Your thoughts on diagnosing this....

[Mike Harding]

Hi all, apologies if I am bombarding with questions, but everyone here is being so helpful, trying not to abuse it !

In my last post (apart from sparking a 'which colour is best' debate by mistake!), I mentioned the starting problems with my new / oldStag. oddly enough it decided to start first time today, ran perfect, slowly coming off choke, I dropped the revs right down before hitting a gear so I didn't get spinal damage, and actually got out of the garage, turned it around and parked on the drive. It started several times no problem, and ran fine. This was a momentus moment. It then decided for no apparent reason to go straight back to refusing to start, end of momentus occasion! Still at least I can now look at it from the front for a while in the garage now! Even after leaving it for 20 mins it was no different - I am still suspecting the coil and ballast resistor so will get them done this weekend.

Round 2. Cooling and my Stag - I expect there may be some good knowledge on this one!

When I got the car the previous owner had experienced an overheating problem. He had the heads off as it had blown a head gasket (they had been done just a few months before and equipped with H/D gaskets), it also has a Kenlowe kit- I don't know if he had them skimmed or not etc. I am trying to get hold of him to find out. When he put it all back together he found it was 'still pressurising the cooling system'in his words. I have never run it up to temp as I want to see if I can find the problem first rather risk blowing head gasketagain (assuming it's not already gone!). A friend with a Stag has looked over it and we were thinking it could be a blocked rad. I am going to have this checked out but decided to take the rad out today and was both suprised and bemused at the outcome. I removed the bottom hose and got about 2 litres of crystal clear tapwater out. The expansion tank has the usual nasty rusty coloured water in! After just 2 litres of water coming out from the bottom hose all dripping stopped. I lifted the rad out and when I tilted it, about another litre came out (half of which was on me!), then, I moved it through 360 degrees and got about half a litre of fresh water with red antifreeze from it! Having a combination of clear water from either the rad or bottom hose, red antifreeze in the rad (very little) and grim rusty water in the expansion tank suggest to me this stuff has not been moving round much!

Daft question probably, but I am concerned by the 'clear water', and assume about 2 litres would have come from both the rad and bottom hose - does this sound about right? I've got not sign of water in the oil, (and no sign of fresh oil after the heads coming off), there is no sign of contamination anywhere and I ran it without the dipstick and there is no signs of pressurising the case either, but when I ran it as soon as it starts to warm up things don't smell to pleasant in the engine bay! But I am not 100% happy that it is not just burning off oil from a possible small leak somewhere, its pretty grubby and oily down the right bank. I just feel that something has got to be causing this and the attention may be more on the effect than cause - the top hose had no coolant at all.

Any thoughts and ideas would be appreciated, if the heads have been done and are not at fault I don't want to rip themboth off for no reason.

PS - tracking history is interesting, Tony Hart confirmed they have reconned it back in 1983, and serviced it later (27 years ago and they have it on record - impressive!).

Thanks, Mike

[mad cyclist]

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if you dont have water in the oil i would flush out or replace the rad, the water should not be clear it should have anti freeze and the rest really should not be rusty..

if an engine has lasted 27 yeras i think you have done well .
rgds Nick

[milothedog]

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Hi there,

The proper way to diagnose a head gasket is with a Block Tester, you should be able to get one from a decent motor factor for under £40. this will show you if there are any combution gases in the cooling system. You could try running it with the filler cap off but because it's such a small opening it would be difficult to see any bubbles (Gases) rising to the top!

Ian,

[MB]

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In bad news checking order for the antifreeze/water not being mixed in the Rad.

1. The rads blocked

2. The thermostat's jammed

3. The water pumps not turning

Your get more water out if you open the drain plugs on either side of the block under the exhaust manifolds.

[Mike Harding]

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Thanks guys, the rad come out easy as it wasn't bolted in, in line with most other things I have found so far. 27 years is impressive without doubt, but it might be a bit like Trigger's broom !

I am gonna gest it tested over at Wessex Rads, these guys were fantastic sorting something else out for me a couple of weeks ago.

Thanks for the Block tester, i'll see if I can borrow one from somewhere if I can't get hold of one, I've not heard of these before, I thought about compression testing it, but assume this is a different technique?

Cheers,

Mike.

