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GTI radiator fan, how long should it run for?

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I've been having some issues with my temp gauge reading warmer than I think perhaps it should, so I took thermostat out today tested it which it opened fully by around 92 degrees or so, took a hose to flush system and refitted.  Its a circoli one from ecp so perhaps not the best quality but on my mfa clocks it sits around centre of the led when driving (2/3rds or so)  which is higher than the one I replaced as it ended up stuck open, but I don't what temp that one said it opened, new one is 87 degrees.

Anyway, when I run the car to temp and let the fan cut in the fan literally runs for about 15 seconds then cuts out for a minute then cuts in for another 15 seconds.. the gauge doesn't drop when it runs as it runs for such a short period. Is that right? I'd have thought to be effective it would need to run longer?

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Was this yesterday in 2c outdoor temperatures?

If so sounds about right. Needle vertical or just to right of LED, fan kicks in and out when stationary or doing 3 point turn and doesn't lose coolant/boil over.

1983 Mars Red 1.8 Golf GTI
1987 Alpine White 1.8 Clipper Cabriolet

The trouble with doing nothing is that you never know when you are finished.

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Was yesterday, yeah. But was probably around 8 degrees down south.

Drove it to work this morning, decided to let pressure out of system once parked (carefully I might add) and the coolant measured 86.1 degrees so I'd say that the cooling system is doing its job.

20211220_070357.jpg

That's what the gauge is reading.

So would you say the fan running for such a short amount of time is normal? Surely it doesn't do that much? I guess if the temp doesn't continue to rise its no big deal. Need to get some rad cards really

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Def get the rad cards sorted so its running full efficency esp whe stationary and drawing from the engine bay not the cooler outside.

Just googled and most rad switchs seem to have 10c drop from on to off but 1 did have 5c drop.

I only run my Golfs in the warmer weather these days and from my experience the fans only come on when stationary for a while or doing a 3 point turn etc. Never timed it but they only run for a short time prob less than minute. So in winter with a colder ambient temp could see it dropping the temp by 5c or 10c in a lot less than a minute.

I'd be more worried if the fan never came on!

Edit: tickover is touch on the high side.

1983 Mars Red 1.8 Golf GTI
1987 Alpine White 1.8 Clipper Cabriolet

The trouble with doing nothing is that you never know when you are finished.

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Sound about right to me as well.  

What do Divorces, Great Coffee, and Car Electrics all have in common?

They all start with GOOD Grounds.

Where are my DIY Links?

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Is there anywhere you can buy the side rad cards from? Or templates that can be copied? Might get some stainless if I have to make them.

I don't think I've ever changed fan switch, and it's never been an issue, was more just wondering if it was normal for it to cut in for only a few seconds at a time.

I know, I've been having issues with auxiliary air valve, last time I drove it cold start was around 750rpm then when warmed up idle was around 1200 rpm! Cleaned it up again and refitted that yesterday and the revs have dropped a bit when warm but still a tad high. Its still messing around a bit but it is better than it was I think. Another thing on the to do list as long as both arms!

 Had new injectors and lines don't know if that would have any impact on idle speed

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www.cabby-info.com has templates for the radiator cards the sides are not as important as the upper radiator card from what I have seen on my Cabriolet (93 Automatic).
pdf and cad are avail at:
Cooling System

Screen Shot 2021-12-20 at 3.20.06 PM.png


How your radiator cards and fan shroud work see the links in my signature, I have a few things there for mk1's general and 93 Cabriolets Digi and Cabriolets in general.

Radiator Fan operation explained? :) | Volkswagen Owners Club Forum

Now with all that said, it is imperative that you make sure that your Fan Switch is Rated the same as your t-stat.
Second, Clean or replace your grounds from the Batter to the Frame and the Frame to the engine.  If you haven't replaced your grounds and they are still the originals, then I would strongly URGE you to Replace it either with a new one piece or 2 piece.  After you have replaced them then spray the FRAME and Engine/Tranny Connection with A Battery Corrosion Preventive spray. Clean the Frame Stud…..

Corrosion spray that I use.

Screen Shot 2021-12-20 at 3.41.16 PM.png

What do Divorces, Great Coffee, and Car Electrics all have in common?

