TD spewing water all over

[Defender110]

Radiator should be hot all over as the water is beeing pumped around the system when the stat is open it does not work like the old no pump vehicles.

NOPE! Hot water is pumped upwards through the thermoststat housing into the top of the rad and cooled before leaving the bottom of the rad. If your cooling system is working correctly and your radiator not blocked the radiator should be hot at the top and cooler at the bottom, if it reenters the engine at the same temperature then your cooling system isn't working.

[citronut]

If your cooling system is working correctly and your radiator not blocked the radiator should be hot at the top and cooler at the bottom, if it reenters the engine at the same temperature then your cooling system isn't working.

this might be the case whilst the car is on the move,

but whenever i re/fill and bleed a cooling system and run it up to teprature,

if all is well the rad becomes evenly hot from top to bottom,
when this and all the pipes/hose's are evenly hot and calm i know the system is fine,

regards malcolm

[Defender110]

How bizarre, coolant that doesn't cool down before re-entering the engine = siezed engine.

[BX Meteor]

"whenever I refill and bleed a cooling system and run it up to temperature"

i.e. as it runs up to temperature, car not moving, fans not cut in yet ?

[citronut]

"whenever I refill and bleed a cooling system and run it up to temperature"

i.e. as it runs up to temperature, car not moving, fans not cut in yet ?

thats a good point

regards malcolm

[Defender110]

"whenever I refill and bleed a cooling system and run it up to temperature"

i.e. as it runs up to temperature, car not moving, fans not cut in yet ?

/\ me too, remembering its not always guaranteed to work first time so don't go ripping the head back off too quickly. Good luck with it hope its ok.

[TB2]

Hello again,

thanks for the all the good advice. I double-checked if the system is bled properly, taping a bottle to the top of the radiator, squeezing the hoses I was able to reach and on that day - a very hot day - everything seemed okay when I revved it and took it for a drive. I noticed the radiator stayed cool on the left hand side, suspecting the thermostat might be seized but apparently it opened eventually since both the top hose and radiator heated up significantly after all. I took it for a quick spin and it seemed like everything was good.

However in the evening (when it was cold outside) I took it for another short ride and the next morning I discovered that it had boiled over again. It just boils over too quickly and if I rev the engine small bubbles appear and the level rises.

Plus I did this short check that docchevron had explained in another thread: Starting the engine, removing the filler cap to release all pressure, refit the cap, rev the engine at about 1500rpm for 60 seconds, remove the cap again - and there was a noticable pressure build-up, where as doc said there should be none if the engine is okay. I suspect a gasket or head fault which is most noticable on a cold engine.

Now before I rip the head of again I have two questions:

1) I could buy a compression testing tool like this http://www.bgstechnic.com/product.php?prodID=01899" onclick="window.open(this.href);return false; It's about 200 swiss francs but that's the same price I'd have to pay for getting the head pressure tested. Would this help? Basically, I think I'd need to disconnect the stop solenoid, remove the glow plugs, connect the pressure testing device and rev the engine using the starter for about 4 seconds. Is this correct?

2) I dug up some of the photos I made when the head was off and re-discovered that indeed there is a very small crack between two valves as seen below. I suspect I was over-confident or naive enough to think that it wouldn't be a problem (after all the guy that skimmed the head said it was in good condition). What is your opinion on this crack?



Closeup:


Well if it's really gone I'll have a tough time finding a replacement

[Geoffrey Gould]

Hi just to settle things a bit, get to a garage which has a gas analiser and get them to 'sniff' the gas bubbles in the header tank. Any combustion gas will be identified and will denote :-

crack - most likely looking at the picture.
head gasket maybe.
warped block face.

but what ever a definite leak from a cylinder into the coolant system.
A couple of things. Age of radiator?? Does it get hot ALL over with out any cooler spot, for example in the center. It has not been unknown for a radiator to be blocked and wipe out a head gasket and for the gasket to be done and that to go as well, caused by the radiator,again.
I don't think that a compression test will tell very much unless there really is a bad leak. A 10% variation in pressures is a normal tolerance and could well cover a leak at the RPM achieved by the starter.
There is a way of telling which cylinder is leaking but it's a bit of a faff and not worth the trouble really.
Best of luck.

