Car Overheating

[manrajf 0]

Hi all

 

My gti for the last couple of weeks keeps overheating while being driven, it has never had this problem before, but now even driving on the motorway at around 70mph i can hear the fan kicking in after about 10 minutes.

 

I normally drive from hinckley to sheffield and back again twice a week as i study in sheff, before the problem the temp gauge would be between the 3rd and 4th bar, but now it sometimes goes just above the 5th one.

 

I have checked the car for an air lock but thers nothing, i took out the thermostat today and dipped in it boiling water and it opened up, so im really confused as to what to do, any help would be appreciated alot.

 

thanks

manraj

[Tom Fenton 1,548]

What is the condition of the radiator itself like? If this has seen better days then the car will run hotter.

[manrajf 0]

What is the condition of the radiator itself like? If this has seen better days then the car will run hotter.

 

I just took off the grill to have a look at the radiator and it looks in pretty good condition,

 

cheers

manraj

[Paulmac19 4]

i would give it a flush out you would be amazed at how much crap can gather over the years

if your fans kicking in i would not be to worried

remember the weather itself is getting hotter so i might have somthing to do with it

or a faulty sender on the rad itself might be to blame

main thing its not getting to the point where its boiling over then you really do have problems

hope this helps

[manrajf 0]

i would give it a flush out you would be amazed at how much crap can gather over the years

if your fans kicking in i would not be to worried

remember the weather itself is getting hotter so i might have somthing to do with it

or a faulty sender on the rad itself might be to blame

main thing its not getting to the point where its boiling over then you really do have problems

hope this helps

 

thanks for the prompt replies, once the weather gets better il start flushing the system, but just wondering is it a hard job flushing it, do i require anything special?

 

cheers

manraj

[richsmells 2]

Remove radiator, insert hosepipe!

[matty_gti 20]

Remove radiator, insert hosepipe!

 

Works a treat!

 

When was/has the water pump been changed?

[manrajf 0]

Works a treat!

 

When was/has the water pump been changed?

 

lol i hope it does.

The water pump was changed just under a year ago, so im hoping thats not the problem...just hpe its a nice day tomoz so i can get the rad out and flushed.

 

cheers

[kyepan 291]

if it's not been kept in decent coolant, the rad (alu ones) will oxidise, and it's thermal efficiency will drop, it might look perfectly fine from the outside, has it run low on coolant or been topped up with water and not glycol?

 

also the fan is dual speed, is it cutting in on both speeds?

[manrajf 0]

if it's not been kept in decent coolant, the rad (alu ones) will oxidise, and it's thermal efficiency will drop, it might look perfectly fine from the outside, has it run low on coolant or been topped up with water and not glycol?

 

also the fan is dual speed, is it cutting in on both speeds?

 

ahhh, so would the rad need replacing if its oxidised from the inside, or will a flush get it backto normal, i always make sure that i have coolant in the system,

 

some time back the car was loosing water so i put in some radweld, but it turned out to be a burst pipe, do u reckon that could be stuck in the system somewhere?

 

yea the fan is dual speed and while driving on the motorway the faster setting has been kicking in, even when i have switched the car off it will carry on for some time and then goes off.

 

cheers

[Paulmac19 4]

Flushing the rad wont take away the internal rot but i will let you see how many bits of rotted rad are floating about the system

Radweld is ok for a quick get me home fix

but i would flush you system like said and try and retrace your original problem

we used to use a pressure tester in work which you hand pumped air into the system forcing the water through the leak

it always found the leak its ideal as you can do this when the rad water is cold so you can go straight to the repair and work on it

perhaps somone on here near you will have one i am talking twenty years ago

 

but the rad i looking like the culprit here

 

good luck let us know how you get on

but our combined guess work usually gets there in the end

[kyepan 291]

coolant percentage mix, too much coolant and it will oveheat, as glycol coolant has a heat capacity of 0.7-8 when compared to water. this caught me out in the past.

[manrajf 0]

thanks for the help everybody, i just flushed out the whole system and there wasnt that much crap in there, i put the hose through the radiator, and only a small amount of dirt came out and then clear water, and the same with the rest of the car.

 

i just refilled the whole system and then realised im out of coolant, so once iv topped that up il take it for a spin and post up the results.

 

cheers

[manrajf 0]

Just took the car out, the temp gauge jumped up and down a couple of times and went back down to 1st bar and it hasnt moved from there since, came home and fan was on...could the temp sensor have broken? if so is it a hard job to change it?

 

cheers

manraj

[manrajf 0]

Hi everyone im still having problems with the car overheating, so far iv flushed the whole system, replaced the thermostat, taken the radiator out and completely flushed it and not much came out.

Driving on the motorway at around 70-80mph for about half hour the temp gauge is sitting on the 7th bar, and i can hear the 2nd radiator fan all the way through my journey. iv read the haynes manual and it says if i dont have pipes with release valves there should be a screw on the thermostat housing, iv bled the system using the screw which i think is the one described in the book but still no glory.

I really dont know what else to do, iv done a search as well but nothing similar to my problem is coming up. Any help would be much appreciated

 

thanks

manraj

Edited June 5, 2009 by manrajf

[Tom Fenton 1,548]

Next step I'd either try a new rad or a new water pump. Either are reasonably cheap to buy for a 205, radiator is probably easier to change though.

Edited June 5, 2009 by Tom Fenton

[manrajf 0]

Next step I'd either try a new rad or a new water pump. Either are reasonably cheap to buy for a 205, radiator is probably easier to change though.

 

Cheers for the quick reply Tom

the water pump was changed with the timing belt around a year and a half ago, is there any way of finding out if the waterpump is gone?

 

cheers

manraj