'NNN' and the overheat saga

[mickthefitter]

I could have posted this on the 'What Have You Done To Your Marina Today?' page, but I felt that I (and it, as in 'NNN') deserved a section to ourselves following the work I've done this weekend, mostly, it seems, to no avail.

Yes, work this weekend. Finally I got some tools out.

Some of you will have heard about my running warm issue, though I've never had 'NNN' boil, and I've already had some advice, particularly from David Painter I think, who recommended I take off the water pump and jetwash the block. This is what I've done in my spare time this Saturday and Sunday.

There was also some question as to the origin of my radiator, as it was sitting funny (having bits of wood locate it at the bottom and it was sitting on some sort of 'tray') and although it took me a while to work out what had been done, I think this is 'NNN's original radiator. I'm going to post a load of pictures (if I can get photo host Photobucket to co-operate) and then comment after, but up front I'll say regarding the rad, the 'tray' is the bottom of the radiator that has either fallen off, or been taken off!

From referencing the Haynes manual, all you people with un-molested Marina radiators have them sitting at the bottom in some rubber grommets pushed into brackets welded to the car chassis. Someone has bolted some black flat plates on mine, forming a bridge across the two structures welded to the chassis each side, and the rubber grommet had been relocated to the middle of the plate.

Then, the 'tray', that is the original bottom of the Marina radiator, is pushed into those grommets - so it is located further back for a 1.8 (I cannot speak for a 1.3, as I have no experience).

On reassembly I discovered that if I sat the rad properly in the 'tray', i.e. its own bottom, it would foul the original yellow plastic engine fan. So, the 'groove' in the bottom of the rad, now it's underside is exposed, sits on the front lip of that 'tray', bringing the bottom of the matrix away from the fan blades.

Still with me? Why, I hear you ask, is my car like this? Saggy engine? Bad gearbox mount? I wondered. Answer, Kenlowe electric fan. The Kenlowe electric fan my car is fitted with, which is, by some standards, a reasonably competent installation, pushes the rad further back. There is already a bit of metal trimmed off the panel under and behind the grille helping to accommodate the fan hub, but if the radiator had stayed put, the Kenlowe would have had to be fitted OUTSIDE the car and lose the front grille!

So the radiator has been pushed further back, with spacers (just bits of rubber pipe) spacing the top brackets back a bit, on the bonnet slam panel, and the bottom of the rad sitting half on, and half off, that tray, which is originally it's own lower panel with mounting stubs, therefore striking a compromise between the rad matrix hitting the engine fan, and allowing room for the electric Kenlowe fan in front. As I said, whether the bottom of the radiator fell off, or was forced off by someone to do the installation, I cannot tell.































As you can see from the last two photos, no change there then...still getting warm, except now I know why there is a recent invoice for Radweld in the history folder I inherited. Now I've flushed everything, I've got a radiator leak.

The engine was filled with pink antifreeze. Isn't that the OATS stuff, for alloy engines? When I jetwashed the water pump cavity and forced water round the sides of the number one cylinder wall, all the old antifreeze came out like Fairy Liquid - all white foam. For a time, I was hoping that was all my problem was - wrong antifreeze, foaming up and not taking the heat away. Sadly, this is not the case.

So, I jetwashed the bottom of the block. I jetwashed inside the thermostat cavity. I tried jetwashing and then just hosing where the block drain plug came out. I could get nothing in there, and nothing came out, except a bit of black grit on the end of my screwdriver when I probed it. Still, my last 'Mini' never discharged anything from the block drain plug, and that never overheated. I got mains pressure through a hosepipe onto the union on the head that connects to the heater matrix, and I also hosed the heater through. Sometimes when jetwashing the lower block, I could get a bit of water to come out of that union in the head. Not a lot, but some. I spent a lot of time hosing, twisting, turning, using one inlet and then the other, on the radiator. Some dirty water came out, then ran clearer. This morning before reassemby, it did sound a bit like there were some rattly bits in it....but they reduced and stopped after I turned it and shook it a bit.

I've also tested the thermostat in a pan of water over a ring on the stove. I have no thermometer so I couldn't check the temperature, but the thermostat (suspended on a wire) opened and closed normally several times. It is brass coloured, 'Made In England', and I can't see any temperature markings on it.

The water pump has a cast impeller. I think it might be the original, as it has flaking black paint on the outside, although with the rad out I can see it looks as though someone in the past has used black brush paint on the timing chain cover. I think the flaking engine block has original black paint on it though. The water pump bearings seemed very good. The engine (and car) only has 27,000 miles on it from the history and odometer readings.

So when I restarted it, after filling with Blucol, no leaks until I spotted dampness running down the side of the rad that has the filler plug - dampness emitting from a rusty looking bleb. So THAT'S why it had Radweld in it. New rad or recore needed, whatever.

