Rupert is pressurising its cooling system! Bugger

[richardthestag]

Last year, due to serious illness in the family, I only managed to clock up 350 miles in the old Stag. So maybe a 400mile round trip to Devon this weekend might be a tall order for it. You wouldn’t have thought so.

Saturday morning set off from HW and all is very well indeed. Got as far as Swindon exit and the low water light is on, thank the Lord for the header tank and switch. Investigation found the header tank to be low but there was also an ominous hissing noise from somewhere on the engine! Unfortunately my hearing is bad and I could not place exactly where the noise was coming from. I then realised that I had left my toolkit in the Range Rover back home. I decided to top up the coolant and go in search of a halfrauds. Releasing the pressure cap carefully let an awful lot of pressure out of the system, the top hose was hard to compress. No water came out! I did manage to get 3 litres of water back in, oops. Meanwhile a copper, young enough to be my son etc, came over and complemented me on the gorgeous car, what is it? etc etc.

After a nice chat I confidently set off into Swindon. Low water light off, water temp normal, engine running sweetly. Found an Esso garage and asked if they had any screw drivers for sale, nope but they could sell me hair straightners or a pot noodle. The chap behind the counter did offer me one out of his toolbox though, what a nice bloke. I nipped all the hoseclips up, none were that loose. I also refilled my 2 litre pepsi bottle with water and set off west again.

Stopped just up the road at the services just after Chippenham junction and while the water level had gone down a little, it seemed ok so I carried on. The light went on just as I exited the m4 for the m5 south, then went out. It came back on again as I went over the bridge at Avonmouth, so I pulled into Gordano services. Released a wedge of pressure from the header and when the pressure filled the header tank I sealed it again. Didn’t add any water until I exited m5 j27. It then took another 2 litres to brim it. This got me to dads house. All the way down the m5 I got the occasional but very strong whiff of coolant. The temp gauge never went above normal, I was running fast but it was drinking the fuel. It needed another 2 litres after cooling down next morning. So nearly 7 litres of water to do 190miles, not good, though some off that did overflow as I released pressure from the header tank.

That evening and after the South Molton Vintage Rally, I k-sealed it, double checked all the hose clips but knew that to be a futile gesture, I did however discover that the rh carb choke was jammed open, I flicked it closed and then plusgassed it and it moved freely. That explains the petrol consumption. Dad reckoned that the hissing noise was from the header tank, it can only have been the pressure cap, we tried another from his Land Rover but then a fine summers evening and several very large g&t’s got in the way so never tested it any further.

On the way back home on Sunday it got to the M5 before the low level light came on and took 2 litres. Next stop was cribbs causeway where I bought another rad cap from Halfords although only 15lb. This got me to the Chippenham services, I put the original 20lb cap back on and gave it 3litre drink, got as far as Membury for 2 litres, then Reading for another 2 litres and then home. Nice relaxing journey.

Oil pressure remains excellent, temp remains normal, engine is sweet and runs beautifully. Just every 5 mins or so I get a horrendous whiff of coolant as I expect it ejects out of the header tank.

Tonight I pulled all the plugs out for a compression test. Did it from cold, all cylinders except 2 and 4 where 145-150psi. 2 was 135 and 4 was 130. Then retested 2 and 4 with a squirt of engine oil and they both went to 150psi. Interestingly while doing the compression test every now and then I got a whiff of coolant. Oil in uncontaminated, I haven’t done a sniff test on the coolant, when running hot with the cap off there is some foam in the header but no big bubbles. Foam could just be the water pump thrashing around. The foam had no substance when rubbing between my fingers. No oil etc

The plugs gaps were all on the nail. Plugs 1,5 were coked up. 1 and 7 were sparkly clean and the rest looked normal. I am using denso w16ep-u plugs they are equivalent to NGK BP5ES plugs, so should be ok. plug #2 is top right, #7 is bottom left.IMAG0536.jpg

So, sorry for the long post but the old girl did the 400mile round trip just with a shed load of careful nursing. The cooling system still pressurises under load but behaves normally while my head is under the bonnet.

