Oil filter, pressure and temp issues
Thread Starter
Drifting
Joined: Jul 2003
Posts: 1,613
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From: Orlando FL
Oil filter, pressure and temp issues
ok...here's what I got...85, 4+3, just changed the oil and filter (K&N), Castrol 10W-30, 64K on the clock
here are my questions:
1) the K&N filter is a lil bigger...does it take a 1/2 quart more?
2) my oil pressure seems to be all over the place, mostly at 80psi, but it will drop as low as 30 sometimes during cruising at any speed in any gear, or at idle. I am trying to figure out a pattern, but there doesn't seem to be one that applies to all conditions. I assume this may be a failing oil pump? :confused: Is there a way to test that? How hard/expensive is that to replace?
3) my oil temp always reads LO. In the mornings its a 30 minutes drive...no way does it stay cool that long. My question is: if whatever sending unit is detached, does the display read LO or just nothing at all? And where is this sensor? (i'm consulting my shop manual now)
I look forward to all the knowledge this forum has to offer
:thumbs:
here are my questions:
1) the K&N filter is a lil bigger...does it take a 1/2 quart more?
2) my oil pressure seems to be all over the place, mostly at 80psi, but it will drop as low as 30 sometimes during cruising at any speed in any gear, or at idle. I am trying to figure out a pattern, but there doesn't seem to be one that applies to all conditions. I assume this may be a failing oil pump? :confused: Is there a way to test that? How hard/expensive is that to replace?
3) my oil temp always reads LO. In the mornings its a 30 minutes drive...no way does it stay cool that long. My question is: if whatever sending unit is detached, does the display read LO or just nothing at all? And where is this sensor? (i'm consulting my shop manual now)
I look forward to all the knowledge this forum has to offer
:thumbs:
Drifting
Joined: Aug 2000
Posts: 1,521
Likes: 0
From: West Islip New York
Re: Oil filter, pressure and temp issues (Orlando85UCFvette)
1) the K&N filter is a lil bigger...does it take a 1/2 quart more?
2) my oil pressure seems to be all over the place, mostly at 80psi, but it will drop as low as 30 sometimes during cruising at any speed in any gear, or at idle. I am trying to figure out a pattern, but there doesn't seem to be one that applies to all conditions. I assume this may be a failing oil pump? :confused: Is there a way to test that? How hard/expensive is that to replace?
3) my oil temp always reads LO. In the mornings its a 30 minutes drive...no way does it stay cool that long. My question is: if whatever sending unit is detached, does the display read LO or just nothing at all? And where is this sensor? (i'm consulting my shop manual now)
I look forward to all the knowledge this forum has to offer
:thumbs:
2) my oil pressure seems to be all over the place, mostly at 80psi, but it will drop as low as 30 sometimes during cruising at any speed in any gear, or at idle. I am trying to figure out a pattern, but there doesn't seem to be one that applies to all conditions. I assume this may be a failing oil pump? :confused: Is there a way to test that? How hard/expensive is that to replace?
3) my oil temp always reads LO. In the mornings its a 30 minutes drive...no way does it stay cool that long. My question is: if whatever sending unit is detached, does the display read LO or just nothing at all? And where is this sensor? (i'm consulting my shop manual now)
I look forward to all the knowledge this forum has to offer
:thumbs:
2. Could be the sending unit. Before you go tearing out the pump put a mechnical gauge on to check the pressures.
3. On my 89, the oil temp sending unit is right above the filter. The manual should have a testing procedure.
Team Owner
Joined: Sep 2001
Posts: 62,160
Likes: 1,733
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: Oil filter, pressure and temp issues (Orlando85UCFvette)
1. I didnt put an extra qt in i think, not at the last change. I just put half qt in the filter, screw it on, dump in 4.5 and see what the level is.
2. Sending unit, stuck into the back of the intake manifold. Replace this first.
3. sensor
[Modified by vader86, 5:37 PM 11/4/2003]
