Coolant change all sorts of issues

[andypinup]

Hi guys,

New to the whole VAG scene as I've mainly had French/jap cars over the years but thought I would try a Seat Leon Cupra and so far its not been clear sailing!

Its an 04 Cupra with a few miles on the clock! but generally well looked after. After buying the car I noticed the temp gauge was a bit slow and sometimes would drop to 60 when driving. After reading the forums I decided to change the stat as first port of call. Well not being that handy with a spanner I finally changed the bugger! not the easiest job in the world, also drained the coolant and refilled. Good job I thought until I noticed the heaters not working, it also appears the fans are not coming on either. I bled the system correctly I hope, and the top hose is getting hot, the bottom of the radiator though does not get hot. The water pump was replaced last year and because of the top hose it does feel this is working correctly. The hose coming from the stat again feels cold. The temp guage now appears to be working fine, it got upto 90 and held there fine although it did creep slightly over but came back down again??.

Any help guys would be much appreciated as I must of missed something

thanks

Andy

 

[wildrides]

if the temp guage is working what is your problem now ? slight movements in temp are normal . That is the stat opening and closing and rad fans coming on and off .

 

[andypinup]

The heaters are not working and it appears the bottom of the radiator is not warming up almost like something is blocked, I think this is why the warm coolant is not hitting the radiator fan switch.

 

[Old Bloke]

Did you back flush the system after dealing with the thermostat? Have you used a good quality anti freeze and not a cheap alcohol based one, if the latter then these will cause air locks in the system causing all sorts of problems. Best way is to back flush first which means taking off heater pipes and putting pressurised water into the system in the reverse of the normal flow. Do the same with the radiator and look at what comes out. If this does'nt work you may need to get the rad looked at. Good luck.

 

[wildrides]

its probo an air lock in the heaters . put heater setting on max and give it a good ragging up some hills.........usually clears it .

 

[Sprogpole]

. I bled the system correctly I hope,

How, it's a self bleeding system! Maybe that's your problem?

 

[andypinup]

Thanks for the suggestions guys, I think it may be because the radiator is blocked somehow. It can be my only thought as to why the bottom of the radiator is always cold. Would you suggest Wynn's radiator flush? When I mean bled the system I followed the guide with leaving the expansion cap off and squeezing the pipes while its coming up to temp. If the radiator is blocked would the heaters still work? sorry if this is a stupid question

 

[googujube]

Hi guys,

New to the whole VAG scene as I've mainly had French/jap cars over the years but thought I would try a Seat Leon Cupra and so far its not been clear sailing!

Its an 04 Cupra with a few miles on the clock! but generally well looked after. After buying the car I noticed the temp gauge was a bit slow and sometimes would drop to 60 when driving. After reading the forums I decided to change the stat as first port of call. Well not being that handy with a spanner I finally changed the bugger! not the easiest job in the world, also drained the coolant and refilled. Good job I thought until I noticed the heaters not working, it also appears the fans are not coming on either. I bled the system correctly I hope, and the top hose is getting hot, the bottom of the radiator though does not get hot. The water pump was replaced last year and because of the top hose it does feel this is working correctly. The hose coming from the stat again feels cold. The temp guage now appears to be working fine, it got upto 90 and held there fine although it did creep slightly over but came back down again??.

Any help guys would be much appreciated as I must of missed something

thanks

Andy

So is the bottom hose staying cold when the top one is hot? If you turn off the car for 5 mins does the bottom pipe stay cold?

Is the engine/bonnet getting really hot and not cooling for ages?

 

[andypinup]

The top hose is nice and hot, the bottom is like very very slightly warm and this is when the car has been idling for 10-15mins+ my guess is the fans are not kicking in because the bottom of the rad is cold and the fan switch is not getting hot enough.

The engine does not feel that hot, there is no hissing or bubbling and the bonnet is not hot. I don't think its headgasket, or I hope its not!

