High Oil pressure

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heinkeljb
Posts: 2754
Joined: Sun Dec 30, 2012 12:49 pm
Location: Lewes, East Sussex - UK

High Oil pressure

Post by heinkeljb »

Lurch has had oil temperature and oil pressure gauges fitted as it is nice to know what is happening inside your engine.

The other week I noticed that the oil pressure gauge was reading it's maximum.... 100psi - this does drop a bit when the engine is idling but not a lot. So out come the repair manual. High oil pressure reading can be damaging.

Oh dear, this means I need to do something before something else breaks. Now as it happens Lurch was due an oil change after going to Holland and back so I took the opportunity to read a bit more and discovered my engine has the late type III oil pump and oil bypass valve based on the "mushroom valve" rather than using a "Barrel valve" as mentioned in the repair manual.

So as high oil pressure is due to some thing (barrel valve, mushroom valve) sticking in the closed position I decided to put an oil flush into the oil before doing the oil change. The one I purchased was from Tool Station (you can look them up). Requires you to run the engine at idle for 5 minutes before changing oil and oil filter. Whilst oil was draining I took the oil pump mushroom valve out and cleaned it and then the oil bypass one which is under the oil pressure switch. Life is easier if you have a magnet on the end of an extending rod to get the mushroom valve out. Cleaned everything I could.

Put it all back together, filled the crank case with oil.

Started the engine and my oil pressure is back to what it should be.

Moral of the story is: Having the gauges helps. Without them I would have been none the wiser to the high oil pressure as the oil pressure light was off.

Maybe some one needs to design an oil pressure switch which has two settings: One to say you have "enough" oil pressure and then to go on to light up again if you have too much oil pressure - only issue I can see with that is how would you know if you had too little of too much oil pressure? Simple I say... two different lights. When you have low / no oil pressure you get the standard RED light. Then if you have high oil pressure it turns on a different light.

There has also been a thread over on another forum with LOW oil pressure at idle - this most likely is down to some dirt getting stuck in the bypass valve face as it only moves a small amount (0.4mm). This suggests that an oil flush at oil change time might be a good idea.

John
Haflinger 703AP LWB 1973 - (Once owned by Lady Sutherland & Sons.) Now called "Lurch" !

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AustHaflinger
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Location: Canberra Australia

Re: High Oil pressure

Post by AustHaflinger »

I agree - having an oil pressure gauge is all important - mine sits on around 40psi at idle and 70 when driving around. The light catches your eye if pressure was to drop.

Just as well that you caught it.

Garry
Haflinger 700AP (73)
Range Rover Sport TDV6 (07)
Landrover FC 101 (77)
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Julian B
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Location: W Sussex, UK

Re: High Oil pressure

Post by Julian B »

Hi John,

I'm away at the moment, and not really in Haflinger-thinking-mode, but will follow up on this when I get back. During the renovation last winter I laid an extra wire from the engine bay to the dashboard, so hopefully it will be a fairly easy installation.

Does anyone know a source of a small gauge that sort-of matches the design aesthetic of the Haflinger instruments?
Julian B
W Sussex, UK

| '62 Early Series I SWB | '72 Series II LWB |
| '56 Citroën Traction Avant |
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AustHaflinger
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Location: Canberra Australia

Re: High Oil pressure

Post by AustHaflinger »

John suggested I post up some pics of my oil pressure indication arrangements. I have the older style oil filter system but have three ports available for sensors.

Pic of the oil filter/senders
Image

You can see the brass four way connector in between the filter and the engine in the centre of the pic. The takeoff top the left has the plastic tube that runs to the gauge on the dash to indicate oil pressure. The top fitting is the oil pressure switch that operates the standard oil pressure light on the dash. The remaining blanked position to the right is where something else could go in like a oil temp sender. I have had the plastic tube style oil pressure sender in many vehicles for over 40 years and never had an issue - just keep the tube out of the sun (you know that yellow thing in the sky that is only visible in the UK for one day of the year) and away from hot exhausts.

The oil gauge (and voltmeter) were fitted by a previous owner. They are aircraft instruments and work well but have no night time illumination. I will replace them in due course with proper instruments. The pic shows oil pressure of 40psi after a cold start and at idle - when warm idle is about 50psi and cruise is about 70psi.

Image

Garry
Haflinger 700AP (73)
Range Rover Sport TDV6 (07)
Landrover FC 101 (77)
Landrover Series 1 SWB Station Wagon (57)
Landrover Series 1 SWB (57)
Jaguar E-type Roadster V12 (71)
Jaguar XJ12C (76)
tpond
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Joined: Sun Jun 01, 2014 12:11 am
Location: Portland, Oregon USA

Re: High Oil pressure

Post by tpond »

I love the gauges!
1964 NA Spec. Haflinger
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heinkeljb
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Joined: Sun Dec 30, 2012 12:49 pm
Location: Lewes, East Sussex - UK

Re: High Oil pressure

Post by heinkeljb »

There is a modified paper element oil filter cover which has two out lets brazed in at the top (like a pair of horns) that is sold by one of the Austrian suppliers. This obviously replaces the your existing one.

I know the mounting system is different between the earlier paper element type and the later spin on filter type, but I think it might be possible to make a "pancake" type adapter to fit the earlier filter housing. From what I can see in the parts book, the difference is that the earlier one has a long bolt that "clamps" the filter cover to the filter body, whereas the later one has a screw thread in the center.

Maybe it is possible to make a "sandwich" plate one with a longer bolt that would be able to clamp it all together tightly enough to seal without leaking?

John
Haflinger 703AP LWB 1973 - (Once owned by Lady Sutherland & Sons.) Now called "Lurch" !

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