95 park avenue oil pressure, what to do?
10-08-2018, 10:15 PM
#1
Junior Member
Thread Starter
Join Date: Oct 2018
Location: Los Angeles
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
95 park avenue oil pressure, what to do?
Hey guys, I recently baught a 95 park avenue (non supercharged 3800). It has 106,000 miles on it. when I first got it, after a long drive the oil pressure would be indicated at 20-30 at idle, it would shake and make light tapping noises. The pressure would shoot to around 35-38 once moving. I changed the oil (10w-30) and put in a purilator filter, I got about the same results. Then I moved to 20w-50, changed the PCV, as well as thermostat and now it idles at around 35Psi when hot, however I still hear the slight ticking/tapping once I'm stopped and I've been driving for half an hour or so. I know that I could replace the pickup screen and put in a new gear for the pump, and I've been liking the sound of the Dan mod or whatever it'* called (https://www.gmforum.com/general-gm-chat-88/oil-pressure-mod-295611/). So, what do I do? Will that mod help my case? Should I be using 20w-50? Or do these engines just like to tap a bit on idle?
For the record, I know that it'* strange for an engine of this mileage to have oil pressure issues. I baught the car for $900. There was a small engine fire in it before I baught it. I replaced a ton of vaccum lines, the fuel lines, filters and cleaned out everything. the previous owner got it from there aunt (original owner) after she passed and aprently seemed to just take it on a joy ride.
For the record, I know that it'* strange for an engine of this mileage to have oil pressure issues. I baught the car for $900. There was a small engine fire in it before I baught it. I replaced a ton of vaccum lines, the fuel lines, filters and cleaned out everything. the previous owner got it from there aunt (original owner) after she passed and aprently seemed to just take it on a joy ride.
10-09-2018, 12:57 AM
#2
Senior Member
True Car Nut
I would switch back to 10w-30 immediately. 3800'* get pretty finicky when it comes to messing with oil weights.
I am pretty sure every 3800 ticked the day it rolled off the assembly line, and tapped the day it spun a bearing at 250k miles.
After years of unknowingly running 5w-20 in mine, my lifter tick has progressed to a lifter tap at hot idle, something that was quieted down quite a bit when I switched to the proper weight synthetic oil. I bought the car with 150k miles on it, it'* now up over 205k.
In your place, I would assess the condition of the UIM and LIM gaskets immediately, as they are prone to failure, and notorious for causing the engine to ingest coolant, or dump coolant in to the crank case.
Where did the fire start? Was it an oil fire from leaky valve cover gaskets? Did it happen when one of the transmission lines exploded and dumped fluid on the exhaust manifold? Was it from a bad FPR that caused the UIM to explode?
Also, another couple of things. The 'general rule' is 10psi of oil pressure is needed for every 1k rpm of engine speed. 20-30 psi at idle is fine, and as long as it picks back once you crack the throttle, you should be good. Also, GM is notorious for inaccurate gauges, and faulty oil pressure sending units. If it really is a concern, oil pressure should be verified with an accurate mechanical gauge before attempting anything to correct it.
Having been around 3800'* for so long, my suggestion is to look at common problem areas first in this case. If it checks out, just keep running it and keep it maintained. It'* either going to get worse, or just keep ticking. If it gets worse, the typical fix is replacement engine. The mod is a quick and easy solution to increase oil flow in highly modified supercharged applications by increasing pressure.
I am pretty sure every 3800 ticked the day it rolled off the assembly line, and tapped the day it spun a bearing at 250k miles.
After years of unknowingly running 5w-20 in mine, my lifter tick has progressed to a lifter tap at hot idle, something that was quieted down quite a bit when I switched to the proper weight synthetic oil. I bought the car with 150k miles on it, it'* now up over 205k.
In your place, I would assess the condition of the UIM and LIM gaskets immediately, as they are prone to failure, and notorious for causing the engine to ingest coolant, or dump coolant in to the crank case.
Where did the fire start? Was it an oil fire from leaky valve cover gaskets? Did it happen when one of the transmission lines exploded and dumped fluid on the exhaust manifold? Was it from a bad FPR that caused the UIM to explode?
Also, another couple of things. The 'general rule' is 10psi of oil pressure is needed for every 1k rpm of engine speed. 20-30 psi at idle is fine, and as long as it picks back once you crack the throttle, you should be good. Also, GM is notorious for inaccurate gauges, and faulty oil pressure sending units. If it really is a concern, oil pressure should be verified with an accurate mechanical gauge before attempting anything to correct it.
Having been around 3800'* for so long, my suggestion is to look at common problem areas first in this case. If it checks out, just keep running it and keep it maintained. It'* either going to get worse, or just keep ticking. If it gets worse, the typical fix is replacement engine. The mod is a quick and easy solution to increase oil flow in highly modified supercharged applications by increasing pressure.
10-09-2018, 07:37 AM
#3
Junior Member
Thread Starter
Join Date: Oct 2018
Location: Los Angeles
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
Yea, that'* a relief. My engine could sound like a rock tumbler for all I care, so long as it'* reliable and I'm not damaging it through negligence. So back to 10w-30 then. What weight synthetic do you use? The engine fire was caused by the fuel line running on the back of the UIM. I was just going to replace the upper, but I might as well do the lower, clean injectors and put on a new regulator then. So that mod really isn't for naturally asparted cars?. Will it hurt me?maybe I'm just paranoid. Anywho, I'll order the lower and upper gaskets. And I'll get me a manual pressure gauge.
10-09-2018, 08:07 AM
#4
Retired
Certified Car Nut
Your OP looks fine. Though, the GM OP do fail and start pushing oil out. I suggest replacing it with a new one.
__________________
Retired Administrator
2002 *-10 5.7 V8
2023 Jeep Rubicon Diesel
Retired Administrator
2002 *-10 5.7 V8
2023 Jeep Rubicon Diesel
10-09-2018, 06:24 PM
#5
Senior Member
True Car Nut
I've been lucky to have no ticks on my 3800 at 227,000 miles and counting. If it'* just a lifter ticking then it has good odds of ticking forever and not being an issue.
I have done an oil pressure sender though. You may as well on yours, once they start leaking, they leak a lot. Then you'll have a real oiling problem.
And yes go back to 10W30 and full synthetic if you can. I use it and it still starts relatively easily down to 20 below, and has never had an issue all the way up to 115 above.
I have done an oil pressure sender though. You may as well on yours, once they start leaking, they leak a lot. Then you'll have a real oiling problem.
And yes go back to 10W30 and full synthetic if you can. I use it and it still starts relatively easily down to 20 below, and has never had an issue all the way up to 115 above.
10-09-2018, 10:24 PM
#6
Junior Member
Thread Starter
Join Date: Oct 2018
Location: Los Angeles
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
Well then that'* that! Lol Looks like I'm probably being paranoid about a very reliable car with relatively low miles. I've ordered a oil sender, and Ill put in full synthetic 10w-30. Until then, I'll just drive my ol fathfull. Thanks guys!
10-14-2018, 10:46 AM
#10
Junior Member
Thread Starter
Join Date: Oct 2018
Location: Los Angeles
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
So, it turns out that my sender was blowing oil everywhere, and half melted and broken off at the connection, it was only in hand tight as well. The new delco sender fixed that. I put in some Mobil one 5w 30 and she runs at 35 psi hot idle. I think I just totally had the wrong idea with the 20w 50. She still shakes a bit, so I'm gonna just do the upper and lower intake as you guys suggested. Thanks everyone!!!
