PontiacBonnevilleClub.com

willwren wrote:They're wrong. You need the CP9115 cable for your car.

Videos mean nothing to us without knowing your REAL oil pressure. Is your sender good or not? Your topic in General Chat should be heeded along with this one:

viewtopic.php?f=8&t=13426

Please verify your oil pressure in one of two ways:

A known good NEW sender
OR
a mechanical gauge.

thanks for the advice on the code reader cable.. good thing i have not paid for it yet..

and since my money is tight like hlaf of america then should buy a new oil pressure sender since its about $12 cheaper then a mechanical pressure gauge in my local auto part stores..?



and thanks for jumpin in bill.;. i got tons of pm's telling me your the man to speak to about low oil pressure..

Assuming (just assuming) the pressure sender is good, my oil pressure acted like yours. It coincided with the appearance of metal flakes in my oil. I had a lifter roller grinding away, and it probably opened up the bearing clearances throughout the engine. I put in a new pump set when I swapped the engine and reused my original front cover.

I can think of one failed pump, and it went in spectacular fashion. And I've seen a couple pics of a gouged oil pump bore.

(read the NOTICE about PM'ing for help, your questions need to be posted for the good of anyone who would read it instead of in private)


We can't see into your engine internals. Our sensory perception cannot determine if your sender is good or not. Please find out if your oil pressure is actually low or not.

We can't help you until we know that.

willwren wrote:(read the NOTICE about PM'ing for help, your questions need to be posted for the good of anyone who would read it instead of in private)


We can't see into your engine internals. Our sensory perception cannot determine if your sender is good or not. Please find out if your oil pressure is actually low or not.

We can't help you until we know that.

sorry for the pm.. its just what i was told to do by a few people.. but i appoligize..


and like i asked.. should i buy a new pressure sending switch or should i buy a oil pressure gauge which is about $12 more ..?

im just trying to fix this low oil pressure but its kind of hard when 30 dirrefent people are telling you to do different things and to replace this or try that first.. i was just at a loss on what exactly to do..

cant afford to listen to everybody and replace everything and buy some pressure gauges and other stuff like sea foam and what not..

sorry for all the confusion.. just did'nt know who to listen to ......

Its hard to say what the problem is..

But lets say the gage is ok.. It does move, but that doesn't mean its reading correct...

Cheap method is to replace the sender... If there is no change at all you either have a very tired motor, or the Gage is messed up..

The right way is to use a mechanical gage to check the true oil pressure...

But if you want Oil pressure sender( New )... Start there... May or may not be the issue tho

Jrs3800 wrote:Its hard to say what the problem is..

But lets say the gage is ok.. It does move, but that doesn't mean its reading correct...

Cheap method is to replace the sender... If there is no change at all you either have a very tired motor, or the Gage is messed up..

The right way is to use a mechanical gage to check the true oil pressure...

But if you want Oil pressure sender( New )... Start there... May or may not be the issue tho

just a thought.. if all 6 of the spark plugs were loose enough that i could take them out with my hand plus they were all gapped at 0.50 instead of the correct 0.60 gap size could this have anything to do with the engine oil pressure..?

and i will check see is pepboys or napa can get me the correct cable fvor my code scanner to see why my service engone light os on..


( also have a used cluster from a 94 from harry's by my house.. so i will try that tomorrow and try to borrow a mechanical gauge from my wifes boss.

do you need a oil pressure gauge?

i'll ship you mine for use

Spark plugs being loose or gapped improperly will have zero effect on your oil pressure.

When the oil pump failed in my '93, everyone was flat out amazed at what had happened and that mine was the only one anyone had ever seen go like that.


That is how mine turned out, but like I said, most people that replied had never even seen a 3800 oil pump go bad, yet alone fail like mine did.


I may be wrong here, it would not be the first time, but I am betting my money on a tired engine with worn out bearings. Just because you hear no engine noise means nothing. Every bearing in that engine could have excessive clearance and cause low pressure yet make no noise. With an engine like this, driving like a grandma is about the only option.

Get the mechanical oil pressure gauge, you need to remove all doubt about oil pressure, and as was said this will do just that, so that you don't replace the sender only to find out the gauge/wiring is the issue. Proceed no further until you know this vehicle is worth your time and money.

And remember, if you are not satisfied with a product *cough* gauge *cough* from a retail chain, you can always take it back

Sensors cannot be returned after install at most auto parts stores.

Don't get the sensor from Advance. I'm running a nearly-new sensor in my '97 and it's failed horribly already. Don got it brand new and even then it was flaky.

Get an AC Delco unit as those seem to be the most accurate.

well i just swapped out the cluster and confirmed that the gauge was ( NOT ) the problem..

oil pressure is still about 30psi when started and about 5 minutes later goes all the way down still to red zone..


will be getting an oil pressure gauge from my wifes boss today but he said its a cheapo from harbor freight that he never used so he cant tell me anything about.. but one of my other buddies might take the hour drive after work today to bring me his decent oil pressure gauge..

so we will see what happens..


o.k so with the oil pressure gauge hooked up in place of the sender then if my oil pressure is reding low still then what would that mean.. ?
and if its reading good then this means my oil pressure sender is faulty correct..?


( off topic-- my 95 bonnie's oil pressure as long as i had it has always been at the number 40 when i start the car and stays there for about 20 minutes then it goes all the way down to about a hair or 2 before the warning zone.. but goes up to 40 and higher when i step on the gas.. is this normal.. only 130k on the clock..


and what numbers should i be looking for on the oil pressure gauge.. rember its 190k about so its up there..

