vw golf mk4 gt tdi (110) - over heating issue. - bmw messed up

hey guys.

i have got a problem with my golf mk4 gt tdi 110.

1) car heats up and temperature goes to 120 degree. but if i drive slow, it come down to 90 degree.

2) heaters blowing cold air even if temperature is on 120 degree.

3) i flushed all the coolant and filled it in again, (( i heard, after you filled the coolant, close the radiator cap and let the temperature goes to 90 degree and then let it cool down. after that, open the radiator cap, the water level must go down so you filled more coolant in. right? BUT in this case, the coolant level was didn't go down.))

PROBLEM

i have checked all pipes,

1) the pipe which goes in the thermostate to bottom hose of radiator, is not hot BUT warm.

2) the pipe which goes from the side of the engine to upper hose of radiator is cold.

SOLUTION

can some body please tell me, what would be the problem??????? coolant is not losing so i guess head gasket is fine.

Edited by bmw messed up on 11/02/2013 at 18:43

vw golf mk4 gt tdi (110) - over heating issue. - madf

Failed thermostat

Failed water pump.

Failed temperature sensor for colling fan (I assume it is not working? At 120C it should be )

Failed cooling fan..

Failed cooling fan fuse or wiring. Or not connected.

take your pick.

vw golf mk4 gt tdi (110) - over heating issue. - bmw messed up

how to check if the fans are working??

other thing, when my car over heats and i turn off the engine, the radiator both fans come on with full speed for 2 mins and it turn off itself.

BUT when my car at normal temperature OR over heating, fans stay off.

as in picking one of them, i bought a thermostate which i am going to change it myself tomorrow, where the thermostate goes in, if i put my finger in, i can feel then impeller so if it is fixed thats mean my water pump is fine???

Edited by bmw messed up on 11/02/2013 at 20:27

vw golf mk4 gt tdi (110) - over heating issue. - Cyd

Initially I was inclined to suggest thermostat stuck shut. However the water flow through the heater matrix will be independant of the flow through the rad so I'm inclined to go with failed water pump. Assuming that you've made sure there's no air locks.

Is there a return pipe to the reservoir? If there is you should be able to discern some flow through the reservoir. If not then case for water pump is strengthened.

I should stop driving it though. If there's no water flow round the system and the water is getting to 120C then you can bet the exhaust valves are way over normal temp and you might risk burning them out.

vw golf mk4 gt tdi (110) - over heating issue. - bmw messed up

yeah there is a small pipe thats goes back to reservior, i will disconnect it and see if there is any flow of coolant.

the pipe which goes from thermostate to radiator was warm but ther other pipe thats goes from engine to bottom hose of radiator was cold, it could be mean that thermostate was shut and didnt open so water can't get passed so thats why the pipe was cold??????

vw golf mk4 gt tdi (110) - over heating issue. - Cyd

If the pipe from stat to rad is getting warm that suggests the stat is opening and some water is flowing, but very little (or it's convection).

I'm still leaning toward pump failure.

vw golf mk4 gt tdi (110) - over heating issue. - bmw messed up

so to check the pump, i need to see if the water is flowing back to reservior from the tiny pipe?

and if i take my thermostate off, i put my finger in, if the impeller is fixed thats mean pump might b fine but it its free, then pump is gone

these two things will put me to direction of pump but i hope it wont be a pump.

actually few months ago, i had a same problem, i bleed the system and if worked fine for few months, it happened twice before and i fixed it.

but all pipes used to be hot, but this time, one pipe was cold.

vw golf mk4 gt tdi (110) - over heating issue. - bmw messed up

RIGHTS GUYS

I HAVE GOT AN UPDATE.

