My engine sounds a bit like a diesel, is this bad?

[spit]

Phil, the sender for the oil light on the mk3 is also based on oil pressure, which is why it extinguishes (or should) as soon as the car fires up and starts pumping oil.

So its effectively a proxy for low oil level (ie reduced pressure as a result of low oil level), but could of course also mean a knackered oil pump  s:lol: :lol: s:lol:  

I read a post here from someone a while back who suggested that if the oil light came on and stayed on it was probably too late for the engine. I suspect that depends on the circumstances of whether its the result of a gradual drop in oil level or a catastrophic failure.

I'd suggest that - if the light stays on a fraction longer than usual at start-up before it goes out - you're overdue for checking the dipstick  s:wink: :wink: s:wink:

[aaronjb]

I read a post here from someone a while back who suggested that if the oil light came on and stayed on it was probably too late for the engine. I suspect that depends on the circumstances of whether its the result of a gradual drop in oil level or a catastrophic failure.

Concensus on Spyderchat is that the oil light only comes on when you get down to some 4-5psi of oil pressure.

If you have that little pressure, at any kind of RPM, your engine will be toast before you can react, pretty much..

[Anonymous]

i just put 1 litre in. ran my engine for a while...


and now folks I'm getting 1/4 of a black oil reading on my stick!??!?!

if there shows oil in the engine, and the noise has gone, shall i still change the oil?

and you guys recommend topping up every month then? cus i checked every couple

You should be more concerned that your engine has burnt that much oil in 2 months.....unless you are doing mega-mileage.  s:roll: :roll: s:roll:  

Just topping it all the way up will not stop it doing the same again, you really need to find out why it is burning oil in the first place. Sticking your head in the sand and hoping for the best is an expensive recipe for disaster.   s:cry: :cry: s:cry:  

IMHO you need to check the oil level every week (it only takes two minutes at the weekend FFS!!) no matter what car you drive. Surely better safe than sorry....

As has been said many times before, get your oil up to full level with fresh and check it VERY regularly to see just how much oil you are burning, then get it looked at/sell it/whatever if you have a problem.

[philster_d]

Or the first time you see a flicker of the light is during a long hard corner like between motorways when you sweep around the bend.

[philster_d]

and so if someone could come up with a second sensor option for somewhere in the system, set to say a few notches above the stock one, there would definately be a market for it huh ?
earlier warrning light

Im especialy thinking this for post turbo when the oil gets o so more important still.


Phil

[aaronjb]

Just get a decent oil pressure guage (preferrably electric, much easier to plumb in) Phil - far better and far more useful, IMHO of course  s:) s:)

[philster_d]

Thanks thats what im after, your brain.

No wonder these poshly modded cars are brimming with gages.

[aaronjb]

Thanks thats what I'm after, your brain.

Nobody ever wants me for my body  s:cry: :cry: s:cry:   s;) s;)

Boost, oil pressure and oil temp are probably the three most important (IMHO, again) on a modified FI car that will see any time on track.  If you're not going to see time on track then you can probably drop the oil temp.

Anyway, we're drifting off the original posters problem  s;) s;)


The folks are right - leon_in_uk (sorry, can't remember if we know your name or not  s:) s:) ) - get the oil topped up (sounds like you have this one covered ish), right back up to proper levels, then get it changed fully at the earliest opportunity you can.

Letting the oil run that low means it gets cooked, cooked oil doesn't protect well at all, and is full of horrible impurities (and probably particulates, if any bearing wear has taken place) that will contaminate and lower the protective properties of any new oil you add.

If you replace the oil totally, soon, then you might, maybe, just get away with this.. though if it was knocking, you'll probably succeed in lengthening it's life, but not really saving the engine.

[philster_d]

EGT ?

Would one of those oil filter magnet things help with the original posters problem ? how much are they ?

Phil

[aaronjb]

EGT ?

Would one of those oil filter magnet things help with the original posters problem ? how much are they ?

EGTs are nice to have, but again tend to be one of those things where if it's all going wrong, it'll be over before you get chance to do much by way of reacting to them.

That said, I have two Greddy peak+hold EGT guages in the Nissan (but then I also have Boost, water temp, oil pressure, oil temp and battery voltage  s:lol: :lol: s:lol:  )  s;) s;)

I suppose it depends what you're going to do with the car - if it's going to see any time on track at all, I'd go for oil temp (especially in our cars - the stock oil cooler is meant to be.. less than efficient). If you're only going to be on the road, perhaps EGTs would be nicer to know - but it's six of one and half a dozen of the other, really.

As for the filter magnets - honestly, I think those are more gimmick than fact.. I'm prepared to be proven wrong, but personally I think a combination of the oil filter pickup screen and a good quality oil filter (stock or better) is more than adequate protection from particulates in every day situations.

I guess, in reality, if there's that much by way of metal shavings in your oil, your engine is toast anyway, and very much due a rebuild.

The only benefit I can see is if you got to see the shavings stuck to it at oil change time - you'd get an instant indication that it's time for a rebuild.

[Tem]

EGTs are nice to have, but again tend to be one of those things where if it's all going wrong, it'll be over before you get chance to do much by way of reacting to them.

