Cooling Conundrums

[dino20vt 3]

I'm in the process of overhauling the cooling system on my Mi16 as it tends to get pretty hot in traffic.

 

I've started by fitting a new radiator as the old one looked past it's best but this made no difference.

 

I suspect the fan switch is faulty as the fan only cuts in on the low speed but I can get full speed by shorting the the diagnostic plug. As a tempory fix I've removed the low speed resistor and joined the contacts to give full speed.

 

My first question is what fan switch do you guys use i.e. what temperatures are stamped on it?

 

 Ive just read a recent thread that recommends the use of the 92/97  so I've just a called couple of dealers (not to buy, just to get an idea) as I'm not at a PC to view servicebox.

 

First dealer only offered a 79/88 switch (£44.60)! for a phase 1.5 GTi with the early contact configuration of |_| not --- as seen on phase 2's.

 

Second dealer spent a bit more time sifting through what was NFP and not and came up with two others for the early GTI;

 

87-83/92-88 126417

93-88/97-92 126418

 

So should I go for one of the three above?

 Another type for a phase 2 that might be still available and swap the fan loom?

One off another PSA car?

Fit one from a 405 mi16 if it's different again?

 

Next question, which thermostat?

 

From what I've read on here, as ive done away with the extra coolant circuit from the rear of the head found on 16v's there's no need for an mi16 thermostat, an 8v will do.

 

First dealer tells me there's two listed for an 8v;

82/83 degrees 13387 £12.17+

89 degrees 13384 £9.98+

 

Second dealer tells me only the hotter one is available as is an Mi16 specific thermostat but no temperature is in the description.

 

Should I go for the colder thermostat, the mi16 one or one from another XU?

 

What about seals?

 

Thanks

[welshpug 1,626]

what do you call pretty hot? the gauge is rather deceptive in that normal operating temperature is quite high up, why would you ever need to know how much it had got too hot by, as long as you know it has got too hot

 

my MI16 runs the 89 degree thermostat, my 205 should have 89, and my gti6 engine runs an 83 degree one, I think the cut in temp for the fan is 92 degrees,

[SurGie 54]

You could always fit a twin fan set up Fit in and forget.

 

The thermo either works or it dont, there's no in-between with them. It could be your sensor wiring, i remember seeing them being taped up with that s*it elec tape instead of soldiered or connector's fitted.

 

Get all the system checked and properly connected and then see if its still getting hot. I know what you mean Dean, i prefer engines to be that bit cooler, they seem to go better and make the head gasket last longer imo

[dino20vt 3]

Hot as in the fan doesn't cut in till the needle is at the warning light, (not that it's ever illuminated and it works) and it gets there pretty quick.

Of the five GTI's I've had over the years this certainly runs the hottest.

There may not be any problems and the gauge could just be over reading but for the sake of £20 odd I may as well change the thermostat and switch as I've never swapped them I'm my ownership.

[Tom Fenton 1,526]

Go to a decent motorfactor and get them to get the catalogue out, there are lots of thermostats with similar dimensions that will fit in the XU thermostat housing. They will also have a list of rad fan switches with the various temps. Personally I have always used the one with the red band without a problem but each to their own.

You will also save a lump of cash by not getting ripped off by the dealer.

[welshpug 1,626]

just found this rather handy link - http://www.smpeurope.co.uk/?p=smpeurope/catalogue&brand=intermotor&SESSID=l8r4mdjvilstnt74q817ockc64

 

part 50103 looks to be the early version with the pins arranged in |_| with a cream ring, and 50106 the later version with the same temperatures but the different lug with the pins in a --- formation, and the red ring that tom mentioned.

Edited August 22, 2011 by welshpug

[marksorrento205 80]

You could always fit a twin fan set up Fit in and forget.

 

Im sure your only having a laugh George But if you have to fit a second fan to keep the car cool there is something wrong. All your doing is masking the real issue. All imo of course I have never had a second fan fitted to my 205's. Thats with an 8v, mi or gti6 engines

[Tom Fenton 1,526]

The real fit and forget solution is the Turbo Diesel radiator to be honest.

