Another MK3 Golf overheating - HELP !!

[Denarius]

Hi, we've just bought 93 Golf as we were after something reliable and not full of electronics (so I could still do something on the car ;)).
Anyway 2 weeks later and its just started to overheat so have joined the forum and here is my first post.
Temp gauge heads up very quickly when idling but cools down when driving. Tried to bleed system by taking cap off expansion chamber and 'burping' top hose, revving etc. Had some air come out but not much. Doing a few unusual things though. It seems to build temperature/pressure slowly at first (this is when engine already hot), sucks water in when revved etc and then just wells up quickly and overflows expansion chamber. Another weird thing is that the top hose does not seem to be have any pressure in it ( actually it's all the hoses), even when the expansion chamber is at boiling point, the hose is very easy to squeeze together -although it is very hot, so getting something. Also the fan hardly ever comes on even when the gauge is at 110 degrees! (it does come on sometimes though - so it does work). Have checked oil filler cap and no mayonaise so fingers crossed. Last sympton is that the heater doesn't generate any heat. So, does this sound familiar to anyone? I thought thermostat but I can't figure out where this is housed.
Thanks in advance for any help.
D.

[Coupe16v]

I think you need to have it pressure tested. This could tell you if the head gasket is leaking exhaust gases into the coolant system. This happened to a car I once had.

[shooey88]

is there water flow....take the return pipe off the expansion bottle and see if water flows through it back to the expansion bottle. seems as if you have no flow of coolant through your circuit!!!!!!!!!!!! looking at broken water pump or thermostat causing poor circulation.
are all the pipes hot? any of them cold when the car is up to temperature and warm?
is the tmperature gauge reading what it should....for example have the engine temperature tested to see if matches the actually heat of the engine...being a possible faulty temp sensor
all my ideas for u

[Denarius]

Thanks for the replies. I think it has got water flow as when I rev the engine with the expansion chamber lid off I can see the water being sucked in. All of the hoses are hot.
Would anyone know if you can put the head leak additives in these or does it muck up the computer management?
cheers
D.

[shooey88]

if it "sucks" takes in coolant...that dosent mean its flowing
that just means it is going one way
is the small thin pipe near the top of the expansion bottle flowing water back into the expansion bottle when engine reved?

i dont understand what ur getting at wiv your last comment.

[Denarius]

I'll check the flowback on the small pipe tomorrow.
I'm a NZ'er and over there you can get a Stop Leak type additive you put into the cooling system that seals up small head leaks. I haven't seen it here yet but I haven't looked for it either. I just assumed you could buy it here.
D.

[shooey88]

never used the stuff before....i have used leak additive that you put in the coolant to illuminate where a leak is coming from then you solve the leak manuaully urself.
i heard new zealand are desperate for mechanics? lol

[Denarius]

Hi again shooey. Looks like you're right, the water is not flowing back into the expansion chamber via the small hose. Does that mean that it was just a vacuum sucking the water in then? So, a water pump then!
And no they're not short of mechanics in NZ, just short of money so everyone has a go a being a mechanic ;).

[shooey88]

did you rev slightly, while at the same time seeing if water runs through the pipe? you have to apply revs to get the water pump spinning faster....may need two people for the job....by the way becarefull not to scold urself if it does flow through btw!!!!!!!!!

if now coolant/water flows through that suggests water pump or thermostat faulty...can you hear a rattle/noise from the cambelt area where the water pump is to suggest its broken?

iv heard theres more sheep then people in new zealand....so maybe thats why the cars arent getting fixed lol:biglaugh:

[shooey88]

sorry bad gramma

i meant to say...if NO COOLANT IS FLOWING THROUGH THAT PIPE THEN IT WOULD SUGGEST A FAULTY WATER PUMP OR THERMOSTAT.

[Denarius]

Hi again, no rattles that I can pick up but have gone out and got a water pump this morning in case. Time to get dirty! Have you done one of these before? I haven't got a manual yet so hopefully won't come across the unreachable bolt by going about it the wrong way round.

