herald 1500 overheating and clutch slip

[aldea]

I have a 1966 herald with a 1500 spitfire engine and box fitted with overdrive, The radiator is standard herald, would I be better fitting the spitfire one with the expansion tank as It overheats after 8 miles or head gasket replacement first (compression good on all four cylinders) AND i get clutch slip but it's a brand new clutch complete could this be a faulty overdrive?? thanks

[Richard B]

I would go for an full width radiator; possibly with a shroud.

There been various discussions regarding Herald/Spitfire clutches. You can do a search for them But the slave cylinder may be preventing the clutch from fully releasing.

[Randal]

When you changed the clutch did you put any of that slick additive in the box?

I did a few years ago and the clutch immeduately started to slip I cured it by draining it all out and replacing with just gear box oil.

Dont exacyly know what went wrong but i was told it had something to do with rubber seals not liking the additive.

[Steve Cureton]

A standard radiator won't cause it to overheat after just 8 miles. I suspect you have a warped cylinder head if it's getting through head gaskets and over-heating.

[Pete Lewis]

are you sure its actually 'HOT' and not a duff gauge reading, does it blow out any coolant from the overflow ??

when was the thermostat last changed ,  is it an 82 88 or even higher 1  , 88 or silly 91 would give high gauge readings as would a duff sender unit or, if you have one, the gauge voltage stabiliser
check its output  is switching    doing 10.5-0-10.5  

dont take the head off if compressions are all even and there;s no coolant loss,, do the simple things first.

check  the bypass tube under the manifold is not blocked  ???  including the heater valve.

just some thoughts     Pete

[Jonny-Jimbo]

Bottle of rad flush and rad weld. Clears out all the bollox that's built up over the years, costs about £5 for the two bottles. Bit of faffing around, but not hard, just involves draining the rad and block a few times.

[Paudman]

And make sure the waterways aren't blocked with crud or scale - this is what I found when I took the GT6 head off last week. This was an unleaded head purchased around 2005 and the rubbish that has fallen out of it ever since is unbelievable. Hopefully the necessary parts were replaced for the unleaded conversion but the waterways were left very much alone, and the amount of rubbish that fell out in transit was amazing - I thought I had blown / hosed / cleaned it out before fitting but as you can see there's still things dropping out four years later.
Colin

[Jonny-Jimbo]

Speaking of getting all the munk and gunk out of heads and blocks and so forth, has anyone ever had their bits (ahem) vibration cleaned?

[aldea]

Thanks everybody for your help, I try what you have suggested as soon as its stops snowing!!! I have removed the thermostat flushed and reverse flushed the system, yes it does blow out from the overflow

[herald948]

1689 wrote:

Thanks everybody for your help, I try what you have suggested as soon as its stops snowing!!! I have removed the thermostat flushed and reverse flushed the system, yes it does blow out from the overflow

But does it "blow out" from the block drain?

[Clive]

So, the first thing, as above, is to drain the water, remove some rubber hoses (i take off the 2 to the heater, plus the 2 radiator hoses) and undo the drain plug on the egine block (hear the back of the engine, under the manifolds) May well be worth taking the thermostat cover off, and getting an 82 degree replacement while you are at it.
Put a garden hose on/in each position on the engine, radiator and heater in turn, I start at the front, and like to see a good flow out that rear plug. If not poke about in there with some wire. Go round each several times until no more crud comes out. Reassmble, and put some radflush in and follow the instructions. Flush this out and hopefully even more crud will emerge, but you should only need to undo the bottom rad hose. Fill with water for now, and test run. If it still overheats then you may well need a replacement radiator...they can get blocked and will not flush out if bad.
Re clutch slip, when does it do it? all the time, just when warm? I had an overdrive slip, felt odd, as it happened when you took your foot off the accelerator, but if it not the clutch then yep, the overdrive is prime suspect.
Oh, as a reminder, I said refill with water to test the car, just in case it needed draining etc again. DO refill with antifreeze or you will have other problems to deal with!

[Fizzy]

it is worth checking the guage is reading correctly. the guage on my spitfire is ALWAYS at least 3/4 of the way across once its warm, but when i put a temp sensor directly into the rad pipe, the water wasn't even hot enough to open the thermostat.

[Jonny-Jimbo]

It's a fair point Fizzy - my Vitesse gauge goes straight round to hot. Annoyingly I think the car does run very hot.

[Zendervision]

My temp gauge also shot to around 3/4 after the car had been running a minute or two. As I was buying an oil pressure gauge anyway I replaced it with one of those capillary oil/water combo types. Expensive, but saves me a bit of worry. Looks smart too.

[Paudman]

cliftyhanger wrote:

S
Put a garden hose on/in each position on the engine, radiator and heater in turn, I start at the front, and like to see a good flow out that rear plug. If not poke about in there with some wire.

Me too! In fact I like to attach a hose to the drain plug and fill the engine from below, so to speak, then let it drain back out by unscrewing the plug so the aperture is at its' largest. You would really be amazed at what falls out of a supposedly clean engine.