2. Sending unit, stuck into the back of the intake manifold. Replace this first.
3. sensor
[Modified by vader86, 5:37 PM 11/4/2003]
Thread Starter
Drifting
Joined: Jul 2003
Posts: 1,613
Likes: 0
From: Orlando FL
Re: Oil filter, pressure and temp issues (vader86)
the stick does say she's full so no worries there. I just hope all these sensors are cheap to replace. I don't mind spending my time twisting wrenches, I just hate dropping tons of cash (i know, i know, get used to it :rolleyes: )
I think I found a pattern with the pressure situation, I dunno why I didn't notice this yesterday. It's a white knuckle oil pressure drop as I brake. It'll go from 80 to 30psi. Right before I parked at work it dipped to 19psi!! That was a real pucker situation as I sat at that stop sign...but then it just dances back up to about 35psi, then once on the gas its back to 80psi. Is that normal after putting new oil in and with a filter such as the K&N I have on it? :confused:
Thanks again for all the replies :thumbs:
I think I found a pattern with the pressure situation, I dunno why I didn't notice this yesterday. It's a white knuckle oil pressure drop as I brake. It'll go from 80 to 30psi. Right before I parked at work it dipped to 19psi!! That was a real pucker situation as I sat at that stop sign...but then it just dances back up to about 35psi, then once on the gas its back to 80psi. Is that normal after putting new oil in and with a filter such as the K&N I have on it? :confused:
Thanks again for all the replies :thumbs:
Team Owner
Joined: Sep 2001
Posts: 62,160
Likes: 1,733
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: Oil filter, pressure and temp issues (Orlando85UCFvette)
No its not normal
My pressure on startup is like 60-65 psi (cold) and gets that high anytime i push the throttle when its warm. Idling pressure gets in the 40psi range usually when it warms up.
Really warm idle pressure is high 20s-low 30s, and it should still be in the 50s at cruise
80psi is pegged value, so the sending unit is probably bad. Thats what it reads when it dies on you.
My pressure on startup is like 60-65 psi (cold) and gets that high anytime i push the throttle when its warm. Idling pressure gets in the 40psi range usually when it warms up.
Really warm idle pressure is high 20s-low 30s, and it should still be in the 50s at cruise
80psi is pegged value, so the sending unit is probably bad. Thats what it reads when it dies on you.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: Oil filter, pressure and temp issues (Orlando85UCFvette)
the stick does say she's full so no worries there. I just hope all these sensors are cheap to replace. I don't mind spending my time twisting wrenches, I just hate dropping tons of cash (i know, i know, get used to it :rolleyes: )
I think I found a pattern with the pressure situation, I dunno why I didn't notice this yesterday. It's a white knuckle oil pressure drop as I brake. It'll go from 80 to 30psi. Right before I parked at work it dipped to 19psi!! That was a real pucker situation as I sat at that stop sign...but then it just dances back up to about 35psi, then once on the gas its back to 80psi. Is that normal after putting new oil in and with a filter such as the K&N I have on it? :confused:
Thanks again for all the replies :thumbs:
I think I found a pattern with the pressure situation, I dunno why I didn't notice this yesterday. It's a white knuckle oil pressure drop as I brake. It'll go from 80 to 30psi. Right before I parked at work it dipped to 19psi!! That was a real pucker situation as I sat at that stop sign...but then it just dances back up to about 35psi, then once on the gas its back to 80psi. Is that normal after putting new oil in and with a filter such as the K&N I have on it? :confused:
Thanks again for all the replies :thumbs:
Jake
Racer
Joined: Aug 2003
Posts: 296
Likes: 2
From: Commerce, MI
Re: Oil filter, pressure and temp issues (Orlando85UCFvette)
Oil pressure changing under braking shows that the oil level may be low. (Oil sloshing away from the pick-up). Butyou said level is OK so that can't be it. However rpm is going down at this point too, so pressure will drop anyway.
Looking at other Chevy v-8's in the 80's and there guages max out at 60 psi, 30 is in the middle. 19 at idle seems low, but the general rule of thumb is 10 psi per 1000 rpm, so by that guide you're OK. One last thought, toss that K&N oil filter for a proper Delco. There are 2 lenghts, the short pf25 and the long pf35. These are old numbers, can't recall the new ones off the top of my head. Use the long if it will fit. I have one on my '88 w/stock exhaust. It may not clear headers though. Change the sender as suggested. It's cheap insurance.
Good luck
:cheers:
Looking at other Chevy v-8's in the 80's and there guages max out at 60 psi, 30 is in the middle. 19 at idle seems low, but the general rule of thumb is 10 psi per 1000 rpm, so by that guide you're OK. One last thought, toss that K&N oil filter for a proper Delco. There are 2 lenghts, the short pf25 and the long pf35. These are old numbers, can't recall the new ones off the top of my head. Use the long if it will fit. I have one on my '88 w/stock exhaust. It may not clear headers though. Change the sender as suggested. It's cheap insurance.
Good luck
:cheers:
