Just noticed this while freeing off a brake caliper and wondered if they are connected.

That is if the OF housing is leaking oil into coolant where it enters the block?

I,ve seen some reports of a gasket on the housing failing allowing the oil past into the coolant but not sure if the design of the oil cooler on the mk1 allows this or if the coolant is only contained in the aluminium tank and does not get channeled into the OF housing?

I,m just trying to decide if I buy the OF housing and the oil cooler as I don't fancy dropping the oil and coolant twice if i need both parts to rectify matters.

I guess it could still be the head gasket that is leaking and the external oil leak around the sump OF housing could be two separate issues.

The car has done 158K and is running fine with no evidence of water in the oil or over pressure in the coolant expansion tank.

I,m going to clean the engine this weekend to establish where the oil is leaking and then will get the parts in if anyone has any words of wisdom, TIA .

The oil cooler has its own coolant feed pipes, not from the block, so any mixing there would be happening inside the cooler.

I can't remember the price of a filter housing unit off hand but I don't think it was that expensive.

Word of warning, if you have to take the housing off at all, have a new gasket ready to go on. If it's leaking already, it's highly likely that the leak will be worse when you put the cooler back on no matter how much you tighten the bolts.

Good luck!

Thks for the tip much appreciated, this evening I managed to syringe the coolant bottle and the coolant is a nice shade of red. I think it's just the bottle thats dirty from the time I ran some sealant thrugh the system.

It looks like it is just the oil leak to sort so will clean up the engine as planned and report back.

Cheers

Does anyone know the size of the four 12 point bolt heads on the housing, I need to get a socket as the allen key bits i have seem a bit too lose to apply a lot of force and I dont want to round off any of the bolts.

7 hours ago, cello said:

Does anyone know the size of the four 12 point bolt heads on the housing, I need to get a socket as the allen key bits i have seem a bit too lose to apply a lot of force and I dont want to round off any of the bolts.

No, well not beyond that "Allen keys" are 6 (SIX) point heads, not 12 so it's no wonder that they don't fit right. I don't even know if the bolt heads are triple squares offset by 30 degrees or bi-hexagon.

They may well be triple square spline. VW/Skoda use them quite a lot. Different from torq although they could be torq as well if they have 12 splines.

Alasdair

Torx are a 6-point design

Will try to look up what these are via parts catalogue.

Look like these?

12-point bi-hex 9mm I expect, since they're M7 screws.

21 minutes ago, Breezy_Pete said:

Torx are a 6-point design

Will try to look up what these are via parts catalogue.

Sorry meant standard spline rather than torq. Brain hasn't woken up properly yet.

Alasdair

@Alasdair1 @Breezy_Pete I was talking about recessed drive fittings, not embossed, since @cello specifically talked about "Allen keys" in the OP. I have sets of triple square and bi-hexagon drivers in my tool kit.

Said tool kit is some 200 miles away though.

Can't see for dirt in my pic, but now that you mention it, these might have a tool recess within the head as well as the external 12-point.

Thanks all, yes Pete allen key head and an external 12 point head allin1.

I,m now wondering if the leak is connected to the oil pressure switch above where the filter screws in and the underside oil is related to a leak of the boost pipe squirting a oil mist onto the underside of the sump.

I'll have to pressure wash the engine as there too much crud to make a conslusive call just yet , at least I have the sockets I need on order now , Cheers All :)