Low Oil Pressure

[simonk]

Changed the oil in my Lister LPWS4 last week using the recommended API CC 10W40 and a manufacturers oil filter (though curiously, there was a smaller filter on there before). Just come back from cruising over the weekend and found that after a couple of hours use the low oil pressure light comes on when in tickover gear (and sometimes in idle too). The light goes out when revving a bit more. There is also a slight overheating problem (90-95 degrees?) which is "cured" by revving in neutral and/or by turning off the calorifier circuit.

 

If the oil pressure is low at low revs does that also mean it is too low at higher revs, even though the warning light goes out? The pressure gauge needle also waves around sometimes. Bearing in mind the engine has apparently done about 7500 hours (is this a lot or not?) how seriously should I take this warning and what's the best course of action?

 

a. Ignore completely and keep using it, hoping nothing untoward happens?

b. Rev it a bit more and be careful not to use in tickover too much?

c. Use 20W50 oil and and then hope it works? I think it has been used in this engine before so am I making a mistake going to 10w40 or 15w40 (just going by the manual...)? If this works, is there any disadvantage to using a higher viscosity oil like this?

d. Get it serviced? What could be the reasons why this is happening?

 

The only other thing I have noticed is that it starts easier than it used to. Is a 10W40 oil the same as a 15W40 oil at normal working temperature?

 

Thanks,

 

Simon (who is mechanically-minded but knows jack about engines/oil and even less before he got a boat).

[Tony Brooks]

Changed the oil in my Lister LPWS4 last week using the recommended API CC 10W40 and a manufacturers oil filter (though curiously, there was a smaller filter on there before). Just come back from cruising over the weekend and found that after a couple of hours use the low oil pressure light comes on when in tickover gear (and sometimes in idle too). The light goes out when revving a bit more. There is also a slight overheating problem (90-95 degrees?) which is "cured" by revving in neutral and/or by turning off the calorifier circuit.

 

If the oil pressure is low at low revs does that also mean it is too low at higher revs, even though the warning light goes out? The pressure gauge needle also waves around sometimes. Bearing in mind the engine has apparently done about 7500 hours (is this a lot or not?) how seriously should I take this warning and what's the best course of action?

 

a. Ignore completely and keep using it, hoping nothing untoward happens?

b. Rev it a bit more and be careful not to use in tickover too much?

c. Use 20W50 oil and and then hope it works? I think it has been used in this engine before so am I making a mistake going to 10w40 or 15w40 (just going by the manual...)? If this works, is there any disadvantage to using a higher viscosity oil like this?

d. Get it serviced? What could be the reasons why this is happening?

 

The only other thing I have noticed is that it starts easier than it used to. Is a 10W40 oil the same as a 15W40 oil at normal working temperature?

 

 

Thanks,

 

Simon (who is mechanically-minded but knows jack about engines/oil and even less before he got a boat).

 

 

Last question - basically yes but it all depends upon if your oil temperature reaches that at which the test for the 40 part was carried out, otherwise it could be a little less viscose.

 

Because both the temperature and oil pressure gauges seem to be acting up a bit I would suggest you double check the negatives (earths) on the engine block and back of the instrument cluster. Then change the oil pressure sender unless you have access to an oil pressure test kit. I think more oil pressure problems are caused by transmitters than anything else.

Edited April 14, 2009 by Tony Brooks

[simonk]

Last question - basically yes but it all depends upon if your oil temperature reaches that at which the test for the 40 part was carried out, otherwise it could be a little less viscose.

 

Because both the temperature and oil pressure gauges seem to be acting up a bit I would suggest you double check the negatives (earths) on the engine block and back of the instrument cluster. Then change the oil pressure sender unless you have access to an oil pressure test kit. I think more oil pressure problems are caused by transmitters than anything else.

 

Thanks, Tony. I will check the panel - I don't know how accurate the instruments are, but they can't be that good as I have noticed the reading changes slightly depeding on whether the panel lights are on or off! How much are these oil pressure senders generally? I fear that the low pressure may be genuine, however. Would my engine be considered 'good', 'old' or 'very old' at those hours? If you use 20w50 when perhaps you don't really need to, will that exacerbate further wear or cause other problems?

[Tony Brooks]

Thanks, Tony. I will check the panel - I don't know how accurate the instruments are, but they can't be that good as I have noticed the reading changes slightly depeding on whether the panel lights are on or off! How much are these oil pressure senders generally? I fear that the low pressure may be genuine, however. Would my engine be considered 'good', 'old' or 'very old' at those hours? If you use 20w50 when perhaps you don't really need to, will that exacerbate further wear or cause other problems?