We're used to the wooly jokes :)

[shooey88]

im used to working on newer cars with technology.
fitted water pumps to lots of mark 4 golfs which can be time consuming as you got to fit a cambelt and tensioner aswell
im not experienced on the mark 3s golfs as people cant afford to take them to a main dealer garage!!!!!
not sure wether its on the cambelt or runs on the auxillary belt. either way should be alot easier as an older car.
u ruling out the possibilty of the thermostat then?
hopefully i been some help and let us know how u get on!!!!!!!!

[Denarius]

Hi, yeah I did rev it. You can get to the throttle lever from the engine bay, so managed by myself. Can't hear any noise but I've gone out and got a water pump this morning as they're only £17. So, I'll replace that and take the thermostat out to check. Have you done one of these? I haven't got a manual yet so hoping I don't go about it the wrong way and find that unaccessible bolt!!

Heard all the wooly jokes :). Does the UK have any equivalent quips?

[Denarius]

Sorry, ignore last. My message and your reply hadn't come up yet, so I thought I'd not hit the right button and it had gone into the ether!

Thanks for the advise.
D

[Denarius]

Hi again Shooey. Well, spent the day replacing water pump and thermostat (decided I'd do this as well as it wasn't that easy to get at). Waste of a day:( . It's doing exactly the same thing. Temperature seems fine for awhile and then suddenly rockets up. The fan didn't come on at all despite the temperature. Wondering if it's to do with the temperature sender unit? I'm very annoyed. Spent 3 hours trying to get the alternator back on. Can't see how it can be done easily as even with the adjuster as far back as it will go (or forward depending on how you look at it) you can't slip the belt over the pulley. Cars eh! So, I guess it will have to go to a garage and see if they can diagnose it.

D

[shooey88]

sorry to hear
does water flow through the pipe now tho? as it should do!!!!!!!!!!!!
u havent got vag com to test the temperature sensor?
i feel sorry for anyone who takes there car to a garage....i have the privelage of working in one. :biglaugh:
hope it will be a cheap repair eitherway

[Denarius]

Yeah, it is coming out of the hose but in spurts. Can't keep it off too long, as when it starts to overheat, it shoots water out the outlet pipe it attaches to.
No, I don't have any of the tech gear. I'm just another hack Kiwi home mechanic;)
Thanks again for the help
D.

[ozzie252]

Please can you tell us what was wrong? Did you get it fixed? This is EXACTLY what is wrong with my Mk 3 Golf. Same overheating on longer journeys when idling lots - no heat coming through to the heater. Was just about to go get a thermostat when I stumbled accross your post.

What did the garage say? Hope it wasn't head gasket. I have no mayonnaise in top of engine but I also have a juddering in my engine when it gets to about 4k revs - like it is misfiring - but only after the car has warmed up. I have tried replacing:

spark plugs
plug leads
distrib cap
rotar arm
fuel filter

stuck a bottle of redex through it

It has done 118,000 miles but still runs really smoothly - apart from the juddering.

[Denarius]

Hi, sorry should have got back earlier. So this is for anyone that needs more info re this problem. Took it to a garage who just said it was the thermostat (which I'd replaced day before and told them this) bleed and refilled the system. It worked fine for about 3 weeks although still showing 100 degrees as normal temp. It then overheated again. Took it to another garage who found that the gasket at the bottom of the carb had a leak and that was what was causing overheating. However this time it did cook the head. i was not a happy chappy with original garage. Anyway bottom line, check the gasket at bottom of carb.