I opened all pipes and thermostate,

the small pipe which goes in the coolant reservior, it was jamed because of mud. so i took the bottle off and cleaned it.

put everything back on and took all the air off.

drove for a bit, the coolant light came on, soo opened the small pipe which goes in reservioe, there was some air pressure, then opened the cap and filled more coolant in.

then i drove for a bit, all heaters were blowing proper hot air. BUT GOT AN OTHER PROBLEM NOW, the pipe which goes in thermostat and bottom hose of radiator, it was cold but the thermostate plastic case was hot though.

the other pipe which goes on the top hose of raidator to engine, it was hot.

Edited by bmw messed up on 12/02/2013 at 15:01

vw golf mk4 gt tdi (110) - over heating issue. - Peter D

This sounds typical of a loose impellor on the pump shaft. Did you check it for movement in several different positions. Regards Peter

vw golf mk4 gt tdi (110) - over heating issue. - bmw messed up

what movements?

the pipe which goes in thermostate to bottom hose of radiator, it was cold and i can feel something inside like coolant moving i think.

rest of the pipes were all very warm.

is it possible if the thermostate didn't open?

but i had proper hot air from heaters inside the car

Edited by bmw messed up on 12/02/2013 at 15:49

vw golf mk4 gt tdi (110) - over heating issue. - dieselnut

It sounds like the small return pipe that was blocked prevented the air from being bled from the engine & stopped the heater from working due to an airlock. Now the air is gone everything is working ok. The bottom hose should be cold at this time of year as it is the return pipe to the engine from the rad.

I would drive it keeping a close eye on the temperatutre guage, it shouldn't go over 90.

vw golf mk4 gt tdi (110) - over heating issue. - bmw messed up

yeah bro hope thats right lol

i went to a garage before, he goes either thermostate or water pump gone so i came here and did some research.

i write it down so if anyone ever has the same problem, atlest he will know what he need to do to fix it before taking it to a garage.

1) i checked everything like no leak at all

2)i open the thermostate, put in a hot bowl which was on fire, the thermostate start getting open and then i put in a cold water, it close itself so thats mean, thermostat is fine.

3) the pipe which goes to the bottom of radiator from thermostat, i put water in that, and opened the tap in the bottom of radiator so the water flows thats mean, there was no blocking on the upper hose.

4) the pipe which goes from engine to upper hose of radiator, i put water in that too, the water flows from the tap so there was no blockages as well.

5) the pipe which goes into the reservior, its very small pipe, i took it off, it was full of mud and blocked, so i might as thought, i clean the bottle too. so i took it off, and cleaned it with hot water. there was so much mud in there.

6) now put everything back together and start filling the coolant, i left the small pipe which goes in reservioe, also called bleed pipe.

7) now there was two pipe, 1 pipe which connects to thermostat and bottom hose of radiator, 2 pip which connects to engine and upper hose of radiator, when added the coolant, squeeze those pips and see the level in the reservior, if its goes up and down, thats mean there is no blockage in the cooling system

8) close the cap and start the engine and rev is on 2000 rpm till water start coming out from the small bleed pipe. if see a water, close it ASAP.

9) now there is an other small pipe which on the top of the big pipe which connects to engine and upper hose radiator, open the pipe and see if water flows.

10) if there was water flowing, then i guess your water pump is fine.

11) water pump would be the last option. do all those step first, actually i did it twice though. car is fine for now, i will take mine for a proper bad drive today to see if its heat up or not. i will pot the updates.

vw golf mk4 gt tdi (110) - over heating issue. - Cyd

That "mud" would probably be the results of serious internal corrosion within the cooling system. If I were you I'd get some 'rad flush' or similar and flush out the cooling system. Then refill with a supply of deionised water and min 25% antifreeze (your car will need the OAT stuff). You can buy coolant premixed (usually at 50%).

vw golf mk4 gt tdi (110) - over heating issue. - bmw messed up

yeah i will certainly do that

i drove my car for like 30 miles but in the end it heats up but this time, heaters were blowing warm air, not hot air.

the temperature needle goes back to 90 degree if i slow down but if i rev hard, it increase.

the pipe which connects to radiator and thermostate, was cold.