What next? Heads off? I will go for a new cap first but with normal running and 1/3 on the temp gauge I wouldn’t expect a 15lb cap to be venting. The 20lb cap looks good, has all its seals. When I did release the cap when hot to top the old bugger up it still had huge pressure behind it.

[GTJones]

Hi Richard

Before you take the heads off would be worth checking a couple of things first.

1. Is there any coolant in the V? - this would indicate inlet manifold failure?
2. I presume you have a header tank above the pump? if so did you make sure there was no air in the system, not only fill from the header tank cap but also remove the plug on the rad until it overflows, tighten it up then add more coolant to the header
3. Check the oil via the dip stick to see if it is creamy? if so indicates head gasket failure.

I am sure you will get more advise soon

Gary

[richardthestag]

Hi Gary

1. yep, there is always coolant in the v (they all do that sir) Probably from the water pump seeping when cold. Could inlet leak cause the system to pressurise? I though only exhaust or compression could do that?
2. My header tank is plumbed in above the pump and it feeds from the union on the top of the rad, as per vmad solution. It is impossible to get an airlock in the top of the rad
3. Oil is fine, no cream, no oil in the coolant either but it is definately pressurising. Going to try a new rad cap when it arrives just to be sure that it is not the weak spot.

Cheers

Richard

[Ian Durrant]

Hi Richard. You do realise the system is under hefty pressure when its running absolutely normally at normal temperature With a 20 psi cap the top hose will become extremely firm even without gas pressuriation.Actually if you think about it its a bad test for gasket issues as the max pressure in the hose is 20psi regardless of the method of pressurisation!!! However two of those plugs do look a bit suspiciously clean. I would run it up to temperature, remove the plugs and crank it over to see if any water is ejected from the plug holes. If none is, then you really need to get a block tester kit which uses a chemical that changes colour if there are combustion gases in the cooling system. These two tests are the only absolutely foolproof ways of checking for head gasket issues. I know I have removed a head off mine in the past with suspected gasket failure and have absolutely failed to find any evidence of a leak by examining the gaskets. If I remember correctly I eventually traced the coolant loss to a heater hose that was leaking behind the bulkhead insulation so preventing the leak being seen!

[Stagsongas]

Richard,

Just two things for you consider before removing the heads;

Did you bleed the heater throughly with the lever/valve set to 'hot' and with the engine running? If not, it's worth a shot.

I have a lot of experience with the RV8 cylinder liner / block problem and because of that I devised a reasonably accurate and quite cheap way of diagnosing cylinder coolant ingress;

1. Select the tool of your choice (3/8" or 1/4" long extension, pozi screwdriver or whatever you can reliably poke (but not lose down) every sparkplug hole. A tool with a bright chrome finish seems best.

2. Place selected tool in the freezer for an hour.

3. Run engine. When it is fully hot, stop it, whip out all 8 plugs, poke the tool down all of the plug holes with the piston close to BDC and look very carefully for condensation on the surface of the tool upon removal.

This check is not absolute proof that no coolant is being inducted, but if you get condensation even from only one cylinder, it absolutely confirms that there is coolant induction and head removal is the right thing to do. Apart from the risk of being caught abusing yet another other kitchen implement by domestic engineering (do not mention the washing machine if visiting!) it is a very cheap test to run.

N.B. you may have to cool more than one tool as they get warm quickly and if so, the condensation may not form.
Most important is that you take out as many tools form the freezer as you put in, you know how this could end.....

Good Luck

Steve

[Paul Goldsmith]

As mentioned above, block tester is essential kit http://www.frost.co.uk/block-testers.html

I recall from our situation some years back, a failing neck on the overflow bottle was allowing air to be sucked in & coolant overflowing. I notice you've a custom header tank but same principle applies about any leak letting in air & forcing coolant out

Also, if the inlet manifold is leaking, this itself could allow coolant down into the cylinders but no gases into the coolant

Best of luck !

