- My model of MX-5 is: __NC 2.0 Launch edition
- I’m based near: __Essex
- I’m looking for technical help or recommendations on: __engine faults.
Having done my own engine service, oil, filter, spark plugs I now have an issue where the engine is burning oil being fed through the crank case ventilation pipe. After a drive I notice that the engine is running poorly at idle and on removal and inspection of the air intake hose and intake there is pooling of creamy bubbly oil. I don’t know if it could be over filling with engine oil or something else. Any ideas are welcome.
Chris
Is it creamy inside cam-box and under the oil filler cap?
If so, that is a water leak into the oil system, maybe the head gasket.
That might be expensive.
Seek expert eyes-on advice.
creamy bubbly oil.
Back in the day that was sign of emulsified oil that was being cooled in rocker covers. Also oil turns milky brown when its been contaminated with water.
I don’t know if it could be over filling with engine oil or something else
How far up the dipstick is it showing?
Well, I have seen overfilled cars before and I have personally overfilled my own car and I can report for the large part that you have to SERIOUSLY overfill for it to make any real difference and risk causing damage. Most of the time it just results in a bit more oil sitting in the sump, and the first negative effect is when the level is actually high enough for the crankshaft to slap the surface of the oil, causing resistance and thus strain for the crank, rods and pistons and also disturbing the pool of oil in the sump, causing the uptake of oil by the pickup to be sub-optimal.
Is your PCV valve worn out and stuck open, perhaps? I would check that before anything else, but if the cause is excess pressure, rather than a failed PCVV, then I would assume your piston rings have a little problem and you’re getting blowby.
I have been checking my oil levels but on an incline facing forward and noticed a drop in oil level. However last night I had the car on a level surface and found this morning that the oil level is now perfect.
So I definitely did overfill , the engine is running steady now with some tapping noise. Have not checked the the intake yet.
I have ordered a new PCV valve but it seems that this doesn’t fit to the ventilation pipe but somewhere else?
The PCV valve is located under the intake manifold. Not the work of a moment to change.
Oh, damn, didn’t realise it was so tucked away… Sorry, I’m so used to the older cars, where it’s just sitting right in front of you when you open the bonnet. Does the car smoke at all, especially at high revs? How do you know you are burning oil aside from seeing it in the intake? Did you see it in the intake MANIFOLD or just the intake? What exactly does “running poorly at idle” entail?
OK, so first you actually need to get several oil readings ON LEVEL GROUND under the same conditions, you’re starting to really confuse me. You should really be doing oil changes on level ground in the first place, unless you are measuring how much comes out and how much goes in. You haven’t checked the intake yet? But you found oil in your intake, so you have checked that, or you mean you have not checked it since? So you cleaned the oil out and you’re checking to see if you find any more?
You can check your spark plugs to get some idea of what’s going on in your cylinders, normally burning oil is quite obvious on the plug.
I generally use the car daily so getting home when its dark. I looked again at lunch time today and there is definitely oil still being sucked through the ventilator hose and into the intake, even with the oil at the correct level in the engine. I removed a spark plug and that was black and the exhaust is black too but no smoke coming out.
When renewing the oil I did pour the oil in when the car was on level ground but, for me , its hard to make out the exact reading on the dipstick. Mind you with a 5 litre can of oil and approximately 0.5L left in the can id guess that 4.5l was poured in.
upon changing the spark plugs I did crack 2 and some small fragments of the porcelain fell into the cylinder head however I used a suction tool to get most of the porcelain out but no all.
The engine now has a tendency to blip up and down in idle, where it didn’t before, but actually its performance is better, pulls harder (maybe because of the new spark plugs) And there is the clicking sound from the valves.
I am away for a couple of weeks now but booked the car in for an engine check for when I get back