Marea 1.8 16v - Oil leaking through studs of exhaust manifold

I have recently discovered an external oil leak on my Marea 1.8 16v.

It appears that oil is leaking at the outer studs of the exhaust manifold.

I initially suspected the cylinder head gasket but I have ruled this out as the gasket is located lower than the manifold, it is dry and there can be now way the oil can find its way from it into the studs.

Any idea what can be the cause?

Do the studs penetrate oil channels in the cylinder head?

Is this a common problem?

This appears to be quite common on some Alfa Romeo engines.

Blocked PCV valve?

MrMigs08 said:

Blocked PCV valve?

Click to expand...

Thanks for the response.

I haven't checked that yet, will do in a couple of days. I am going to renew the carter hose as it is cracked so I will come across it.

By the way, does the 1.8 16v engine have a PCV valve in the first place? I'm questioning it as my Fiat agent looked it up in the parts manual and it didn't show up.

I called the agent today about this leak and according to them this leakage can come from the oil channels. I've been advised to remove the leaking studs, clean them and the holes and fit them again with loctite.

Any experience with this??

Ehh, i wouldn't block them off just yet as the leak may be venting excess pressure from something, it might be helping you in some way, its quite unknown yet.

Whats your oil level like by the way?, on my fiat, they decided to do the PCV return back into the air intake on the inlet rubber piping, so if you wan't to take a picture of the air intake system (The rubber bit) i will attempt to help you identify it, i wouldn't locktite anything just yet thought mate.

Migs

Hi Migs,

The engine does have carter overpressure. When I bought the car 6 yrs ago, I had the engine checked due to this. The cylinder pressures were found normal. The garage claimed that the carter ventilation was also good however I can see that the pcv (if fitted) was not removed as the hose still has the factory clips. the garage advised me to use a thicker grade oil, which I never did.

The engine does consume oil and I top it up now and then.

I have tried to attach a pic of the carter vent hose. it's in JPG format with only 135 kB. But I can't manage. It takes hours uploading with no result. is this normal?? I'm also a member of the Alfa Romeo BB forum and there it's not a problem.

Anyway, i will try and explain how it looks like. It's Y shaped with a very long foot. Like this: ------<. The two ends (branches) are short. The foot (left end of the symbol I drew) goes in the tappet cover. If there is a pcv valve, then it would go at one of the other ends.

What do you think?

I'm also curious to know where the hose has been exactly attached on the inlet hose on your car. Wouldn't this affect the engine performance?

Joseph

You can see the return feed into the inlet piping before the inlet manifold, you can also see that pressure is relieved off through the oil feed

And yes, i think it is contributing to problems, i have an issue where i have to clean my sensors weekly because they keep getting wet with something (Petrolly smelling Imo)

Maybe your 1.8 is similar?

I need to get a filter for the pcv piping really, i have one but it has a split end!

Shouldnt be too much though.

It now appears that the oil is seeping between the cylinder head and the gasket right in the corner next to Cylinder 4 exhaust outlet. There is an oil galley there.

I have had the suggestion to re-check the torque of the head bolts and eventually tighten a bit (after 100.000 kms!!). However I have no idea to what torque I have to do this. Originally, the bolts are torqued to 40Nm and then three times 90 degrees. I can never know the final torque value.

Any clever suggestions?? Of course the chance is that this does not work however I've heard of cases when it did. The leakage is minimal.