Oil Pressure Drop

[Big D]

Has anybody ever had a sudden drop in oil pressure? I was up to about 3800 RPM and suddenly pretty close to zero pressure. Starb engine pressure gauge reading was the only thing out of the ordinary. The oil pressure alarm did not sound off. Throttled back and up she came again. Cautiously tried to duplicate the fault but could not get it to happen again!

440s have external oil pump (thank you Chrysler). Couldn't find anything wrong there. Looking for an electrical issue, but I'm pretty confident in my wiring. New oil and filter. I'm thinking some dirt blocked the opening in the oil sender for a minute or so.

Any ideas??

[foofer b]

Just call our "Community organizer in Chief" , He will fix it all up for ya.

[k9th]

Interesting problem and kind of scary too. The dirt issue sounds right since you couldn't duplicate the problem.

[turtlem1969]

could have been a little dirt, an air bubble, hic up in the pump.

[hodgkinsbrian]

There is also a relief valve on the oil pump which my have opened do to a sudden increase in pressure. This is not uncommon but usually goes un-notice it happens so quickly as a rule.
You might also check your new filter as they do come appart internally some times and this will cause a blockage in the system creating a suddent increase in pressuse if this is the cause they will usually clear themselves. Also a bad filter will quite often give you lower pressure readings at max rpm.
You can test your gauge simply by srewing another gauge into the block were the sending unit is.

[alexander38]

Are u using cram oil filters ? They come apart and cause what you seen.

[Stripermann2]

Regarding Fram filters, I'm not a big fan. But here is some reading for your pleasure just the same, of oil filter comparisons.

"This filter cartridge has a small outside diameter with a rather low filter element surface area (193 sqin), and features cardboard end caps that are bonded in place using a thermal adhesive. The rubber anti-drainback valve seals the rough metal backplate to the cardboard end cap. In practice these seem to leak, causing dirty oil to drain back into the pan. If you use this filter and have a noisy valve train at startup, the filter is likely the cause. The bypass valves are plastic and are sometimes not molded correctly, which allows them to leak when they should be closed. The backplate has smaller and fewer oil inlet holes, which may restrict flow."

http://minimopar.knizefamily.net/oilfil ... rence.html

[sehord]

Man, I have never heard that about the Fram filters.... I have some on my boat, but it looks like I will be switching those on my next oil change....

[hodgkinsbrian]

I have been reading the replies to this subject and was QUITE AMAZED TO FIND THAT SOME HAVE SERIUOSLY DUG DEEP INTO THE SUBJECT OF OIL FILTERS. (stripermann 2 in particular)
PLease don't let some of these findings over infulence which filter you use.
I am a automotive jobber retired an during my years selling filters I have sold all of these different brands. They all have their ups an downs in reguard to quality. You refered to Wix filters and Chrysler use to have all their filters built by Wix at one time, I don't know who is manufacturing Fram filters at this time but I would not be scared to use a Fram filter.
The main point is what was the cause to Big D's problem an the filter may or may not be the cause only time will give us an answer an everyone's input may assist in finding the problem.


P.S. My nickname when I was in business was " SPAREPARTS"

[sehord]

how was your oil level Big D? too low could be an issue, but if its too high it can also cause the oil to froth and create an air bubble. Air would be a much more likely candidate than debris blocking the sender....

[Stripermann2]

hodgkinsbrian, you are absolutely correct. While we didn't mean to stray from the topic, the info passed along, at least on my part, was for information purposes.

With this and tons' of other informative articles out there, one should form their own opinions and use, for each product.

[prowlersfish]

I would bet on a lose wire or connection somewhere


On the subject of filters fram will swell up if you have Hi pressure very thin housing . AC makes a very good filter with a strong housing . Mopar had a bulletin a while back saying some filters came apart inside and caused engine damage on the Cummins diesels , They only found 3 filters that would pass the test Mopar of course and AC and fleetguard ( OEM cummins brand )

I only used AC on my gas boats AC or fleetguard on my Diesels .
Next time you get a cance take a old a/c filter and a fram try and pock a hole in them you will find out how weak the fram case is .

This comes from 36 years of working on engines for a living

[Big D]

Wow guys, thanks for all the replies. Great artical Striper, thanks for that. Sehord, thanks for the input, makes sence , though the level is fine. I'm pretty meticulous about that, check it all the time. Checked the relief valve, all ok there. Surprizingly, the pump's components looked great considering the age.

I must say that I have not used Fram oil filters for years. Had two, count 'em, two new ones fail on me. Same thing; pressure dropped off but did not come back. In both cases, found some blob of what looked like rubber or a caulking material floating around in the filters. Figured it was a manufacturing thing. That was about 6 years ago, maybe they've changed but do I really want to find out the hard way that they haven't!!

I installed a separate mechanical test gauge and left the original electrical gauge as well to see if there was a difference in the readings if it happens again. Changed out the filter....we'll see what happens, but I'm thinking it was a fuzz ball or something.

Will post findings.

[sehord]

I did have a fram oil filter that I replaced last month that had a hole appear about the size of a pencil lead. My bildge was full of oil, no low pressure or alarms, but when I checked the engines in the morning, I saw the oil in the bildge, but none anywhere else. The black "hand Grip" coating that fram covered gthe back of the filter had a hole right through it.... sprayed a nice stream into the bildge when I fired them off. It just rusted through I guess but the rest of the filter looked brand new with no rust anywhere. I chaulked it up to a simple defect, but now all the anti-fram talk has me concerned.

[Big D]

So I have an update and what I'm sure/hope was the cause of the oil pressure drop. I removed the sender and tried a spare I had. Guess what? happened again. Took the new one off and a brass T fitting to which the sender and a switch are hooked up. I found buried in the T fitting a piece of twisted fabric which I suspect is a single strand from the carpet. Must have dropped into the rocker cover during an oil change, can't see any other way for it to get in there. Just goes to show you how important it is to keep your work area clean. I'm convinced this was the issue. Thanks for all the input guys.