Oil Light Randomly Illuminating On FR-V

[securespark]

Thought I'd posted about this here, but can't find anything.

This happened in September when we were on holiday. The level was grand but it was preying on me, so I dropped it into a garage. He plugged in a code reader but nothing came up.

Looking at the oil, he said it looked thin.
We said it was due a service the next month and he left it at that.

So, it had its service at the end of November and a week or so back, the oil light came on again.

Each time it comes on, it only spends a relatively short time on.

From what I know, it could be an easy fix like the oil pressure switch, a medium pig of a job like the oil pump or it could be something like a majorly worn big end. Game over.

But from what I know about Honda Diesel lumps, they're pretty bulletproof so I'm hoping it isn't major mechanical wear.

Any suggestions, please?

 

[sxturbo]

What year is it?

Oil lights connected to ECUs is believe it or not a relatively new thing. Usually there a sensor on their own not connected to anything else.

Does this vehicle have a dpf?

When diesels get long in the tooth the injectors do play up, but they hide it well. In an ideal world the injectors should get replaced quite often, 40-50k miles being generous but they are very expensive. On large industrial engines they tend to get replaced every 1000 hours on newer engines, older engines could be as low as every 250 hours, however now ECU's have become so advanced that we plug in the laptop load the engine and carry out an injector test and it tells us if the injectors are within tolerance or not and points which ones are out, increasing the life span enormously.

Anyway I digress...

If the engine is long in the tooth you could have over fuelling injectors and washing the bores and thinning dow the engine oil, this will make the oil light come on.

Alternatively it could just be it's long in the tooth and requires a rebuild.

Personally I'd advise first and foremost
putting a new oil pressure sensor in, there only a few quid, I'd do an oil change aswell.

The I'd be getting the injectors removed and tested if your planning on keeping it long term, along with changing the oil.

If you want to get shot of it, change the oil and filter, if it still flickers on (after fitting a new sensor) you could get a thicker oil, I think you would usually have a 5w30 oil in this, and you could change it to a 5w40. You could go to 10w40, but you will need to change the oil more regularly as 10w40 is rarely a fully synthetic oil (you'd also need to make sure that a low ash oil is used as it will cause big issues with the dpf otherwise)

 

[sxturbo]

Just looked at an old post of yours and see it's a 2009 frv, I see that dpf's are listed for it.

So this is another avenue to look down, when a dpf requires a regen one way to do so is to over fuel so unburnt fuel finds itself in the exhaust, this gets trapped in the dpf and causes it to heat drastically, this heat burns a lot of the bad stuff and the metals used to make the filter create a reaction, and also other deposits get loosened and the exhaust pressure blows them out.

It could be the dpf hasn't fully completed a number of regen cycles and the over fuelling has thinned the oil down.

This thinned oil could have them caused the excess wear as you wouldn't be aware of the thinned down oil.

I know on ford diesel's since 2014 (maybe earlier I don't know as don't have experience of older )they have a sensor in the oil that detects thin oil (because of the above) and advises an oil change. Before damage occurs.

 

[securespark]

It's 59 plate registered, but a 2007 build, if that makes any difference.

AFAIK, it doesn't have a DPF. How would one be able to tell?

 

[sxturbo]

It's 59 plate registered, but a 2007 build, if that makes any difference.

AFAIK, it doesn't have a DPF. How would one be able to tell?

It's odd to be sat around for 2 years.

Can only tell by the vin number on a parts system. Honda should be able to confirm for you.

It might not have a dpf, which would indicate the injectors over fuelling.

Sometimes if it really bad you will see the oil level on the dipstick increase if it's really bad. But sometimes the level won't increase

 

[securespark]

If Diesel is thinning the oil, won't it show in appalling mpg?

 

[carmanmemoranda]

Does it use much oil ? Any smoke, or signs of burning oil?

What is the oil level like when the light is on ? Was it good quality oil and filter used? Does the light only come on at tick over or under load ?

What mileage is it ?

 

[carmanmemoranda]

If Diesel is thinning the oil, won't it show in appalling mpg?

If diesel is thinning the oil, the oil level will rise, or if it's burning oil to hide the rise in level there will be noticeable emissions issues and smells.

Do you have the emissions figures from the last mot ?

 

[securespark]

I'll look it up, thanks.

 

[securespark]

Does it use much oil ?

Funnily enough, it used to. It needed regular topping up between services from new until about 100K. But since then, no.

Any smoke, or signs of burning oil?

Not that I can see.

What is the oil level like when the light is on ?

Up to 100K, the light never came on, but weekly checks would show a small drop. Between 100K and 155K the light did not illuminate and weekly checks showed the level OK.
After that, the level was good whether the light was on or not.

Was it good quality oil and filter used?

Bought in November 2009 new and the first 5 years servicing was done by Honda. After that it was serviced by Pro Tyre and latterly by a local ex-Honda fella. Outside the warranty, I always requested the correct spec fully synthetic oil and a decent filter.

Does the light only come on at tick over or under load ?

Once it's on, it doesn't seem to follow a pattern, it's on whether we're on the motorway, slower roads or at idle.

What mileage is it ?

Currently 169K.

 

[carmanmemoranda]

There's a lot of info in there and some of it is conflicting, or at least confusing.

But the main 1 that jumps out....


Once it's on, it doesn't seem to follow a pattern, it's on whether we're on the motorway, slower roads or at idle.


Suggests that it is an oil pressure switch issue. If the oil light was on at motorway speeds, for more than a flicker, then I would expect the engine to be toast. Noise, rattles etc at all speeds and a distinct lack of pressure at start up.

The confusing part is that it used to use oil between services up to 100k and now doesn't, might suggest the oil level is being topped up by diesel, but the light coming on at speed would still be the major concern.

 

[Harry Bloomfield]

Replace the oil pressure switch, they are cheap enough and an easy swap usually.

 

[securespark]

Yeah, I thought it was running in up to 100K!

So, I'll look at getting the pressure switch swapped out.

Then I'll get the injectors checked, as starting is not as smooth as it has been and last time that symptom appeared, replacing an injector solved the issue.

 

[carmanmemoranda]

Yeah, I thought it was running in up to 100K!

So, I'll look at getting the pressure switch swapped out.

Then I'll get the injectors checked, as starting is not as smooth as it has been and last time that symptom appeared, replacing an injector solved the issue.

Possibly you have more than 1 fault.

Try the oil pressure switch 1st before going further, try to eliminate or confirm other issues, in stages.

 

[securespark]

I'll look it up, thanks.

I have found the MOT cert.

Sadly the emissions printout has not been attached to it as it normally would.

I think I should get another emissions test done.

Obviously it passed the MOT at the end of Nov. Let's assume it was the maximum allowable emissions. Would that tell you anything?