Having just returned from the garage (and £2000 less wealthy) I found my temp gauge not working. The lead connecting to the tang on the engine block was disconnected (I suspect because the garage had fitted a new servo). Once it was working I was distressed to see the temp creeping up to that final quartile on the gauge. The Kenlowe light was on as it often is on London trips. Shortly afterwards, steam and coolant streaming from the point where the hose joins the bottom of the rad. Later refilled but leak persists so must be a split hose. I suspect here that the Kenlowe fan might not have actually worked on my way home from the garage and hence the engine running too hot. Does anyone know in relation to the Kenlowe if when the light is on does it mean it's definitely working ? There appear to be two settings for the Kenlowe rocker switch - one for auto and one for just 'on' (I suspect). If I turn the ignition on such that gauges and fuel pump start up would that mean that the Kenlowe could also be turned on ? When I do this it doesn't appear to work ? Is there a fuse for the Kenlowe that might have gone; if so where would this be ? Any advice here would be much appreciated

 

I've no real experience, but, as no one has replied, I'll chip in what I recall from a friend's MG. It might help, but a lot depends on how the fan is wired up. His was from a switched live. The warning light came on when the fan was running whether switched by the thermostat or the dash button. Both the dash and the thermostat were connected to a relay. The temperature sensor was in the top hose so it should work unless the water level is very low. That's about all I know.

In your case, do you rely on the electric fan or is the engine driven one and its cowl also present? Apart from that, I do wonder about your mechanic returning your car with the temperature gauge sensor disconnected and a leak in the bottom hose.

 

Personally I do not like Kenlowe fans.
To me they are like putting a plaster on a broken leg.
Find the reason your engine is over heating first and fix it before sticking a fan on the front.
When Jaguar engines were new they did not over heat but after 30 to 50 years of misuse and the wrong coolant the water ways do clog up. This is the cause of the over heating in most cases and putting a Kenlowe on the front of your radiator might push some extra air through the radiator but the water is still not going to flow through the blocked water ways. A good flush with first plain running water will remove many rust particle and aluminium fur. Next a flush with a high power hose pushed in to the upper and lower hose points on the engine block and finally a flush with a block cleaner. Obviously a complete engine strip down and clean will do the trick better with a new radiator core which is what I did during my rebuild and having been cleaned the original fan and radiator keeps the engine cool even in the warmest conditions. I flush my coolant system every year when I do my main service. The only extra I have fitted is an expansion tank system so I do not lose fluid via the over flow pipe on the radiator.
As for how a Kenlow fan works, Sorry but I do not have a clue.

 

Clean system as suggested above:

Go to Northhampton Radiators that makes an excellent uprated "Tropical" unit for the Jaguar S Type & Mk 2. They look identical, top tank & all, but have twice the cooling capacity. Cuts out Barratts etc middle men that want to make their slice of the cake.

That's what I have done with my S type & it consistently runs at just below 70 deg C in hot South Africa, nevermind how hard I push it.

Ensure that you use the shrouded thermostat that blocks off the bypass port so that all coolant goes via the radiator hot. There is an error in the parts manual. Picture correct. P/N wrong. Correct P/N C3731/1* ~ Barratts make these thermostats themselves in their large workshop. They work excellently. No need to have Thermostat housing machined.

Throw away the Kenlowe.

 

Thanks so much - that's an interesting overview and some sensible advice. Thanks for taking time out of your day to respond

 

Thanks so much - I'm going to mention this to the garage where I'm taking it. Thanks for taking time out of your day to respond

 

Barratts is out of stock as is David Manners. They all supply one another. They are made in batches & go in & out of stock.

Martin Robey has stock.

 

Thanks to all of you who contributed to this post. If anyone has time, I just had an additional question - how much labour would changing a radiator on a MK2 actually require ? would this be substantially more than a normal or newer car ? Many thanks

 

If anybody took longer than 2 hours they would be slacking. Cass ~ how long did your radiator swap take when your engine mounting broke & the fan went through the radiator? (Cass car does not have the 2 front engine stabalisers. Unwisely deleted IMHO on late cars) I think the rear stabaliser & 2 front stabalisers were put there for a reason. If you fit a Northhampton Radiators tropical radiator the cooling exceeds the engine's requirements & the temperature is controlled by the thermostat.