 

[andycupra]

do you know how much coolant you drained out and how much you put in!?
should 4-5 litres


try this:
when car is cold:
remove expansion tank top and start car, leave it running and watch the coolant level. If it drops then top up as required. As its a self bleeding system it should clear any air locks.
Have heater set to max temperature.
best to leave the car running till its up to temp.

Then once up to temp and circualted for 5 mins switch off and let it cool down. after its cooled check level and put expansion cap on.

should be ok now.

 

[andypinup]

Hi Andy,

This is the thing we only put in 3.5 litres and the expansion bottle is up to max, I will try the below but I have done this a few times, I do think I have a block somewhere

 

[wildrides]

Did the water pump you fitted have a plastic impeller .............. if so replace it again with a metal impeller pump . The plastic impeller ones cause a lot of probs ........... the impeller comes loose on its shaft and so ceases to pump at full output or at all depending how loose it has become . Eventually it will break up and bits of plastic can block the water ways . Did your last one break up ?

 

[andypinup]

I'm not sure as the previous owner changed the part, he got it from ECP with a sku of 201440655 looks like it could be the copper version rather than plastic?

 

[Kambo]

Is this a cupra diesel or proper cupra?

I figured diesel as you say changing the thermostat was a pain like I found, I believe on the cupra/r its alot easier

Anyways, first of all I would do as andycupra mentioned to make sure its bled properly, I know its self bleeding but you still need to follow a system

Heaters not working after thermostat/coolant change is usually because the system needs to be bled, doing the above should hopefully get them going again, was they definitely working beforehand?

Your bottom hose not getting hot is completely fine, mine never does this time of year or hardly, if the top hose is hot/very hot and your bottom hose is very slightly warm then thats fine, only if after a hard long drive you stop in traffic on a very hot summers day and your bottom hose is stone cold then your radiator is kaput, but you would probably notice your temp gauge rocket up first and your fans unable to do there job properly

Quick check (ok not that quick) for the water pump is get the car upto temp and make sure that top hose is nice and warm and give the hose a good squeeze, get someone to blip the throttle and you should feel the hose expand, if it does then your water pump is fine

Sometimes if your water pump (impeller) is about to drop off you will notice you have pretty much no heater but I'm not sure this is 100% confirmed as its either turning or not, the above squeeze will confirm that

Your fans not coming on could be a number of things, there is guide on here for people that have no fans or only one fan working, but try first opening the bonnet and switching the air con on and making sure one of the fans runs slowly, the other fan is the main one which will only run at higher temps, I think over 100 anyway

There is a fuse on top of the battery which blows if your fans are goosed so quick check of that will confirm, there is a thread on here for this issue so if you find your heaters and temp are fine and working properly now after its been bled but your slow fan does not come on with the air con switched on then come back here and we can deal with that then, there is also your engine coolant temp sensor radiator fan switch etc etc but try the above first and see where you stand

 

[andypinup]

Thanks Kambo much appreciated, its a proper Cupra! 1.8T

I will try the above and keep you guys posted

 

[wildrides]

Great post Kambo .

A proper cupra would be the cupra R not the Cupra 20VT according to most SCN followers ........just to avoid confusion ( I have a 20 vt by the way , so not proper ! )

 

[BoostHard]

Sounds like the it hasn't got upto temp and the thermostat hasn't opened,
It will take around 4.5l ti fill it up.

Take it for a drive, It will tell you when you need to top up.

 

[richman711]

Hi

Ive never done it my self but to check the water pump if working, take off the expansion bottle cap ( when cold ) and atart the car . You should be able to see flow going back to tank

 

[BoostHard]

Can see it with the cap on.

Sent from my GT-I9300 using Tapatalk

 

[Alexis27]

Great post Kambo .

A proper cupra would be the cupra R not the Cupra 20VT according to most SCN followers ........just to avoid confusion ( I have a 20 vt by the way , so not proper ! )

My Cupra says Cupra on the boot

The Cupra R is just a Cupra with a slightly bigger turbo