Oil filler neck

[PedigreeChummy]

I am now going through the process of upgrading the cooling on the car, as advised by many on here in recent weeks... 4 blade fan etc. and am at the stage of giving the system a good flush.

This has led me to remove the inlet branch (?) on the side of the block, which is fouled by the oil filler neck which won't budge... before I start "persuading" it a bit, could I check if it is standard or left hand thread, so I don't end up knackering it.

Any tips on the persuasion front greatly appreciated also....

I'm assuming the flushing is a case of rinsing with plenty of water and probing in as far as I can get with a piece of wire to remove the crud?

I'll make sure to prevent any water ingress into the engine by blocking up the filler hole and the dipstick aperture...

Thanks again. Temps touching 40 degrees around here have made it a "must do" job....

[Michael D]

I'm no expert (far from that my lads) but overheating usually is not as much caused by blocked water passages in the engine block itself but by blocked up radiator passages. So I would first of all drain that system, remove and check the radiator.....maybe have a new cooling / radiator block fitted. Actually I'm quite surprised to read about. your Seven overheating as most people claim they run quite cool.. but perhaps southern -France temperatures are at work here.....

IF you do feel the need to do something to water passages in the block and / or head... I'd try blowing it through with high air pressure first; if you think rinsing with water would work than high pressure air would work as well and there's less risk of that water seeping into your sump.

Furthermore IF the block and / or head really need some decrusting then I'd rather rtake the. whole thing apart and have it properly / professionally cleaned; rinsing with water and probing with lengths of wire may then not really be effective....

[bob46320]

I too am in France (SW) and if you search under "Vapour Lock" you will see that on a very hot day, the water temp of our 1932 RN was still only 69 deg C. That is with a modern cored radiator albeit with a false honeycomed mesh in front of it to make it look right, a 4 blade fan and nothing else. My problem is Vapour Lock as the bulkhead tank gets pretty hot. I have now taken advice and re-fashioned the fuel pipe to have a horizontal expansion loop and await some exhaust bandage.

[Chris KC]

In answer to the original question, Ruairidh posted a picture of a jolly good tool a few weeks back so it's worth having a look for that. Failing that, wrap something around the neck to protect it then apply as much heave as you can by means of big mole grips or whatever you have. Just don't grip it so hard in the jaws that you crush the tube. Grip the main 'shaft' of the tube not the top or the two will separate. A bit of gentle heat from a blow torch at the joint may help - or run the engine first.

I certainly agree check the radiator, but I wouldn't shell out for a new one unless I knew the old one was no good. They are not cheap - worth eliminating other factors first. I also agree you need the block off to clean it properly, but having the side branch off will at least enable a glance inside the thing to see what you're up against. It is also a bottleneck where loose crud tends to accumulate. Worth a peep I'd say. The thing to take care of is not to shear the side manifold studs - or worse still the bit of block they screw into - when you undo them, or indeed when you do them up again. This is a weak spot.

I'd run some rad flush through it first, having the side manifold off subsequently will enable you to ensure the resulting debris has not caused a blockage.

[PedigreeChummy]

Thanks chaps.

It's more a precautionary measure on a car I haven't had very long, so don't know the characteristics of through the 4 seasons.

That and the fact there are a lot of inclines around here, an unseasonably hot summer already, and I have had a bit of blowback through the rad cap just make me want to give it all the once over. I had the fan housing off anyway, as it was rattling due to a missing felt washer, so had to fiddle about with the radiator position anyway, so I thought, what the heck, do it all now while the radiator is loose.

Flushed the rad through earlier and the flow seemed very quick in all directions, so I'm pretty satisfied that that is not going to need replacing in the foreseeable, but just wanted to make sure the passage are running clear and fast to avoid having to do it all over again.

So is the filler neck standard thread direction ie. counter clockwise to loosen?

[Reckless Rat]

Yes counter clockwise to loosen. However I will add this caveat - if you have never taken the side water branch off, then you could be opening a can of worms if you do - they are best left well alone. Stripped or sheared studs are very likely and corrosion may have seen off the bit that is threaded. If in doubt about the water circulation properties of the head/block then take the radiator off and flush the block/head through with a hose pipe.

[Chris KC]

Perhaps take the hose off the side manifold so you can squirt/ poke into it without removal? 

When I last flushed my system the side manifold was almost blocked solid. But I share Reckless's fears about the studs.

[PedigreeChummy]

Understood... thanks for the latter two warnings. It is loose now as far as the filler neck, so I will call it a day there, and spray water in through the gap and back, just in case but not go any further with taking the branch off... discretion and valour etc.

[nrzam]

You might want make sure that the overflow pipe just inside the radiator filler isn't blocked. Any blowback at the radiator should go down this rather than out the top. This also allows the water to find its own correct level when hot.

Ian

["Slack Alice" Simon]

I gather you have removed the water branch nuts or studs because "it is loose as far as the filler neck".

In which case, if you are going to have trouble with it, you have incurred the problems already and may as well remove it after you have undone the filler.

A 12"/30cm hacksaw blade is a good thing to poke between the cylinders middle cylinders, and if you can get something like the old curtain wire - maybe an old bike or car brake cable - and run it slowly in an electric drill, that may be fiddled round some of the other passages in the block.

If the water branch and associated opening in the head is clear of gunge then you probably don't have a problem with water passages, anyway.

If it is completely blocked with stuff, you may need "stage two" - which is removing core plugs (you cannot normally get at the rear one) - to get at the gunge, and drilling out (carefully) the water passage holes in the head and the block.

And if the block has lots of stuff, the head passages will need cleaning too.