My '72 P6 V8 is back in use on UK roads and once again wearing its silver on black 'K' plates!

Electromagical, I know the stuff, it seems to exist in most old cars, something to do with Joseph Lucas Prince of Darkness
 
My elation was short lived. The rev counter works, but the indicators, oil pressure gauge, fuel gauge and coolant temperature gauge have all given up. Took the rev counter back out, didn't make any difference, all four functions still defunct. I'm stumped. Any helpful hints what to do next?
 
but the indicators, oil pressure gauge, fuel gauge and coolant temperature gauge have all given up.

I take it you mean the indicator tell-tale warning lights rather than the indicators themselves, if so I'd look at the multiplug on the back of the PCB as a first stop.
 
Hello Harvey. I have no indicator lights themselves, no clicking noises from the flasher unit, and no tell-tale warning lights on the dash.
 
I have no indicator lights themselves, no clicking noises from the flasher unit, and no tell-tale warning lights on the dash.

The hazard switch can give problems with the indicators, so I'd operate that a few times to make sure the hazards work, as for the guages, and the indicators for that matter if the hazard switch doesn't fix things, I'd look at the fuses.
 
Doh! I now realise I refitted the rev counter without the thin white plastic insulator that goes between the instrument and the printed circuit board. I think I must have sent it away with the rev counter for repair, and somehow it didn't get returned. Fortunately I have a spare instrument panel, so I've now fitted a spare insulator. Which however hasn't magically restored my gauges to life. I found a blown fuse for the heated rear window. I can't find a fuse for the hazard lights in my car. Looking at a spare old fusebox cover from my miscellaneous parts trove, the hazard light fuse is in the position occupied by the heated rear window fuse in my car. I'm confused.
I have a spare instrument binnacle to hand, albeit without a rev counter. Might I have "cooked" the three gauges that seem to have kicked the bucket by not fitting the insulator?
 
Shouldn’t there be a voltage regulator in the instrument cluster? Maybe that decided to pop it’s clogs.
 
Full function is restored! Thanks for the helpful pointers Harvey!
The problem had nothing at all to do with my having neglected to refit the plastic insulator between the rev counter and the PCB. Nor was the multiplug behind the PCB at fault.
In the fusebox, one of the blade connectors wasn't firmly seated, and had moved backwards out of the fusebox towards the firewall. I simply unmounted the fusebox from the firewall, fumbled out the loose blade connector, and using a teeny tiny watchmakers screwdriver bent the itsy bitsy little retaining tang or tooth outwards, so that when pushed back into place, the blade is now properly located in the fusebox. Voila! Fuse sufficiently gripped. Brake lights, indicators, hazards, tell-tales, oil pressure indicator, fuel gauge and coolant temperature gauge all work again! Yippee!
 
Despite a new filler spout and pressure cap on the radiator, and two new heater hoses to and from the heater matrix, I'm still losing coolant. Now and then I get a whiff of it in the car. I could see dried white spray marks above the fan belt on the underside of the bonnet, and a little puddle of coolant on the top of the timing case where the distributor is clamped. Put a pump on the rad and achieved 3/4 bar, ran the engine, revved it a bit and could see a fine thin spray coming from the right front cylinder bank. Head gasket is leaking. :(:eek:
My mechanic pal suggests trying Holts Rad Weld. I seem to recall having heard it just settles in the rad and clogs the matrix. What do y'all reckon? Worth a shot, or should I just roll my sleeves up and change the gasket, again? If so, just the one, or should one change both head gaskets as a pair? Also, if I'm going to take the head(s) off, should I invest in a new set of head bolts to be absolutely certain that I get the torque spot on? I've no idea how many times the bolts have been torqued by previous owners and wonder if they might have stretched?
 
Nobody wants a head gasket leak :-(

Best practice will definitely be to replace the gasket, but I have recently had good experience of Radweld Plus on a modern car. This isn't as gloopy as the normal Radweld, and works by fine copper particles wedging themselves into the leak. I have a Vauxhall engine with a persistent coolant leak near the EGR valve. After changing its gasket twice, I established that the cylinder head casting is slightly porous. I stuck in some Radweld Plus as a last ditch effort because taking the head off is a major headache on this car (not to mention the expense). Over a year and about 15,000 miles later, it's still going fine. No coolant loss and no problems with the heater or cooling systems.

If you've the time and resources, definitely change your head gasket, but based on my experience, Radweld Plus might be worth a look.
 
always had a bit of coolant loss since i got the car. after changing inlet gasket. all pipes. thermostat gasket, heater coolant pipe under carbs ( with stainless ) still had a vert small but persistent leak .after a run would get few spoonfuls coolant on inlet manifold. despite booting paper. testing wet hot etc was unable to pinpoint what would seem to be a pinhole and steam /misting , collecting into droplets onto manifold. added rad weld ..no more leaks! was concerned about adding any sealer is I dislike any risk clogging rad or pipes , plus I now use waterless coolant. luckily they have advised I can add that so a drivable car though still having minor heating issues in traffic . bought an electric fan to fit and assist cooling in traffic but not yet bought anything to measure temp that i can fit in circuit and auto on/off fan to keep temp normal in heavy slow traffic .
 
