mk2 1.9tdi over heating

[lambretta man]

out fri over heating looked like classic cylinder head /gasket got hot under load up hills etc
coming home today and if i had climate control on hot no over heating in fact if i got it up to boil your brain temp the temp gauge dropped that far i stopped to check i still had water could not always get it toblow hot but that may have been due to temp in the car
checked radiator hoses top red hot bottom stone cold except for right next to engine block and radiator stone cold and no fans running
if i remove expansion cap water level rises
am i right to assume faulty thermostat and or air lock
water comes out of overflow into top of expansion bottle
no error codes recorded according to vagcom
thanks terry

[johnnyroper]

Firstly I would check the small hose to expansion bottle restrictor it's plastic and should have a 2mm hole in it.
The thermostats fail open usually so don't cause over heat normally slow warm up.
Also worth checking the impeller on water pump if plastic one they are notorious for being loose on shaft.
Finally after that I would look at head gasket issues,it's not uncommon in pd lumps.
As for the lower hose and rad being cold this is fairly normal on these engines as they produce very little waste heat to warm coolant,it would take a long drive under load to get stat open fully

I would hazard a guess the restrictor is blocked on yours personally

[lambretta man]

thanks i have water coming out of the restrictor but not a strong flow and in fits and starts
drove back from whitby today and rad and bottom hose cold all the way
belt and i assume pump replaced by previous owner nov 2015
water in expansion bottle frothy on the top

[lambretta man]

should add if i open expansion too soon plenty of pressure and water spurts out
leave till the morning and no pressure in the system

[johnnyroper]

There isn't a big flow through restrictor as only a small hole.

If water pump is ok then I would defo suspect head gasket then if pressure in bottle.
I can get mine very hot and only get a little hiss when releasing cap.
Certainly worth checking pump first though as even if it was changed a plastic impeller type could have been fitted

[lambretta man]

what about the rad not getting even slightly warm after 200 miles

[johnnyroper]

If water pump not doing anything it won't as the flow from run on pump is just enough to prevent over heat under normal conditions but not enough to fully circulate and get stat open.

[lambretta man]

o k  if it stops raining i will get the return pipe off and replace with a plain pipe if that doesnt work i will take thermostat out and check impeller

[lambretta man]

took off small pipe from expansion bottle and looks like someone has been there before 2mm drill rattles in the hole so later today new thermostat and rad flush
took it for a run last night and can do 70+ without over heating on the flat but hit an incline and up shoots the heat although heater on will bring it down

[johnnyroper]

Make sure you check water pump impeller while thermostat is out.

[Chrispb]

Firstly I would check the small hose to expansion bottle restrictor it's plastic and should have a 2mm hole in it.
The thermostats fail open usually so don't cause over heat normally slow warm up.
Also worth checking the impeller on water pump if plastic one they are notorious for being loose on shaft.
Finally after that I would look at head gasket issues,it's not uncommon in pd lumps.
As for the lower hose and rad being cold this is fairly normal on these engines as they produce very little waste heat to warm coolant,it would take a long drive under load to get stat open fully

I would hazard a guess the restrictor is blocked on yours personally

A few good points there johnnyroper although I dont agree about thermostats.
Bellows type thermostats (not seen one for years) when failed stayed open.
Wax type stat (most common) fail closed due to the wax pellet capsule leaking, the spring will keep the valve closed, having said that I have seen a few with a foreign object caught in the valve keeping it partly open causing a slow warm up.

[Chrispb]

took off small pipe from expansion bottle and looks like someone has been there before 2mm drill rattles in the hole so later today new thermostat and rad flush
took it for a run last night and can do 70+ without over heating on the flat but hit an incline and up shoots the heat although heater on will bring it down

the symptoms your having could well be from a failed water pump, acquiring a car with these symptoms is risky, even if the pump has been changed as damage may have already been done.
Unchecked overheating if initially caused by failed pump will end up with head gasket failure.

The cool/cold bottom hose is normal on the diesel, you may notice some slight warmth in summer months.

[johnnyroper]

A few good points there johnnyroper although I dont agree about thermostats.
Bellows type thermostats (not seen one for years) when failed stayed open.
Wax type stat (most common) fail closed due to the wax pellet capsule leaking, the spring will keep the valve closed, having said that I have seen a few with a foreign object caught in the valve keeping it partly open causing a slow warm up.

