996 Oil and coolant loss.
Discussion
I'll be brief.
Bought a 1999 c4 109k with engine rebuild (top and bottom), done within the last 5k miles. 3 cylinders were re-lined together with the usual bearings throughout etc.
Driven for approx 2k without any issues. Last few hundred miles the oil consumption has gone from nothing to approx 1.25 litres over the last 300miles.
Also, had to top up coolant (1 litre), but that's the first check I've done. The idle is now erratic when the engine is hot and in traffic but no overheating at all. No mayo on dipstick and no oil in the coolant. There is some mayo on the oil cap and adjacent section of the filler pipe.
Previous owner trying to be helpful and is a porsche enthusiast. He ( and the mechanic who rebuilt the engine) have suggested an air leak on an oil pipe somewhere causing loss of pressure and oil to by pass o rings in engine. Although coolant loss would be a separate issue.
Has anyone on here had a similar problem? I would like to consider all possibilities before writing the engine off.
Bought a 1999 c4 109k with engine rebuild (top and bottom), done within the last 5k miles. 3 cylinders were re-lined together with the usual bearings throughout etc.
Driven for approx 2k without any issues. Last few hundred miles the oil consumption has gone from nothing to approx 1.25 litres over the last 300miles.
Also, had to top up coolant (1 litre), but that's the first check I've done. The idle is now erratic when the engine is hot and in traffic but no overheating at all. No mayo on dipstick and no oil in the coolant. There is some mayo on the oil cap and adjacent section of the filler pipe.
Previous owner trying to be helpful and is a porsche enthusiast. He ( and the mechanic who rebuilt the engine) have suggested an air leak on an oil pipe somewhere causing loss of pressure and oil to by pass o rings in engine. Although coolant loss would be a separate issue.
Has anyone on here had a similar problem? I would like to consider all possibilities before writing the engine off.
Take it to a garage.
If the idle is erratic then it's probably due to a loss of pressure in the oil system. You can replicate similar symptoms in a perfectly healthy engine simply by loosening the oil filler cap for example.
To go from not using much oil to using the amount you described sounds like an oil leak.
The engine is probably fine.
If the idle is erratic then it's probably due to a loss of pressure in the oil system. You can replicate similar symptoms in a perfectly healthy engine simply by loosening the oil filler cap for example.
To go from not using much oil to using the amount you described sounds like an oil leak.
The engine is probably fine.
king engine? I think we need to know his name so that we can start shaming the knob jockey.
Stephen Pook said:
Thanks Kenzy. The engine still runs very sweetly all of the time except during this one journey. I'm starting to wonder if it's an AOS issue. When they start to go wonky is it possible that it can give intermittent symptoms (only when stuck for a long time in traffic for instance?)
Does the idle become smooth above 3000rpm or so and then return to being erratic if you lift off the revs?If so, likely an oil leak I think.
But there's only so much you can learn from asking randoms on a forum - if it were my car I really would get it to a garage asap and not drive it very much in case of making the problem worse.
HTH
In terms of the creamy residue in the oil cap and filler pipe, mine does that even though it uses no oil or coolant. It is made worse if the car is not brought to full operating temperature for long enough during drives. It is a mixture of oil and condensation from engine parts that cools and deposits in the extended filler pipe on the 996. You wouldn't get it if the cap sat straight on top of the engine, avoiding the change in temperature.
In terms of the creamy residue in the oil cap and filler pipe, mine does that even though it uses no oil or coolant. It is made worse if the car is not brought to full operating temperature for long enough during drives. It is a mixture of oil and condensation from engine parts that cools and deposits in the extended filler pipe on the 996. You wouldn't get it if the cap sat straight on top of the engine, avoiding the change in temperature.
meerkat911 said:
In terms of the creamy residue in the oil cap and filler pipe, mine does that even though it uses no oil or coolant. It is made worse if the car is not brought to full operating temperature for long enough during drives. It is a mixture of oil and condensation from engine parts that cools and deposits in the extended filler pipe on the 996. You wouldn't get it if the cap sat straight on top of the engine, avoiding the change in temperature.
+1. So does mine. Scared me witless the first time I saw it but a quick internet search revealed it's perfectly normal and nothing to worry about. As Meerkat says, more common if you do short journeys.Gassing Station | 911/Carrera GT | Top of Page | What's New | My Stuff