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Discussion Starter · #1 ·
Hi, i was driving my 4Mo along the M23 the other day quite happily at around the speed limit when the 'Stop Check Coolant Manual' etc lit up and when i glanced at the temp it was sitting at arouunf 120 degrees. i pulled off and let the car cool down.

After a few minutes i started off again and the temp sat at 90 for a few minutes then up it went again.

Again i let her cool down for a few minutes, there was no visual sign of overheating or water loss. I restarted the car agian and the temp was at 90 again and the fans spinning.

I got another 3/4 of a mile and up it went again just as i passed a VW delaership! Hooray i thought.

They have called today to say that the 'fan switch' isn't working and will cost ?105 to replace but that they are not 100% this will fix the problem.

I didn't think the fans would contribute to the natural cooling effect of the air passing through the rad especially at motorway speeds? The fans seemed to be working and seemed to be able to keep the engine at 90 when stationary even after the overheating.

I thought it sounded more like a waterpump problem but they say unless they do the switch first they cannot be sure. (apparently there is pressure and water is circulating, but to what degree they cannot say)

Any ideas, i'm speaking to them tomorrow to give the yah or nah to the switch and if there are other ideas i'd be grateful.

Thanks N
 

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It sounds like your 40 amp fuse has blown... thats why it has been ok
till now.... when the fuse goes and you lose high speed yuou will
overheat almost no matter when....

The stealers plan is to charge you for a thermostat, ?105... that wont
fix it then they will try it on for a fan controll unit, that wont do
it... then they will change the fans.... and you will be ?1100
down .
 

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Discussion Starter · #5 ·
The penny begins to drop!

If i go there tomorrow and buy a 40 amp fuse,

a) is it accessible and can i fit it at the roadside, and
b) Will it be safe to drive the car 20 miles to get it home b4 i do the mod.

BTW have read you 'sticky' - and i do understand the probs and with the fuse in place i guess i can do the check for fans etc.
 

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I guarentee the fuse wont be in stock ... always the way.. yes it is
accessible its one of the fuses in the tray bolted directly to the top
of the battery you will need a pliers or a 10mm spanner or socket..

Drive 20 miles - of course theres a helluva lot off of people that have done 20k with fans not working .. me included.

so basically what I would do is go the dealers check the fans and
the fuse.... when its not working kick up a holy stink and tell them of
the updated fans etc . do this to get out of there unnecesary charges
as there tech should have just read the VAG engineering updates on
overheating v6/v5's

chuck a piece of 30amp domestic fuse wire (doubled over) on the
offending fuse turn the air con to economy and drive home... orde rthe
fix kit and drive round as normal, but with the air con on ECON then
fit the kit and use air con as normal
 

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Discussion Starter · #7 ·
Morning, just got back from the dealer.

The dealer had wired up the fan switch in a effort to prove to me their theory that that was the problem so i took it for a spin (the fan appeared to be going full wack as soon as the key was in the ignition) and of course within a couple of miles it's overheating again!

I put the connector back and removed any trace of what they had done. The 40 amp fuse was corroded at the back but not 'blown'. I replaced it anyway as there was a spare sitting under the cover (think this has gone before as the plastic is damaged around the bolt heads).

I do have the dreaded fan problem as i followed the test on AM's link, they only come on to high speed and then nothing, then high then nothing.

Couldn't drive her home as she's boiling away and visable steam coming from expansion tank now!

Can't help but think water pump, obviously the fans have been knackered a long time but the car runs great with that fault so this must be somthing new i guess. They say the water is circulating but could this just be the electric water pump? or does that only come on when the engine is switched off?

Sorry to be a bore about this but you all know how it feels when your pride and joy is sick!

N
 

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This sounds identical to a problem I had with my old MK4. It had 65,000 miles at the time.

I was travelling up the M25 at 70% and exact problem - overheating then cooled down. I did this about 7 times until I got my destination. Was quite a painful experience!

Once there I called the AA. Chap came out, tried loads of things like remove the thermostat, checked the temperature of the in and out and found out one was hot and one was cold. In the end I had to get a tow back to Brighton.

Took it to my local garage and he guaranteed it was the water pump seal had corroded as it was made of plastic. Changed it... ?155 later all sorted.

So I would maybe call out your AA or equivalent first and then take it to a non stealer garage. Ideally someone you trust.