[PJ0]

you mentioned that the fan takes very long to come on,so you mayhave a faulty thermoswitch,which is siutuated on the side of the radiator,-it activates the fan at the right time,ensuring the engine doesnt get too hot ,and if faulty could take way too long to activate your fan. I'd suggest you replace it to be on the safe side.This could be the reason why you having all these problems

[neilcowhey]

have a mk3 vento, virtually identical, even down to the freaking problems you described, have changed

head gasket
sensor
o - rings (all of them)
radiator
thermostat
inlet manifold
fuel injector mount,
had the rotting inlet manifold re-machined(loads of corrosion)

still overheating on my drive two months later.....................suicide is my only out nowwwwwww

[idriveanything1]

I had a similar problem with a mk3 1.8 golf for overheating it found it to be caused by not enough tension on the belt the does the alternator and the water pump, i changed the belt as it was getting on a bit and also changed the coil spring that puts the alternator in tension, cured the problem. if theres not enough tension in this belt when you get upto higher speed the belts changes shape slightly and bows futher out in the middle which'll mean it;ll slip the water pump pulley at higher speeds

hope this is helpful

[coons88]

Long time reader first time poster lol
My car has a very very similar problem. It's a 1995 16v GTI

All the same symptoms, except the heater still works on my car.

Runs fine when driving, but when your stuck in traffic idling the temperature gauge starts to head right rapidly, and the oil starts to go up as well. As soon as you start driving it cools down again.


- All the hoses are hot
- Replaced the fan switch, they switch on and off but don't seem to come on often enough or stay on long enough, and they never come on high speed, even at 110 degrees
- However if you manually turn on the fans it does cool the system down (suggesting the radiator is ok?)
- Same thing if you run without the over flow bottle cap, it runs fine, then suddenly it just completely over flows out of the top
- Heater remains hot at all times
- Vag-com scan brings up no errors and confirms the temp gauge is reading correctly
- No water seems to come out of the small over flow hose that goes up to the over flow bottle, however when the system is hot that bottle fills right up


That's about all the symptoms I can think of right now
I was going to do the thermostat next, thinking maybe it is either jammed half open, or it is not opening/closing completely or properly?

Any other ideas?

I'm also from NZ :p

Cheers

[Denarius]

Hi again, well mine seems to have sorted itself out - almost! It hasn't overheated since 2nd garage fixed it. We did have problems with the heater not going, so took it back and he rebleed/flushed the system and heater ended up so hot you couldn't hold your hand over outlet or you'd get burned. :D

Have since got problems with heater again. I found if you squeeze bottom hose it comes right and then gunks up again after awhile. Guess there is something in the system partially blocking the heater inlet and the back pressure of squeezing hose clears it for a bit.

I won't touch the system now as I hate the overflow bottle - can never work out where the full point is, bottom of neck or top. I did find out though that you can only look at levels when it is cold as it's pressurised and will basically empty the system of fluid when you remove the cap or the small overflow hose at the top - duh!! Why didn't I figure that out for myself :o I'm used to whipping the radiator cap off to see how good the flow is (I do like old cars ;))

Hope you get yours sorted. It seems a bit of a pig of a car to resolve water problems on. Don't forget to post your solution when you finally solve it -hopefully before you slash your wrists:D

cheers

Dennis

[martinwhu]

Hi guys, I'm also having similar problems with my Mk3 1.4 Golf. See my post on here http://www.vwaudiforum.co.uk/forum/showthread.php?t=62433.

Basically when I got the car the temp gauge didn't work so I've done the following, in this order;

Got new temp sensor from GSF, gauge works but goes up to 110+ degrees

Changed thermostat - same problem, but fan does comes on.

Checked thermostat in saucepan of water - all ok.

Ran car without stat - same problem, gauge goes to 110+ degrees.

Replaced temp sensor from GSF with another from GSF just for piece of mind - same problem.

Tried another new thermostat - same problem.

Tried new rad fan sensor - same problem.

Ran hosepipe through all hoses and rad - no blockages.

When doing these first three things I distinctly remember the bottom hose getting hot, when the gauge was about 110 degrees, and the fan cutting in abit later.

Made my own 'gauge' using digital temp readout, thermocouple and silicone (thanks to work).

Now this is where it gets abit weird - car got up to 100 degrees on my own gauge and fan kicks in - but bottom hose is cold!

Tried without stat and car gets to about 95 degrees and bottom hose is hot.