other pipes were hot and other thing i noticed, my car was 100 degree but radiator fans were off, but asap i turn off the engine, both fans start working to cool the engine i guess.

but should fans be working when if my car was over heat like when i was driving or idle??????

i turned AC on, both fans start working then.

other question i want to ask, can i drive with out thermostat? what advantage and disadvantages will it cause?

vw golf mk4 gt tdi (110) - over heating issue. - Collos25

So you are driving the car with it overheating without curing the problem,I can see a new engine on the horizon.

vw golf mk4 gt tdi (110) - over heating issue. - bmw messed up

I dont think you read my whole conversation but anyway i am not driving the car, i am trying fix it and trying to find out the problem of over heating.

anyway guys, when i drive slow like under 40mph and 5th gear, car don't over heat and heaters are blowing little warm air as well.

I am thinking the water pump is working but not proper, like getting weak or somthing. but please do tell me about the radiator fans, when temperature goes 110 degree still my fans not working but asap i turn off then engine, both radiators fans start working for 2 mins. then cut off itself.

vw golf mk4 gt tdi (110) - over heating issue. - skidpan

The fan switch is in the radiator, if the radiator is not getting hot the fan will never switch on.

The up and down temp sounds like air locks to me but the Golf used to be easy to bleed but with newer cars that may have changed.

Could still be the stat fit a new one before doing anything else.

vw golf mk4 gt tdi (110) - over heating issue. - Collos25

"anyway guys, when i drive slow like under 40mph and 5th gear, car don't over heat and heaters are blowing little warm air as well."

Sounds very much like you are driving it to me.

If you drive it at under 40 and it does not overheat or loose any coolant then the radiator itself could be blocked but you should still have a hot heater which makes me think that the HG has gone.

Edited by Collos25 on 14/02/2013 at 13:14

vw golf mk4 gt tdi (110) - over heating issue. - bmw messed up

how radiator be blocked? when water is coming back to reservior and plus i open the top hose and put water in in the pipe and it flows out from the bottom tap of radiator.

then i put water in the put water in the pipe which goes to bottom of radiator, waters flow out from the bottom tap.

thats mean radiator is not blocked.

i did a compression gas test on and the color of the fluid didn't change thats mean no gasses in Head gasket so HG is fine.

vw golf mk4 gt tdi (110) - over heating issue. - Collos25

how radiator be blocked? when water is coming back to reservior and plus i open the top hose and put water in in the pipe and it flows out from the bottom tap of radiator.

then i put water in the put water in the pipe which goes to bottom of radiator, waters flow out from the bottom tap.

thats mean radiator is not blocked.

Doesn´t prove anything its the rate the water and the volume of water that will pass through the radiator in a given time.It can half the core blocked you will still get water passing through.

Your HG test is flawed to say the least you can have water to oil,water to water ,and water to air, the latter will not show only use water and the heater wil run cold till all the water is used up.

vw golf mk4 gt tdi (110) - over heating issue. - bmw messed up

the garage has done the HG test few weeks ago and he said, it is fine.

heaters are blowing warm air but when i rev it, it blow proper hot air.

bottom rad hose pipe is cold even car is at normal temp or slightly more.

thermostate is new as i checked it manually.

in the thermostat, housing, i put my finger in and felt like a wall. felt something fixed? heard it meant to be like that?

other things which bugging me is, the pipe which goes on the top of the radiator hose and the side of the engine, i opened the hosing few months ago, car was bit hot so the O ring expand alot.

i cut the O ring and took a little part off and glued it to the housing.

after that car was fine.

do u recken, or anyone that can cause any problem? as there is no leakage there though.

also, i want to say, it is possible that temperature sensor is gone? as heaters are working, coolant is circulating and top hose is hot and bottom hose of rad is cold.

Edited by bmw messed up on 14/02/2013 at 20:03

vw golf mk4 gt tdi (110) - over heating issue. - bmw messed up

the system is been bleeded so many times but m sure, there wasn't any air lock. as the water circulating from all pipes.