I took 'NNN' for a run, with some top-up water in the boot, just in case, still optimistic at this stage that it wouldn't overheat. I'd not done much above two miles when the gauge crept past centre. Going up Bostocks Lane (an incline) towards the Derby A52 I soon gave up on the idea of heading there. The gauge climbed, the car wouldn't pull the skin off a rice pudding in second gear. I can feel it struggling. From suggestions at Quorn that my issues might stem from incorrect timing, I've checked it at 1000rpm with my timing light and initially it seemed to be set to 15 degrees BTDC. I've tried it at 7 degrees BTDC and currently its set to factory spec 10 degrees BTDC. If anything its slower and worse to drive than before I moved it. I've had the plugs out and I thought they looked normal, but I'm wondering whether the car is running weak. Which would contribute to overheating. With twin carbs I know I need a Carbalancer which I've yet to get, but I'm still nervous about adjusting twin carbs. One SU wouldn't bother me. If there was somewhere I could take the car to get it tuned up (cooling problem aside) I would, but nowadays I don't think your average garage knows what to do unless the laptop computer plugged into a car tells them what's wrong.

So that's it then. An almost lost weekend. I certainly can't flush that engine any more thoroughly than I have, and aside from putting in the right antifreeze and verifying the water pump is okay and the thermostat SEEMS okay, and putting on my new top and bottom hoses, and making my radiator leak, I've achieved nothing.

Finally, can anyone advise me where this bump stop on the offside engine mount is meant to be set? As usual I can turn it by hand as it's not been done up. I don't know if there's meant to be a gap, or if it's meant to be in contact with the engine mount at all times.

Cheers,
Mick

[david painter]

If it was my car, looking at the state of the Radiator. I would replace it with a new one and refit in original position. Then see what happens. Is the cars performance generally poor or just when it runs hot?
Dave

[lock1506]

Can't say I've seen one of those bump stops before on an engine mount. None of my 1.8's have had one.

[Kiwi Ute]

Is the timing mark on the crank in the right location? Because if it isn't a timing that is not advanced enough will make an engine run hot - the more retarded the hotter it gets.

And is the motor REALLY hot or are you just going by the gauge?

[MarinaCoupe]

I haven't seen a bump stop like that in a Marina before, but I think the I know why it is there. Because the radiator has been moved back closer to the fan, the bump stop limits how far forward the engine will rock under braking and still avoid meshing the engine fan and the radiator matrix.



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[mickthefitter]

Is the timing mark on the crank in the right location? Because if it isn't a timing that is not advanced enough will make an engine run hot - the more retarded the hotter it gets.

And is the motor REALLY hot or are you just going by the gauge?

Oh believe me, it's hot. If I take it into the red, I'll be looking at a blown cylinder head gasket at the very least.

[mickthefitter]

If it was my car, looking at the state of the Radiator. I would replace it with a new one and refit in original position. Then see what happens. Is the cars performance generally poor or just when it runs hot?
Dave

Well...it's generally poor, but becomes more noticeable at the same moments when the temperature needle begins to rise further, such as when driving up inclines. The engines seems to be making a lot of noise but not pulling. I also think the auto box intermittently sticks in second gear and holds it for too long, which sort of emphasises the problem. Though that mostly occurs when the car is cold, having stood for a few days or a couple of weeks, and seems to improve (usually) as it warms up.

My old automatic KRB 158P I owned in the 80s didn't change into top until it hit nearly 40mph when I first got it. You could encourage it into top gear by lifting off the throttle. I had a nearby auto 'specialist' look at it (retired by now) who changed the fluid and,from what I recall he told me (in 1981) he recalibrated the dip stick for some reason. He also detected a dropped exhaust valve and took the head off and did that for me, as that car was a poor performer even though I got it off a dealer with a so-called 42 point pre-sale check. Those were the days when dealers sold dodgy motors and if they didn't feel like being helpful, you just had to pay someone else to do it. KRB was a lot better after the head work, but still changed into top at 40mph. Six months down the line I discovered the kickdown cable, and adjusted that myself, until the car slurred the gears nicely on a gentle throttle, but held them on fast acceleration, but the price to my DIY adjustment was the kickdown no longer operated at speed. If I wanted a lower gear, I just flicked the T handle back a notch. The fact that 'NNN' changes into top earlier when warmed through suggests a simple kickdown cable adjustment isn't the issue. It dropping ATF, so it needs looking at anyway, and this is despite (and this is becoming the pattern) invoices for checks and new fluids applied to the auto box in the thick history folder dated six months before I bought the car. I reckon whatever garage 'NNN' was taken to in Yorkshire by the previous owner, he had toe-rags working on it who just fobbed him off.

