Help identifying mystery engine part

[voicey]

I am half way through fixing my brother's Peugeot 306 (1.8 16v) engine. One of the core plugs in the cylinder head opened up a big hole and started leaking a lot of water. I have taken the head off to access the plug and am waiting for parts.

When I was looking into the engine bay after the head was removed I noticed this little green plastic part lying in there. It looks like a one way valve - there is a ball bearing at one end held in place with a weak spring. There is a rubber seal at the other end. The part was oily.

I've got no idea where it goes and, despite looking at all the bits I took off, cannot find a suitable looking home for it. Can anyone point me in the right direction please?

Cheers....

[DrDeAtH]

Looks like a breather valve to me. I have no knowledge of that engine though.

[voicey]

A breather valve makes perfect sense (given the location I found it in). Thanks for the help!

[B'stard Child]

No help now I know but I just wondered why if you have the ability to remove a head why you didn't just pull the engine and box out to get access, probably slightly longer time wise but way cheaper in parts costs, head gasket, head bolts, head skim and all the other parts required. Not looking for an argument just trying to understand the logic?

[voicey]

It's a valid question. Firstly, I didn't know the state of the head after it dropped the coolant out on the motorway. Thankfully it is straight and doesn't need to be skimmed.

Also, the car was towed to my parents who are 250 miles away from me. I popped up last weekend to take a look and made the diagnosis. There isn't the space at their house to store an engine out of the car and I didn't have the time/parts to finish the job over the weekend so decided to whip the head off. The head is currently in the loft with the other bits and pieces. The car is parked on the drive to minimise disruption to my parents (I put some oil into the cylinders to stop the pistons seizing/rusting). It's going to be some weeks before I get the time to go back up there to finish the job off.

[CrutyRammers]

Don't think I'd ever remove an engine just to get the head off, unless you absolutely had to.

[B'stard Child]

CrutyRammers said:

Don't think I'd ever remove an engine just to get the head off, unless you absolutely had to.

It's OK to be confused - OP removed the head to access a core plug which had corroded and started leaking - I assumed it wasn't on the head but under it on the block - hence why I asked why he didn't pull the lump out.

OP has provided a good rationale for why he didn't go that route and it make sense to me as they were factors I wasn't aware of.

[voicey]

Yes - the offending core plug was in the head, between the exhaust ports of cylinders #2 & 3. Helpfully, Peugeot installed this engine sloping back towards the car so I couldn't access it from above. Although I could see the plug from underneath (with the exhaust downpipe and manifold removed) I couldn't get any meaningful access as the subframe and steering rack were in the way.

Taking the head off wasn't too bad - the only issue I have is that I can't get the crank pulley off to renew the timing belt. I applied a load of heat to the bolt and my impact wrench (rated at 450Nm) just split the impact socket!

[S0 What]

B'stard Child said:

CrutyRammers said:

Don't think I'd ever remove an engine just to get the head off, unless you absolutely had to.

It's OK to be confused - OP removed the head to access a core plug which had corroded and started leaking - I assumed it wasn't on the head but under it on the block - hence why I asked why he didn't pull the lump out.

OP has provided a good rationale for why he didn't go that route and it make sense to me as they were factors I wasn't aware of.

from the very first post
"One of the core plugs in the cylinder head opened up a big hole and started leaking"
You wern't unaware you simply didn't read the post properly, hense i guess his confusion as to why you wanted the whole engine removed.

[B'stard Child]

S0 What said:

B'stard Child said:

CrutyRammers said:

Don't think I'd ever remove an engine just to get the head off, unless you absolutely had to.

It's OK to be confused - OP removed the head to access a core plug which had corroded and started leaking - I assumed it wasn't on the head but under it on the block - hence why I asked why he didn't pull the lump out.

OP has provided a good rationale for why he didn't go that route and it make sense to me as they were factors I wasn't aware of.

from the very first post
"One of the core plugs in the cylinder head opened up a big hole and started leaking"
You wern't unaware you simply didn't read the post properly, hense i guess his confusion as to why you wanted the whole engine removed.

I hadn't spotted that - thanks for pointing it out.

I think I'd still pull the whole lump rather than remove the head for all the reasons already covered if there wasn't access in situe (but then I don't have the other restrictions - not at home at parents drive etc)

[andyiley]

Personally, I would not have removed the head & would have done it in situ......... But obviously that is assuming I could see the core plug & had access.

[S0 What]

The only reason i can see to remove a whole engine just to do a head core plug is if a new head gasket is not available or expensive/timing chain tensioner is a 1 hit wonder (like the sierra DOHC).