88bonnsse wrote:o.k so with the oil pressure gauge hooked up in place of the sender then if my oil pressure is reding low still then what would that mean.. ?

That you have a problem with the oil pressure within the motor. Start with the pressure relief valve (inside the oil filter adapter) on timing cover. If it screwed up, the motor is dumping oil back into the pan instead of pushing the oil up into the block.

88bonnsse wrote:and if its reading good then this means my oil pressure sender is faulty correct..?

Correct. The sensor is either faulty or the wiring has a problem (but this is actually the best news...the motor is OK.

88bonnsse wrote:and what numbers should i be looking for on the oil pressure gauge.. rember its 190k about so its up there..

I would be inclined to live with anything over 20psi at idle. Most of the motors I've seen can live with that. Bring the motor up around 2000rpm and you'll be closer to 40psi.

so can i buy this new as a kit or are they seperate peices... (pressure relief valve (inside the oil filter adapter)

and also if my sender is not faulty and the mechanical gauge is still reading low then my last hope would be
the pressure relief valve..? after that its just engine toast..?

im crossing my fingers.....

will have the mechanical gauge about 7pm tonight.. will post back up with some readings..

so for some advice on how to use it correctly..

i just remove the sender and put the mechanical gauge in its place.. then start the motor and check the pressure right away or wait for the car to warm up.. ? or start the car and rev the rpm to about 2000..?

just want to do this right.. also i will try to record this as im doing it for your thoughts.. thanks agian everyone..

88bonnsse wrote:i just remove the sender and put the mechanical gauge in its place.. then start the motor and check the pressure right away or wait for the car to warm up.. ? or start the car and rev the rpm to about 2000..?

Screw the mechanical gauge in, start the engine up, and watch it as it warms up. Oil will thin out as it gets hot, so it is normal to see a higher oil pressure in a cold engine. Once the engine warms up, the oil pressure will level off at idle. Then bring the engine speed up a little at a time and the oil pressure will follow up to the point where the bypass valve opens and starts dumping the excess oil into the pan.

On my '90 with 100K on the clock, the oil pressure on the cold engine runs 50psi...once the engine warms up it still runs 50psi...come to think of it, it nearly always runs 50psi, except on a really hot, humid day I might see 45psi at idle.... probably since the relief valve on mine opens near 50 psi and the pump's output is always higher than the valve's preset pressure. Mine's not a good example of anything other than how good the pump design on the 3800 is.

Following the rest of your question... if you really are seeing low pressure at the sender port, then the valve is the most likely cause and it can be replaced. Clean it first and see if the spring is kinked, busted, rusted, etc. You can buy a stock replacement one or get one from Intense that opens at a higher pressure. Reinstall the valve and the oil filter adapter and re-test to see if the pressure is normal with a new valve in place.

If that doesn't correct the problem, it's time to dig a little deeper into the motor by dropping the oil pan and checking the pickup tube and screen (like I detailed in the other post.)

well i have hooked up the mechanical gauge and it was a snap on so it was a good one..
the video is uploading now.. bare with me for like 20 minutes.. its a 5 minute video i am uploading thru photobucket..

will be back.


o.k well i had a 5 minute video but photobucket would not lwt me upload it as it was 375mb and the limit is 300 per video..
so i will upload on you tube if these videos dont help..

here are 2 quick 1 minute videos.. i think the part where the engine is reved to 2000 rpms is in the 5 minute video..
i will upload later..

check these out.. now im really worried............

88bonnsse wrote:

well i have hooked up the mechanical gauge and it was a snap on so it was a good one..
the video is uploading now.. bare with me for like 20 minutes.. its a 5 minute video i am uploading thru photobucket..

will be back.


o.k well i had a 5 minute video but photobucket would not lwt me upload it as it was 375mb and the limit is 300 per video..
so i will upload on you tube if these videos dont help..

here are 2 quick 1 minute videos.. i think the part where the engine is reved to 2000 rpms is in the 5 minute video..
i will upload later..

check these out.. now im really worried............

o.k i also just checked the pressure relief valve and the spring is in good almost perfect condition..


will be dropping the pan now to see of the screen and pick up tube is good...


and advice on how to do this..?

Drain the oil, remove the bolts and the pan drops. Caution, there will still be a little oil in the pan. You can't miss the tube. One bolt removes it and check for any holes or blockage.

88bonnsse wrote:check these out.. now im really worried............

Yeah, that's not good. 10psi on start up, dropping to 5 after it warming up. Way too low.

Next stop, now that you have checked out the filter adapter and relief valve is to drop the pan. No special tricks to it. Drain the oil, remove the oil level sender off the side of the pan, and remove all the bolts around the perimeter of the pan. Wiggle it a little and it will drop right off the motor. While I think they are all the same size, it wouldn't hurt to take a piece of cardboard, draw a rough outline of the pan, and punch holes in it with a screwdriver where each of the bolts go...that way you can stick the bolts through the cardboard and keep them organized so they can go back in the same place during reassmbly.

Once you have the pan off, take a look at the tube hanging off the block and see what is down in the bottom of the pan. The pickup tube should be cleaned and checked over to make sure there are no cracks in the pipe, and it's not packed full of crud.

Here's a picture of the underside of the motor with the pan off (note, the motor is upside-down on an engine stand in the photo...you'll be upside-down looking up.)

o.k so i will be going to do this within the next 15 minutes...

if the screen is clean and the tube is clear with no holes then its settled down to my motor being toast correct...?

im can hear the yelling and screaming now.. i can even feel the smacks....