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polo10v Oct 19, 2011

  1. polo10v

    polo10v New Member

    Hi all

    not posted much on here since i had my last a4 a couple of years ago and was planning my first post this week with pics of my latest a4, but unfortunatley as the title suggests im having a little problem at the min with it!!!!

    apologies for there being no pics once i figured how to then i will get um up!!

    anyhow a little bit about the car before i beg for advice!

    i have owned a 05 black 2.0 tdi s line a4 for for approx 4 months and spent quite abit off ££££ on it in the little time ive owned it, mods include coilovers, 18'' matt black bbs ch's, tinted headlights and windows all round, it has has factory sat nav in the dis screen which to be honest isnt brilliant!, upgraded sony i.c.e, i would like leather but dont fancy forking out £700+, only other things i have planned are bit of paintwork in summer just to tidy it up a little.

    now not to the not so good stuff, i have been searching on net for last couple of days to try and find some answers but im finding alot of threads/posts conflicting so hopefully someone on here can help me.

    3 months ago i had full cambelt kit and w/pump fitted along with full service of oils and filters, with the weather being alot warmer a few month ago i used the aircon alot which worked fine. now that the wheather is alot colder i have noticed that my heating isnt great in the car, i usually have it set at 24 but all i get is cold/luke warm air coming through and it doesnt really increase when i turn up temps.

    whilst the car was at mechanics yesterday having coilover height fine tuned ( he's done cambelt and w/pump on my last 4 cars) i asked him to bleed the coolant system as i suspected a airlock in system somewhere, he noticed that lower radiator hose was stone cold whilst the top hose was hot as it should be. he replaced the thermastat with a new one and got the car back up to temp. the lower hose is still cold and has very little water inside it compared to the top hose which is hot and you can hear water squishing inside it when squeezed. also the the hose going to heater matrix are both hot when car at temp.
    when i got home today i checked the lower hose and again it was cold but alot harder to squeeze than before, i opened the expansion tank lid and approx 3 seconds of air expelled out of it and the lower hose went soft again?

    i must note the car has never overheated and stays bang on 90 once its got to temp 10-15 mins from cold in the morning.

    my mechanic along with 3 people i spoke to are diagnosing a faulty water pump as it would seem the water isnt being forced all around the engine hence to stone cold lower hose? does this sound familier to anybody?

    i have used this make of waterpump (metal) x3 before on previous cars and never had a problems before!

    the only thing i have been told it could be is a blockage in the radiator and maybe a full flush could be done to try and fix the problem? is there any good ' how to's' links?

    sorry for the long post but i just want to elimanate all possibilties before i have to put it in for another w/pump at my cost, as i supplied all the parts to my mechanic

    thanks in advance for any advice/assistance i recieve

  2. Mike B

    Mike B Well-Known Member

    Dont think it can be the waterpump if its not overheating and would try a flush with an additive cos it seems that there may be gunge in the matrix and/or the bottom of the rad.Have you mixed antifreezes cos I have heard that they can react
  3. polo10v

    polo10v New Member

    hi thanks for reply

    the coolant as pink and clean as cud be. both matrix pipes are hot as they should be. the lower hose stays cold but is pressurised with air after a drive in car, if i open expansion tank lid then all this pressure gets released so its maybe a sign of air in system.

    im guna test if its the waterpump anyhow by removing thermostat and running car ti temp, if the pipe gets hot and has water running through it then the pump is working fine and that will point to a thermostat issur or pressure in system causing stat to not open. im deffo guna try this before i entertain putting another w/pump in. i will prob try a flush it wont hurt to try it.

    still welcome more advice

  4. murran

    murran Well-Known Member

    both matrix pipes are hot going thru the baulkhead but the heater only blows luke warm air?
    have the heating system code read for faults.... you'll probably find one of the flap motors are knackard.

    thermostat wise... are you sure your running it up for long enough. these things take ages to warm up enough to get the thermostat open.
    unless its over heating or producing enough pressure to come out of the overflow at expansion tank i wouldnt worry if youve had a metal impeller water pump fitted.

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