Oil light warning

[Boater Sam]

 Forget RCR, they will not repair it for nothing as it is still running. If you blow it up they will only tow you to a yard.

 

Check the cable from the engine to the panel for a short or damage on the wire that connects the sender to the warning lamp. A short here when the engine shakes at tick over will give you the same symptom.

 

Get a local fitter to replace the sender unit. Minimal cost, may solve the problem. If he has a pressure gauge, get him to check it out when hot.

 

In the past I have taken faulty senders out and tapped them hard with the inlet bit downwards to empty any oil and sludge out, sometimes it works.

 

At 11000 hours it probably needs a rebuild anyway.

 

If it only come on when at full working temperature and at a slow tick over I would change the oil for a better spec possibly thicker 20W/50 synthetic and see how you go. Low pressure does not mean no flow and its the flow through the bearings that matters. Yes, a worn engine will show lower pressure but as long as there is some pressure with a FEW revs on it will probably run like that for a long long time. Then when it is completely knackered just replace the engine with a new Canal Line unit, probably cheaper than a rebuild anyway as Isuzu no longer supply boat engines.

 

I know this is a fairly modern engine but I have run old diesel lumps with oil lights flickering on for years and never had one seize or break up, just feed it good oil regularly.

Edited December 7, 2018 by Boater Sam
smellings & Added

[Mike Adams]

Oil pressure 1000rpm  21psi, 1800rpm 43, 2200rpm 50-100. cn't find a value for mine at tickover

[Sea Dog]

A brief Googling gets this information from the Quayworks website :

 

Isuzu Oil Switches / Senders

Isuzu marine engine oil pressure switch, for 33, 35, 38 and 42hp. This also fits industrial engines based on the Isuzu 4LC1 and 4LB1 engines. 

There are two options available:

A) Oil pressure switch - this activates the panel light and buzzer only. Part number is Isuzu 8982014720

Oil pressure sender - this is for engines that have both a panel warning lamp and an oil pressure gauge, so mainly those with the Deluxe engine control panel. The cost of this sender is astronomical and we are trying to get this down - we currently make £1 if we sell one...

 

They want £49.99 for the pressure switch, which is probably what you need from your description.  You may find it cheaper elsewhere and it is a common engine so you may source a cheaper alternative, possibly even locally. Its a very simple job to unscrew your old one and screw in a new one.  I'd start there - 50 quid is a good investment to eliminate potentially the most likely fault and avoid a call out fee.  If it works, the jobs a good 'un.  If it doesn't, you've eliminated the first thing a mechanic will do anyway.

 

I'd be wary of simply sticking thicker oil in as a first resort. That may, potentially, mask the symptoms but won't cure the problem.  Isuzu didn't specify engine oil so you could upgrade to thicker stuff when something isn't right - they did it because it's the right oil for their engine given its clearances.

[Boater Sam]

31 minutes ago, Sea Dog said:

 

I'd be wary of simply sticking thicker oil in as a first resort. That may, potentially, mask the symptoms but won't cure the problem.  Isuzu didn't specify engine oil so you could upgrade to thicker stuff when something isn't right - they did it because it's the right oil for their engine given its clearances.

All true but if its well worn the clearances are now larger so a higher viscosity will probably suit it better, maybe?

I suspect that its knackered anyway.

I've never paid that much for a pressure switch,  I would take out the original and go to a factors with it, damn sure that they will match it up for a few £s. These things are nothing special, not rocket science.

[Jess--]

before you go and start replacing things....

are you absolutely sure you have enough oil in the engine?

 

after the engine has been sat (not running) for about 30 minutes pull the dipstick, wipe it with a rag and put it back in then pull it out and see where the level is

[ditchcrawler]

I know what I would put my bet on, but its not my boat or engine.

[Tony Brooks]

5 minutes ago, ditchcrawler said:

I know what I would put my bet on, but its not my boat or engine.

So do I and a sits just as witch it will only cost few pounds to replace with a pattern one, but as you say, its not my boat.

 

Reasoning: -

 

Experience tells me senders and switches like this are less reliable than other parts of the engine/instruments.

The OP said at the start they checked the oil.

Loose/dirty contacts & connectors ware far more likely to keep the lamp out rather than come on.

