loss of oil pump prime

RobM

RobM

True Classic
RE 1977 Scorpion #1792
Since I made this car roadworthy in 2015, it's had an issue where after 12 hours or so, the oil pump loses its prime. My procedure for starting the engine has always been: pull the spark plugs, crank engine till I get oil pressure (approx 10-12 seconds), then start. It's been a PITA that I've lived with until now. I just dropped the oil pan, removed the oil pump, and could see nothing obviously wrong with the pick up or pump-to-block gasket. However, I put a new gasket on, torqued it to 18 lb ft, reassembled the oil pan, and still have the same problem. The only 2 things remaining that I can attribute the loss of prime to are (1) pressure relief valve is not fully closing or (2) the oil filter mount gasket is allowing air to enter. Do you agree? I hesitated to open up the oil pump since no pump seals seem to be available. Any thoughts on how to solve this? I'm tired of doing this "pull the spark plugs" routine prior to using the car each time. Thanks in advance.
 
Cold startup should give you oil pressure almost instantly so your 10-12 second delay is clearly not correct. How about trying a replacement pump assembly?
 
Hi Rob. I dont know if a Scorpion is like an X1/9 - where the oil filter sticks out sideways - but if it is...perhaps your trouble is simply due to the oil filter you are using ! On an X1/9...likely a Scorpion is the same....there is - well should be - an anti-drainback valve built into the oil filter. Without that valve...or if that valve is defective...when the car sits overnight....the oil will drain out of filter overnight by gravity...and when you go to start the car.....the oil pump must first fill up the filter before pressure can build up in the rest of the system. Which kinda seems to be the symptoms you are experiencing ?

There are many oil filters that "fit" a Scorpion...but dont have that anti-drainback valve built into them. Or...on many crappy aftermarket filters...that valve does not work like it should...or is defective. What oil filter is on your Scorpion now ???

I would suggest you change your oil filter to a proper, quality filter like a Mann or UFI.....and see if that solves your problem. I suspect it will...

See this recent thread for more info:

Oil pressure time to ramp up

Here is a small video cold start to observe the oil pressure ramp up delay of my car after they are parked for more then three days . The oil is Shell Rotella T4 15W-40. Video Oil Pressure ramp up In my case the delay for turn off the warning red light oil pressure after the motor have start...
xwebforums.com
 
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have you hooked up a mechanical gauge to make sure the sensor isn't false reporting. I have seen them go bad and report weird stuff.
 
There is a current thread about an oil filter causing a similar problem. Have you tried changing the filter?
 
Oil filter has no or non-functional anti-drain back valve.

~What brand and filter part number currently in the Lancia?


Bernice
 
Thanks for the replies.

For years I used the Fram PH2857A purchased from TMH, but recently fit a Bosch 3402 bought from MWB. Same results. (Yes, the Scorpion has the oil filter mounted parallel to the road surface.) Once pressure is built and the cold engine is idling, I get 50 psi. That will drop off quite a bit when hot, but I still have about 35-40psi at highway speed.

I don't need to fit a mechanical gauge to test the oil pressure. Both the light and the gauge (two different senders) report the same zero pressure. But worse, if I were to start the car without first cranking to build pressure, I'd get a rod knock. I certain don't want that!

If someone knows where I can get a new or good used pump for a late 1800cc, I'd love to give it a try. (MWB has a NOS pump, but it's
for an early 1800. Does anyone know if this will fit properly on a late engine?)
 
RobM said:
Thanks for the replies.

For years I used the Fram PH2857A purchased from TMH, but recently fit a Bosch 3402 bought from MWB. Same results. (Yes, the Scorpion has the oil filter mounted parallel to the road surface.) Once pressure is built and the cold engine is idling, I get 50 psi. That will drop off quite a bit when hot, but I still have about 35-40psi at highway speed.

I don't need to fit a mechanical gauge to test the oil pressure. Both the light and the gauge (two different senders) report the same zero pressure. But worse, if I were to start the car without first cranking to build pressure, I'd get a rod knock. I certain don't want that!