Put stat back in, car gets to 100 degrees, bottom hose cold, fan kicks in and settles at 95 degrees, bottom hose still cold!

Connected dash temp gauge up and car got to 115 degrees before fan came on.

Throughout all this work the water pump has not been noisey and water spurts from the small return hose to the expansion tank.

So i've come to a conclusion - temp gauge from GSF is rubbish so going to get a genuine item, BUT i've still got a car where the bottom hose isn't getting hot.

Any ideas? Sorry for the long post but its been going on for a couple of weeks now.

[Denarius]

From memory (our VW is actually my wife's car) the normal temp on the car is quite hot. It is the mark after the 1/2 way mark. I was surprised by this as usually it's under the halfway mark on a gauge. I think that is 100 or 110 isn't it? Bottom hose is weird suggests thermostat isn't opening or blockage in heater unit. Does having heater on or off make a difference? How hot are the hoses coming from the heater?

These are a pain aren't they. Why does everyone rave about Golfs :confused:

Best of luck

Dennis

[martinwhu]

I think normal temp should be around, or just over 90 degrees - well thats what everbody seems to suggest, and other Golfs I've had have been like that.

Heater hoses are hot, as is the air coming from the vents inside the car.

I'm going to double (or is that triple!?!) check everything tomorrow, including the carb gasket.

Hopefully i'll post some good news on here tomorrow night!

[Denarius]

OK, crept into the bedroom (so as to not wake the wife) and got the workshop manual. Its for '92 - '96 golfs. Thermostat on 1.4 & 1.6 opens at 84C fully open at 98C. All other models thermostat opens at 85C fully open at 105C. Stage 1 speed on fans kick in at 92 to 97C turn off at 84 to 91C. Stage 2 speed fan on at 99 - 105C, off at 91-98C. Stage 3 speed on at 110-115C, off at 105-110C.

Hope that's useful. Doesn't quote a normal operating temp!

[martinwhu]

Dennis - thanks for the info, especially with the risks involved!

Today I think I have success - and I'm very happy. I think the bottom hose wasn't getting warm because of an air lock. Its important when you are bleeding the system to rev the engine to 2000rpm occasionally (to get the water pump spinning faster) and massage the hoses you can get your hands on. I found it even better to fast idle the car just below 1500rpm using a block of wood. I felt abit daft as i'd been doing this last week but complacentcey got the better of me.

That got my stat opening and on my home made digital temp gauge it sat at a nice 90 degrees for a while, and then the fan cut in when the temp increased. Lovely.

Fitted my new genuine temp gauge sensor and it all worked perfectly. Fingers crossed it stays that way - MOT tomorrow!

I think if i'd have fitted a genuine temp sensor to start with i wouldn't have had all this hassle and it would've been done in 20 minutes - not 3 weeks on and off.

Thanks for all your help guys, i hope to return the favour one day.

[coons88]

Thats good for you Martin

I'm starting to think my problem is to do with water circulation, one of the reasons being no water comes out of that small return hose when it's disconected. It is the original water pump aswell and has done 230,000km, however there are no leaks or noises..

Bloody cars :(

[martinwhu]

General opinion seems to be if there is no flow through the small hose, even when you rev it, then it is a circulation problem.

I think these its quite common impellor to fail when the pump goes hence you get no noise or leaks.

Worth running a hose pipe through the waterways to check for blockages though, I'm not sure if a blocked rad would restrict flow through the small hose or not.

Good luck!

[coons88]

I think that impellor problem is more common on Mk4's though as they have plastic impellors which crack and then don't grip onto the shaft properly. The Mk3's have a metal impellor
I am starting to think again that it's not the water pump, because all the hoses I can get too are hot, which would suggest it is infact doing it's job, and it's not leaking or making any noises which are common water pump symptoms?

