Which oil?

[Plasticman]

midnight oil ? beds on fire
mm

[ghost123uk]

Never been sure if my bod works either. Bus has previously had an aftermarket oil pressure gauge fitted which was reading ok ( if only I'd looked at that before topping up - or checked the dipstick) oh, we'll, lesson learned.

Just to point out that an oil pressure gauge does not give you any idea how much oil is in an engine. (unless it gets to the point that there is barely any oil in there at all and the oil pump starts to suck air !) You can still have oil pressure with only a couple of litres in the engine, the gauge reads pressure, not quantity.

And yes, the oil light came on as I was passing a motor spares shop

Ahh, that's ok then, I was thinking you might have actually driven it with the oil light on

[cosmicsheep]

Diagnosis from my local independent VW specialist is that the engine is probably toast. She's suffering from a huge misfire and unless this is a massive coincidence and not caused by my overfilling of oil, then I've done serious internal damage to the engine. His solution is a new engine.

I know it's hard for anyone to judge without looking at the engine, but does this sound right? I'm not mechanically minded enough to rebuild an engine myself and the mechanic thinks it would be more economical for him to do a swap.

[Allanw]

Diagnosis from my local independent VW specialist is that the engine is probably toast. She's suffering from a huge misfire and unless this is a massive coincidence and not caused by my overfilling of oil, then I've done serious internal damage to the engine. His solution is a new engine.

I know it's hard for anyone to judge without looking at the engine, but does this sound right? I'm not mechanically minded enough to rebuild an engine myself and the mechanic thinks it would be more economical for him to do a swap.

It does sound very possible - when the oil light comes on, and the engine is running, IT'S TOO LATE - the engine is turning and the pressure has already dropped. It may have been sucking air for some time too, but not enough to turn on the light.

The pressurised oil actually stops many of the metal bits in the engine from touching each other - when there is no oil being pumped in at pressure, they can more easily touch and the damage starts.

If you are lucky, it's just sucked excess oil into the intake.

Did you check the dipstick, or did you just fill the oil to the top? I've seen that before!

The light is there to warn of impending imminent catastrophic failure, not to check the oil.

[cosmicsheep]

Did you check the dipstick, or did you just fill the oil to the top? I've seen that before!

Ummm, No. <slaps wrist> i just bunged some extra oil in. I'd checked it the night before and noticed it was a bit low (about mid way) but nothing to worry about.

Would too much oil pressue cause damage to the metal bits?

[Mocki]

Too much oil could cause damage to seals, but wouldn't damage anything else!

Depends how far you went with the oil light on, and if the oil light was a genuine warning or a wiring failure.

Your garage may be correct, but I would want a second opinion . One thing is right about is it will be quicker and cheaper for you to swap engine rather than repair and rebuild yours if it is "toast"

I'm sure you realise now RED means stop! Immediately!

[New Kentish Campers]

Diagnosis from my local independent VW specialist is that the engine is probably toast. She's suffering from a huge misfire and unless this is a massive coincidence and not caused by my overfilling of oil, then I've done serious internal damage to the engine. His solution is a new engine.

One other thing, if you have a bad misfire following the oil overfill, have the garage checked the plugs to see if they are oiled up? I would have thought that a lot of oil would do just that. Just a thought.....

[ghost123uk]

As said, overfilling with oil will not cause a huge miss-fire, except, again, as said, unless it is a fouled plug and the garage surely at least had the plugs out for examination.

Any garage should be able to tell you exactly what is wrong, not just "it's got a bad miss-fire".

You need to find out what is wrong, ie compression test and oil pressure test as a starting point. If you can tell us the results of those two (very basic) tests we will be better able to suggest what to do.

[cosmicsheep]

Garage have done a compression test and said everything looks fine.

They did an oil pressue test and said that it was "acceptable"

RAC guy changed the plugs to no avail and last i spoke to the garage he was going to do the same.

I'm not particularly convinced by the "expert" diagnosis from the mechanic and will be looking for a 2nd opinion before forking out the best part of £2k for a new engine.
To be far to the mechanic though, he's only had the bus since yesterday so i'm still hopeful for a proper reason for the mis-fire.

Thanks for all your input guys.

[Ian Hulley]

VW Elite 'recon' WBX engine is about a grand, add a clutch, water pump and a day's labour to swap the exhaust, plumbing, petrol pump, alternator and the engine itself over.

[Mocki]

Misfire could be as simple as a duff plug lead or indeed duff plug, or air filter full of excess oil or carb full of excess oil both via the oil breather system ?

Vac advance pipes bunged up or disconnected now or a totally un connected issue?

[Ian Hulley]

Sorry, yes ... I wasn't confirming the diagnosis just making sure the "best part of 2 grand for an engine" bit wasn't PLUS fitting

[cosmicsheep]

Good news.... She lives

Final diagnosis was crap in the fuel system, a hole in the filler neck, and a leaky exhaust but will all be fixed this time tomorrow.

Lesson learned about not checking oil level before topping up.

Still have a possible faulty oil warning light to keep an eye on.

[California Dreamin]

That diagnosis is all a little bit vague to me.
Massive misfire could be something as simple as a plug or plug lead. I wouldn't go righting off your engine on the strength of opinion without some sort of fact.
If you have a missfire which cylinder is it?
What is the compression like on that cylinder?
ARE THERE ANY NOISES apart from it sounding sick on 3 cylinders.

Martin