 

 

Price - depends where you source it from and if its American or European standard resistance. In 2007 ASAP Supplies were listing them @ about £25.

 

Those lights are shouting bad earth or voltdrop on the positive for the whole panel.

 

Engine in a boat - barely run in yet. However I know some Lister have suffered worn oil pumps so it might be a good idea to hire or borrow an oil pressure test kit. You unscrew the sender, screw in a push fit adaptor to suit the thread and the clip a mechanical gauge onto it. Thus you get an accurate reading. If your Lister is the one with hydraulic valve lifters oil pressure on cranking is vital for easy cold starting so a worn pump could lead to other problems (Note - only if you have those hydraulic valve lifters).

 

I would be reluctant to put 20w50 into a boat with hydraulic lifters but if yours uses mechanical ones then apart from more sluggish cold starting I expect it would cover up some wear without too many problems.

 

This could be a stuck open oil pressure relief valve which may be internal or external. If its external it would be worthwhile unscrewing it (watch out for a spring, ball or plunger and possibly some "washers") and making sure the ball/plunger is free to seat. NEVER add more "washers" or try to stretch the spring.

[simonk]

Price - depends where you source it from and if its American or European standard resistance. In 2007 ASAP Supplies were listing them @ about £25.

 

Those lights are shouting bad earth or voltdrop on the positive for the whole panel.

 

Engine in a boat - barely run in yet. However I know some Lister have suffered worn oil pumps so it might be a good idea to hire or borrow an oil pressure test kit. You unscrew the sender, screw in a push fit adaptor to suit the thread and the clip a mechanical gauge onto it. Thus you get an accurate reading. If your Lister is the one with hydraulic valve lifters oil pressure on cranking is vital for easy cold starting so a worn pump could lead to other problems (Note - only if you have those hydraulic valve lifters).

 

I would be reluctant to put 20w50 into a boat with hydraulic lifters but if yours uses mechanical ones then apart from more sluggish cold starting I expect it would cover up some wear without too many problems.

 

This could be a stuck open oil pressure relief valve which may be internal or external. If its external it would be worthwhile unscrewing it (watch out for a spring, ball or plunger and possibly some "washers") and making sure the ball/plunger is free to seat. NEVER add more "washers" or try to stretch the spring.

 

Great, many thanks for your detailed advice! I have to confess to not unstanding all of what you describe but I will sit down with the workshop manual and parts lists later to see if I can work out where the various bits are. The oil pressure is 2-3 bar when the engine is first running (before it gets really hot) so I'm guessing it may not be the oil pump, but as you say it could be.

[Yoda]

Changing from 20w to 10w will reduce your oil pressure. You need to find out what the normal oil pressure should be when hot. Below this pressure and the mains and big ends will wear.

 

Secondly, did you change from a mineral oil to a chemical oil? The scavenge facility of chemical oils will cause a blocked filter in no time.

 

Thirdly, You need to check the oil pressure relief valve piston for wear. If the piston is leaking oil, the oil system will run at a lower pressure, ie it spills to reduce pressure.

 

Fourthly, Is the oil getting too hot to operate the engine and why? Have you surrounded the engine with rubbish so to not allow cool air to circulate? perhaps the engine operates above the new oils temperature band and is therefore overly thin.

 

My advice is to check and clean and change the filter again for a new one. Perhaps the filter is faulty. If the problem is still occurring and you know it isn't a gauge fault, then change the oil to a 20/50 or similar.

 

In the mean time do not load the engine heavly.

[simonk]

Changing from 20w to 10w will reduce your oil pressure. You need to find out what the normal oil pressure should be when hot. Below this pressure and the mains and big ends will wear.

 

The manual reckons 1.0 bar at idle and 2.5 bar at 3000 rpm IIRC

 

Secondly, did you change from a mineral oil to a chemical oil? The scavenge facility of chemical oils will cause a blocked filter in no time.

 

Er, not sure, I'm using what the manual says now, but before there was some 15w40 stuff from Asda in it. Also changed the filter. Running about 20 hours since the change now (wouldn't a blocked filter cause an increase in pressure? Or have I got this wrong, is the pressure measured after the filter? Thinking about it, that would make more sense)

 

Thirdly, You need to check the oil pressure relief valve piston for wear. If the piston is leaking oil, the oil system will run at a lower pressure, ie it spills to reduce pressure.

 

Will do this, if I can find it!

 

Fourthly, Is the oil getting too hot to operate the engine and why? Have you surrounded the engine with rubbish so to not allow cool air to circulate? perhaps the engine operates above the new oils temperature band and is therefore overly thin.