 

The radiator should not take more than an hour to remove but it depends on if you know what you are doing. You do need a small pair of hands to get to the nuts and bolts and the patience of a saint.

Top and bottom hoses need to be removed and the radiator drained. On my car because it is a BW35 Auto box I have a gearbox oil cooler in the base of the radiator and these hoses x2 have to be removed.
The fan shroud if fitted needs to be removed from the back of the radiator. There are four small (7/16) nuts on studs that hold the shroud to the radiator. Once removed the shroud then hangs on the fan as you cannot get the shroud between the fan blades and the back of the radiator. This also means the shroud cannot be removed whilst still attached to the radiator.
The radiator is held on to the car with four bolts (1/2) down the back of the radiator where the shroud sits. Once removed the radiator can be lifted vertically out of the car. On my car the bottom of the radiator has two spikes that sit in two rubber grommets and you have to wiggle the radiator from side to side to release the spikes.
As a tip I normally slide a piece of cardboard down the back of the radiator between it and the fan blades so when lifting the radiator up or lowering it down the fan blades do not damage the fins on the back of the radiator.
When refitting don't forget the shroud needs to be hung over the fan before the radiator is lowered into position.

With the radiator out of the car it is a good time to clean behind the grill or even remove the front grill for polishing as you have easy access to the nuts.
With the radiator out of the way it is also a good time to stick a powerful hose in the engine block and flush out the coolant system. Remove the thermostat so the water jet can circulate right around the water ways. Also flush out the heater Matrix radiator. You will be surprised at how much muck and rusty water comes out of the system.

 

Rob, In the nose change between your car & my car I don't know whether it makes life easier or more difficult. My unit popped in quite easily without damage.

 

Thanks Glyn, I had a large invoice from the garage but it did include other work - just trying to get a rough idea of the time it would take

 

Many thanks Cass for including so much detail - very useful

 

There is plenty of room to lift the radiator out but sods law and all that means the cardboard will stop any mishaps and the inevitable cry of "I knew that was going to happen!"

 

Not a problem always a pleasure to help. On a scale of one to ten, ten being a definite garage job, I would say this was only a 2 or 3 to do yourself and save a lot of money. Maximum two hours to get the Rad out and get it back in. Working out what to disconnect, where the nuts and bolts are, what size spanner you need and how to get to them is the hard bit. The job itself is very easy.
The joy of doing it yourself at home allows you to tidy up the area when the Rad is out which you would not be able to do if you let a garage do it for you.

 

While you are working on the radiator out and in for MK1 and MK2 cars I would like to suggest that this is a good time to have a look at the metal hydraulic brake line which travels from the distributor on the RH side of the engine bay to the left hand front brake system.
I have been involved in the restoration or revival of about 10 MK1/MK2 cars and again and again I have found this line badly corroded. It is easy to replace with the radiator out.
I am not sure if this applies to S types and 420s

 

Good call Bill ! ~ It applies to S Types. Later models had a larger servo & no remote servo breather. (breather built into the servo). It likely applies to the 420 as well with its semi dual circuit brakes. They have to get from the right side of the car to the left side.

 

I would like an 80 or 90 degree proper thermostat for early spring and late fall.
The car even runs too cool in the summer with the 70 degree one, an 80 would be best all year round.

 

If you look down into the space where the radiator was, you can see the line running between the two triangular gussets that support the radiator when it's in place. It's held by a clip o the flange at the back of the front cross brace. Interestingly and typically of my Mk2, in spite of sitting for years covered in mud, the brake line in my car is fine, though what little remains of the steel around it is largely rust.

 

Thoughts have changed on this matter over time. Today people run cars a lot hotter than before for efficiency. VW, as an example would like to run at a bulk oil temperature of 127 deg C. (Coolant still below boiling)

Mercedes designed their 4 way thermostat to run engines at more optimal temperature for their designs and variable/varying conditions.

Modern thinking is running hotter. Why Jaguar chose approx 70 degrees who knows? (70 to 75 thermostat)

Barratts can drown you in thermostats that operate at 82 deg C & 88 deg C. They just wont have the sleeve.

Merc 4 way example. ~ heated by an element, monitored & controlled by the ECU.