 

Since fitting one to my turbo 205 it runs lovely and cool, this is remember with the turbine core water cooled so dumpnig quite a considerable amount of energy into the cooling system.

 

It did run hot for a couple of weeks recently, that was a knackered thermostat that would only open about 1mm.

[Anthony 1,000]

As above, a twin fan setup simply isn't needed in the mild UK climate - a single fan is more than capable of keeping the engine cool even in the height of summer.

 

The thermoswitch not working as it should does sound like a likely culprit, but worth checking that the fans are working properly - the slow-speed resistor is often dead which means that it waits until the engine is very hot before the high-speed fans come on. Easiest way to check is to unplug the thermoswitch and short the pins on the connector with a short length of thick wire - from the common pin to one of the others will run the fan on slow, and to the other will run it on full speed.

 

Depending on the age of your car, it's worth checking where the switch is mounted - some Phase 1.5 cars had the switch mounted on the drivers side near the lower radiator pipe, and these cars need a lower rated switch compared to the usual passenger side mounting near the top radiator outlet. Also, early cars have a different pin arrangement on the thermoswitch to later cars, as mentioned by Welshpug above - the later setup is shared by most 90's non-aircon PSA models (eg 106. Saxo, 306, Xantia, 405 etc) and thus I usually swap earlier cars over to that for better future parts availability.

 

Personally, I use a lower rated 92/97 switch (purple band) and usually just make it come on high-speed straight away - means that the fan comes on a little past halfway on the gauge, and turns off again about halfway, sitting there cycling quite happily in traffic and never getting particularly hot. I also run an adapted version of the diesel relay setup, as I've never been keen on the standard GTi setup that runs full current through the fan switch and connector pins, although clearly it can and does work fine for most people.

 

If it's only hot in traffic then chances are the thermostat is fine, but no harm in changing it as a precaution. No need to go to a dealer for one though - any decent motorfactor will likely have them in stock, or if you have access to a Halfords trade card, they are (or certainly were last time I bought one) dirt cheap to buy and come with the seals as well. Personally again I go for the cooler 82 degree 'stat option, which normally sits around 1/3 on the gauge in normal road running, and only really starts to noticeably climb from there when the oil temperature is sky high following a prolonged thrashing on track.

[pug_ham 242 3 Cars]

You could always fit a twin fan set up Fit in and forget.

The twin cooling fan has no effect on how hot the engine gets, it just means it'll cool it faster due to pushing more air through the rad leaving the fans on for a shorter time.

 

One fan is just as effective but simply runs for longer to acheive the same amount of cooling.

 

I run a 75' thermostat on my car which I got through my local motor factors for under £10 including new seals & iirc it was from another XU engined Pug so a direct fit.

 

If you're that concerned then rather than mess with twin fans or different thermostats, fit a manual switch so you can control the water temp when in traffic.

 

g

[SurGie 54]

Mark was correct, i was having a laugh with Dean

 

For my own set up, i will be fitting twin fans myself, whether it needs it now or not, the engine will be having more power next year anyways.

[welshpug 1,626]

still no reason to fit a twin fan really, I remember Dixon's XU7 race car build, that used a 205 rad in a 306 with a single fan and around 230 bhp in its revised incarnation, Sarty's 240 bhp 2.2 ran standard 205 rad with a single fan as well.

 

think of all that power sapping load you get with twin fans

[SurGie 54]

Thats why im fitting a separate button, and i have a diesel battery too

 

I dont like my engine too hot when in traffic, it was with my old 2.0 mi and carbs and all of that worked fine. My 6 goes about 90over 100 degrees on hot days or traffic. I ant buying a D rad when i already have it all as part of my engine kit i bought.

 

Back on topic

[dino20vt 3]

It turns out IE9 doesnt like the multiquote button so bear with me!

 

 

You could always fit a twin fan set up Fit in and forget.

 

The thermo either works or it dont, there's no in-between with them. It could be your sensor wiring, i remember seeing them being taped up with that s*it elec tape instead of soldiered or connector's fitted.