The funny thing was that the day after it had broke down I was due to pick up my new car, which I havent announced on uk-mkivs yet (waiting for the sun to clean it before posting!!) and I think I am the only person to have one on here!!!!!!!!
 

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Sorry been fitting My brothers shower...

Now if the fans are working even without low speed the car should not
be heating up as it is .... first ssupect would be the water
tempreature sensor .. there was a recall on some and it is prone to
failure on some vr6's and late 1.8t's .

now you say the water is boiling over... is that you reading the temp gauge or you actually seeing boiling liquid?

if the liquid is boiling (IE the temp gauge is telling the truth) then I suspect that it is the water pump.

If thee wate syetsm is not too hot but the gauge is saying its overheating I would cahnge the tepreature sensor.

however dont let them meddle with the fans anymore unless they want to replace them under warranty
 

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Discussion Starter · #12 ·
Thanksfor that guys. Stealer being a bit slow but they now accept the fans are an existing prob and that they need to look past them if they are going to sus this out!

I'll let you know how this works out but thanks again.

N
 

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Discussion Starter · #13 ·
heard from the dealer tonight and they are confident that the water pump has gone. there apparently is some water circulation but not to the level it should be.

fingers crossed.
 

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Unfortunately i am forced to re-open this post [:mad:]

A couple of months ago, a few miles from home, my dash beeped, "check coolant" *flashy flashy* car overheated. I ended up changing the battery as it was buggered. Problem solved!

Yesterday night on the way home from work the same thing happened again: my dash beeped, "check coolant" *flashy flashy* car overheated. I was only 500 yds from home so i let it cool down and i got home reet.

Today on the way to work (10 miles approx 35 mins, A roads) twas fine.

Tonight, way home: my dash beeped, "check coolant" *flashy flashy* car overheated. It did this approx 5 or 6 times before i got home!

Now, the first time tonight i lost some water, hence me knowing it is physically overheating. Also, i heard the fans kick in after i re-set off.

Each and every time it did it again, whilst sat in the seat, i could feel a rumbling! Upon further inspection it appears to be the water in the pipes. Is this normal?

So, my car is obviously overheating, but what the buggery is causing it? Any help mucho appreciated coz i obviously cant drive around with it doing this! Could it be the v6 fan problem? or the water pump? i just dont know!

Shawzy.
 

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same thing happen to me a couple of months ago. got AA to 'escort' me to mechanic's place (he works for VW) and all he did was take off the fuse above the battery and stuck in some wire as a temp measure and that worked. new fuse + spare one....GRATIS....
 

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Phew, andymac hasnt cottoned on to my post and absoloubtly slated me [:$]

I managed to find the post - panicked first, read second!

Anymac, big al and co are genius.

Ive just found the duff 40 amp fuse. Once this is repaired i can do the fan test. Fingers crossed itl be reet.

But.............. surley my 40 amp fuse going means the high speed fan has blown it, because the resiter on the low speed fan has failed?
 

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Guys, i do need your help. I dont think its as simple as my low speed fan is knackered.

I replaced the 40 amp spanner fuse this morn, and low and behold the low speed fan does not kick in when i turn climatronic on. So..........am i right in thinking its buggered and i need to do big als repair?

I have been driving around this morning to try and see if i can work out why my car is poorly. Now, it is ok for about 10 mins hovering at 90degs. then it starts to rise, get to 110degs and BOTH fans kick in. If im stationary, the temp drops, if im driving it hits 130degs.

Could this be the THERMOSTAT? If it is jammed shut the water will not be getting to my radiator to be cooled. Is this correct thinking?

Another alternative is my HEAD GASKET. If the head gasket is buggered it will be forcing fumes into my water system causing it to boil. I need to check my filler cap.

So.....

  1. My low speed fan doesnt work when climatronic on, do i need to do the repair?
  2. BOTH fans come on to cool radiator
  3. Even the BOTH fans are on my water is still boiling away in there!

PLEASE HELP ME!
 

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Your low speed doesn't work s the resistor if blown. ie you need to do the repair.

However, this won;t be the cause of your overheating.

The high speed fans work ok so it seems that the temp sender is not faulty.

Sounds like your water pump.

The as you drive around the engine is working harder than when at a standstill. If the pump is not circulating coolant then it doesn't get to the radiator to cool down.
 
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