 

The engine is closed circuit water-cooled, with a good amount of free space around it (under deck boards) though I will check the water pump, as it does get (more than) a bit hot if the revs are too low.

 

My advice is to check and clean and change the filter again for a new one. Perhaps the filter is faulty. If the problem is still occurring and you know it isn't a gauge fault, then change the oil to a 20/50 or similar.

 

I am slightly confused as to why there was a different (smaller body) filter to the recommended one on there before. I have some spares so may give it a try, but don't want to waste what may turn out to be a perfectly good one.

 

In the mean time do not load the engine heavily.

 

Fortunately, it's downstream back to our mooring on the river so I'm in with at least a chance of that!

 

Thanks,

 

Simon.

[scrumpylurcher]

Whilst all the advice given is sound, your main problem is that you dont know the actual pressure, you are looking at a light that goes on and off. Oil light senders are notorius for having very low pressure settings, often less than 10 psi, if the light comes on at tickover particularly on an engine that is overheating it could mean a worn engine and or pump, what is more relevant is how quickly that pressure rises as the revs increase. If at 1000rpm there is approaching the recommended pressure and at 3000 somewhere near the 2.5 bar I would not worry too much, If my memory serves me right I bar represents approx 14.5 lbs.

You need to solve the overheating problem, and either temporarily fit a pressure guage, or for what cost is involved make the gauge a permanent addition. It is far to soon to consider major dismantling, try the cheap and easy first.

[Tony Brooks]

Thanks,

 

Simon.

 

 

1. A faulty or blocked oil filter is extremely unlikely to cause reduced oil pressure. All modern filters have a bypass valve in them so if they do block the valve opens and passes unfiltered oil around the system. If this valve was stuck shut the filter case would probably blow up like a balloon and split.

 

2. Do not get too concerned over the smaller oil filter, it probably was cross-referenced from a different manufacturer or for a different application of the Lister engine. Even if the old one was too small it would just have clogged sooner and the valve above would have opened.

 

3. Oil & water temperature are two totally different things (as is cylinder temperature) the oil is mainly cooled by radiation through the sump into the surrounding air and a boat does not have loads of cool air rushing under the engine like a car or truck. However the light loading typical of inland boats means that there is less heat to get rid of in the first place, but it is still worth checking.

 

4. It is extremely unlikely you would have got synthetic oil - it cost about £30 for 5 litres. Even if you did and it blocked the filter - see point 1. However a high detergency oil could have freed something that has stuck under the oil pressure relief valve.

 

The only sure way is to check the oil pressure with a mechanical gauge and then decide what to do next based upon those readings (hot, cold, idle and revving. However still check for an electrical fault first.

[onthecut]

Changed the oil in my Lister LPWS4 last week using the recommended API CC 10W40 and a manufacturers oil filter (though curiously, there was a smaller filter on there before). Just come back from cruising over the weekend and found that after a couple of hours use the low oil pressure light comes on when in tickover gear (and sometimes in idle too). The light goes out when revving a bit more. There is also a slight overheating problem (90-95 degrees?) which is "cured" by revving in neutral and/or by turning off the calorifier circuit.

 

If the oil pressure is low at low revs does that also mean it is too low at higher revs, even though the warning light goes out? The pressure gauge needle also waves around sometimes. Bearing in mind the engine has apparently done about 7500 hours (is this a lot or not?) how seriously should I take this warning and what's the best course of action?

 

a. Ignore completely and keep using it, hoping nothing untoward happens?

b. Rev it a bit more and be careful not to use in tickover too much?

c. Use 20W50 oil and and then hope it works? I think it has been used in this engine before so am I making a mistake going to 10w40 or 15w40 (just going by the manual...)? If this works, is there any disadvantage to using a higher viscosity oil like this?

d. Get it serviced? What could be the reasons why this is happening?

 

The only other thing I have noticed is that it starts easier than it used to. Is a 10W40 oil the same as a 15W40 oil at normal working temperature?

 

Thanks,

 

Simon (who is mechanically-minded but knows jack about engines/oil and even less before he got a boat).

 

Hi Simon

 

Must go along with the previous comment that you should properly check the pressure with an accurate gauge. The good book says you should be looking at 1 bar minimum, hot, at tickover and 2.0 bar at 3000 rpm.

 

May I suggest also you turn the sequence around ---- have you an overheating problem cropping up which is causing the oil to become hotter and thinner more quickly ? Either way, don't ignore the situation --- these aren't the relatively bomb proof Listers of old and won't tolerate serious issues in the lube and cooling departments. Bits aren't cheap either and the longer you leave it, the more you are likely to have to buy !