 

The multiplug wiring has been done properly now, soldered together and waterproof shrinkwrapped so should be spot on now

 

 

Go to a decent motorfactor and get them to get the catalogue out, there are lots of thermostats with similar dimensions that will fit in the XU thermostat housing. They will also have a list of rad fan switches with the various temps. Personally I have always used the one with the red band without a problem but each to their own.

You will also save a lump of cash by not getting ripped off by the dealer.

 

Rang GSF today and the guy seemed to know what he was talking about so I might use them. Only tried the dealer first to give me an idea of their prices and what they thought should be fitted.

 

 

just found this rather handy link - http://www.smpeurope.co.uk/?p=smpeurope/catalogue&brand=intermotor&SESSID=l8r4mdjvilstnt74q817ockc64

 

part 50103 looks to be the early version with the pins arranged in |_| with a cream ring, and 50106 the later version with the same temperatures but the different lug with the pins in a --- formation, and the red ring that tom mentioned.

 

Good link that, cheers, I also stumbled across this: http://www.thepartspeople.co.uk/Cooling-Heating/Switches-Sensors-Cooling-Heating/Peugeot-205-1.9-1989/Parts.aspx?SubGroup=CO%7eCooling+%26+Heating%7eSSCH-CO%7eSwitches%2c+Sensors+-+Cooling+%26+Heating

 

 

As above, a twin fan setup simply isn't needed in the mild UK climate - a single fan is more than capable of keeping the engine cool even in the height of summer.

 

The thermoswitch not working as it should does sound like a likely culprit, but worth checking that the fans are working properly - the slow-speed resistor is often dead which means that it waits until the engine is very hot before the high-speed fans come on. Easiest way to check is to unplug the thermoswitch and short the pins on the connector with a short length of thick wire - from the common pin to one of the others will run the fan on slow, and to the other will run it on full speed.

As crusty as the resistor looked it did work, i was getting both speeds from the test plug, i just removed it and looped the connections so i gort full speed.

 

Depending on the age of your car, it's worth checking where the switch is mounted - some Phase 1.5 cars had the switch mounted on the drivers side near the lower radiator pipe, and these cars need a lower rated switch compared to the usual passenger side mounting near the top radiator outlet. Also, early cars have a different pin arrangement on the thermoswitch to later cars, as mentioned by Welshpug above - the later setup is shared by most 90's non-aircon PSA models (eg 106. Saxo, 306, Xantia, 405 etc) and thus I usually swap earlier cars over to that for better future parts availability. Just bought a new rad and luckily the switch and hole are both on the passenger side.

Personally, I use a lower rated 92/97 switch (purple band) and usually just make it come on high-speed straight away - means that the fan comes on a little past halfway on the gauge, and turns off again about halfway, sitting there cycling quite happily in traffic and never getting particularly hot. I also run an adapted version of the diesel relay setup, as I've never been keen on the standard GTi setup that runs full current through the fan switch and connector pins, although clearly it can and does work fine for most people. Ive got my eye on a diesel setup in a scrappy so may do the same.

 

If it's only hot in traffic then chances are the thermostat is fine, but no harm in changing it as a precaution. No need to go to a dealer for one though - any decent motorfactor will likely have them in stock, or if you have access to a Halfords trade card, they are (or certainly were last time I bought one) dirt cheap to buy and come with the seals as well. Personally again I go for the cooler 82 degree 'stat option, which normally sits around 1/3 on the gauge in normal road running, and only really starts to noticeably climb from there when the oil temperature is sky high following a prolonged thrashing on track.

 

 

The twin cooling fan has no effect on how hot the engine gets, it just means it'll cool it faster due to pushing more air through the rad leaving the fans on for a shorter time.

 

One fan is just as effective but simply runs for longer to acheive the same amount of cooling.

 

I run a 75' thermostat on my car which I got through my local motor factors for under £10 including new seals & iirc it was from another XU engined Pug so a direct fit.

 

If you're that concerned then rather than mess with twin fans or different thermostats, fit a manual switch so you can control the water temp when in traffic.

 

g

 

What other pug was the 75 degree stat listed under? I've has a quick gander on tinternet but not found anything yet.