If someone knows where I can get a new or good used pump for a late 1800cc, I'd love to give it a try. (MWB has a NOS pump, but it's
for an early 1800. Does anyone know if this will fit properly on a late engine?)
Click to expand...

Fram filters are Poooo.... have been for years.. since they were taken over by share holder well-being centric organization.
Just say No to Fram filters..

Bosch oil filter.. was the cause of slow oil pressure ramp up in this previous discussion,

Oil pressure time to ramp up

Here is a small video cold start to observe the oil pressure ramp up delay of my car after they are parked for more then three days . The oil is Shell Rotella T4 15W-40. Video Oil Pressure ramp up In my case the delay for turn off the warning red light oil pressure after the motor have start...
xwebforums.com

Seems there is a Rinse & Repeat here... Bosch replaced with a Mann, problem went away.

Ditch the Bosch Oil filter.


Bernice
 
Rupunzell said:
Fram filters are Poooo.... have been for years..
Just say No to Fram filters..

Bosch oil filter.. was the cause of slow oil pressure ramp up in this previous discussion,
Bosch replaced with a Mann, problem went away.

Ditch the Bosch Oil filter.


Bernice
Click to expand...

Agree 100%.......well having said that....no guarantee this will fix your problem.......but seems quite likely....note replacing the crappy Bosch 3402 solved the same problem for Yves.....

Certainly worth the $10 and the few minutes it will take you to try. No need to even change the oil if it is fresh...just change the filter......
 
I happen to have a Bosch ST3402 (recommended by someone here) on my car right now for the first time and so far it pressurizes immediately. I've only got about 1K on the motor and filter so I will keep an eye on it. After I dumped the Fram PH7 many decades ago, I usually look for a Wix or Mann. The Mann oil filter is a W 920/21. The Wix filter is 51189. They both have drain back valves and bypass valves with specified pressure.
 
dllubin said:
The Mann oil filter is a W 920/21.
Click to expand...

I think....that W920/21 is correct for an X1/9....but this thread is about a Scorpion.......

I get conflicting Mann part #s for a Scorpion...but not a W920/21 it seems. Although I think it would actually fit.

it is all quite confusing......as I think there are MANY oil filters that actually "fit" a Scorpion.....but are not quite proper for this application.

The on-line Mann catalog I found was somewhat confusing. In the North American catalog...they dont recognize Lancia at all. But...in their European catalog....they do show a Monte Carlo....but only S2 '80-'81. They do show a different part # for Beta models....Both oddly show a filter with 2 anti-drainback valves. Specs seem to show that one is slightly longer than the other.

Both are not the W920/21 X1/9 filter...which is shown with only one anti-drainback valve..and a different bypass valve pressure value.

To confuse matters even more.....the North American catalog shows a different oil filter for an X1/9 than the European catalog.....that seems odd...

To add to the confusion....some sources say Mann have recently bought out Purolater..and that some of the Mann filters sold in North America now are just re-boxed crummy Purolater filters

All kinda sad....and confusing...and a real shame... as I reckon the real German made Mann filters are super quality...likely the best out there....so is likely worth the effort to figure out the proper part #s...and a good source for them.....
 
rx1900 said:
I think....that W920/21 is correct for an X1/9....but this thread is about a Scorpion.......

I get conflicting Mann part #s for a Scorpion...but not a W920/21 it seems. Although I think it would actually fit.

it is all quite confusing......as I think there are MANY oil filters that actually "fit" a Scorpion.....but are not quite proper for this application.

The on-line Mann catalog I found was somewhat confusing. In the North American catalog...they dont recognize Lancia at all. But...in their European catalog....they do show a Monte Carlo....but only S2 '80-'81. They do show a different part # for Beta models....Both oddly show a filter with 2 anti-drainback valves. Specs seem to show that one is slightly longer than the other.

Both are not the W920/21 X1/9 filter...which is shown with only one anti-drainback valve..and a different bypass valve pressure value.

To confuse matters even more.....the North American catalog shows a different oil filter for an X1/9 than the European catalog.....that seems odd...