[richardthestag]

damn and blast, enter key not working, double damn and blast!!!! evidence tells the story!!!!! I did fit the vmad header tank, quality product and inspires more confidence than the 20+ year old ford xr4i tank that I had before. Plus gives better access etc etc. I brimmed the tank to the neck and ran the engine. Quite a lot of bubbles. Then the test kit arrived yesterday and attached are the pics. IMAG0541.jpgIMAG0546.jpg Heads coming off today! wish me luck

[Goldstar]

Good luck

[Andy Rundell]

The great thing about the block tester is that you now know the score, saves time on discussion that is needed for doing the work
Hope it all goes smoothly!
...... Andy

[richardthestag]

Not a horrific day, at least it was sunny.

First issue was that some of the inlet manifold bolts were very rusty. This took some serious loosening and tighening to get them all out intact. why would they be so rusty? I am sure I lubed them up before they went in last time in 2002. Anyway there are a couple of suspect threads, been helicoiled already what can I do next?

Next problem was n/s head 4th bolt in, was extremely tight. I tried to tighten it and then loosen but it was very reluctant. squirted load of 3in1 and wd40 but evertually it just went crack bugger. Sheared just about where the thread starts, hope there is enough when I get the head off to get the remains out. Anyone else been here?

Not snapped any studs yet. 4 are out, one came out without the double nut method . The others are tighter than a camels arse in a sandstorm and all those sharp edges and my habit of shaving chunks off my knuckles means I chickened out. Next step is the Hart stud extractor - at least my hands will be clear

Loads of lube down the stud holes. The stuck ones have all had plenty of action from the impact gun today but now all my head nuts are buggered. Good news is that the four that came out are still clean and rust free, showing signs of the grease that I used when they were installed in 1999.

Shopping list is growing

Set in inlet manifold bolts
Set of head bolts and studs
Head Gasket set
Stud Extractor
Oil and antifreeze

Some way to get the remains of the broken bolt out
Some was to recover the thread for the shagged out inlet manifold threads

I will also go for timing cover gaskets, mainly because the chains are 16k miles old and I want to see how far out the tensioners are.

enjoying Gin now in the sunshine, all quiet here as Mrs and kids have gone to the Capital summertime ball at Wem ber ley

[Goldstar]

Richard,, I hope it all goes well but just in case I have a head puller which has been used (not by me) to good effect. I'm only in Henley so just shout if you need it.

[StagnJag]

Probably too late for you now, but if you can still run your engine, get it up to temperature and try and release the studs before it cools down. I've been told by two separate people that it works well. (The studs all came out of my engine using this method).


(You don't need all of the bolts/studs in place to do this - you are taking the heads off anyway so it doesn't matter if anything blows past the head gaskets).


Rgds

Dave

[KOY 23]

Mine too, suggested by the green Dalek man. I had a broken bolt too but just enough thread protruding to get moles onto.

[StagnJag]

Hi Richard

...
3. Check the oil via the dip stick to see if it is creamy? if so indicates head gasket failure.

...

Gary

True, but the Stag Head gasket rarely fails this way as far as I know. The normal method of HGF in the Stag pressurises the cooling system and doesn't affect the oil at all!

Rgds

Dave

[richardthestag]

Richard,, I hope it all goes well but just in case I have a head puller which has been used (not by me) to good effect. I'm only in Henley so just shout if you need it.

Hi

If the head puller is still available I think I am going to need it. PM'ed you

I am travelling down to Devon tonight and will return early Sunday afternoon. Maybe collect.

Else it will be Mr Bottle jack.

Stud puller extracted one snapped 2 despite loads of fluid, easing back and forth and excessive use of the impact wrench etc etc I guess sometimes they dont want to shift.

I am left with 3 but now the thread is starting to go on the puller and my patience is disappearing. Loads of oil down the stud holes and see where it goes.

Cheers

Richard
Edited to add, if anyone in HW area fancies giving me a hand I would be eternally grateful