What I might do is play about with a twin fan set up, wire the first to work off the rad fan switch as it would in a GTI but via a diesel relay then wire the second fan to a switch under the dash, hmmm not sure yet.

[dino20vt 3]

Bought a new 82 degree thermastat from GSF but its bigger than the original and wont fit into the mi16 housing.

 

Looking at the top of the original thermastat not only is the total diameter slightly smaller the inner circle area is smaller too

 

Original - support legs closer to main spring hence more 'lip'.

 

New - support legs further away from spring so less lip.

 

New left, old right.

 

My suspicions were correct though, the original thermastat was had it, it only opens a couple of mm max.

Edited August 29, 2011 by dino20vt

[welshpug 1,626]

doh, was there a pug part number on the box or any other reference?

 

might be a diesel stat as IIRC some of them are a two stage unit and a little larger, the seal for the mi is 53.5mm, the diesel 57mm

Edited August 29, 2011 by welshpug

[dino20vt 3]

doh, was there a pug part number on the box or any other reference?

 

might be a diesel stat as IIRC some of them are a two stage unit and a little larger, the seal for the mi is 53.5mm, the diesel 57mm

 

The GSF part number on the box and receipt is 176PC0080.

I was under the impression 8v and 16v thermastats were interchangable (at least one way anyway, 8v in a 16v) if the extra cooling circuit on a 16v was blanked off as:

1)The 16v extra stroke wasnt needed

2)Theres more temperatures to choose from with the 8v design

3)8v thermastats are cheaper.

[welshpug 1,626]

that isnt an 8 valve XU thermostat you have there though, it'll be a diesel one if as you said its larger diameter, well stil 8 valve but XUD!

 

http://www.ebay.co.uk/itm/CITROEN-PEUGEOT-1-9-D-2-0-HDI-THERMOSTAT-176PC0080-/300547207216?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item45fa027030

Edited August 29, 2011 by welshpug

[dino20vt 3]

Yea that's the one!

 

I think because there was only an 89 degree stat listed for a GTI and not 82 or 75 degrees which I wanted he just gave me the first XU stat he came across albeit a diesel.

[dino20vt 3]

Went to a different branch today to swap the the thermostat for the correct one and was given 176PC0040.

 

Its the correct diameter:

 

But isnt the same length as its for an 8v so not dual stage (which I want):

 

It didnt come with seals so was given a couple of universal seals. Round not flat like the originals:

 

Fitted the new thermostat but found the new seals were too fat so fitted one new and one old and no leaks.

 

This is where it gets interesting, topped up the coolant id lost all over my drive, let it idle for a bit whilst bleeding but before finishing I had to nip somewhere.

 

It stood for an hour but on the way back the temperature flew up but thinking id not bled it thoroughly put it down to that.

 

Got back and attempted to bleed it but not much in the way of bubbles coming from the thermostat housing or matrix hose but plenty in the header tank, also the rad was cold and the fan wouldnt go off but ran out of light so couldnt investigate any further.

 

Duff thermostat or air lock?

Edited August 30, 2011 by dino20vt

[dino20vt 3]

All soted now, I fitted a twin fan set up, not that it's needed but the loom is more reliable as it uses relays, does away with the low speed resistor and as I went for the phase 2 variant has a better sensor plug. I fitted the relay box and relocated the shunt box (and fitted a longer feed from the battery) behind the front bumper below the near side headlight using two unused holes in the panel.

 

I also changed the high temperature switch (for the warning light) as the spade had snapped off and the temperature sender for the gauge as it looked like the original and wasn't sure if it was over reading.

 

As i'd gone from a phase 1.5 to 2 loom I also needed to get a new radiator fan switch. After alot of research I opted for 87-82/92-87 item, originally only fitted on Citroen C15 vans with the part number 1264 49, but at £35 + vat (I think) I got a Facet 75700 for £15 from a motor factors.

With the duff original 92-87/97-92 switch the low speed fan wasn't cutting in until the needle was near the end of the gauge, now it cuts in just before 90 degrees:

 

Now whilst cruising with a bit of stop and start the needle hovers anywhere between a third and half then once stationary slowly gets to 87 degrees, the fans cut in on slow speed and cut out shortly afterwards.