Coolant Loss through Filler Cap? - Page 3

BrainKing · 12th November 2013, 16:34

Quote:

Originally Posted by James.uk

>>>Open your bonnet after running your engine and turning it off and CAREFULLY (IT CAN BURN YOU) unscrew the cap<<<

DO NOT TRY THE ABOVE if the engine is up to norm temp....

When the engine is up to running temp the coolant temp is ABOVE boiling point. Undoing the cap lowers the pressure in the system allowing the fluid inside to boil, and it then comes out of the filler cap like a volcano!! It will hit the raised bonnet and bounce forward all over you....... I saw this happen, the guy was in hosp for a couple of days, and still has scars on his face.............

...

Ive released the pressure before by taking the cap off? Yeah its very hot steam, but at least you will see if its over heating. I took the cap off bare hand. And this was about 5 minutes after switching off the engine. Tbh just use common sense and be careful.

James.uk · 12th November 2013, 16:43

If the coolant is above boiling temp when the cap is removed, boiling water shoots out! NOT just steam, I know, I saw it, and the guy has the scars to prove it! It is not something we should advocate...
...

Ratty · 12th November 2013, 16:44

Quote:

Originally Posted by MangoMan

Trouble is 'M123' hasn't been back to confirm certain things, like"Oh, I was filling up to the brim".....??? Or, "No, I only fill it to the Max mark"....

It's hard to make proper assumptions without all the facts.

NB. In actual fact that really niggles me when you get a member who has maybe posted a dozen times or so since joining, asked a question in relation to a problem, gets a few suggestions, but is never heard from again until the next problem..... I know it seems petty, but good manners cost nothing!

I totally agree with you Bill

T-Cut · 12th November 2013, 19:18

Quote:

Originally Posted by James.uk

If the coolant is above boiling temp when the cap is removed, boiling water shoots out! NOT just steam, I know, I saw it, and the guy has the scars to prove it! It is not something we should advocate...
...

This graph tells us about the boiling point of 50% OAT coolant at various pressures.

From this, you can see that the temperature would have to get near 128°C to blow the 100kPa pressure cap relief valve. This is the early type cap. The current cap is rated 140kPa (22psi/1.4 atm.). This obviously needs more than 128°C to blow.

You can also see from the graph that the normal boiling point of standard coolant is around 108°C (the 760mm curve). Few engines reach this temperature, but a severe hazard still exists. When a hot engine is stopped. the bulk of the coolant is below the boiling point, but when pump circulation stops, it's the energy retained by the cylinder head that super-heats coolant around/within it. If the pressure cap is removed, this small quantity of super-heated fluid will boil instantly, forcibly ejecting a large volume of hot coolant from the filler hole.

Coolant at normal running temperature is hot enough to be life threatening.

TC

MangoMan · 12th November 2013, 21:35

24 posts since the original query and still no response from M123.... And here we, (well you) are arguing without knowing all the facts.... All quite academic.

M123 · 9th January 2014, 12:58

Hello again. Sorry for the delay – I have been away. Many thanks for all of your comments.
The fluid level was set correctly between min and max. There was * a lot * of pressure after 24hrs after leaving the car to stand.
Over the last 4 months added over 8L of coolant!
Mainly for interest purposes, I went and purchased a combustion leak test kit: http://www.ebay.co.uk/itm/Block-test-kit-for-petrol-and-diesel-engines-original-combustion-leak-tester-/181059430832
Sure enough the fluid changed from dark blue to yellow indicating HGF gases present in the coolant. I did not have to wait for the cooling fan to start to get the result. However, the temp gauge was midway and the vehicle was warmed up. It is worth noting that I did the test with 900ml of coolant missing to allow for expansion during the test. Everything went fine.
Also, now on closer inspection there is a small amount of mayonnaise on the inside of the oil filler cap!
The kit is quite neat in that you can run the test each time with each spark plug disconnected at a time to find out which head has the faulty gasket (s). But I have not done this yet. Also, I have taken photos of the kit in operation.
Also, found out that you can run a compression test on each cylinder to determine this.
My question now is has anyone had one or both of the head gaskets on the 2.5 V6 replaced by a garage and how much should I be expecting to pay? And are there any pitfalls or potential issues that I should be aware of?
Are there any quick fixes (OK I expect you to say no!)

Many thanks in advance.

jn12 · 9th January 2014, 15:53

If you need a garage in your area i would contact this gentleman.

http://www.tsautos.com

sure that is his link if not search for TS autos.

Used to work for MGR.

SD1too · 9th January 2014, 18:07

Hello Marvin,

This isn't as straightforward as it seems is it? Back in October you put K Seal in it:

Quote:

Originally Posted by M123

I did some research and saw the review for K-seal ... So I gave this ago.

After that, not surprisingly, you had heater problems:

Quote:

Originally Posted by M123

Just gone for another test drive. It seems cold air when stationary \ slow, but when driving 30mph+ etc get hot air ..

Something very unusual was happening in your cooling system, probably due to the K Seal. Now, a couple of months later, you think that you have head gasket failure. KV6 engines are not susceptible to HGF in the same way as the 1.8 litre engine because the factory fitted gaskets are of a more robust design. If you have managed to blow one or both, then you'll need to find out the cause otherwise it may happen again. It's more than likely that the K Seal was responsible. One club member found a huge lump of some kind of sealant almost completely blocking his oil cooler. You may have something similar, somewhere in the cooling system. You may like to check the bottom radiator hose to make sure that it isn't cold.

Simon

DMGRS · 9th January 2014, 22:02

I also think the K Seal may have played a part - it can 'accumulate' in slower flowing areas and block up coolant passages. Heater matrix is usually the first to suffer in our cars, as their design inherently allows the settling of sediment and any other suspended particles in the passenger side of the matrix.