 

There are no fewer than seven different oil filters listed by Lister for the LP series, depending on build. If you are keen to know which you should have, let me have the full engine number and I'll check for you.

 

Mike.

[bottle]

From post one:

 

Quote: There is also a slight overheating problem (90-95 degrees?) which is "cured" by revving in neutral and/or by turning off the calorifier circuit. :Unquote

 

This needs sorting. and may or may not be connected with oil problems.

[martyn 1]

I would agree with the other posts about accuratly measuring that the oil pressure is within limits, but would heavily warn after much experience rebuilding LPW's and LPWS's that the earlier (pre 1994 ish )4 cylinder versions are fairly good at running out the bearings futhest away from the oil pump if the pressure gets low. so until your problems are rectified I would avoid using it to much. otherwise if there is actually a oil pressure problem you will be looking at an expensive rebuild. Out of interest has the problem only appeared since you change the oil and filter or was it doing it before.

 

On another note the comment about 7500 hours being just run in, this is true but only if very well maintained, e.g. oil and filter changes with good oil every year irrespect of hours. But noting the lister spec the LPWS engine are due major overhaul at 6000 hours. I have seen many a NB LPW or LPWS 4 that is well worn by these hours due to spending there life on light load.

 

If you need any help with your LPWS drop me a PM.

 

Martyn

 

 

Changed the oil in my Lister LPWS4 last week using the recommended API CC 10W40 and a manufacturers oil filter (though curiously, there was a smaller filter on there before). Just come back from cruising over the weekend and found that after a couple of hours use the low oil pressure light comes on when in tickover gear (and sometimes in idle too). The light goes out when revving a bit more. There is also a slight overheating problem (90-95 degrees?) which is "cured" by revving in neutral and/or by turning off the calorifier circuit.

 

If the oil pressure is low at low revs does that also mean it is too low at higher revs, even though the warning light goes out? The pressure gauge needle also waves around sometimes. Bearing in mind the engine has apparently done about 7500 hours (is this a lot or not?) how seriously should I take this warning and what's the best course of action?

 

a. Ignore completely and keep using it, hoping nothing untoward happens?

b. Rev it a bit more and be careful not to use in tickover too much?

c. Use 20W50 oil and and then hope it works? I think it has been used in this engine before so am I making a mistake going to 10w40 or 15w40 (just going by the manual...)? If this works, is there any disadvantage to using a higher viscosity oil like this?

d. Get it serviced? What could be the reasons why this is happening?

 

The only other thing I have noticed is that it starts easier than it used to. Is a 10W40 oil the same as a 15W40 oil at normal working temperature?

 

Thanks,

 

Simon (who is mechanically-minded but knows jack about engines/oil and even less before he got a boat).

[churchward]

Changing from 20w to 10w will reduce your oil pressure. You need to find out what the normal oil pressure should be when hot. Below this pressure and the mains and big ends will wear.

 

The 20W to 10W will only make a difference to oil pressure when the oil is cool/cold as this is how the multigrade is behaving at low temperatures the other value is how it behaves at high or rather normal engine temperature.

[Hooligan50]

Hi,

 

sounds to me like fuel in the sump.

 

H50

[Tony Brooks]

Hi,

 

sounds to me like fuel in the sump.

 

H50

 

 

It could be save for two points.

 

1. It has external fuel pipes and components unlike the earlier air cooled engines.

 

2. This is directly related to an oil change and internal fuel leaks normally take a short while to show up in low oil pressure, also I have not noticed any reference to the oil level having gone up.

[simonk]

Hi there again, thanks for all your replies. I haven't had the time to really look at it the past few nights, but something odd happened yesterday, the engine just stopped whilst running out of gear (it had been running in low idle for a while, but the oil pressure wasn't giving a warning (that only seems to happen in gear mostly). Seems OK after I checked the oil and restarted it but this can't be accepted as normal?!? (and I couldn't be bothered taking off the fuel filter to check that).

 

I don't think the oil level has gone up, how else can you tell apart from this symptom?

 

I believe, as has been suggested, that the problem is exacerbated by overheating (I should mention that I also changed a frayed coolant pipe at the same time as the oil change - still can't work out exactly what's happening with the cooling system... may post more questions about that soon!)

 

While it's still working, I may have to risk travelling one day this weekend back to my permanent mooring - THEN I can start playing around with things a bit more.

 

Given the serious possibility of going too deep to a point where I can do no more without proper knowledge and equipment, does anyone know a good engineer in the Bristol area?

