owned five v-6 alfas, they all show "0" on the gauge at hot idle, 55+ at higher RPM. If it bothers you then check it on a mechanical gauge. Replacing the sender is a waste of money.
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tImBoWe
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o pressure

Post by tImBoWe »

Mine has a fresh engine and the guague still reads 0 at idle when the oil is hot/warm. No biggie.
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Post by MALDI »

For what its worth, I replaced my stock filter with a larger K&N oil filter and saw higher oil pressures on the gauge at all conditions, from cold start to hot idle. (I use Valvoline 20W50 synthetic.) My winter cold idle pressure is about 70 psi and my summer hot idle pressure is, well, not zero anymore because now a small deflection of the gauge is apparent. The sending unit is about 2 years old.

Questions: Does this mean that the filter is between the pump and the gauge? Shouldn't the bypass valve make the type of filter irrelevant in terms of oil pressure? Do I have a blockage somewhere?
'84 GTV6 3.0L
'81 X1/9
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sh0rtlife
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Post by sh0rtlife »

i was kinda figureing it was semi normal since cold it reads higher...again im used to BIG castiron v8's and they dont realy change as much as this in comparitive terms "little" v6...

maldi most "cheep" filters especialy fram suck up alot of PSI just to push the oil thru them ..its tricky finding good ones that filter well and dont restrict
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x-rad
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Post by x-rad »

Increase filter flow by using a longer filter barrel and end plate holes. I use a V8 filter ...Fram TG8a (it has a good sealing silicone anti drain back seal) ...and still get great pressure. All my bearing tolerances also in "normal " range per specs.

As for sender, it is worth replacing if the old one doesn't work. If you do get some movement of the guage needle, likely your sender is OK...When I checked mine, the little inlet hole was filled with oil sludge.

Rarely, but if you never get good pressure, you may have lost a crank dowel.

If you do tear the engine down, there is a spec for oil pump gear clearance. Check the sump intake holes. Mine were filled with crap.
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Post by MR2 Zig »

For good filters try Wix brand.

Scott
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dcefali
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Post by dcefali »

I agree on the WIX, but sometimes they are hard to find. Napa Gold is a WIX filter and are pretty easy to locate.

Doug
1986 GTV6 3.0
1991 Spider
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