My stat failed on the so called safe side as it took an age to warm up and never got over 80 and temp plummeted when heater turned on. When I removed it the stat wasn't actually open but was very easy to push by hand,I can only assume if the wax fails the water pressure is enough to lift stat of seat?

Having said that I can't imagine a pd engine with a stat stuck closed would be evident unless on a hot day and engine under some big load,especially a galaxy with a large cooling system.
Given the restrictor is clear I would say problem lies either with water pump impeller or head gasket failure from previous over heating.
When I acquired mine the seller said it had over heated previously and suffered loss of coolant through expansion cap,I never had any issues driving 100 odd miles back,but the gasket was clearly at fault as there were witness marks from no2 across to cooling jacket. In my case it was the common issue of head bolts stretching with heating/cooling cycles. Apparently the 115bhp pd's in all applications around 2001-2003 can suffer from this due to poor quality bolts or torquing from factory. According to info from vw forums anyway.
The head was checked and found to be perfectly flat and no cracking so just a gasket change needed.

[lambretta man]

changed the thermostat old one i struggled to open by hand new one has not stopped over  heating although may not be as bad or i am easing off sooner
checked pump and i could not feel any movement going for a good rad clean out next and will have another check on pump when i have someone to turn engine over

[johnnyroper]

Is the impeller plastic or metal?

Sounds to me like head gasket issue.

The flow through rad is minimal on a pd unless under serious load and it's hot due to very little waste heat,I feel a rad flush would be a waste of time for your issue.

[lambretta man]

i expect you are right but at the clutching at straws stage at the moment after the flush it will go for a sniffer test and if that shows head gasket will just run it as is an take it steady  as its  not worth the cost of repair

[lambretta man]

am trying the holts 2 part at the moment part 1 is in and am leaving it for a few days but at the moment the expansion tank is full of crap bobbing around and the temp display drops from the middle when i put the heater on which it never did before
still could be worse following an 06 plate touran this morning that looked like it had been converted to run on coal

[lambretta man]

looks like i have had a result with the holts 2 part stuff
ran it a couple of days and started to get the smell of coolant in the car
opened up the expansion tank the next morning and loads of coolant poured out
i had filled it to just before max and ow it was full to above the filler neck so a lot of liquid came from somewhere
car now takes about twice as long to warm up and did 200 miles today to llangollen and back and hammered it up the hills with no over heating
in the expansion bottle there are what look like black fibres but when you touch them it crumbles and feels like soot/carbon so its flush and part 2 in the rad next and hopefully no more grief till the next problem

[Chrispb]

I certainly don't think your out of the woods yet, when you're  finished with the flushing and get the coolant antifreeze back in then see how it performs.
Fluctuating coolant levels and excess pressure are signs you still have problems.

[lambretta man]

i dont have fluctuating coolant levels as such
just suddenly gained a lot of coolant from somewhere drained it back to max and it has stood steady at that level since
i assumed the flushing liquid  had cleared a blockage or air trap and allowed a lot more coolant into the system

[johnnyroper]

If a block or air lock had been cleared I would expect level to drop.
To have it rise suggests something is leaking in to system oil,fuel etc. Have you had any kind of emulsifying?
Also you say it had a lot of pressure in expansion bottle was that just the once or does it happen after every run?

[lambretta man]

no sign of ol in the water
never had it rise before its just been a 1 off after adding the flushing agent after removing the excess has stayed steady
after a long run a get pressure/rising boiling water if i loosen the expansion bottle cap
left till the morning get a very slight release of pressure like opening a flattish bottle of pop
drained the rad today and added the 2nd part of the flushing agent which is just a neutraliser and went for a good blast plenty of 80+up long gradients with no sign of over heating before i struggled to do 50 to 60

[johnnyroper]

Sounds very much like head gasket to me if its pressurising like that especially if still hot pressure next morning. That's how mine was when I got it.

[SiC]

Sounds like potential HG to me.

FWIW, when a HG fails on a PD engine you won't necessarily see coolant contamination in your oil (I speak from bitter experience).

For the cost of a sniffer test, it's worth doing even though they aren't 100% accurate at detecting a slight HG failure (sometimes you have to hold the revs high for a couple minutes as opposed to letting the engine idle over in order for a small leak to be detected).