A short to earth between lamp and switch is more likely to keep the lamp on permanently UNLESS a wire gas chaffed through and is vibrating against metal on idle BUT that should be fairly easy to see when looking around the engine.

If the bearings were worn enough to cause this so should the pistons. rings, and bores so the OP would have been complaining about oil use and smoke to a degree.

As long as the oil & filter changes have been done then a jammed oil pressure relief valve (anther cause of these symptoms) is far, far less likely than a faulty switch in my experience.

 

Of course the correct thing to do is to fit a test gauge and check the hot oil pressure at speed and at idle but who has such a gauge to hand. I am with Sam on this. I would have been on my way to a Motor Factors yesterday.

 

 

 

 

[Guest]

Going back many years, LPG and diesel engines alike but in fork lift trucks, the oil pressure switches were known to fail displaying similar results to the OP. It would be my first port of call, and if that didn't work I would try a temporary jumper wire to the warning light, bypassing those horrible connectors. 

 

[bizzard]

magictime really needs take the old switch out and take it along to the factors to compare size of threaded stub and thread and whether tapered or parallel and needing a new sealing washer.

[magictime]

Blimey - lots of activity this morning!

 

Anyway, RCR sent someone out and the oil pressure's reading fine, so it does seem to be the sender that's the problem. Just waiting to hear if this is something they cover, but whether it is or not, at least it wasn't a more serious issue.

 

Thanks for all your input everyone!

Edited December 7, 2018 by magictime

[bizzard]

3 minutes ago, magictime said:

Blimey - lots of activity this morning!

 

Anyway, RCR sent someone out and the oil pressure's reading fine, so it does seem to be the sender that's the problem. Just waiting to hear if this is something they cover, but whether it is or not, at least it wasn't a more serious issue.

 

Thanks for all your input everyone!

So he took the sender out to screw in a test gauge?

[WotEver]

7 minutes ago, bizzard said:

So he took the sender out to screw in a test gauge?

Are we opening a book on this?

 

[bizzard]

[magictime]

1 hour ago, bizzard said:

So he took the sender out to screw in a test gauge?

Yes

[Arthur Marshall]

You do get some RCR bods that know what they're doing. Not many, and they tend not to stay long, but there are some. 

[Wanderer Vagabond]

4 hours ago, Arthur Marshall said:

You do get some RCR bods that know what they're doing. Not many, and they tend not to stay long, but there are some. 

In fairness, all that they do is call out a marine engineer (or whatever) local to you, which could be a competent one or otherwise. That was the main reason that I gave up with RCR since, with the internet I can find a local guy myself, speak directly with him and get some sort of timescale of when he can get to me if necessary. They are much the same as the AA or RAC, they just use local franchises, and since I have previously had to wait a day for the guy to turn up in the first place I couldn't see much advantage in comparison to what I can do myself (probably tempting fate and will break down soon and regret not having RCR, but it hasn't happened in the 4 years since I gave up membership so I have £600 that I haven't had to spend on membership).

 

A poster above mentioned that if RCR blow your engine up they will tow you to a yard, has anyone ever had any experience of this? I know it is in the conditions of membership but when I got talking to the girl on the line when my sensor failed (as a bit of a newby at the time I was concerned that there may have been some serious problem) the impression I got tows very rarely, if ever, happen. The tow is apparently limited to something like 3 hours and that includes the time that it takes them to get their boat to you so you are probably looking at a maximum of a 4 mile tow. They also wont tow you on a tidal river, so I'd be interested if anyone has ever had a tow from RCR.

[MtB]

On 07/12/2018 at 01:05, Boater Sam said:

At 11000 hours it probably needs a rebuild anyway.

 

Frankly I'm with Sam on this. At 11,000 hours I'd be staggered if it WASN'T giving low, low oil pressure at tickover.  The flickering goes away once you blip the throttle yes?

 

I'd say the previous posters forecasting doom are being just plain silly on an engine of this age, it's living on borrowed time already. Most on my A-series engines did the same from about 40,000 miles up to 120,000 miles when they just croaked it.

 

Just carry on using yours and consider every day it runs with no trouble a bonus, you may well get to 20,000 hours before any real trouble occurs. Stop worrying and keep up the RCR premia.

[Boater Sam]

A true story, may be relevant, maybe not.