They all start with GOOD Grounds.

Where are my DIY Links?

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Thanks briano, i will definitely have a read. my next question was going to be what temp should an 1800 dx fan be cutting in? I looked at some  switches which are mostly 84-91 or 84-95⁰c and the stat opens at 87, presumably that would then start to close the stat as fan cuts out when gets to a temp lower to that of the stat opening? I don't know/haven't looked at my switch so couldn't tell you which I have. I may still have the thermostat somewhere that failed which has started all this in the first place, I may have bought a different rated stat.

I need to go through all my earths, my clocks are very intermittent, always have been. Though the fuel and temp gauge have always been solidly reliable. It's a bit annoying driving home in the dark when your backlighting has decided it doesn't want to work. Difficult to find time with young family etc, plus I don't know what I'm doing when it comes to electrics.

Idle speed was back up to 1200 rpm when I got home too. Grr

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I made my own rad cards. I did look at the diagrams Briano references but the side ones weren't right for an 83 dx with oil cooler. So, I found some pictures of the right ones and through some carful scaling and drawing manged to get so vaguely correct drawings. I then transferred to cardboard, tweaked a few times until they were about right then transferred to millboard. I won't lie, it was a faff and they aren't oem perfect, but they are good enough to do the job. I can share my drawings, but you will need to do the same process I did. If I didn't have to take the grille out to fit them I'd take them out and measure them - sorry, I know that's lazy of me :)
I should add, mine has twin lamps, so there is a cutout that you won't need. I'll adjust the drawings to sort that. I'll post them up sometime tomorrow. I may have put some pictures on my build thread. Can't remember..

J

My rebuild thread I will try and keep up to date: here

K-Jet fuel pressure test guage How-To

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I'd not expect you to start taking your car apart to measure something for me! I would however very much  appreciate some pics of the side cards, as they seem to be like hens teeth!

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Old thermostat has 87 stamped on it too, though it is closed (symptoms suggested it was stuck open when running it) I might test it tonight if I get a spare few minutes

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Karlos1987 said

I'd not expect you to start taking your car apart to measure something for me! I would however very much  appreciate some pics of the side cards, as they seem to be like hens teeth!

This is the internet - you never know what people expect  :lol:
Couple of pics here, but I'll dig out my drawings.
https://vwgolfmk1.org.uk/forum/index.php?page=topicview&id=projects%2Fyour-mk1-golfs_2%2F83-gti-now-mot-d&start=100#post_1654638

My rebuild thread I will try and keep up to date: here

K-Jet fuel pressure test guage How-To

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Here are some pictures that I found (these are what the geniuine ones look like - at least for a car with twin lamps).
radcard2.jpg

radcard4.jpg
radcard5.jpg
radcard6.jpg

The curved cutout you can see is what you won't need. I suspect you can just straight line that - but try it with cardboard (cereal packets work well) first. The drawings are rough, but with the images above they will make sense. I would advise against catting the mounting holes until you've got a workable cardboard template. I didn't cut them in the millboard until the last moment. I actually used tipex around the radiator mounting hole and pressed the millboard to it so I could get an exact location.
Good luck!
Attachment
RadCards.pdf

My rebuild thread I will try and keep up to date: here

K-Jet fuel pressure test guage How-To

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Back in the day (late 80s!) when I was running a MK1 as a daily driver and just wanted a quick fix I made some from plastic 'currugated card board'  from an old college tech drawing folder, similar to the smallest in the pic. The top one was easy and one side copied from the remains of the orginal and the other one trial and error and all cable tied into to place.
corrugated-cardboard-sheets-250x250.jpg


1983 Mars Red 1.8 Golf GTI
1987 Alpine White 1.8 Clipper Cabriolet

The trouble with doing nothing is that you never know when you are finished.

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Early-1800 said

Back in the day (late 80s!) when I was running a MK1 as a daily driver and just wanted a quick fix I made some from plastic 'currugated card board'  from an old college tech drawing folder, similar to the smallest in the pic. The top one was easy and one side copied from the remains of the orginal and the other one trial and error and all cable tied into to place.
corrugated-cardboard-sheets-250x250.jpg



Yeah, that would work. I just didn't know what it was called to buy it!
My Father in Law had some millboard that he'd bought for retrimming his MGA, so I asked him to get me some - does the job, but it's hard to cut! I did toy with getting some made up out of stainless as I know a chap who's business does that kind of thing, but I'll save that for a future enhancement!