To add to the confusion....some sources say Mann have recently bought out Purolater..and that some of the Mann filters sold in North America now are just re-boxed crummy Purolater filters

All kinda sad....and confusing...and a real shame... as I reckon the real German made Mann filters are super quality...likely the best out there....so is likely worth the effort to figure out the proper part #s...and a good source for them.....
Click to expand...
The W920/21 shows up for all the Fiat twin cam cars listed. They only show 1981 and later. No Lancia listing.
 
Thanks again. FWIW, Darren Cooksey from the UK (Montecarlo Consortium) recommends Mahle OC383 or K&N PS-2004 filters. Maybe I'll buy one of each to try. Something has to work. I'm off to Lime Rock historic races for the weekend.
 
dllubin said:
I happen to have a Bosch ST3402 (recommended by someone here) on my car right now for the first time and so far it pressurizes immediately. I've only got about 1K on the motor and filter so I will keep an eye on it. After I dumped the Fram PH7 many decades ago, I usually look for a Wix or Mann. The Mann oil filter is a W 920/21. The Wix filter is 51189. They both have drain back valves and bypass valves with specified pressure.
Click to expand...
I use Mann and Bosch and so far have not seen a difference. I think Yve’s experience was an outlier but changing to an alternative is certainly a cheap and easy way to avoid a problem. Wix (NAPA filters are made by Wix) are also a good product which I also use on some of my vehicles.

I had Yve’s experience on my Toyota using a K&N so there are no guarantees with any of this stuff. Sigh.
 
Most people are not aware of this (as most times their sum knowledge of the engine comes from one book written by some English guy) but there are two styles of oil filter mount gasket.... to do with the position and size of the discharge hole. Using the wrong gasket allows oil to bypass the filter... not sure if it would give the symptoms you're experiencing (I've never fitted the wrong gasket to try it) but could be something to investigate.

20230901_210018.jpg


I'm assuming as you've owned the car for a while you've changed the filter at least once... did you use the same brand /style of filter each time? Drain back is a common problem on Fiats that have the filter mounted not vertical when the wrong filter is used. While a particular filter may "fit" the engine, if it is without an anti-drain valve the filter will drain out overnight.

SteveC
 
kmead said:
. I think Yve’s experience was an outlier but
Click to expand...

I dunno Karl......but see this thread where Eric had the same problem with 3 Bosch oil filters...and scroll down to where Fiatfiend had the same problem with 2 Bosch oil filters...and Yves experience....and now this - well TBD - issue from Rob.......

Oil filter experience

For years I've used Mobil-1 oil filters on the three daily-driving X1/9s. When I did the mass oil change last spring, the local autozone was out of these, so I bought and used three Bosch filters instead... and I noticed that it took way longer for the oil pressure to come up on a cold...
xwebforums.com
 
rx1900 said:
I dunno Karl......but see this thread where Eric had the same problem with 3 Bosch oil filters...and scroll down to where Fiatfiend had the same problem with 2 Bosch oil filters...and Yves experience....and now this - well TBD - issue from Rob.......

Oil filter experience

For years I've used Mobil-1 oil filters on the three daily-driving X1/9s. When I did the mass oil change last spring, the local autozone was out of these, so I bought and used three Bosch filters instead... and I noticed that it took way longer for the oil pressure to come up on a cold...
xwebforums.com
Click to expand...
Hmm perhaps it’s time to move over to Mann and Wix. Disappointing to say the least. I don’t see that on our Miata or my Hondas but it may indeed be a trend.
 
rx1900 said:
I dunno Karl......but see this thread where Eric had the same problem with 3 Bosch oil filters...and scroll down to where Fiatfiend had the same problem with 2 Bosch oil filters...and Yves experience....and now this - well TBD - issue from Rob.......

Oil filter experience

For years I've used Mobil-1 oil filters on the three daily-driving X1/9s. When I did the mass oil change last spring, the local autozone was out of these, so I bought and used three Bosch filters instead... and I noticed that it took way longer for the oil pressure to come up on a cold...
xwebforums.com
Click to expand...
Oil and oil filter threads are always spicy :)
 
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