Overheating (Update Post 35, please help!)

[bildo]

Firstly, I know people will say do a search, I have done but the main problem with overheating on these seems to be with people going above a certain rev range rather than my issue.

I've noticed mine getting a bit warmer than normal recently when stuck in traffic, but I've never seen it go into concerning zones, just breached over the 90 mark a bit. Yesterday I got stuck in some particularly bad traffic and didn't really move for around 10 minutes, I could see it creeping up and expected it to come to a stop but it carried on going until the warning light came on.

I pulled over straight away, lifted the bonnet and waited for about 20 minutes for it to cool down and for the traffic to clear and then started again, drove approx 10 mins home without having to stop for anything more than a light and it was fine.

It points to the fans not kicking in, as the coolant level is still where it should be. I started the engine again this morning for a few minutes, neither the small or the larger fan came on even with air con turned on, is this normal?

Could people please tell me the checks I should be carrying out to diagnose which issue it is that I'm suffering from?

Many thanks.

 

[bildo]

Just checked the three fuses on top of the battery, all appear to be working absolutely fine so I'm guessing that's not the problem.

Are there any other fuses to check? What should I be looking for now?

 

[rs-tuner]

What engine?

 

[bildo]

It's the 225 LCR engine bud in an '04 plate. I think BAM is the code for it?

 

[mark garfoot]

it could it be your thermostat on its way out?

 

[bildo]

When I lifted the bonnet it wasn't a very cold day but I could see steam was quite clearly coming out so I think it was a bit hotter than normal, as far as I'm aware it doesn't seem that warm normally over just sitting in traffic? It hadn't been run hard before hitting the traffic or anything, just calm driving in 30/40mph zones.

If it was a thermostat problem I'd assume it was just giving a false reading?

 

[rs-tuner]

When I lifted the bonnet it wasn't a very cold day but I could see steam was quite clearly coming out so I think it was a bit hotter than normal, as far as I'm aware it doesn't seem that warm normally over just sitting in traffic? It hadn't been run hard before hitting the traffic or anything, just calm driving in 30/40mph zones.

If it was a thermostat problem I'd assume it was just giving a false reading?

It will be either the waterpump or thermostat.

the thermostat Controls engine temp by controlling the coolent flow if the thermostat does not open it does not let water in to the radiator so the engine overheats.

 

[mark garfoot]

if it is the thermostat it would just over heat maybe its not opening to its full potential so it gradually increasing til it over heats i would start there as there not very expensive you dont even really need them but on as cold day it would just take longer to warm up

 

[chris c]

As above, try removing the thermostat altogether and see if this cures it. it may be stuck shut. Have you added water recently? You may have an air lock in the system which stops the water from circulating. There's a fair chance it is the water pump though.

 

[bildo]

My understanding from reading previous topics is the waterpump is more likely to be a problem if you're booting the car, making the turbo spool quite heavily then the car overheats that way. Can it also be linked to the fans?

I just went for a drive as I needed to get some petrol anyway, drive was approx 15 minutes with barely any stop/starting since I use back roads. I put my foot down a couple of times and drove normally 90% of the journey, there was absolutely no overheating issues at all.

As soon as I got back to mine, I thought I'd let it sit still for 3-5 minutes or so, I did that and in this time it reached about 100-105 degrees and was climbing quite quickly. Upon popping the bonnet both at my house and the garage neither of the fans were on. This was the same whether the air con was turned off, on low or on its highest setting, they never kicked in once throughout the entire journey.

I assume it's safe to rule out water pump and focus on the fans more based on that? More feedback is appreciated of course, just trying to rule out the possibilities.

Thanks for the help so far chaps!

 

[mark garfoot]

daft question have you checked fuses for fans?

 

[chris c]

Hopefully someone more knowledgeable will chip in but you can rule out an airlock by letting it idle with the tank lid off. any air will escape when it gets hot then. I had this with an old escort i had and the fan would not come on til the air lock was cleared. i also had steam coming out when it got hot.

 

[bildo]

daft question have you checked fuses for fans?

From the searches I did I could only find info stating that the 3 fuses on top of the battery are the ones that control the fans, checked all 3 and they were absolutely fine when tested.

Thanks for trying though!

 

[bildo]

Hopefully someone more knowledgeable will chip in but you can rule out an airlock by letting it idle with the tank lid off. any air will escape when it gets hot then. I had this with an old escort i had and the fan would not come on til the air lock was cleared. i also had steam coming out when it got hot.

I'll go out and give this a shot mate, thanks. Seems the fans have absolutely no life in them though as I haven't heard them on for a while!

 

[Alexis27]

Could try disconnecting the battery for a while?

 

[Applemobile]

If memory serves me right, the fan switch is on the n/s o the radiator. I you either discone t the plug, or short it out, it will bring the fan on. Someone else should be able to correct me, but it is the place to start.

 

[traumapat]

From the searches I did I could only find info stating that the 3 fuses on top of the battery are the ones that control the fans, checked all 3 and they were absolutely fine when tested.

Thanks for trying though!

sounds like youve done your research. its not so much the fuses its the holder, it gets hot and melts screwing up the connection.
Ive been led to believe that the fans should kick in as soon as the temp gauge rises past 90. Based on that it sounds like the fans. Youve probably already tried but see if searching fans and try on the vw forums to to confirm and possible repair.

Good luck

 

[LEE69]

you dont even really need them

Of course you do, it regulates the temp to 90 deg which is the optimum temp for the engine to work efficiently.

If it just wandered over the 90 then the fans came on and it cooled down nothing to worry about.
It' when the temp goes well past the 90 mark when driving that shows the water pump as gone.

 

[LEE69]

Fan problems? http://uk-mkivs.net/forums/p/59897/449470.aspx#449470

 

[bildo]

Fan problems? http://uk-mkivs.net/forums/p/59897/449470.aspx#449470

I've seen you post this all over the place, but I couldn't find where on there it generally applies to me, and as far as complete newbie guides go I didn't find it very useful as I don't have any idea where most of these bits are located.