Jump to content

Series 3a Cooling Problem

robert cockling

Recommended Posts

My 1998 Series 3a kit (with 1988 2.0litre SOHC Pinto, Single Weber, Viscous fan and Cortina radiator) seems to overheat the minute I take it out for any reasonable length journey.



Car has new water pump, and all hoses have been tightened and or repalced where necessary. The car originally had a 13 or 15psi cap, but would make the impression of a kettle every time you stopped......lots of steam and water pouring out of overflow spout. I fitted a 20psi cap and this seems to have cured the problem for short journeys (up to say 5 miles)

On a longer journey the temperature seems to gradually creep up until it gets towards the red and once I stop and let the thing cool it usually only loses approx a pint , most of which I collect in an overflow bottle


Engine has done 100, 000 and won't pull more than 80mph (I tried it round Knockhill) but am assuming that is a carb / tuning problem..........I haven't looked at that yet although I have checked timing etc and seems OK. There is no oil in the water so head gasket seems OK


1 Can it just be that radiator is needing flushed out or is single core radiator just not up to it?


2 Would removing thermostat be of any benefit?


3 How good are the Coolman double core radiators sold by LoLocost ......do they make a great difference or would I be better off buying say a Polo one and electric fan from a scrapyard as some one else has done?


Any advice? Thanks in advance B)

Link to comment
Share on other sites

  • Replies 32
  • Created
  • Last Reply

Top Posters In This Topic

most radiators from various cars seem to work even smallish ones looks like you have a definate problem it seems to be blocked some how,the first thing i would probably do is flush it out with a rad cleaner and try it with the thermostsat out.

i have read that running the car with the thermostat out can over heat the car as it doesent allow the car to mix between hotter and colder water,but with water of a consistent warmer temp.

you may have a thermostat stuck closed so running without one will rule this out or not.the thermostst can also be tested with a thermometer and a bowl af hat water to see it opening.

hope this helps until someone who knows better.

cheers Jamie <_<

Link to comment
Share on other sites

Thermostat should opening ok if you're getting that much happening when it gets hot. Worth checking. Some of them are a bit reluctant & open late (I had one like that). You can also fit the 1.6 Primera one which opens at lower temp. See Pics I sent Jim on the NW site. That could help & also has a "pass through" (small hole in flange) with crude non return valve which helps with bleeding.


I would say you either have an airlock, not enough air moving through the rad or simply not enough capacity.

If it gets hot when you are driving it's nothing to do with the fan.


The Cortina rad is a bit low on capacity. The coolman rad is very good. One from a Polo is good too but you'll need to move to a pressurised system (like the Sierra had) rather than the "suck back" Cortina system you currently run (I guess from description).


Mine runs find with Cortina rad with solid cap & a pressurised header. Electric fan (doesn't come on often) but to be honest I am going to fit another rad (I have a coolman waiting to go in) & a heater to help increase the capacity.


With the Coolman rad on my old car (well ducted, that made all the difference - rad is a long way back on the S3 same as on the slimey pillock 2b) it was fine even on a track day....


Cowling on first car



Pressurised system. Header from a Volvo. Click to make them bigger.








Dan :)

Link to comment
Share on other sites

Engine has done 100, 000 and won't pull more than 80mph
This may be your problem. Is the timing correct? i.e. advance working in disy etc. Is the mixture correct? weak mixture will cause overheating. Is the engine "breathing" heavily? May need a rebuild.

If none of the above apply then try back flushing the rad it may be partially blocked usually indicated by cold strips.

As for fitting a 20lb cap IMHO it's a bit high do you not have a catch bottle fitted so what blows out gets sucked back in?

Link to comment
Share on other sites

Thanks for the info above guys. I checked the Disy and the advance appears to be working OK. I used a timing light and the set the timing according to Haynes ..car runs on unleaded..(previous owner had it out by quite a bit but think he may have done this because valve from inlet to brake servo was bust and making engine idle funny.......and brakes feel lethal!!). Although carb is far from correct plugs are showing dark so if anything slightly rich.


I currently have the overflow tube from the radiator going into a plastic drinks bottle (got it for free and sits nicely between body and steering shaft / alternator. Hot coolant from radiator goes into this but don't think it is getting sucked back into radiator...think it remains in the bottle.


Only other things I can think of are that number plate is partially obscuring nosecone (this will be sorted next week after nose is painted and "sticky" numberplate goes on) and that whilst heater matrix remains plumbed in actual motor has been removed as it doesn't work (which means with sidescreens up I am either hot or hotter!!)


If I can solve the problem I am interested in making system pressurised ........so Dan what Volvo does the header come from...(so that I know what to look for in scrapyard)


Cheers Robert

Link to comment
Share on other sites

To get it to suck back everything has to be airtight along the way.... mine was leaking around the rivet of the rad cap. I stuck some araldite on it to cure it. I also had to tap the retaining lips on underside of cap with hammer to affect a tighter seal.