Thanks for the input Telford81 and Classicalgreen. With your encouragement I thought I'd try the Radweld approach.
So on Friday I drained the coolant, because I wasn't sure how much antifreeze was in there, and re-filled with new, getting the mixture right. Added half a bottle of Holts Radweld, immediately went for a half hour drive so that the super special Snake Oil gloop could work its dark magic and seal the leaking head gasket from within.
Yeah, right!
Needless to say it, didn't work, and I'm still losing coolant. Herrumph! In fact, I'm losing even more than before!
Damn and blast.
New plan;
I'm going to remove the entire engine and automatic gearbox in my own garage, separate the two (it is finally time for my long awaited manual gearbox swap!!!), strap the engine to a pallet and transport it back across town to Classic Wheels. There my professional mechanic friends and I can take a proper look at the state of things inside. I want to look closely and determine the overall condition of the engine, as I suspect the bearings are all worn to copper! Quite apart from having coolant loss, when I welly it (and to be honest, I do like to press the gas pedal firmly!) the motor sounds knocky and clunky and noisily knackered, to my untrained ears! I reckon at the very least the rocker gear is past its prime, and quite possibly I'll discover more as we inspect.
I've got a sinking feeling this is going to end up being horribly expensive. Watch this space as my tale of woe unfolds...
 
I had parked my car in the workshop I share with some friends over the other side of town on Dec 31st, and not driven it until this afternoon. During January I had the heads off, and availed myself of the opportunity to repaint the intake manifold which had started to peel badly after only a few years since my restoration. I gave everything from the top end a thorough clean and using a straight edge satisfied myself that the heads weren't warped. I've now fitted composite gaskets using a new set of bolts from Rimmer Bros. Reduced compression ratio, because I didn't skim the heads, but hey, I reckon I can live with that! I didn't change the cam and followers or the rocker gear, which my learned friend who fixes classic cars all week for a living pronounced eminently serviceable!
The rocker gear was harder to loosen than the head bolts, and I had pronounced piston crown wash in cylinders 8 and 2, so I reckon I've been driving a V6 since I last did this job in 2015! Last time I used a borrowed torque wrench that must've been out of calibration, and re-used old cylinder head bolts that must've been past their best.
I dropped a quarter inch drive cross head bit into the valley as I was taking off the valve covers, which meant I had to remove the sump to retrieve it. I managed to only strip one brass exhaust nut refitting the downpipes, and shear the head off one 10 UNC bolt holding the choke light switch, which I then drilled right through to the water jacket whilst trying to removing it. Fortunately my fairy godmother, sorry, mechanic friend, rode to my rescue and fixed what I f#*ked up.
I also ham-fistedly managed to break one of the brittle plastic petrol overflow pipes that run along the top of the engine between the valve covers and intake manifold, then down the front of the timing cover. If anybody has one (or a pair) they'd like to sell please don't hesitate to get in touch. I've temporarily bodged the remains by bypassing the clamp on the intake manifold and going diagonally down and forward from the carb to the front of the engine, but it looks really naff!
Anyway, my car is back on the roads, and seems to be retaining all the fresh fluids I filled it up with, and sounds nice with a deep bass rumble, and idles smoothly without hiccuping, and responds to a crack of the whip very responsively. All in all I am very chuffed! Now I am sipping a well earned glass of Bordeaux, and admiring the dire state of my fingernails, or whats left of them, and marvelling at the way my hands smell of motor oil despite ages of scrubbing! All in the life of the hopelessly stricken P6 fanatic!
 
I know, I know. It is about to celebrate four years languishing on a pallet in my lock-up. I sat and had a cup of tea whist I plucked up the courage to turn the ignition and fire up my car this afternoon, and gazed at the shiny gearbox and associated bits'n'pieces. I most certainly don't want to be posting the fifth anniversary of my having taken delivery and bugger all else a year from now. I need to make it happen! When the oil light went out and the pressure gauge went up to the happy zone I ventured forth for a test drive, and then meandered home. No disasters en route, so I can't be that bad a mechanic after all. So here's hoping I can make the manual magic happen in due course...
 
You will, you will, finish the bottle and then resolve to do it before the season opens. I cant tell you how much you will enjoy it when done.
 
So my car runs, but still conks out now and then at idle waiting at traffic lights. Or even when off throttle and slowing towards a red stop light. Dwell angle checked out ok today. I'm at my wits end. Most certainly at the end of my understanding. Guys, help! Short of firing the money cannon, what can I do?
 
Thank you Harvey. Guess its time to fiddle with the carbs. Is it par for the course that changing from tin to composite head gaskets means the carburettors need attention?
 
Thank you Harvey. Guess its time to fiddle with the carbs. Is it par for the course that changing from tin to composite head gaskets means the carburettors need attention?

You'll have a lower cr, so I'd expect to have to richen things up a bit.
 
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