Oil pressure bouncing !!!
Thread Starter
|
New User
Joined: Apr 2007
Posts: 4
Likes: 0
Oil pressure bouncing !!!
Have a 1997 Ford F-150 with a 4.2 engine. This truck when it got warmed up the oil gauge would jump all over going down the road and go to 0 when stopping and check engine light would come on, then when speeding back up, the check engine light go off and gauge goes back to mormal , but then it starts to bouce again. Put 2 new oil sending units on (truck stayed the same). The put a new oil pump on, which was defective! Replaced with another new oil pump and of curse new oil and filter. The truck is STILL doing the same way. No improvement at all. This truck has a 190,000 miles on it and does not use oil or coolant or leak anywhere. Any idea's. I am stumped as to what to try next.
Thread Starter
|
New User
Joined: Apr 2007
Posts: 4
Likes: 0
Originally Posted by clglpn
Have a 1997 Ford F-150 with a 4.2 engine. This truck when it got warmed up the oil gauge would jump all over going down the road and go to 0 when stopping and check engine light would come on, then when speeding back up, the check engine light go off and gauge goes back to mormal , but then it starts to bouce again. Put 2 new oil sending units on (truck stayed the same). The put a new oil pump on, which was defective! Replaced with another new oil pump and of curse new oil and filter. The truck is STILL doing the same way. No improvement at all. This truck has a 190,000 miles on it and does not use oil or coolant or leak anywhere. Any idea's. I am stumped as to what to try next.
Hotshot
Joined: Jan 2004
Posts: 19,760
Likes: 1,079
From: St Louis
Remember, your stock "oil pressure guage" is nothing more than a mechanical idiot light. If the sending switch sees 4-5 psi or more, it will cause the in-dash "guage" to read around mid-scale. It only has two possible readings: Zero and mid-scale.
You really need to add an external oil pressure guage to determine if your oil pressure is okay but your instrumentation is the problem, or if, in fact, your oil pressure is actually varying.
Since you have a CEL, you also need to have your codes scanned to see what the computer is complaining about.
Steve
You really need to add an external oil pressure guage to determine if your oil pressure is okay but your instrumentation is the problem, or if, in fact, your oil pressure is actually varying.
Since you have a CEL, you also need to have your codes scanned to see what the computer is complaining about.
Steve
Thread Starter
|
New User
Joined: Apr 2007
Posts: 4
Likes: 0
Originally Posted by clglpn
Have a 1997 Ford F-150 with a 4.2 engine. This truck when it got warmed up the oil gauge would jump all over going down the road and go to 0 when stopping and check engine light would come on, then when speeding back up, the check engine light go off and gauge goes back to mormal , but then it starts to bouce again. Put 2 new oil sending units on (truck stayed the same). The put a new oil pump on, which was defective! Replaced with another new oil pump and of curse new oil and filter. The truck is STILL doing the same way. No improvement at all. This truck has a 190,000 miles on it and does not use oil or coolant or leak anywhere. Any idea's. I am stumped as to what to try next.
Lead Driver
Joined: Sep 2006
Posts: 7,907
Likes: 143
At 190,000 miles, the rod and main bearing clearences may be getting a bit wide.
If you try some #40 oil and the running pressure increases, it's a good bet.
If so, this is one of the only reasons to run heavier oil in a worn engine to get more life out of it without rebuilding.
If you try some #40 oil and the running pressure increases, it's a good bet.
If so, this is one of the only reasons to run heavier oil in a worn engine to get more life out of it without rebuilding.
Thread Starter
|
New User
Joined: Apr 2007
Posts: 4
Likes: 0
oil gauge bouncing
We kind of thought that this engine was about to give it up. Will try the 20 wt oil and baby it till I can get a remanufactured engine in. Thanks you so much for your help
Trending Topics
Laughing Gas
Joined: Oct 2003
Posts: 967
Likes: 0
From: DC
There are other posts on here that mention oil pressure at idle being around 10 psi. I seem to recall that its pretty normal. Not sure I'd go running out to find a new engine quite yet.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Senior User
Joined: Feb 2007
Posts: 347
Likes: 0
From: Newark, Delaware
My old truck which was a 1997 F150 with the 4.2 did the same thing, i replaced everything from the gauge to the switch. Took it to a REAL mechanic not the ford dealer, and the guy told me it was the bearings on the cranshafts and i trusted him, and he was very much right. So instead of buying a new engine which would take years to repay me back in driving, i bought a new truck. But that 97 was a very very nice truck, sure miss it. Got a better one anyway!
Laughing Gas
Joined: Nov 2003
Posts: 794
Likes: 3
My 97 4.6 w/ 208k has been doing the same thing. I have put about 5k miles on it since the gage started bouncing and I have not seen any ill affects and I drive it like I stole it every day of its life.
The gage fluctuation stopped for about 1k miles but now its back. I never had a CEL only the low pressure light. I had some people on here tell me that the cable on the oil sendin unit was bad or maybe the sendin unit itself. Have you checked any of those?
I do not know anything about the oil pressure with which you reported. But if your pressure was too low wouldn't you notice a decrease of engine performance and very very quickly lose the engine?
After I realized that if I was really losing engine pressure that I would not have my engine anymore I knew I did not have a real problem and just ignore it now. If it goes it goes I got my 208k miles & counting out of it.
Good Luck w/ your truck!
The gage fluctuation stopped for about 1k miles but now its back. I never had a CEL only the low pressure light. I had some people on here tell me that the cable on the oil sendin unit was bad or maybe the sendin unit itself. Have you checked any of those?
I do not know anything about the oil pressure with which you reported. But if your pressure was too low wouldn't you notice a decrease of engine performance and very very quickly lose the engine?
After I realized that if I was really losing engine pressure that I would not have my engine anymore I knew I did not have a real problem and just ignore it now. If it goes it goes I got my 208k miles & counting out of it.
Good Luck w/ your truck!
Senior User
Joined: May 2007
Posts: 417
Likes: 0
From: winnipeg
my truck a 90 f350 bounced a bit and went to zilch, low milage but lots of ideling on it(ex city truck) drove it well and fast for a few days a couple smoke shows... till it blew up.. dropped 2 pistons broke the camshaft lost a lifter rod ....somwhere ? hah and put a big hole in the side of the oil pan... I think i did a good job on her...
so I'd get a mechanic to look into the oil pressure thing
opened her up it looked like sombody packed it full of grease......lots of sludge in there atleast a 4L pail or more could be filled....(idleing is hard on a motor)
so I'd get a mechanic to look into the oil pressure thing
opened her up it looked like sombody packed it full of grease......lots of sludge in there atleast a 4L pail or more could be filled....(idleing is hard on a motor)
Thread
Thread Starter
Forum
Replies
Last Post
killerfrogs
1987 - 1996 F150 & Larger F-Series Trucks
1
Apr 21, 2016 03:04 AM
Dcnnnghm
1999 - 2003 7.3L Power Stroke Diesel
10
Apr 4, 2016 05:35 PM
dmenkhau
Explorer, Sport Trac, Mountaineer & Aviator
5
Jan 27, 2016 04:16 PM
