Overheating...

[Bar Vitelli]

The engines in two of my 126s are overheating. 

We set off on a trip on Saturday and gave up after 3 miles as both cars kept breaking down.

I'm determined to sort it but could do with a definitive list of what to look for.

Here's what I am aware of so far:

1. Check that there is oil in the engine
2. Check that there is sufficient oil pressure
3. Check that the thermostat is working
4. Check that the fuel tank is not rusty as apparently this can cause issues (as per an old post)

What else do I need to check?

Any advice much appreciated...

[Bar Vitelli]

PS

Forgot to mention, they are both air cooled.

[DeVilleChris]

Hi Garry.

You can check the thermostat quite easily.

If you look at the right hand side of the engine next to the distributor cap, there will be a little flap on the metal housing which should open and close on a sping connected to the thermostat.

If you are stuck I dont mind coming down one evening and having a look for you, hopefully wont be anything major!

Give me a ring if you want me to come down

Chris

[Rusty's Uncle]

Sounds like double bad luck there BV and most distressing. I would suspect that the cars would not overheat in just 3 miles unless the fan belts were broken or severely loose in which case the ignition warning light would stay on as the generator would not be charging. So you have now got to play the auto detective and work out if it was a fuel or ignition problem. So were the cars previously driven regularly with no problems ? Have they had any recent work carried out?

[Bar Vitelli]

Thanks, Chris, I may take you up on that offer, I'm haemorrhaging cash at the moment.  These cars are more expensive than a Ferrari! Work is a week from hell next week so I'll give you a buzz next week if I don't get sorted.

Thanks, Rusty, I like the sound of the fan belt thing, it's something I've not checked so worth a look.  One of the cars is the one that engine previously blew up on and was 'rebuilt'. It has never run the same and leaks oil badly. The red light is always on so it's in line with what you've described.  The other is one that has just been recommissioning after 28 years in a garage. It runs super for a few miles and then cuts out. I don't think it is the thermo stat as I have wedged the flap that Chris describes open with a bit of wood.

Heartbreaking really. We don't get many driving days in this country so it was a shame to miss out.

The rusty red car came to the rescue, though, so we finally reached our destination albeit 3 hours late!

[AvB]

What kind of oil are you using? Remember that air cooled engines cool themselves with the oil. Also, as others said, check the belt of the alternator o dynamo. In last case check the fan inside the engine if it is OK, i mean not broken or anything.

Cheers

[Rusty's Uncle]

Ok I think you will have to tackle the cars separately . So the one that had the long lay up is most likely muck in the tank. Symptoms are car starts and drives fine but after a short time will suddenly cut out with fuel starvation. Engine will restart after about 10 mins and the same thing will keep happening because the small particles in the petrol tank clog the fine mesh filter at the end of the pick up tube and held there by the suction from the fuel pump. When the engine stops there is no suction so the particles fall back into the tank and so it goes on. When I had this with my car it would happen after about 12 miles at first then steadily got worse until I could only do 2 or 3 miles. I was pretty certain it was muck in the petrol but as a test before I took the tank out I just drove around my little block accelerating then braking in quick succession to thoroughly stir up the fuel and managed to get the car to cut out after about 100 yards. So then it was tank out 

[Bar Vitelli]

Thanks, Rusty, that makes sense as well.  Does that mean I should order a new petrol tank and/or the kit that goe with it like a fuel sender?  I'm going to have a crack at tightening the fan belt later this week but my instict (and experience of these cars) says it is probably more than one thing.  Would leaking oil (on the other car) be part of the problem as well?

[Rusty's Uncle]

Do the test first to confirm the problem. Then you have a choice of new tank, removing & flushing out existing tank, treating inside of existing tank and/or removing the fine mesh filter on the pick up tube then catching the muck in an online filter downstream of the fuel pump.
The other car, well normaly a red light on the dash is kind of a warning  So if as you say it is always on then that should tell you something 
You should have two red lights with the ignition on , oil & charging which should go out when the engine is running. So which one stays on ?
Is this the engine you had rebuilt by your "mechanic" ?

[Bar Vitelli]

That's the one, Rusty, to be fair he got it running again but my beautiful and favourite blue car has never been the same. The GEN light is almost always on and the oil light comes on and off intermittently even when the oil is full which suggests that the pressure is not right. It leaks a lot as well, on the floor and on the engine. 

[Bar Vitelli]

PS

The oil I use is 15w 40 Castrol.  It works fine in my other cars so I assume it is okay.

[Rusty's Uncle]

BV if I read this right you set off on a trip in the blue car when the ignition light is on all of the time and the oil light some of the time 
It sounds like the only things that are working properly are the warning lights.
The ignition light is possibly the least serious . If it is on all the time then forget loose fan belt. Has the wiring been altered? Could be worn generator brushes or voltage control problem. Worst case knackered generator.
Ignoring your oil leak problem it might be worth testing the oil pressure switch by substitution. Maybe Chris has a spare you could try    if the engine is worn and on the way out then the oil light can go out when the engine is cool then come on when it is up to temperature in which case you are looking at a major engine rebuild with new bottom end bearings and maybe a crank regrind. If your oil leak problems are bad then it sounds like the engine needs an overhaul anyway apart from the other problems, good luck 

[Da Londo]

The other is one that has just been recommissioning after 28 years in a garage. It runs super for a few miles and then cuts out.

Also check the float in the carb on this one. Could have a leak.

[Bar Vitelli]

Well, an exhausting day and I was just watching. Chris dropped by and helped me out with a few bits but we've still not cracked it. Jobs done are, oil change, rocker cover gasket change, coil was upside down so that's been changed, new thermostat fitted and some other unrelated jobs done. Still not working so the next jobs for another day are new HT leads, little rubber bits that fit over the spark plugs and then the timing.  This one is Mrs BVs car so desperate to get it working before the end of the year, parts on order then will try again next weekend.

[dadandlad]

If you boys need a hand give me a shout and I can pop down with a van full of tools, meters,  timing light, nuts bolts etc