1.0 overheating - links to guides / troubleshooting?

Hi all, new to the forum, thanks for having me!
i've seen a few references to overheating troubleshooting, is anyone able to send me a link to these? i cant seem to find them for the life of me.

Typical issues:
Loosing coolant over approximately 100 miles of driving, coupled with overheating (question, does an overheating engine almost always result in twisting of the head in peoples experience, or is this an exaggeration?)
Bubbling tank
no signs of head gasket failure as yet (appreciate that it wont always show, but no white goo thus far).
fan switch installed by previous owner.

A few questions:
does anyone know of a Hijet literate garage near Bristol?!
what are peoples experiences of costs related to head replacement?
are reinstalled heads more reliable than the originals - any recommendations on specific kits (if there are any)

first steps (based on what i've seen)
replace caps
clarify whether rad and lower pipe is getting hot - (indicates thermostat issue?)
change out thermostat / remove override switch (?)
replace clips and hoses
assume its the head gasket (please no).

Any help, links and pointers very gratefully received!

Thanks!

Alec

First steps sound a good plan but would add at the start, flush cooling system and move change rad caps earlier on in process. Add check face where rad caps seal to is in good condition, not totally pitted etc. Also after re filling ‘properly’ bleed the system. Plenty of advice on here about how to do that properly. Remember to raise front of van to bleed as it helps get air out as heater matrix is highest point in system.

Thankyou Raggy!
I’ve been trying to perfect the refill process based on the info here. It is required every 100 or so miles and up to that point, the van runs perfectly. I’d be interested in understanding whether the speed of coolant loss relates in any way to whether it is more likely to be a head gasket or leak. I guess it totally depends on the size of the leak/damage done…
I’ll keep you posted on results. We are breaking vanny out of winter hibernation in about a month!
Thanks again,
Alec

Leakage could be from anywhere if over 100 miles, radiator, pipe, clamp etc as depends how much is lost. Do you see the level has gone down in the radiator or in the inside overflow container? Did you say the container overflows?

yeah so after 100 miles or so (sometimes more if I've just recently topped it up), there is the classic gurgling form the overflow tank under the seat, and it is clear that the levels have dropped within the overflow tank. air is definitely being pushed through the small overflow pipe (which is concerning), but my assumption is that if there is a leak, this allows air to enter the system, which in turn just makes the problem worse. is that about right?

water out
air in
issues caused with airlocks / flow of coolant
more water lost due to this issue
overheating

is that about right?

i guess if it is head gasket then it's the same, except instead of water leaking, it is air being forced into the coolant system?

other key things i think i need to determine:
compression check (are the cylinder's showing any signs of failure) - i currently don't think this is likely, given the perfect start and running i've had so far (it idles perfectly, i would expect it to struggle to start or to run lumpy? is that correct?)

whether any gas is making its way into the cooling system - this would indicate gas from the engine, and a head gasket issue - is this correct? (i've seen kits for this, but no idea how to use one.)

Air in will cause water to be expelled as air is compressible and water isn’t. Air can get in various places but the most common will be the head gasket where as you say air would be forced into the water system pressurising it more, overcoming the seal of the rad cap and forcing it into the expansion tank. If you have a leak then as the system cools it will have to replace that lost liquid by sucking in air through the leak, hence getting more air in the system and inefficient cooling, more air expands pushing out water into the expansion tank and around we go again. Be for analysing it any further, do the steps you were going to first and take it from there otherwise you end up trying to pre guess everything.

Hi all, reanimating this thread.

tests booked for tomorrow that will cover:
pressure test of cylinders
pressure down test of cylinders
pressure test of coolant system
sniff test of coolant system.

numbers will be put up here once I have them.

going back to the original questions:
any advice on the type of head gasket to use if it does turn out to be that? i've seen discussion surrounding metal as opposed to paper?

a few more bits of info, following a bit more research:
bottom hose gets warm (this appeared to be an issue for several people, indicating an air lock)
air will blow warm or cold depending on absolutely nothing - not sure about this one - sticky thermostat?
it appears only one side of the cab windscreen blowers is operational - could this indicate anything?
bubbling from pipe into header tank is accompanied by a lot of vapour, i'm sort of assuming this is normal given the temperatures within the system.

