OK, I have a 2L Pinto with auto box in my Indy.
After 5 miles around local roads, less than 50 mph, and it's boiling
The cooling system is as simple as I could make it - top hose, bottom hose and a loop from manifold to pump. It has an overflow bottle which does appear to work properly (slurps the water back as it cools down) There is no separate header tank.
I'm concerned that the radiator may not be up to the job - it's a single-row Escort 1300 rad, new when fitted to the car.
I'm pretty sure I've got rid of any airlocks, having run it up to working temp and let it cool right down a couple of times, topping up as necessary.
Has anyone else used one of these rads? (It is vertical flow with top and bottom tanks)
Or could it be that the air flow is inadequate? The nosecone air inlet has a stainless steel 'grille' and the MK logo...


Front, closer

I've even thought of running a second radiator, mounted on the nearside, under the inlet manifold, and cutting vents in the side panel to help the hot air to escape.

VW polo radiators recommended. Though it might be worth checking for trapped air, knackered water pump or simply the waters not going round properly

Yup. Polo rad. Alloy, cheap as chips and fits nicely under the nosecone.

But I'd still expect any old rad to work considering the amount of air going through the nosecone.... check for air locks etc....

VW Polo, keeps my St170 engine cooooool

Thanks guys!
Looks like a Polo rad, then.

I see part no. 867 121 253E for 1982-1990 Polo 1.3 - is that the one to go for?

What about the thermostat not working properly, that would stop the water circling in the system, wouldn't it?

Before you change anything else, I'd start with the thermostat.

Try removing it and then going for a drive. If it still brews up then start looking at the rad.

I can't believe I'm going to fess up to this amongst such esteemed company but I had a similar problem (on the pinto) - OK when idling up to temp but brewed up during a short drive.................. some numpty, ie. me, fitted the stat the wrong way round.... (waits for slack jawed locosters to point and laugh!)

Part number is a VW302 any motor factors/radiator supplier will recognise the number.

Thanks, again.

I'm pretty sure the thermostat is OK - I can feel the top hose becoming warm after five minutes when it's fired up from cold. And the manifold-to-pump loop gets warm. The radiator itself gets good and hot after a few miles' driving. It then just keeps on getting hotter...!
I think I'll give it a try removing (and testing) the 'stat and if there's no improvement I'll go for the Polo rad.

I'm concerned that the Escort rad, being single-row, may not have the internal capacity to sufficiently cool the water as it circulates?

Hi John

I used an Escort rad on both my race Locost and my current road one with no overheating problems at all.

Top hose btm hose and a tall Fiesta thermostat housing with a small outlet on it. Instead of running into an overflow bottle I have run a hose from the rad filler neck to a pressurised bottle (on the bulkhead) with the outlet from the thermostat housing "T"d in, with non pressure caps on the rad and thermostat housing.

Hope that makes sence.

Is there a fan on your car, is it running the correct way?

Nick

Hi Nick,
Is your rad single or double row? Mine is single - the core is only about 3/4 inch thick - so I'm wondering if there's just not enough volume of water being cooled at any instant.

The fan is behind the rad and draws air the right way!
Thx for the advice,
John.

Totally off the present topic, but are your auto box cooling lines going to the rad, chec oil temp in trans, may be causing your problem

There are at least 2 types of polo radaitor; I went and got one without knowing t his and ofcourse I have the wider one...... that won't fit in my F27.

It is brand new, overall size is 62 cm (width) x 33 cm (height) Outlets are 32 mm diameter, same as many Fords.


£ 25 + p/p, a bit less than I piad for it.... or offers.

I received it with some fins being bent - no damage to core, just cosmetic that I did straighten out a bit.
Rescued attachment DSC04421.JPG

@Canada EH!: I don't (as yet?) have any cooling for ATF. The pipes are just connected with a length of hose. Maybe a dedicated oil cooler at a later date. But I don't trust these coolers that use a heat exchanger, dumping ATF heat into the water.

@02GF74: 'Fraid your rad is too wide for the MK, the max it will accommodate is 500 mm, but thanks for the offer!

No progress yet today; now that the dentist's anaesthetic has worn off I'm off to remove the thermostat....
But, pondering on Craig1410's parallel thread, I think the first thing I'll do is to pinch the pipe from the inlet manifold to the water pump. Maybe the impedance of that route is lower than the 'stat/radiator path and the water flow is preferentially going round 2 feet of 1/2 inch ID pipe?

With the car stationary, bonnet off, pinched the bypass hose from manifold to pump....
2:30 Start engine
2:32 'stat housing warming up
2:33 'stat housing hotter
2:34 top of radiator warm (+ small drip from a joint in the bypass, not noticed before)
2:35 rad warm all over, temp gauge @1/3
2:36 gauge @1/2
2:37 gauge @2/3
2:38 gauge @3/4 Fan on (manually)
2:40 gauge @top of normal. Engine off and wait for it to cool down...
Will check level when it's cool and top up as needed, then repeat the test later.

The manifold-pump loop stayed cool
Once the fan was on, the centre of the radiator cooled down, as expected.
Maybe I should have let it run a bit longer, but either
a) there's too much heat being generated by the engine - unlikely as it's a bog standard unit
b) the radiator just doesn't have the flow capacity
c) something else (poss. air lock if the level is significantly down when it's cooled) - although, now, it's as simple as it can get: engine, top hose, radiator, bottom hose (+overflow bottle)
More later,
John.

It took about half a cupful of water to top up when half-cooled, so I don't think there's any significant airlock.
I've just ordered a VW302 from AdRad so will hopefully see that in the next day or so and then set about re-doing the brackets and plumbing to suit. And I guess there'll have to be a remote header tank on the scuttle as the new rad is crossflow...

Subsidiary Q re. Pinto plumbing:
Do you connect to the little stub on the 'stat housing (about 5/16 inch dia)? Mine has a Ford rubber boot, so was never connected in the donor.

John.

This might sound a silly question but is it actually over heating or just over pressurising? If you have no seperate expansion bottle have you an air pocket on the top of the radiator to allow room for expansion if not as your system heats up and the water expands it will pressurise your system if this exceeds the rating on your cap the water will then blow past the cap giving the appearence of over heating.

It definitely overheats - I can hear it boiling and gurgling in the engine.
I ordered a VW302 Polo rad. yesterday at 4:10pm - it arrived at 9 am today!
Well done AdRad

So now to rework the mountings and plumbing...

I'm going to start another thread re. pipework.
John.