[TB2]

I got them to sniff the bubbles in the expansion tank using that blue CO2-detecting fluid and when the guy frist did it it turned slightly green after two strokes of the pump. He tried again and it wouldn't turn green anymore. He said that he doesn't really trust this test, because as I had taken the head off, there could be all kinds of 'stuff' in the cooling system that may trigger the CO2-Test without there being a problem.

I will try two more things:
1) Thoroughly check if the radiator gets hot all over.
2) Replace the filler cap. It's rare but it happens that the filler cap let's go at a lower pressure than it's supposed to.

Maybe I'll also install a temperature sensor to see more clearly what is happening.

[Defender110]

The garage should be able to do a pressure test where they manually pressurise the cooling system to 15psi or cap pressure without the engine running with a pressure gauge fitted to see if the cooling system holds pressure i.e. not leaking. If the manually pressurised system looses pressure you have a leak somewhere where you would first check for external water leaks like leaking hoses etc. if no external leaks then you have an internal leak like head gasket or cracked head.

[Way2go]

The garage should be able to do a pressure test where they manually pressurise the cooling system to 15psi or cap pressure without the engine running with a pressure gauge fitted to see if the cooling system holds pressure i.e. not leaking. If the manually pressurised system looses pressure you have a leak somewhere where you would first check for external water leaks like leaking hoses etc. if no external leaks then you have an internal leak like head gasket or cracked head.

A good test for an external cooling system leak but if that pictured crack is responsible then its going to be harder to force water at low pressure through it than the ease with which hot gases at higher pressures will go the other way.

[Mothman]

Hi bud,

i wouldnt waste your time looking for other reasons why your header tank for the rad is frothing, its because your head gasket has gone, blown, buggered and needs sorting.
Get it fixed and there wont be a problem.
My new TZD Turbo had zakly the same problems with identical things happening. Malcolm did the head,pressure tested it nd fixed it and she is running perfectly so far.
Dontreally feel you need to look elsewhere.

Head off time again methinks. I think you are just wasting your time looking for other reasons and its time to just bite the bullet.

Andy

[andycadabra]

I had the same problem with mine. Less than 2 years ago I had a new cylinder head and gasket but made the mistake of keeping the crappy radiator in which meant that within 6 months I was inexplicably getting the amber light of death while driving up the motorway, which should never have happened with a healthy radiator/cooling system.
I did change the radiator but I think it was too late as the bubbling got worse, and when I did I broke the old one open in the middle to find it was completely solid, mainly lime scale from the vast amount of water I topped it up with, mixed with various coolant leak 'cures in a bottle' . It even weighed 500 g more than the replacement one. I tried K-seal, but it never worked for me - it has for others apparently who have used 2 bottles at once, so that might be worth a shot..
Because I feared a warped block or cracked head, and because the water pump was suspect, I went for a replacement engine from an allegedly low mileage Peugeot 306, but I had been quoted just a little more labour charge for the engine change than the head gasket. As it turned out, when the head was taken off it appeared that it was just the head gasket gone.

[mat_fenwick]

its because your head gasket has gone, blown, buggered and needs sorting.
Get it fixed and there wont be a problem.

It may not necessarily be the HG - I did a HG change on a neighbour's ZX a few years ago and had the head skimmed and pressure tested before refitting, only for excessive pressurisation to return a week later. I never got to the bottom of what the problem was, but put in a replacement engine for him. It would seem likely that in this case there was a problem with the block, as it turned out it had previously had the HG changed not long before he bought it, and the cooling system was spot on.

[barry badger]

From my experience with xud engines cracks across the valves are quite common and i regard them as normal and usually ok. I've refitted many heads with quite deep cracks across the valves with no problems. One of my own cars used to blow the head gasket approx every 35000 miles (3 times) until the last time my friend who assisted noticed there was damage to the block in between cylinders 3 and 4 . He smoothed the damage with an oil stone so that it was an undulation rather than a pit. The head was refitted without skimming and it lasted another 6 1/2 years until the car was scrapped because of rust. I agree with Andy just take the head off again and check the block with a straight edge and if ok i'd source another head to be on the safe side. I'd say the crack in your picture is ok but there may be hidden cracks in the combustion chambers.