[bottle]

Simon

 

Since you have now mentioned changing a coolant pipe, I suspect that you have an air lock in your system.

 

You did mention before that if you turned off the calorifier circuit, cooling improved.

 

Have you bled the water cooling system.

[onthecut]

Hi Simon.

 

Your engine will quite likely have a temperature safety switch, which cuts the fuel in the event of overheating --- if you are suffering cooling issues, this may account for your involuntary stop.

 

Mike.

[simonk]

Simon

 

Since you have now mentioned changing a coolant pipe, I suspect that you have an air lock in your system.

 

You did mention before that if you turned off the calorifier circuit, cooling improved.

 

Have you bled the water cooling system.

 

Yes I tried to, after I noticed some overheating, and it seemed to work - the engine appeared to run cooler. But now it's gone back to overheating easily. Can air get back in and how can I tell? The cooling system it the bit I find the most confusing at the moment. There seems to be some kind of expansion tank above the level of the engine, and this has a cap without any kind of pressure relief valve. Going into the top of this tank is an 'overflow' pipe coming from a tee off the main pipe to the skin tanks, just after the exhaust water cooling housing. Revving the engine causes water to spurt out of this 'overflow' pipe back into the expansion tank. I think there is something not quite right here - This must mean that some of the water is not circulating around the skin tanks but taking a 'shortcut', no? (I may try and post some pictures). But water *is* circulating because both the domestic water and skin tanks get hot.

 

Initially I thought it may be because I replaced the 65cm of flexible pipe with one of a *slightly* smaller bore but I wouldn't expect things to work that marginally.

[simonk]

Hi Simon.

 

Your engine will quite likely have a temperature safety switch, which cuts the fuel in the event of overheating --- if you are suffering cooling issues, this may account for your involuntary stop.

 

Mike.

 

Really? I didn't expect canal boats to incorporate anything that 'automatic'!

[onthecut]

Really? I didn't expect canal boats to incorporate anything that 'automatic'!

 

Listed as standard fit for a pukka marine LPW, although not certain if that is for all years.

 

Mike.

[Ebb Hecht]

Still some valuable knowledge to obtain, here 14 years later.
Thanks for all the effort
o|-)
 

[Steve56]

On 14/04/2009 at 17:07, simonk said:

Changed the oil in my Lister LPWS4 last week using the recommended API CC 10W40 and a manufacturers oil filter (though curiously, there was a smaller filter on there before). Just come back from cruising over the weekend and found that after a couple of hours use the low oil pressure light comes on when in tickover gear (and sometimes in idle too). The light goes out when revving a bit more. There is also a slight overheating problem (90-95 degrees?) which is "cured" by revving in neutral and/or by turning off the calorifier circuit.

 

If the oil pressure is low at low revs does that also mean it is too low at higher revs, even though the warning light goes out? The pressure gauge needle also waves around sometimes. Bearing in mind the engine has apparently done about 7500 hours (is this a lot or not?) how seriously should I take this warning and what's the best course of action?

 

a. Ignore completely and keep using it, hoping nothing untoward happens?

b. Rev it a bit more and be careful not to use in tickover too much?

c. Use 20W50 oil and and then hope it works? I think it has been used in this engine before so am I making a mistake going to 10w40 or 15w40 (just going by the manual...)? If this works, is there any disadvantage to using a higher viscosity oil like this?

d. Get it serviced? What could be the reasons why this is happening?

 

The only other thing I have noticed is that it starts easier than it used to. Is a 10W40 oil the same as a 15W40 oil at normal working temperature?

 

Thanks,

 

Simon (who is mechanically-minded but knows jack about engines/oil and even less before he got a boat).

Here's a little info that may help. As you can see the Alpa engines always had a relatively low oil pressure from new and this causes no problems. Is your idle speed correct, it should be around 950 rpm under load. If it has dropped off which is quite common with this engine your oil pressure will also drop off at idle. Also info on the various filters fitted to the Alpha range of engines. Yours should be fitted with with letter B. You can check against the dimensions to see if you have the correct one. But in all honesty it will have no bearing on your oil pressure whichever one is fitted.

[Alan de Enfield]

1 minute ago, Steve56 said:

Here's a little info that may help.

 

Useful information, but I'm guessing that in the intervening 14 years he will had resolved the problem one way or another.

 

 

[Steve56]

1 minute ago, Alan de Enfield said:

 

Useful information, but I'm guessing that in the intervening 14 years he will had resolved the problem one way or another.

 

 

That'll teach me to check the date first.