[richardthestag]

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re the red antifreeze, i am sure that i read somplace that red and normal green antifreeze (sorry don't know proper names) are totally incompatible with each other and that when mixed a jelly type solution is created which bungs up the rad and heater matrix.
Or did i dream it

[Mike Harding]

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I thought you were not supposed to use red antifreeze with alloy too? May be wrong but I thought it was an antifreeze for winter but not a coolant for summer, and potentially erodes alloy? I used to sell the stuff years ago in a car shop, but can't remember as 20 years has gone by - more concerned that the rad could be blocked and that the dribble of red may have been from the 'past' and it has actually been filled up with simple tap water.

Thanks for the tip on the drain plugs on the block, I was wondering how to get the rest out, it apparently holds 10.5 litres, I'm lucky if I have 2!

Mike

[milothedog]

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For your info, all a block tester does is it draws in some of the air above the water level in the expansion tank through a fluid in a glass tube, my one uses a green fluid. if combustion gases are detected it turns yellow which means bad news!

Ian.

[Stagdad]

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Mike Harding wrote:

Thanks for the Block tester, i'll see if I can borrow one from somewhere if I can't get hold of one, I've not heard of these before, I thought about compression testing it, but assume this is a different technique?

Cheers,

Mike.

What Ian said

[flying farmer]

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You will never get any circulation of coolant if there are only a couple of litres in there as the water pump is trying to pump air.

Probably explains the bad smells in the engine bay as parts of the engine that should be water cooled are only air cooled:shock:

When you get the rad back in make sure it is properly filled with a 30% mix of traditional green or blue antifreeze and look for the inevitable leak, all that coolant must have gone somewhere!

Neil

[V Mad]

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Red antifreeze is usually the modern (OAT) version suitable for modern engines.

Some types (not all)of this red antifreeze, if combined with the old ethylene glycol stuff will turn to jelly and block your waterways. This could be the cause of the overheating.

There is no circulation of coolant in the expansion bottle so the state of the coolant in there is no indication of the sate of the coolant in the remainder of the system.

If you have the rad tested and that is clear the rest isprobably are OK. In that case remove both block drain plugs and drain off and flush outall red fluid. Then, if the rad is good, refit it andfill the whole system (via the top rad plug)with blue (2 or 3 year) ethylene glycol antifeeze (Bluecol etc).

Run the engine and top up again. The overflow bottle should be filled to 1/3 then put the cap back on and leave it alone. Dont remove the cap unless the rad plug is on or the botlle will fill up.

[Arbman Al]

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A couple of additional points:

When you remove the engine drain plugs they could well be blocked up with crusty sludge, so have a dig around with a welding rod or similar.

When refilling put heater control to hot, and it helps to jack up the front nearside as high as possible, it helps to get air out whilst filling.

Good luck
Al

[Mike Harding]

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Hi everyone,

Progress of a kind - I took the rad down to Wessex rads, they have pressure tested it and flow tested and said the core was as good as new! They did find the joint for the lower hose was leaking however - maybe this explains why things were getting so hot, when I pulled the bottom hose off I only got about 2 litres of water out and the top hose was bone dry.

They are giving it a clean up and repaint for me this afternoon, I am hoping to get it back in tomorrow and take it from there.

I was thinking of running without a stat to keep flow going well (or with the guts of it out - is this recommended ?

PS - I am seriously impressed with the Wessex Rads guys, tested, repaired and repainted for £28 + VAT - I think thats pretty good going!

Regards,

Mike

[milothedog]

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"Under no circumstances run it without a thermostat" tears will follow:shock:

Ian.

[singapore stag]

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When thethermostat is closed, cold engine, the cooling water circulates through the by-pass without going through the radiator to speed up engine warming.

When thethermostat is fully open,no water flows through the by-pass and all the water flows through the radiator.

Withnothermostat fitted, at all times you have water flowing through the radiator and at the same time the by-pass. So you have a % of hot water leaving the engine and going straight back into the water pump cover uncooled at all times. Not good.

Thus you must never run a stag without a thermostat.

Withnothermostat it will take longer to reach normal running temperature.

Once you reach normal running temperature you have reduced cooling because hot water can still by-pass back into the engine.

So short runs would be okay until you reach normal running temperature...which take longer...then long runs could be problem...

Sukh.

The above explanation Coutesy of MJheathcote.