 

Many years ago we ran  Pontiac Bonneville sedan, a monster. Big V8 lump of an engine, hydraulic lifters.

It had done a fair mileage when we got it  but was in sound condition.

In line with our usual preventive maintenance program it got an oil change quite soon after purchase.

 

Now big Yank motors of this age were designed to run for ever with no maintenance apart from tune ups. So it had probably had little  if any servicing in its life.

After a while the oil warning light became reluctant to go out. It still ran silently, whipped up the 100mph+ very quickly. First  thought, duff pressure switch so we carried on running it for months till eventually the light never went out no matter what revs.

Getting fed up with the light, a new switch was fitted. Horror! Still stayed on!

A pressure test showed nil to 3 psi pressure at best. No tappet or bearing rattle or smoke, still running like new. Another oil and oil filter change made no difference.

 

I took the sump off to check the oil pump and bearings. The course strainer in the sump for the  pick up to the pump was choked with sludge which had been washed down out of the block with our nice clean modern detergent oil.

Cleaned it all out, Checked the bearings, perfectly OK. Put it back together and it ran perfectly, never again saw the light on with the engine running even at tick over and hot. It did several years hard running after that.

So don't worry about tick over flicker, it will run for years like that.

 

Edited December 8, 2018 by Boater Sam
smellings & Added

[Sea Dog]

19 hours ago, magictime said:

 

Anyway, RCR sent someone out and the oil pressure's reading fine, so it does seem to be the sender that's the problem. 

 

Having established this ^^^^

 

There's really no need to do this.... 

3 hours ago, Boater Sam said:

 

So don't worry about tick over flicker, it will run for years like that.

 

 

Seems to me his engine is just fine despite its 11000 hours and a new sender is a step in the right direction towards keeping it that way.  If he ignores the flicker henceforth and doesn't fix the sender, he'll never be able to tell between "It always does that" and "Oh sh**!"

 

 

 

[magictime]

6 hours ago, Sea Dog said:

 

Having established this ^^^^

 

There's really no need to do this.... 

 

Seems to me his engine is just fine despite its 11000 hours and a new sender is a step in the right direction towards keeping it that way.  If he ignores the flicker henceforth and doesn't fix the sender, he'll never be able to tell between "It always does that" and "Oh sh**!"

 

 

 

Don't worry... even if I was comfortable with that risk (which I'm not), I'd happily pay for a new sender just to shut the thing up! It's not so much flickering now as staying on solidly accompanied by an extremely shrill beeeeeeeeeeeeeeep, so bad enough when inside the boat charging batteries and pretty much intolerable while on deck cruising.

[Alan de Enfield]

1 hour ago, magictime said:

Don't worry... even if I was comfortable with that risk (which I'm not), I'd happily pay for a new sender just to shut the thing up! It's not so much flickering now as staying on solidly accompanied by an extremely shrill beeeeeeeeeeeeeeep, so bad enough when inside the boat charging batteries and pretty much intolerable while on deck cruising.

From what you are saying, it has gradually got worse and worse, from a 'flicker' to now being on continuously. I wouldn't have thought a sender could be a 'little bit broken' and get steadily worse.

How did the mechanic guy actually test the pressure to confirm it was OK (and what was the pressure, and is that within the specification ?)

[WotEver]

12 minutes ago, Alan de Enfield said:

How did the mechanic guy actually test the pressure to confirm it was OK 

 

On 07/12/2018 at 11:28, bizzard said:

So he took the sender out to screw in a test gauge?

 

On 07/12/2018 at 13:27, magictime said:

Yes

 

[Alan de Enfield]

3 minutes ago, WotEver said:

 

 

 

I read those, but I guess time will tell - if the problem goes away by simply replacing the sender unit then that was the fault.

I'm just not convinced.

[alan_fincher]

So what dis RCR's pressure gauge say the pressure actually was when running in similar to conditions to those where the light s on and the buzzer sounding?

[Wanderer Vagabond]

1 hour ago, alan_fincher said:

So what dis RCR's pressure gauge say the pressure actually was when running in similar to conditions to those where the light s on and the buzzer sounding?

Wouldn't the pressure test gauge be put into the hole wot the sender came out of? If so the light would clearly no longer be on and buzzer sounding