Anyone in the South-West know the ins and outs of these? i dotn have a garage and so the struggle is real with regards to any home maintenance..
any advice on replacement hose clips? best ones to go for that you can get in the uk? jubilee clips ok?

all getting very frustrating, as it starts, runs and otherwise is in perfect working order....

Many thanks in advance!

Good idea to do the sniff and pressure tests. I've never seen a paper head gasket - is that really a thing? Probably best avoided, if possible.

If the HG is at fault you'll need to get the head checked/skimmed - look for a local engine restorer, must be some down Brizzle way.

Temperature of air blown depends on temp of the radiator - did you flush it earlier in the year? T/stat can be eliminated from the question by removing it (temporarily - I think I still have a few new ones in stock if needed, though am on hol from tomorrow for 10 days)

If you're not getting air from one side of dash-top vents it'll be down to the ducting that directs air from the blower - bit of an unusual problem, I'd say.

I'd get stainless steel clips, try a local boat chandlers or I can recommend www.seascrew.com

Amazing, thanks so much for all the info. I’ll hi to out a suitable specialist to take a look at the head… I’m a little nervous that if it’s cracked, I’ll never find another, as they appear to be few and far between!
The guy at the testing place (top bloke) also suggested testing the rad separate to the system, just to confirm that it isn’t that.
The vans also had a fan override switch fitted - I can’t honestly work out the logic behind this - surely replacing the fan switch on the rad is a load easier, and I’m wonder why this is done on other vans?
I’d be interested in a t-stat, def worth changing, no rush, so I’ll give you a buzz when you are back.
Thanks again,
Alec

The override switch is just or should be a preventative measure to use when in traffic queues but allowing the rad switch to control the fan at other times or at least that’s how I use mine. If the head is cracked and you can’t find another then it is possible to get it welded then skimmed and if done correctly it will be fine.

Great, thanks so much, fingers crossed it doesn’t come to that, but we’ll cross that bridge when it come to it etc.
It may well have been the case previously, and the original setup was like yours, which makes far more sense in my mind. Worth setting it up like that again for future use I think.
Alec

update on results:

Cylinder 1: 180psi
Cylinder 2: 160psi
Cylinder 3: 180psi

Considered acceptable and within 10%.

Sniff test detected exhaust gases - HOWEVER, i was advised that some additives will give funky readings - previously i had put UV dye in to test for leaks, and i had flushed with Prestone - some of that may remain - however i think ultimately, it will be a head issue.

Coolant pressure test found an abnormal result - the suggestion  (i'm not sure how they determined this bit  - i might ask) is that it was affecting 2 cylinders.

Recommendations were:
Remove head, get it pressure tested, reviewed for cracks and skimmed - i have a cost for this of £130 for full testing (not removal).
Clean out cooling system - he advised there was a lot of rubbish in there.
test radiator - he advised testing the radiator in isolation to ensure it isn't the initial point of failure.
sound advice.

other jobs to do prior to this:
test / replace thermostat, and potentially test without thermostat in place - can anyone advice where the thermostat is? is it a ball-ache to do myself?

replace all hoseclips - this i scan handle myself i think...

reinstate fan switch so that is comes on when it gets to temp - THIS i think is the crux of the problem - manual fan switch installed, automatic switch failed, wasn't noticed by previous owner, overheated.

a few final queries:
can the head be removed and reinstated without dropping the engine?
has anyone had the head completed recently - what should i be looking at cost-wise? if someone has a recommendation for a garage, id be very interested in hearing about them - i can travel and there is not immediate rush to get it done.

Many thanks for all your help, i'm keen to keep the van, but id really like it t work properly for at least one summer!

Alec

Yes the head can be removed whilst the engine stays in the van, I had the head repaired and skimmed about 6 years ago and done 30K miles since up and down the country, just in again to have it looked at. Can’t give you a price and the garage only does mine as a bit of a favour as the old man used to work on them and he does it as and when he gets chance between other jobs. Would probably tackle it myself but just don’t have the time at the min with work. Search on here and you will find plenty of info from others who have done it or try the FB Daihatsu Hijet Owners page.