I bought a new thermostate for 11quid from BMS. before i put it in, i checked it in hot water so it works, ( open and close)

i am concern about the pipe which goes in radiator bottom hose and thermostat. i can feel proper coolant movement inside the pipe and its cold pipe.

the other pipe which goes in engine and upper hose of rad, was prety hot and also the small pipe which goes back to reservior was hot too.

i am so confused, what would be the problem as my heaters are warm when car is idle and when i drive, it goes soooo hottttt.. that i had turn it off even its minus outside.

vw golf mk4 gt tdi (110) - over heating issue. - Collos25

A sure way to bleed the system properly is to start the engine and let it run without the cap on the expansion chamber when it reaches temp and the thermostat opens any air will be expelled through the expansion chamber ,this can take a while to remove all the air.Plus you will need the heating on full heat.

Edited by Collos25 on 14/02/2013 at 21:59

vw golf mk4 gt tdi (110) - over heating issue. - bmw messed up

thanks bruv

i will try that tomorrow and also got block test to check for head gasket like any gases in radiator.

a quick question, can a car over heat because of temperature sensor?

other questions, the pipe which goes in to thermostat from radiator, does it have to be cold?? when car is at normal temperature, i can feel the coolant inside but other pipe which goes from engine, i cant feel the proper movement of coolant..

so does it have to be like that?

vw golf mk4 gt tdi (110) - over heating issue. - Cyd

I'm still picking up on your description of a pipe blocked with "mud". I think you've got severe internal corrosion in the cooling system. If it was bad enough to be able to block a 8mm ish pipe then it's certainly bad enough to block the cores of a heater matrix or radiator.

Flush out the heater matrix and the radiator using high pressure water from a hose. Do it in both directions. Flush through the block in the same way too. then treat with rad flush prior to refilling.

vw golf mk4 gt tdi (110) - over heating issue. - bmw messed up

bruv can u tell me the proper procedure to flush the core of heater matrix and radiator? like how can i do it?

it took my 15 mins to clean the bottle, which was full of mud.

the radiator has been changed last year in feb 2012.

Edited by bmw messed up on 14/02/2013 at 23:43

vw golf mk4 gt tdi (110) - over heating issue. - Peter D

"it took my 15 mins to clean the bottle, which was full of mud." What exactly do you mean "mud" where do you think it is coming form How clear is the coolant. Regards Peter

vw golf mk4 gt tdi (110) - over heating issue. - bmw messed up

coolant has been changed so many times by me.

whenever car heats up in past, i changed the coolant and then never heat up and last for few months.

raidates has been changed last year.

mud is cean, brownish material and today i was checking pipes so the pipes which goes to heater core matrix, two pipes right? one was hot and other one wasnt, when i sequeeze thoses pipes, i can feel the crunchy feeling.

so tomorrow, i am going to open all pipes and wash them proper. but how to clean the heater core and inside the engine??????

vw golf mk4 gt tdi (110) - over heating issue. - galileo

When you kept changing the coolant, did you add antifreeze each time or use fresh water?

Antifreeze has chemicals which prevent corrosion, without it you get brown rust.

vw golf mk4 gt tdi (110) - over heating issue. - Cyd

the radiator has been changed last year in feb 2012.

How does that affect if it's blocked or not now?
That was then, this is now.

vw golf mk4 gt tdi (110) - over heating issue. - bmw messed up

how to remove the blockage if its got any??

can anyone tell me the proper procedure, what shall i do clean my coolant system ( heater core matrix, engine, pipes and radiator)) please.

i will spend my next two days doing that...

vw golf mk4 gt tdi (110) - over heating issue. - ali1978
Hi did you resolve the problem on the golf I've got same problem on my golf cheers
vw golf mk4 gt tdi (110) - over heating issue. - Asfurniture
Did you find out the problem as it is happing my car to thanks
 

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