low oil pressure

Post by **racer** » Thu Apr 15, 2004 8:37 am

After fitting piper cam&oil pumpto match cam drive to my re-con engine .I have low -10@idle(was 30/40)30when hot @high speed (was approx 60) oil pressure . I didnt prime the pump b4 fitting ,couldnt get pressure up,so primed it thro' the by pass valve hole . the eng. was running /cranking for a short while with no pressure -could this have damaged the pump? Could the pump gasket be fitted wrong ,blocking a supply/return hole @the pump? Could the pick up pipe in sump be loose ,causing lack of suction up the pipe? Other posts talk of oil pump not physically fitting in the back plt. hole -I had the same prob -had to grind the pump edge to fit . -poss. gone too far &holed the pump . Any ideas on this one?I know the inevitable is to pull the engine -AGAIN-(groans)

Post by **rayofleamington** » Thu Apr 15, 2004 9:03 am

The quality of new parts is sometimes shameful...
There is a possibility that the clearance between the gear elements and the housing is large causing a lot of leakage internally in the pump.
I bought a new pump for a rebuild in 96, but after inspecting it when I got home I decided that the old one was much better

I can't rememebr the measurements but there is an allowed tolerance for the gaps in the oil pump.

Have you removed the sump? If not, then it's unlikely to be a loose pickup pipe. Best idea is to focus on the things that you worked on first if there was a problem when it all went back together.
Some engines (eg 90's Cavalier) have a stupidly small pick up strainer that suffers from blockage. The Minor has a nice large one so it's unlikely ever to get blocked, however if the sump is off it's a good idea to remove all the crusty + slimy bits anyway.

Post by **racer** » Thu Apr 15, 2004 9:54 am

Just spoke to Bull Motif -they reckon do as you say ,go back over everything again ,also check oil pump has correct drive ,and that the bypass valve is seating ok. So its engine out this pm . Will keep you posted .

Post by **racer** » Fri Apr 16, 2004 11:55 am

Have just got my eng. back in !Now have 80psi oil press as opposed to 25 b4!! What I found was the oil pump bolts were loose! Oil gushed out of the cover when it was removed .The manual says there should be a tab washer on bolts ,but THERE WAS NONE . I stipped an old eng,and robbed the tab washer from that . The 3 pump bolts were bottoming out in their threads ,causing the pump to be tight but not tight enough ,so leaked oil . tHE old eng. I stripped oil pump was deeper than the one i had on my eng. by about 3/16"The original bolts were too long by about 1/8"I had the old prob of having to shave off part of the top 2 lugs to get the pump to fit .

Post by **rayofleamington** » Fri Apr 16, 2004 12:04 pm

It's a good job you noticed the low oil pressure then!!! It would have been sad to scrap the engine within days of having it rolling road tuned

Well done for getting it fixed so quickly! Happy motoring

Post by **Kevin** » Fri Apr 16, 2004 12:21 pm

There definatly appears to be a problem with some of the new oil pumps as regards physical dimensions, glad you sorted it so quick and looking at the speed of it you must have quick release fittings on yours

Post by **57traveller** » Fri Apr 16, 2004 2:59 pm

This highlights the advisability of fitting supplementry gauges, e.g. oil press., ammeter/voltmeter etc. Gives a better idea of what's actually happening. Without an oil pressure gauge there would have been no indication that there was a problem possibly until disaster. Low pressure warning light may not have come on until pressure actually failed. Aren't those pressure switches set at about 8 - 10 psi?

Did anyone see the BBC's Watchdog programme earlier this week with the bit about the alleged (got to be careful here!) failure of Land Rover Discovery Diesel engine oil pump drives?

Post by **racer** » Fri Apr 16, 2004 3:23 pm

Your'e absolutely right about guages ,although driving to a given oil pressure ,and ammeter reading can get tedious !! I think I look more at the guages than I do the road !!! TTFN ROD

Post by **Cam** » Fri Apr 16, 2004 3:30 pm

Did anyone see the BBC's Watchdog programme earlier this week with the bit about the alleged (got to be careful here!) failure of Land Rover Discovery Diesel engine oil pump drives?

No, but a mate at work told me about it! Quite scary!

The oil pressure lights are set to 8psi I think too.

I like lots of gauges myself, it gives you info in what's going on which is needed for a freshly rebuilt engine as you need to keep an eye on temp and oil pressure.

Post by **racer** » Fri Apr 16, 2004 3:30 pm

bULL mOTIF HAVE JUST TOLD ME THAT THE TAB WASHERS FOR THE PUMP (HORSE SHOE SHAPED WITH 3 HOLES) Arent always available ,so only spring washers are available . The bottoming out of the bolts is a very cautionary tale though ,isn't it ? Also the new gasket I used (from AVONBAR RACING) IS SORT OF RUBBER COATED ,WHEREAS THE OLD ONE IS JUST GASKET PAPER .

Post by **rayofleamington** » Fri Apr 16, 2004 3:42 pm

It might be worth writing this one to the tech tips ppl in the club mag. That way a lot fewer people will get caught out, especially as there are many people who've had problems with the shape of replacement oil pumps.

Post by **57traveller** » Fri Apr 16, 2004 5:24 pm

You're right Rod, I get a bit paranoid about the oil pressure and state of charge/discharge.
Cam has, in my opinion, fitted his gauges in an ideal position. I didn't want to make holes in the dash, only for fear of cocking it up, so fitted ammeter and oil press. to right of and just under dash in one of those two meter sub panels which is I suppose a bit more dangerous with them being more out of sight.

Thought it was 8psi Cam, so without a gauge it would be very easy, as in Rod's case to be driving around with a dangerously low pressure, soul destroying on a recon engine.
Best not go into the LandRover thing, could be a legal minefield! Briefly the oil pump is chain driven and it was reported that on some engines the bolt securing the pump sprocket has come adrift, hence no oil pressure and seized engine. Land Rover have been quoting £6000 plus for fitting a replacement engine, so some not too happy customers.

Post by **racer** » Fri Apr 16, 2004 8:35 pm

Because I want the 60's look on my a35,My guages are in Pods too, they are mounted low so you have to momentarily take your eye off the road .I'm sure one day when I look back up ,I'm gonna see a car stationary in front of me !!! TIP -you can use a large (ex camaro etc?) "racing "style door mirror ,remove the glass and fit aly plate -takes 2 guages -mount on base as per mounting to door -looks really pro. The other one of the pair I used upside down as an interior mirror mounted on the rooflining ,on my Amazon led sled .

Post by **Cam** » Fri Apr 16, 2004 9:29 pm

I didn't want to make holes in the dash, only for fear of cocking it up, so fitted ammeter and oil press. to right of and just under dash in one of those two meter sub panels which is I suppose a bit more dangerous with them being more out of sight.

The panel I made is just painted 3mm Aluminium sheet shaped to fit the dash. It's held in place with 2 tabs bent at 90 degrees away from the plate and held in place using the existing screws. I did it this way so it would be VERY easy to convert back to the original dash if so required.

On the A35 there is a very nice space behind the steering wheel to fit those meter sub-panels. 4 should fit?? It blocks the parcel shelf but you can't have everything!!

on my Amazon led sled.

Nice!

Post by **racer** » Fri Apr 16, 2004 10:13 pm

Idid that some years ago on my minor trav. I also mounted the centre four gauge pod ,cut from the middle of one of those after market 105e f/glass dashes (remember those ?!!) blended into the top of the dash over the speedo area .