Fix all coolant leaks properly IMO - I've had a spot of bother with K Seal in the past and wouldn't touch it again.

M123 · 10th January 2014, 09:55

The problem was apparent months before K seal was used. I had noticed coolant dripping from the fan housing and assumed it was the radiator and used K seal to "fix this". It was only later that I found out that the coolant was exiting the filler cap and dripping down to the fan housing. I have also found out that the inefficient heating was not due to any blockages in the heater matrix (the system has been completely flushed out now) but simply due to a low level in coolant due to the loss of coolant out of the filler cap each time the vehicle is used. Once the level is back up to between min \ max then heating OK.

The fact is that the system is pressurized, I have run a test and found combustion gases in the coolant and mayonnaise on the inside of the oil filler cap. The car is cooling / running as normal. If it is not a head gasket / cracked head what else could it be??

12th November 2013, 21:35	#25
MangoMan This is my second home Looking.... Join Date: Oct 2010 Location: England Posts: 10,911 Thanks: 862 Thanked 1,111 Times in 868 Posts	24 posts since the original query and still no response from M123.... And here we, (well you) are arguing without knowing all the facts.... All quite academic. __________________ *Regards, Bill - (MangoMan).* (Member 00854) http://i1110.photobucket.com/albums/...d.jpg~original Last edited by MangoMan; 13th November 2013 at 07:20..

9th January 2014, 12:58	#26
M123 Newbie 2006 Rover 75 Connoisseur SE Saloon 2.5 V6 Join Date: Nov 2011 Location: Birmingham Posts: 27 Thanks: 25 Thanked 0 Times in 0 Posts	Problem Solved Hello again. Sorry for the delay – I have been away. Many thanks for all of your comments. The fluid level was set correctly between min and max. There was * a lot * of pressure after 24hrs after leaving the car to stand. Over the last 4 months added over 8L of coolant! Mainly for interest purposes, I went and purchased a combustion leak test kit: http://www.ebay.co.uk/itm/Block-test-kit-for-petrol-and-diesel-engines-original-combustion-leak-tester-/181059430832 Sure enough the fluid changed from dark blue to yellow indicating HGF gases present in the coolant. I did not have to wait for the cooling fan to start to get the result. However, the temp gauge was midway and the vehicle was warmed up. It is worth noting that I did the test with 900ml of coolant missing to allow for expansion during the test. Everything went fine. Also, now on closer inspection there is a small amount of mayonnaise on the inside of the oil filler cap! The kit is quite neat in that you can run the test each time with each spark plug disconnected at a time to find out which head has the faulty gasket (s). But I have not done this yet. Also, I have taken photos of the kit in operation. Also, found out that you can run a compression test on each cylinder to determine this. My question now is has anyone had one or both of the head gaskets on the 2.5 V6 replaced by a garage and how much should I be expecting to pay? And are there any pitfalls or potential issues that I should be aware of? Are there any quick fixes (OK I expect you to say no!) Many thanks in advance.

9th January 2014, 22:02	#29
DMGRS Discount MG Rover Spares Rover 75 CDTi, 2x MG ZS180 Join Date: Jun 2011 Location: Hythe, Southampton Posts: 11,354 Thanks: 456 Thanked 3,377 Times in 2,027 Posts	I also think the K Seal may have played a part - it can 'accumulate' in slower flowing areas and block up coolant passages. Heater matrix is usually the first to suffer in our cars, as their design inherently allows the settling of sediment and any other suspended particles in the passenger side of the matrix. Fix all coolant leaks properly IMO - I've had a spot of bother with K Seal in the past and wouldn't touch it again. __________________ Your trusted MG Rover specialist! Tel: 02380 001133 / Email: [email protected] We now have a 'chat' function on our site for even quicker replies. Give it a try! Remember - discount code FORUM5 for 5% off

12th November 2013, 16:43	#22
James.uk Passed Away 2002 Pale Blue. Rover 75 CDTi Connoisseur auto. 170K miles Join Date: Dec 2008 Location: Near the M67. Posts: 14,509 Thanks: 199 Thanked 585 Times in 397 Posts	If the coolant is above boiling temp when the cap is removed, boiling water shoots out! NOT just steam, I know, I saw it, and the guy has the scars to prove it! It is not something we should advocate... ...

9th January 2014, 15:53	#27
jn12 Gets stuck in MG ZT SE 180 V6 Sports Auto Join Date: Dec 2006 Location: Newcastle upon Tyne Posts: 938 Thanks: 74 Thanked 37 Times in 36 Posts	If you need a garage in your area i would contact this gentleman. http://www.tsautos.com sure that is his link if not search for TS autos. Used to work for MGR.

10th January 2014, 09:55	#30
M123 Newbie 2006 Rover 75 Connoisseur SE Saloon 2.5 V6 Join Date: Nov 2011 Location: Birmingham Posts: 27 Thanks: 25 Thanked 0 Times in 0 Posts	The problem was apparent months before K seal was used. I had noticed coolant dripping from the fan housing and assumed it was the radiator and used K seal to "fix this". It was only later that I found out that the coolant was exiting the filler cap and dripping down to the fan housing. I have also found out that the inefficient heating was not due to any blockages in the heater matrix (the system has been completely flushed out now) but simply due to a low level in coolant due to the loss of coolant out of the filler cap each time the vehicle is used. Once the level is back up to between min \ max then heating OK. The fact is that the system is pressurized, I have run a test and found combustion gases in the coolant and mayonnaise on the inside of the oil filler cap. The car is cooling / running as normal. If it is not a head gasket / cracked head what else could it be??