No idea which Volvo the header came from. I didn't build it. Sorry. The rover SD1 header is a nice one (can use with Cortina "suck back system with 4lb cap or pressurised with a 15lb one - halfords £2.99 for cap & also do the solid "no spring" cap for rad you'll need if moving over to this system).


I would suggest some sort of cowling from nose cone to rad as in picture (red car). I know your bonnet & nose cone is slightly different but on yours it should be even easier. Mine had to be the way it was as I had the "Alligator bonnet". That made the biggest difference of any of the things I did! Make sure you seal it on all 4 sides.


Having heater matrix in system is a good thing as it increases capacity. Make sure it's not airlocked! To make sure all the air was out of mine when I finally fitted a heater (using same system as you, incl drinks bottle header tank & 15lb cap) I jacked the front up about 2 feet in the air to make sure the rad was higher than the heater & then ran it...


Getting hot is probably not due to the matrix if you have no blower on it. More likely to be hot air coming back through gaps from the engine bay. Fitting bonnet vents & sealing all the gaps helps with this a lot.


Dan :)


Oh... by the way... Join the club, it's 15 quid well spent, gets you a mag & an insurance discount too...


Dan :)

Link to comment
Share on other sites

Thanks for the above


Will try bleeding heater matrix the way you describe...........and I am a club member ....have been since March 2006............just been slow to log on to community.......although I had been reading up on a lot of the various topic and links


Cheers Robert

Link to comment
Share on other sites

Welcome to the community... :) Hope you get it sorted.


Try jacking it up ( you could drill a couple of 3mm holes through the flange of the stat to help too) & make sure you've got good ducting from nose cone to rad.


Dan :)

Link to comment
Share on other sites

The monocoque cars were notorious for cooling problems.

You've gone part way to sorting it, but you'll still not win with the set-up that you've got.


If you look, you'll see that the viscous fan is too low in respect of the radiator, there about 30% actually below the bottom of the rad. It's also some distance away from the radiator to be effective.

the way to sort this is by making a cowl around the radiaotr & fan, I made a wooden block then made a fibreglass cowl from it (I still have the block) that makes to fan draw it's air through the radiator only.

This was fine for "normal" driving, but should you want to get a bit enthueastic, the rad just wasn't up to it. There were no Colman rads available in those days, so I had a mark 2 Escort rad fitted with a double core from a V6, everything was fine then. (I still use that rad with the Vauxhall engine fitted)


1 other thing, the viscous fan's can go "weak" we found out with the Jeep when that overheated, you could be running the engine at reasonable revs, and stop the fan ever-so-easily (not with your hand!!) a swap of fans cured that.


My opinion is to get a Colman rad, fit a GOOD electric fan close up to the rad, or cowl it in (not a RHSC one) with a switch in the top hose wired as per our site, and fit some vents into the bonnet (again check our website for these)


The photo's are of the cowl I made and fitted.



Link to comment
Share on other sites

Stpuid one this, but I had it, make sure the thermostat is the right way around!



good point Mat, we've not had anyone do it for a while (well not that's owned up!)


This is how it should look when fitted, with the "bulb" going into the engine water, not the hose water.


Link to comment
Share on other sites

Taking on board all this good advice. Last night removed grotty looking thermostat.......gasket ring was perished.....but it was fitted in the correct way as per photo and tested it in an "approved" (by my wife) pot on the stove. Didn't have a thermometer handy but checks the water came towards boiling point and it opened and closed as it cooled. Have decided to fit a new one anyway so have purchased straight repalcement......they didn't have a Nissan one at my local Halfords, but will go to one in next town tomorrow and see if they have one.....I can swap them over.


Decided to bite the bullet , save all the flaffing about with the radiator and go for a Coolman as from all the info above it will be less grief in the long run. Ordered today from Lolocost......delivery hopefully Monday and cost doesn't seem that bad when put into perspective of talking to a neighbour who is building a (Cosworth ) Dax Rush and who has just paid about £300 for their own one(ouch!!).


Tomorrow I'm also targeting scrapyards for electric fan (Citroen if I can get one) and SD1 Rover expansion tank.


Looking at the space I have was thinking of moving new radiator (when it arrives) as close as possible towards the Water pump pulleyand mounting fan behind it, rather thanon other (nosecone side) of the bulk head. Has anyone done this or is their any reason why I shouldn't?


My engine bay seems to be more cluttered (and a lot less tidy than Nigel's!!)



Link to comment
Share on other sites

get the right fan some suck and some blow....my 3a has the same set up as you but i have no probs with overheating it does cook my legs but it has'nt boiled over yet in normal use ...once when i gave it a good thrashing on a very hot day and then had to sit in traffic for an hour


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.

  • Create New...