I believe that depends on what's happening. Of course a sudden engine breakdown is over before any meter can measure anything. But say you're doing a long run and notice the EGT starting to slowly go up. Plenty of time to keep an eye on it and let go before it turns into an issue.

[leon_in_uk]

right then guys, not driving my car till the weekend.. it has 1 litre in.. and

as soon as saturday comes i am draining oil and refilling?!! so i defo need a oil filter? and i cant remember if they are easy to change!!

so i will just have to keep my fingers crossed now!!

and 5w30 for a full change?

cheers guys, oh and aaron - the name leon_in_uk refers to my name being called leon   s:lol: :lol: s:lol:

[Tem]

so i defo need a oil filter? and i cant remember if they are easy to change!!

Never hurts to change it...it's easy to change once you're down there anyway.

[leon_in_uk]

cheers matey. hopefully the noise will stop also when i have changed it and hopefully wont take that long... thinking about 2 hours...

[leon_in_uk]

i nicked my dads car this morning, and checked my oil again just, its still 1/4 and lookin ok the oil is brownish black like it should be. but just drove it a short way to work and its making a horrible diesel noise. and its louder then yesterday...

i think the damage has already been done!! after the oil change what should i get checked? what has gone in my engine?

[edward.carter]

1/4 is still fairly low in my opinion i would be putting more oil in for a start.

[philster_d]

I sometimes notice a diesel'y sounding noise and think oh god, no! but more often than not I realise im at traffic lights and surrounded by massive white vans and lorries drowning out my real sound.   s:roll: :roll: s:roll:

[Anonymous]

i nicked my dads car this morning, and checked my oil again just, its still 1/4 and lookin ok the oil is brownish black like it should be. but just drove it a short way to work and its making a horrible diesel noise. and its louder then yesterday...

i think the damage has already been done!! after the oil change what should i get checked? what has gone in my engine?

 s:roll: :roll: s:roll:    s:crazyeyes: :crazyeyes: s:crazyeyes:  If it were me, I would fill it up to full with oil and get it to a garage pronto for them to at least have a listen....if it still sounds bad, then a diagnosis without a peek in the engine is very difficult.

[rmowbray]

Sorry to be the bearer of bad news:   s:( s:(  

If your oil was too low then the damage will have been done. No amount of adding or changing oil will fix it. Low oil level would lead to loss of oil pressure which in turn results in massive wear in the engine internals, the crackcase bearings usually take the brunt of it.

This wear is what causes the "diesel" sound. What you are hearing is the crankshaft slapping around in its bearings (metal hitting metal). Before the wear the clearances between bearing surfaces was probably measured in 10s of microns, after oil starvation it will be more like millimeters.

I don't know how much you've driven since noticing the problem but if you've added oil you are unlikely to make the problem much worse. Have you noticed whether the sound changes depending on throttle position? A crank rattle tends to sound worse when around neutral throttle (just maintaining speed), but sounds less severe when accelerating or under engine braking.

As far as definative diagnosis goes very little can be done without extracting and stripping down the engine. Paying MrT to do this will cost almost as much as replacement (2nd hand) engine. Also if after investigation MrT decides the root of the problem is that you didn't put oil in (whether true or not) they will make you pay for the investigation, the replacement short engine and the labour, probably around £3500 altogether. Bear in mind that by now they've got your car and it's in bits!

Sorry to paint such a gloomy picture mate. I sincerely hope that it isn't crack wear/failure.   s:? :? s:?  

Damn those pre-cats   s:evil: :evil: s:evil:

[leon_in_uk]

oh fcking great....

when neutral it sounds absolutly fine.. its just when going past bite point and accelerating slightly over 2.5k.. and it is louder then yesterday.

so theres no point in an oil change etc?

and by the sounds of it i might as well crash it on purpose and claim off pissing insurance...

[rmowbray]

Important question:

Does it rattle if you rev the engine in neutral?

If not then it's probably not the engine internals, more likely a gearbox problem.

[SteveJ]

If the noise is only when under load then the big-ends are almost certainly toast  s:( s:(

[Anonymous]

In my old Fiat Bravo that I had, I ran out of oil and fcuked the engine, it was running like a diesel just like yours seems to be Leon, I took it into a garage to get fixed, they stripped the top half of the engine and replaced whatever but they said who knows what long term damage is done to the bottom, patch up job done to the engine then traded it in.  

My brother who's garage I traded it into said that the person who bought it after me, it packed in on them, luckily for them it was under warranty but just glad I got rid of it and also shows how nice it is to have a warranty for this kind of thing.

I've just phoned my local Mr T to ask about getting the precats taken out and how much, the Technician is away to check because he has never heard of this being taken out.........what chance have you got!!!  s:roll: :roll: s:roll:    s:roll: :roll: s:roll:    s:roll: :roll: s:roll:

[leon_in_uk]

just revved my car. no real noise.

but its pissing oil out of the exhaust... and alot of smoke also..

this is a major problem isnt it?

[leon_in_uk]

oh and for the sound it defo sounds like a diesel when i put it into gear and rev it..