The floating bits in your coolant header tank have probably originated from engine/hose internals during the boiling of your coolant.  It would be worth back flushing your heater matrix & radiator as it's common for these small piece to collect here and slowly clog your Matrix.

[lambretta man]

removed the thermostat and shoved the hose pipe up every available orifice and gave  a real good flushing
topped up with fresh anti freeze and water at 50 /50
went to wicks and brought 250 kgs ogauge stayed rock solid at 90f gravel i need for a job at home and ragged the life out of the old gal up every incline around here that was giving me over heating gauge stayed rock solid at 90 the whole time going to derbyshire next week to strap the caravan on the back and show her some proper hills and then i will know one way or the other
only draw back at the moment is i am going to have to sort out the aux heater when i took my lad to work it used to give warm air through the blowers by the time i got there now i am home again and still no heat

[johnnyroper]

you sure there is not an air lock in it? I have turned my aux heater off now weather is a touch warmer and I get warm air within a mile or 2 and it reaches 90 on gauge after about 4-5 miles and gives full heat output?

I had very stubborn air locks after changing my thermostat gauge rock solid at 90 but heater hoses stone cold. After running the flush through it and finding the floating bits I would re check the restrictor as that could well be blocked now stopping any trapped air venting back to expansion bottle.

[lambretta man]

restrictor is clear and a good flow
once gauge gets to 90 i get heat from the blowers just takes twice as long so prob 6 miles instead of 3

[lambretta man]

sods law went to drag the caravan around and the tow electrics socket is buggered so took a chance and went for a short run at about 40 just a couple of minor gradients and temp stayed rock solid on 90
since have changed the expansion bottle cap and now i can take my lad to work come home again and heat is only up to second line on gauge
then friday got the red stop check fluid and no sign of any coolant in the bottle topped up to just below max checked next morning expecting to add a bit more now fluids had cooled down but instead i find the bottle is over filled starting to scramble my mind now

[lambretta man]

well its the head gasket took caravan out for a drag flew up first hill no sign of over heating by by hill 3 it was up in the red
going to try some k seal and if thats no good will just run it for a year as is then chop it in for a newer one

[Chrispb]

Sorry to say I told you so seen the symptoms so many times.

There is a product called steel seal  iirc offers a money back guarantee if it don't work

here it is http://www.steelseal.co.uk/

[lambretta man]

 i know lived in hope and clutched at straws all the bits i did have helped a bit
went up to huddersfield sat 70 to 80 most of the way with no overheating so if the k seal doesnt work at least i can use the car for everything else bar towing the caravan give it till dec then trade in for a newer one and make sure i have an engine warranty and take the van out for a drag straight away

read elsewhere that steel steel is just something called liquid glass under a brand name at twice or more the price

http://www.ebay.co.uk/itm/NEW-500ml-Water-glass-Sodium-silicate-liquid-glass-/181748933183

[johnnyroper]

When I had mine with gasket gone and very similar symptoms to yours I did a lot of reading about it being common on the 115hp lumps,constant heating and cooling cycles caused head bolts to stretch/slacken on certain engines between 2001 and 2003 for some reason. On the vag sites a lot of people went another quarter of turn on the bolts with a cold engine and sorted it.

Kind of see this could help as my bolts were not the tightest when I did head gasket,the head on mine was checked and found to be fine just had witness marks where combustion gas entering cooling jacket from no2 but no damage to gasket. I dare say had I tried tightening it would have resolved it. Might be worth whipping rocker cover off giving them a tighten as you are only keeping until end of year?

[lambretta man]

yes i have been thinking about that read the same thing believe it was something to do with sub standard bolts

[johnnyroper]

Way I see it head gasket leaking anyway so worth a try as you are gonna chop car in.

[lambretta man]

had a quote of local garage Ã,£500 plus vat to change cylinder head gasket as long as its not a cracked cylinder head if head they will sot out a good replacement
is there any way of telling if its gasket or cracked head before i let them have the car

[johnnyroper]

No there's no to tell until head is off,once head off if it's just gasket you will see some witness marks. Also when removing the head bolt tightness can be a tell tale also

[lambretta man]

o k  thanks will have to bite the bullet and hope for the best at least they have said they will find a good used one if needed as the cost of new ones are megger