My rebuild thread I will try and keep up to date: here

K-Jet fuel pressure test guage How-To

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Thanks  I looked at some  switches which are mostly 84-91 or 84-95⁰c and the stat opens at 87, presumably that would then start to close the stat as fan cuts out

Well my original to me Diesel back in 81 had a 97 degree
t-stat.  So I would have to say that even on my 90 cabbies they still used it that is the 97.  How ever as I was having a high oil temp on the highway at 80mph, (automatics) I opted for the 84, and changed the Radiator switch..(it didn't help, but the addition of an external oil cooler was the answer for my Automatic Tranny temp issue)  I didn't notice too much of a difference in the temp, but unlike the UK I live in the south here and highway temps can reach 140F in the late spring and all summer long.  

I have a good story about driving my Diesel in rush hour traffic with no a/c (never bothered to fix it), and after a 2 hour trip (normally a 40 minute one) I got out of my car in the Carport stripped gown to my undies and jumped in my pool.  

I need to go through all my earths, my clocks are very intermittent, always have been. Though the fuel and temp gauge have always been solidly reliable. It's a bit annoying driving home in the dark when your backlighting has decided it doesn't want to work. Difficult to find time with young family etc, plus I don't know what I'm doing when it comes to electrics.

The first thing I would do is add a ground to the rear of your clocks, pin2 usually (brown) to the frame of the car, you can use a scotch lock wire splice to make it and drill a small pilot hole behind the clocks sand the paint to bare metal, using a ring wire connector and a washer head sheet metal screw affix it there.  I have a good how to in the archive section see the signature link, as well as a intro or primer on electrics for the novice that I wrote for a Cabriolet user that I was helping about a decade ago.  

Adding a ground to your cluster:
Improving your Cluster Connections and ground. | Volkswagen Owners Club Forum

Basic tools I use for Electrics
http://www.toplessrabbit.com/forums/viewtopic.php?f=7&t=3211

Electrical Primer for Novices:
https://www.volkswagenownersclub.com/threads/electric-primer.32254/

Hope these help.

What do Divorces, Great Coffee, and Car Electrics all have in common?

They all start with GOOD Grounds.

Where are my DIY Links?

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Really appreciate all the help chaps, might have a crack at the rad cards over Xmas if I get the time.

Briano, to be honest I think something dirty has already happened with my clock earth now I think about it, IIRC an earth for the light switch? Has been spliced to the clock earth wire, how good the solder joint is is anyones guess, I don't know if it would be worth unsoldering that and grounding that behind the bulkhead first to see what happens?

The wires into the light switch connector block are a bit corroded and insulation has perished somehow. Do the wires go back in once they've come out of the connector blocks?

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If you pry out the keepers if they haven't been to badly burned corroded or mangled.

What do Divorces, Great Coffee, and Car Electrics all have in common?

They all start with GOOD Grounds.

Where are my DIY Links?

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I guess it would be easier if I could get hold of another connector block with better condition wires and cut off the corroded wires/block and solder replacement onto good wire? Not that it's a job for right now. Need to get running issues resolved first

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paceman said

Here are some pictures that I found (these are what the geniuine ones look like - at least for a car with twin lamps).
radcard2.jpg

radcard4.jpg
radcard5.jpg
radcard6.jpg

The curved cutout you can see is what you won't need. I suspect you can just straight line that - but try it with cardboard (cereal packets work well) first. The drawings are rough, but with the images above they will make sense. I would advise against catting the mounting holes until you've got a workable cardboard template. I didn't cut them in the millboard until the last moment. I actually used tipex around the radiator mounting hole and pressed the millboard to it so I could get an exact location.
Good luck!
Attachment
RadCards.pdf


Are the drawings in the attachment 1:1 scale? If so would they fit onto a sheet of a4 for printing? Looking at ordering some stainless for top rad card and the smallest I can get off ebay long enough is 600x500mm. I'd imagine the amount left over would do the sides but I'm just assuming/guessing.
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