I think my next step will be go and buy a new top radiator hose which has that small return hose moulded into it and replace that over the weekend

[sattmad]

i have a 1994 1.8 driver. after reading this post i noticed that when in traffic my car heats up to 110. the fan kicks in fine and when driving the temp goes down. Had a new thermostat fitted but after reading this post should i bleed the system? All the hoses are fine and i am gettin recirculation through the small pipe. should i be worried??????

[coons88]

Well lucky for me it seems I fixed my car for $20 :D

I decided to take the advice of someone who said that the o-ring on the bottle caps often comes off, or doesn't seal the system properly meaning there it doesn't hold the pressure, so I replaced that.
Then I also cleaned out that little return hose and it seems to be running fine now, car doesn't go past 90 at any time on the water gauge

[larrydlooter]

hi al been on the site for a few weeks now, i actually joined when my golf was runnin fine but alas my first post is a problem!! started car the other day and noticed dash lights nd tachometer not workin continued to drive thinking it was a fuse when car started to over heat! then had a look under bonnet to discover altinator belt snapped! does this also serve water pump? mines a 1.9 diesel n/a.. was searching for answers when i came across this thread.

anyway i wasnt far from home and it was dark so i chanced drivin home (probably bad idea i know) got home and steam was pouring from reservoir even though temp stuck at just over 90 all the way home.

changed the belt yesterday hoping all my probs would be fixed. its still running at 90 according to temp in car but also still spouting boiling water out of reservoir!! :(

could it be that the water pump failing caused the belt to snap??

Any help appreciated thanks!!

[manc]

Hi, The new stat on my mk3 isn't opening with the gauge showing 95, so can you tell me how you are bleeding your car, which hose are you undoing and which end???

Manc

[coons88]

Take the cap off the expansion tank and start your car. Let it idle for a good 5 minutes or so, and while it is running massage the top radiator hose a little bit (squeeze it basically) so that it helps to get the air out. While it is running, if you look into the expansion tank you should see a consistent flow of water shooting out of that little return hose - if it isn't that hose is blocked and you should either try and unblock it or replace the whole thing.

Anyway, after 5 min or so most of the air should be out, chuck the cap on, give it a minute or two to pressurise, then shut her off.

Hope that helps

[manc]

Thanks for your reply,

I'm doing as you say to bleed my car, only using both hands on the top hose, but I don't think I'm getting a jet of water out of the little return hose.

I had the thermostat housing off and blew through this pipe, the hole for this pipe inside the housing is about 1.5mm? max

I would like to see another housing to compare.

[coons88]

If that little return hose is blocked and it doesn't squirt out a jet it isn't the end of the world, I ran by car like that for a couple of years (atleast) as I was unaware it was blocked - it never caused any problems. So I wouldn't worry too much

[manc]

Mine does trickle, but I'm considering everything and anything to find the cause of my problem, which remains.

[coons88]

How do you know it's not opening? Are all the hoses hot?

[manc]

I got home last night with gauge on 90 and the bottom hose was cold.

So today I took the VAG thermostat out, and put it and my spare motor factor thermostat in a dish, poured boiling water over them until they were submerged and neither of them opened a smidgin!!!!!!!!!!!

And this makes three thermostats, which I am putting in the right way, and can't believe I can be so unlucky.

[coons88]

Sounds like the thermostat is the culprit then, 4th time lucky!?

[manc]

The VAG stat was fine after all, as before I did a rough and ready kettle test, but today I tested the stats in a pan of water and used a jam thermostat to get an accurate reading.

Car now fixed.

[maxmc2]

Mines been overheating, flushed the system and now all seems good, must have been and air lock somewhere.

[extensa]

Hi mate,
my golf was overheating as well. It didn`t happen often but time to time. I was searching alot on internet about engine system overheating and found one interesting video on youtube about engine wear, overheating and fuel consumption. http://www.youtube.com/watch?v=6o47ub7ArDQ&feature=player_embedded I have trued the resurs after ordering it on ebay and it helped me with my overheating problem, of course not for 100% but at least is not overheating as before and the fuel consumption is not like it use to. It might work for you mate.