Oil in coolant

[Andy McGhee]

Hi all
I recently (2,000 miles ago) replaced the head on my F6 van, which had then done 172,000 miles. There was clearly something wrong with the original head; the van lacked power and I suspected there was a valve problem. When I removed the head, I saw immediately what the problem was - one of the exhaust valve seats had receded so far into the head that the valve had burnt badly.
Anyway, I fitted a good second-hand head, ran the van for 500 miles and then retorqued the head bolts; everything seemed fine for the next 1,500 miles. However, yesterday I noticed that the coolant level in the expansion bottle had dropped, and (more worryingly) that there was a little oil in the coolant. There are no overheating issues, no bubbles in the coolant, no sludge on the oil filler cap and no water on the dipstick. I retorqued the bolts this morning and rechecked the valve clearances.
I replaced the head on my GTL 50,000 miles ago - absolutely no problems since then - and followed the same procedure with the van. I was careful not to disturb the liners, and cleaned out the head bolt holes (I suppose one or two drops of oil might have got into the coolant while the head was off, though!). The new head wasn't skimmed, but I checked it pretty carefully with a straight edge.

Would really appreciate your advice on this.
Thanks
Andy

 

[angel]

When you say "a little oil", how much do you mean?

From what you describe, it seems that there is nothing seriously wrong. It may be the head gasket itself. Recently, I had a problem with a Peugeot 204 head gasket that I had just replaced, that leaked oil at the region adjacent to the oil feed to the head, and another with a Mini that weeped coolant around the head before I even fired the engine! Both problems disappeared when I replaced the head gaskets with another manufacturer's ones (coincidentally both of them were Ajusa, although i never had any problems with these.).
It seems that spare parts manufacturers don't pay too much attention on parts for older vehicles, or what?

 

[Andy McGhee]

Thanks, Angel.
There was a small (3-4mm) spot of oil in the expansion chamber, and obviously a light film on the surface. I emptied the bottle and refilled it with fresh coolant; after a short run (20 miles), the light film is back. I can also smell oil in the bottle.
I don't really want to go the trouble of replacing the gasket if there's nothing seriously wrong; the van runs well and doesn't overheat - do you think it'll be okay for a few months?
I used a good-quality (Payen) gasket set - has anyone had problems with them?

 

[Steve Hennessey]

Andy, it is possible that the oil may have been present in the water holes on the second-hand head. Just need to keep an eye on it.
Before you fitted the head did you have it checked for straightness? When you retorqued the head bolts did you undo them one turn first?

For the record I always recommend checking aluminium heads for straightness and skimming if there is any doubt.

 

[Andy McGhee]

Thanks, Steve - fingers crossed that that's where the oil's from, although the 'new' head's been in my shed for a while; I cleaned it/reground the valves two or three years ago. I didn't have it checked, so I suppose that could be the problem (although there's no overheating). I checked it as carefully as I could myself, though. Having said that, I removed it years ago from a van with an unknown history.
I'm tempted to leave things as they are for the moment. Perhaps I should drain/flush and refill the cooling system and see if the problem disappears?