Yes Dave, it needs a new rad or a recore. Probably a new rad. The only near reference I've seen online is looking for van rads, and one website lists a Sherpa rad for something like £240, though I've got to check the dimensions. Another alternative is that way back, before I had Minis (where everything is online) I used to use a business in Mansfield called Parts For Older Cars. I got a rad for a Cortina from him, but it was plastic and had fewer cores than the original. It also didn't cure the warm running on THAT car's rebuilt engine, but I think that was an issue with the engine where something hadn't been done right and I ended up selling the car. I won't know whether there's anything else causing the overheat on 'NNN' until I've sourced and fitted a new rad. The leak alone condemns it. In the meantime if I can get to the bottom of the correct timing or mixture settings, that might help, but I need a Carbalancer and a deep breath before tackling twin carbs. Over the weekend I checked all the valves were going up and down, but no time the check the clearances. That's my next job when I get time - which won't be in the week.

[mickthefitter]

Can't say I've seen one of those bump stops before on an engine mount. None of my 1.8's have had one.

Thanks. That explains why I found no reference to it in the Haynes manual!

Another 'Bob the Builder, can we fix it? No but we can bodge it' mod then!

[mickthefitter]

Is the timing mark on the crank in the right location? Because if it isn't a timing that is not advanced enough will make an engine run hot - the more retarded the hotter it gets.

How can the timing marks be in the wrong location?

It's got the five little pointers on the crankcase, like the top illustration on page 82 of the Haynes manual, and according to that the pointer nearest the crank is TDC and the one nearer the right inner wing is 20 degrees BTDC.

I've checked the timing with a Xenon timing light, set the rpm to 1000 (using the car's tacho) and disconnected the vacuum pipe. I've done everything right as far as I can tell. The only other option is to try setting it statically - I had to do that with my Wolseley Hornet as my light wasn't bright enough to illuminate the timing marks in a mirror, looking through that small hole in a Mini bellhousing. That DID improve the Mini's performance though I set it to factory spec and disregarded any 'unleaded petrol' concerns. That engine had got some wear anyway, which is part of what appealed to me about 'NNN' when I saw it listed at auction (27,000 miles) but by all accounts, the Mini went better!

[MarinaCoupe]

I have read about (but never seen) where the inner and outer parts of the front pulley 'slip'. They are joined by a rubber fillet which breaks down over time. It's there as a harmonic dampener.

To check whether the TDC is accurate without taking the head off.

1. Disconnect the battery
2. Take the rocker cover off
3. Take no. 1 spark plug out.
4. Rotate engine until both no. 1 inlet and exhaust valves are relaxed, this will then be the compression stroke.
5. Slip a probe (I use the back end of a long pencil) down inside the spark plug hole until it touches the piston top.
6. Move the crank pulley back and forth and feel how the probe moves until you are happy that you are at TDC. Sometimes there will be a up to a 5 degree spread with no apparent piston movement. Split the difference.
7. Now check the position of the pulley mark against that on the timing chain cover.
8. If it is different mark true TDC and highlight with a white line.
9. Re-time to your new mark if different.

10. Whilst the rocker box is off check the gap on all the rockers as this will sap power away.

11. Come back and tell us what you find .




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[david painter]

Here is a method of establishing TDC. Without any pointers and just a vacuum gauge, used it myself several times. Where valves not easy to see on modern engines, where cam carriers are part of rocker cover and on old side valve engines.
https://www.youtube.com/watch?v=u2sA-q7_FtQ
Dave.

[jiversteve]

Coming to this a bit late, but using a standard temperature gauge is less than accurate.
It's fed from a very crudely regulated supply, that erratically switches the supply on and off to acheive an average 10v and then a bimetallic temperature gauge.
Marina powered Marlins suffer from poor air circulation and an undersized radiator. My recommendation has always been, not to rely on gauges but an infra red thermometer.
Often the gauges are only a good guide, the temp at the radiator cap is more reliable.
Having said that, I have come accross water pumps where the vanes have all but corroded away, so water circulation has been minimal.

[Kilroy]

My 1800 engine from an HL has exactly the same device on the right side engine mount.
Its purpose is obviously to prevent the engine from moving forward too far - presumably because of the risk of the fan interacting badly with the radiator.
I set mine to have 1/8" clearance as there does not seem to be much apparent movement in the engine mount rubber itself, so I figured not much clearance was necessary.
I am unsure if it ever makes contact.

I used to notice that either the torque converter or the auto itself did not seem very well suited to the behaviour of the 1800 engine.
It tended to load up in second gear at too lower revs for the engine to deliver enough power to accelerate properly.
After I increased the engine capacity and tuned things correctly that problem disappeared - so it seems to me it is a symptom of an underperforming engine.
That could be fuel or timing or low compression.

