Discussion
Dragged my Chimp out of the garage today to go for a spin after the winter. I started it up and it had a tapping noise. I decided to leave it to warm-up, but when I came back five minutes later the tapping noise had turned into a VERY loud tapping. It sounded more like there was a percussion ochestra practicing in my garage. Looked at the dash, no pressure. I shut it off staright away, but what I want to know is -
Have I done much damage to the engine? (it was just idling)
Is it worth changing the oil pump myself, and hoping for the best or should I have the engine dismantled first.
If it does turn out to be okay when I have changed the pump, have I shortned the engines lifespan?
Ive had a brand new 4.6 crossbolted block put in which is meant to be stronger, so am I going to be a lucky man?
Have I done much damage to the engine? (it was just idling)
Is it worth changing the oil pump myself, and hoping for the best or should I have the engine dismantled first.
If it does turn out to be okay when I have changed the pump, have I shortned the engines lifespan?
Ive had a brand new 4.6 crossbolted block put in which is meant to be stronger, so am I going to be a lucky man?
quote:
Dragged my Chimp out of the garage today to go for a spin after the winter. I started it up and it had a tapping noise. I decided to leave it to warm-up, but when I came back five minutes later the tapping noise had turned into a VERY loud tapping. It sounded more like there was a percussion ochestra practicing in my garage. Looked at the dash, no pressure. I shut it off staright away, but what I want to know is -
Have I done much damage to the engine? (it was just idling)
Is it worth changing the oil pump myself, and hoping for the best or should I have the engine dismantled first.
If it does turn out to be okay when I have changed the pump, have I shortned the engines lifespan?
Ive had a brand new 4.6 crossbolted block put in which is meant to be stronger, so am I going to be a lucky man?
Any idea what caused the lack of oil pressure? Suppose it could be the pump had drained after an extended lay-up but I've never heard of this happening to anyone else.
Whatever caused it, the bad news is cross bolting is no substitute for oil pressure, it's very possible that your engine has been wrecked. Five minutes is long enough to cause all sorts of damage and you may have taken out the cam and / or bearings. If there has been any damage at all this may have produced swarf which will now be kicking around inside the engine. When you start it this could be pumped around all the bearings, potentially causing expensive damage to bits which haven't been damaged so far. Unfortunately it's very hard to tell this without stripping the engine, which is a large part of the cost of repairing it anyway.
If you're feeling brave, you could try to get some oil pressure up and then restart it and see what happens. I would be quite surprised if the engine is still OK, but you don't have a great deal to lose now. For a pre-serpentine engine, I'd mark and remove the dizzy and drive the oil pump with a power drill to prime it and circulate the oil. Otherwise you are left with the 'pack the oil pump' routine and then spin the engine over with the fuel pump disconnected. Either way I'd suggest you don't think about firing it up until you've got oil pressure.
As soon as you have it fired up and running, I'd stop it and drain the oil. If this has metal in it, you've certainly got significant damage inside the engine, by flushing the oil you can stop it spreading but be prepared for expensive repairs in the near future. If the oil is clear, you may have got lucky and not have scrapped the engine but don't count on it.
Next year, make sure the battery voltage and oil pressure are normal before you go inside for your cup of tea!
Hope this helps,
Peter Humphries (and a green V8S)
quote:
No expert but I doubt the damage would be that severe if the engine only ran a few minutes and wasn't under much load.
Not so sure - idling places the greatest pressure on some of the turning components in the engine, esp. when cold. That's why when you fit a new camshaft they tell you to keep between 2-3k rpm for 5 minutes.
Right, I drained the oil and then cranked the engine with the leads and fuel pump off, but the oil light still wouldn't go out. So I decided not to ire it up. I then re-drained the oil and checked it for metal particles. It looks fairly clear, theres just a tiny patch of particles.
I have just had the dizzy replaced, could that have become disconneted from the oil pump somehow? How could I check?
If I take the oil pump off, what signs do I look for?
I have just had the dizzy replaced, could that have become disconneted from the oil pump somehow? How could I check?
If I take the oil pump off, what signs do I look for?
Stuck pressure relief valve, worn vanes, lack of drive from distributor shaft to name just a few. Blocked oil filter non-return valve and so on...
Steve
www.tvrbooks.co.uk
Steve
www.tvrbooks.co.uk
if your engine is pre-serpentine and was ok the previous day most probably pressure relief valve stuck open. advise replace oil pump base plate assembly.agree with Greenv8s 5mins is enough to cause damage to engine, no oil pressure means metal to metal contact sorry to be so negative
Gassing Station | Chimaera | Top of Page | What's New | My Stuff