Another discussion on Hi-Jet engines overheating.

Scotia, Raggy and I have been having an interesting discussion about the usual favorite, common discussion, that of overheating and the inadequacies of the Hi-Jet Cooling System.

It was in of all places, in Your Pictures under ExHi-Jet now Suzuki Carry Project. Very interesting and un-heated ( sorry about that) discussion.
At least Scotia with his very pretty Suzuki van doesn't have overheating problems like the Hi-Jet but they are a bit underpowered compared to even the Hi-Jet 3 cylinder.

Check it out. A few useful tips there.

I had overheating on my 993,did the head gasket and had the head tested and skimmed,after about 18months it started again and no amount of bleeding checking clips etc. did any good-then I recalled many years ago as an aprentice mechanic we used to retorque the head bolts after 5-600 miles no-one seems to do it now,anyhow bolts retorqued then moved the rad up about inch and half bled the system keeping the engine running while doing the heater bleed at the same time keeping the rad topped up{you need your missus} and that now has worked for me for 18 months now,if I ever have to take the dash out I will be looking to lower the heater rad.Long one from me sorry

You in my opinion GEORDIE can't do that as it is inside a two piece moulding and has the blower motor control flaps and the matrix all integral parts, plus the plastic concertinered moulded fittings to the windscreen. Not an option and why would you want to.

If you pressure bleed the same system as per the articles in the Forum it should be fine,, provided everything else is in order.

When I had my head gasket sorted the garage did actually ask me to co e back after 400 miles to have the head re torqued and a check around all the hoses etc that were disturbed to do the job, all within the original charge.
On the fan temp issue, could do with a variable fan temp switch that fits inline in the water hose...so... the challenge is out there to find a solution.
Think Woodie is correct though, prevention is better than a cure.

a lot of good info is pread all over this forum.
maybe it could be a good thing to try to get the facts and solid info and tips to one topic.
thats easy to find and easy to view.
we could make another topic regarding the 1.6 conversion to.

i realy like the things HJ did with the extra pages regarding manuals/1.6 conversion
but i see hes losing his interest a bitt and it would be a shame if his and other info would be lost in time.
i copied a lott of the manuals and other things from those pages and am spreading it to other drivers
trough the microvanpage i set up.
its not that i want to flaunt "his" collection around like its mine or i have some other financial interest.
i dont use my real name nowhere and dont sell parts.
i like helping others out and have the time to do this.

so what do you guys and girls say?

Yes would be good if we have an area where relevant info is kept.

Was having a think this morning how to best describe the override switch and overheat issue when I was riding by bike to work so here goes.

Think about riding a bike (cycle) along a road, eventually you will get warm then low and behold a set of traffic lights so you stop. Not long after stopping you start to really sweat as you system does not suddenly stop, blood still going around etc so it requires cooling so you open your jacket to cool down...but... opening your jacket without any movement of air only helps a little and you start to overheat after a while until your body adapts to not needing the blood moving as fast. When you get going again you get hot as you have build up the hear inside.
The solution to getting too hot when you stop would be to have a fan on the handlebars blowing cool air whilst you are stopped so that when you start again you are not overheating and so sweaty that you feel uncomfortable whilst riding again...but...not very practical!
Anyway can you see the similarity to the Hijet issue? The body being the Hijet, the problem is that the heat needs to be dissipated when the van is moving slowly or stopped so we have a fan, unfortunately the fan only comes on after we have got too sweaty not before we get too sweaty!
Hence overheating should not be the issue but just making sure the temp stays within acceptable limits. I think the value set in the sensor is too high so the fan ends up as a last ditch attempt by the van to dissipate the heat when in fact its too late really as there is so much heat build up already. The prevention is to have the fan set at a lower temp so that it has far less of a job to do to as the heat build up is therefore less. Now how that is achieved I don't know at the minute. Sure I have seen somewhere about temp sensors that go inline of the hoses so its getting the actual water temp, could do with being adjustable as well. That would take the manual element out of it and have a happier cooler running van. But remember this is all not a solution to an overheating van, that's just good maintenance ect just a solution to a more practical issue of keeping a van running sweetly and extending its life by not giving it temperature spikes. With modern vehicles this is all more technically controlled so its nothing new just not available on the Hijet as standard.

Now, if you have read this far...well done...if you have understood what I have written...congratulations, have a coffee...if you have read it, understoold it and have a solution or comment...post it! (after you have had the coffee though!)

yes i understand.
the hijet has an overall sensitive coolingsystem regarding faulty things like radiatorcaps/hoseclips etc
and its not adequate to deal with heavy moments like a long drive on hot day and then stopping at the lights or something.

so buying a decent hijet without problems and then when youre fitting the 1.6 lump you can prevently change all clips and caps.
bleed it properly fix an overide switch for problem days and then do recent checks for leaks and give it good maintanance in the future.
and then it will be all good?

Got it in one, but would be better to find an automatic way for the fan to come on when required rather than relying on user input...always a weak point in any system. As for long journeys I did 9hrs back from Scotland in my 993 with a majority on motorway and it behaved perfectly.

I have somewhere a Kenlowe Variable Thermostat that has a very thin length of copper capillary tube with a small bulb on the end of it. By bulb I don't mean light bulb. It is like a tiny balloon made of copper or brass and soldered on the end of the copper pipe.
This is inserted into the cooling system via one of the ends of the radiator hoses using a specially designed sealing rubber.

The Copper Capillary tube is connected to a control unit inside the cab with a rotary dial with which you can set the cut in temperature for the fan.
This was probably 30 years when I "found" this one on a Land Rover I broke up. Kenlowe were established 60 years ago and still going but don't supply the public now. Only to motor manufacturers and wholesalers. It still uses the Capillary system I am amazed to find out. It has a range from 40° - 125° C

I have done bit of a search session and found one similar to the Kenlowe on eBay for £16-99 plus postage. It is adjustable up to 120° C.. Comlany is based in St. Albans, Hertfordshire.
bbclassiccars

I will post some pictures of the unit and details of where to find it and a YouTube video.

this is the one I was thinking about but a tad more expensive[ fan controler ]£75.60 inc VAT

The link doesn't appear to have appeared Raggy.

just click the [Fan Controller] words

This one I got from a Hi-Jet I broke up a couple of years ago. It is a fixed temperature one though. Don't know what the temperature range is through. No markings on the Sensor.

You would have to sti k a meter on it and test with water to see if its a sensor or a fixed sensor that trips at a certain value. I would think its a sensor and would feed a control unit or variable switch so would work that way rather than being an integrated variable sensor all in one. Obviously someone had the same idea.

It would definitely be an on/off switched sensor. The little brass sensors like this usually had just one spade or pin connector and used the vehicles engine to earth to send a current /signal, through to a live ignition switched instrument or a Relay.

This one because it is insulated in both rubber hoses would be an on off switch to a relay. It wouldn't be up to coping with the large amperage that a Cooling fan demands on start up.
When the fan cuts in on the 1300 it causes a huge draw on the battery and the alternator cutting in to meet the demands actually slows the engine down on tickover and if the lights are on as well it seems as though the engine is going to stall momentarily.
It is not so pronounced on the 993cc as the fan is a good bit smaller.