I have found that the distributor settings are very critical for best performance, and have often suspected that the vacuum advance was not very effective.
Several times I have found the vacuum advance unit to be full of fuel.
There is no danger in experimenting with the timing by simply moving the distributor by small amounts in the mounting clamp - making sure to mark clearly the original position.
From your description I would suspect that you should try more advance - and should you move it too far - the engine will attempt to fire too early at cranking speed and simply stop turning.
One other thing I have found on several distributors.
The screw that retains the points has both flat and spring washers.
Should the spring washer be lost or left out - the screw will travel far enough to lock the two plates together thus preventing any operation of the vacuum advance.
Very simple oversight but quite significant effect on performance.
Removing the points plate and oiling the balance weights to ensure they have full range of movement is also wise.
Wipe away any excess oil to prevent it reaching the points and becoming a problem.

A simple compression test is to remove the power connection from your ignition coil and simply crank the engine over for several revolutions.
You will hear if the engine speeds up over any particular compression - indicating a low one.

[mickthefitter]

Wow. Thanks for all the useful advice. I didn't know about the crank damper. That's certainly worth looking into. My gut says it's probably okay, but I won't know until I check it, and I want to check it to rule it out.

The tip about the number of washers on the points securing screw is also worth checking. I did remove, clean and adjust the points before I began messing with the timing, and I cannot remember how many washers were on the points securing screw. The points were in good nick, and I did start and drive the car after adjustment, and re-setting the points alone had not altered the car's performance at all at that time, and it was a week or so later before I attempted to change the timing.

As stated in an earlier post, on a different thread, when I checked the timing it was, before adjustment, 15 degrees BTDC, way too advanced, when the book says 10 degrees BTDC and someone recommended 7 degrees BTDC to account for unleaded petrol and to deter pinking. Since moving the distributor the car has been harder to start and a worse performer, although now I'm getting to know it, the first impression after aquiring it, some thirty years after last driving my single carb SDL auto, is the correct one....it doesn't go as well as my old Marina did. And that had 48,000 on the clock when I bought it in 1981 and nearly 70,000 when it was sold for £200 four years later.

Regarding the accuracy or otherwise of my temperature gauge, I can partly understand people's questioning of its reliability, although the only failure I've ever encountered with BL and BMC temperature gauges (and Ford) is the sender failing, which results in the needle barely coming off its stop. The thing that, in my mind, tells me the gauge isn't lying, is that the car will pootle around town at 30mph as long as you like, and the needle on the gauge will stay on or near the centre, with, by most definitions, the car having reached 'normal operating temperature'. Make it do some work, like climb a hill or take it up to 50 or 60mph, and the temperature gauge rises. And the top and bottom hoses on the rad are both very hot - one is not cooler than the other. On my test drive yesterday, after reassembly of the water pump/radiator/electric fan and putting in fresh antifreeze, once I'd seen the gauge start to climb towards the red, I found a place to stop, text a few people about how my day's work had not been fruitful, and after about five minutes started for home. When I restarted the car, the gauge went past centre to start with - it hadn't cooled much. Most of the two mile trip home was downhill or on the flat. The car didn't have to do much work. The gauge went back to centre. Now to me, that suggests the gauge is telling the truth. I've got an underperforming engine for reasons I've yet to establish, and a poorly looking radiator. When the engine is working hard and struggling, the temp goes up. When its coasting, it goes back to normal.

The distributor - when did they stop putting felt pads on the cam spindle that you were meant to oil? They did stop doing it, didn't they? I've never taken a base plate off to expose the balance weights - I assume it is something I can do without breaking anything with my level of experience!

I'm now glad someone else's Marina had a bump stop on the engine mount - at least that is something not bodged up by a previous garage, even if its of little worth.

I've got a compression tester (another Gunsons gadget, I think) but I'm not sure it measures pressure AND vacuum. It's got a button to release a saved setting, so I think it only does vacuum. I'm probably going to need a long pencil to test for TDC!

Does anyone already know of a good place to source radiators, or is it every man for himself for a car like the Marina (which isn't a Mini, Morris Minor, MGB or Triumph sports car well catered for by marque specialists.) The 'Sherpa' radiator schematics I'd seen online are from UKcarcooling online, and it was for a 2.5 diesel, and it is too big.

Just found this on eBay - seems a perfect size - why the heck did they put the inlet and outlet on the same side on a Sherpa?
http://www.ebay.co.uk/itm/LDV-Radiator- ... SwU-pXqdNk

[MarinaCoupe]

If you go to your local radiator repair shop, and ask them to fit an early Sherpa core matrix into your existing radiator then there will be no problem.

I have one in mine as does Lee Marinaman480. They have half as many cores again compared to the Marina. It's made a big difference.


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