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Hello All,

 

My cooling system has been a tale of woe since I first fired the engine (2 litre pinto) up during my build. I fitted a new head gasket as I had unleaded valve seats fitted, so when my bottom hose split during my IVA test, I never even considered the head gasket as the problem.

 

Having replaced the radiator with a Polo unit, got rid of the header tank for an inline filler neck and overflow bottle and fitting silicone hoses, the thing still overheated and leaked every time I drove the car.

 

Amongst all the jobs I have done over the winter, I replaced the jubilee clips with proper hose clamps, topped up the fluid and thought nothing more about it until last week when I checked everything over before putting it back on the road. The water level had dropped, so I checked the compression, the results are 1: 110, 2: 78, 3: 111, 4: 118.

 

I tried some oil down the cylinder and the figures stayed the same. Do those figures look like a knackered head gasket.? I thought 2 cylinders were down when a head gasket failed?

 

Cheers

Nige

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Depends on where the failure is, if it's betweeen two cylinders then yes you'll have low readings on two cylinders, but if it's gone between a cylinder and a waterway then you you may get the symptoms you desrcibe.

You could try one of the kits that detects exhaust products in the coolant.

For the sake of an hours work I'd be tempted to whip the head off and look for signs of damage on the gasket, then if it's that it's only a couple of hours to ut it back together.

If you need a lift i'm only down the road

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Hi. A wet test proves either valves/head fault against piston rings.

If rings are gone, your reading improve when you use oil. If it's valves or head the readings would rise except on the faulty cylinder.

Your head definitely neads removing for further diagnosis.

As long as you know how to time up your cam on rebuild, Pinto engines are not to difficult work on.

I would still accept Steves generous offer though.

Regards, Ken.

 

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Any indications of where the water is going?

There is a test that can be carried out at a garage where the cylinders can be pressurised with air, which gives a good indication of piston/ring failure.

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Certainly having one cylinder giving a reading significantly below the other three, even after a wet test, leads to strong suspicion of a problem in cylinder 2 and it could be a head gasket failure, (or valve damage or cracked cylinder head or block or major ring break up) but it doesn't confirm it. Don't rush to haul the cylinder head off. You may not be able to see the problem. Do a running test for exhaust fumes and if you can a cylinder leakdown test. These should confirm a leak from number 2 into the water jacket. Then take the head off. Careful inspection of components should then be done. Hopefully the failure will be obvious. I note that this engine has always 'overheated' which needs thought but may just mean that there has always been the same problem. Just don't assume a new head gasket will sort it. Try to identify it first.

 

Nigel

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Maybe Im trying to teach grandma to suck eggs, but my school boy error was not to clean the oil completely out of the head bolt holes. When the head was torqued down, oil then flooded onto the gasket/head surface and blew the gasket within a couple of hours.

 

 

 

 

And lets not forget the pinto is a **tch sometimes to get air locks out.

Andi

Edited by Andi
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I've a spare head gasket if you need it

peter2b

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Hi All,

 

Well I found the reason why No 2 cylinder compression was low, the inlet valve was wrongly adjusted so never actually closed. I also took the top hose off and the water level was actually in the neck of the thermostat housing level with the water in the rad. I have a small hole drilled in the thermostat so water did have somewhere to go.

 

My question is: would a wrongly adjusted inlet valve cause the engine too run hot? (it was way out)

 

It's worth noting that I've never actually managed to stop the engine from running on the rich side and it's always been a bit "sooty" when cold, I have blamed this on a worn carburetor as it was the same after I serviced the carburetor.

 

I'm just trying to eliminate everything before this gets expensive! :wacko:

 

Many Thanks

Nige

Edited by ECAM

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One valve gap would not lead to overheating, just a burnt out valve.

You will need to carry out a further compression test, after adjustment, to make sure this has not unfortunately happened to your engine.

Week mixture causes overheating and valve burn out as burn temperatures are much higher .

Soot could be through air starvation or overfuelling through wrong jetting or more commonly faulty chokes.

It would not Cause overheating, just clog up your spark plugs and eventually stall the engine. Also possibly poor hot starting.

If your coolant in the engine was at the same height in the radiator, that would mean it has found its own level as it should. Try poring some into your rad, blanking off the hose fitting on the rad. Water should now rise in the thermostat housing. If it does there's nowt blooming wrong wi that laddy.

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I hope you found that before you pulled the head off. If you are running a standard carb from the pinto with four runners coming from the plenum below the carb the goodness knows what effect a pulse of burnt gas blowing back into the plenum every fourth bang would do. Certainly worth adjusting the valve gaps, all of them, and giving it a run. Let it run up to temperature with the rad cap off and you topping up the rad almost continually to keep it full and let it bleed the air out. You would also be able to watch for bubbles which should stop after 20 minutes or so.

Fingers crossed.

 

Nigel

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Thanks for the replies :) I had exactly the same thoughts about what effects this valve would have, it doesn't seem to have caused more wear on the cam lobe and when I think about it I remember a couple of times when there were "pops" from the carburetor that led me to check the timing.

 

I haven't actually used the car that much, I've run the engine during the build, whilst playing with the cooling, at the IVA and a few spins round the block, so it's never been driven hard. Whilst it's an ancient engine, it looked to be in good enough condition not to start having it re-bored etc. for a car that never is going to do high miles.

 

All I can think about the inlet valve adjustment, is that I just missed adjusting the valve completely when I refitted the valves after the unleaded seats were done, all the others were perfect.

 

I'll put it back together get the gunson out to check the mixture, run it with the cap off and see where I go from there.

 

Cheers

Nige

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If you have the head off then you should take the opportunity to run through all the checks as above. Just because you found one problem doesn't mean it was the only problem.

 

Nigel

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Check your new unleaded valve seats carefully.

I had one crack in a modified head, that upset the valve clearance badly over a period of time.

It took some finding. IIRC it was an exhaust valve that kept closing up..ie staying open.

it made a b&*^%y funny noise in the exhaust.

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