V6 coolant loss and overheating - but cant find problem - Page 2

chrissyboy · 27th January 2013, 17:46

Quote:

Originally Posted by tonybel

Thanks Simon and to chrissyboy - i'll read up on the mike Hurley threads.

I didn’t tell all in the first post (it was long enough!). But on a previous invoice from 07 was "block weld"

). The garage cannot find any trace of it, but it adds a worry. The garage are starting to think towards a cracked liner.
This car has had some money spent on it over the years! Bills show that everything has been done – sometimes twice. If it wasn’t an SE with all the gear you can be sure it would have been scrapped years ago.

Correctly means the Haynes removing tank and elevating way. I have done the check and top up over months, and have had some clear advice from Keiser how to do it. Just when it starts to settle down it will get full of air again. Opening the cap is accompanied by bubbling, and its been doing that for one year and 5k.

There is never a puddle under the car and the coolant smell is immediate on start up - not when the exhaust gets warm.

again all advice is very useful as it makes us consider something we may have missed.

seems there was a fault in the block that was repaired and is again playing up. seek a smoke test if there is a crack in the block the smoke will escape from it .as i said it was found to be the problem on mikes car in the en he did eveything you could think of to solve his issues which sound the same as yours .a bill though for a block repair is certainly some history that the car has suffered this before .

tonybel · 27th January 2013, 22:07

Thanks for the reply. Hopefully we will have the heads back tomorrow and can then look further if they are OK.

What did mike do? Strip and replace the block or switch engines?

Arctic · 28th January 2013, 00:57

Hi Tony.
Are you going to change all the hoses if and when you put the engine back together if not at least check the hose with the bleed screw in it as this can leak very slowly and you would not notice it, as the thread in the rubber hose can perish maybe worth a look Arctic

kaiser · 28th January 2013, 04:30

It should be bleeding obvious (pun intended!) that no amount of bleeding, is going to get rid of air in the system, if there is a constant leak.

Since there has been no success in removing the air in the system, it has to be concluded that it is being continuously generated, by water continually being lost.

There are only two ways water can be lost.

As a drip on the floor, somewhere, or

As an internal "consumption" that might not be seen easily.

If there is water lost internally, you should be able to see it under the oil filler cap, as it should be full of mayonnaise, even when the engine is warm. A possible exception would be a total ejection through the exhaust, which is rare.

If we look at all possibilities.
Outside: water pump, metal pipes, thermostat, inlet manifold gasket, radiator, any pipe or connection.
Inside: crack, leak past liners, inlet manifold gasket, oil cooler, leak behind water pump, leak at sump seal (certainly possible on 1.8)

My original problem with my V6 was diagnosed as HGF, but was in retrospect leaks past liners.

My subsequent loss of water in the 1.8T was leaks past liners and from unsealed water ways at the sump. That was totally cured by using Wondarweld. Following a much later cambelt incident, the engine has subsequently been rebuilt, and the liners glued with Loctite.
http://www.the75andztclub.co.uk/foru...=1.8T+pictures. The engine is as new!
(well, actually better

, it uses no water, and I think/hope it will never!)

chrissyboy · 28th January 2013, 06:50

Quote:

Originally Posted by tonybel

Thanks for the reply. Hopefully we will have the heads back tomorrow and can then look further if they are OK.

What did mike do? Strip and replace the block or switch engines?

mike ended up getting another 75 but that was his choice,

Gate Keeper · 28th January 2013, 09:32

If all else fails before you spend more ££££ you could consider a recon engine. I have been down that road with another car and that solution can be fraught with issues. I do know someone who did it on his ZT and he changed the engine. It worked out ok. It is not an easy decision to take given you have had lots done by the garage.

tonybel · 28th January 2013, 12:49

ahh, some good advice there. Remember that this is not a new problem and I have been reading threads and getting advice for a year before taking current head removal action.

When we changed the thermostat we also changed the inlet manifold gaskets and the hose with the bleed screw. They system was refilled by removing the headed tank (didn’t see it myself but they say they did and this lot are quite consensus and always go the last mile). Since then I have had the system more or less stable – before a longer run and the problem kicked in again. It is clear that the coolant system is being over pressured and this is affecting the integrity of the system. We have the heads off and can see all. Sadly there is not a lot to see…
So a replacement engine is high on the list as, apart from anything else, I am fed up with it. How do I justify owning what I think is a great car if the blooming thing won’t go more than 10 miles without a problem? It’s a £1,000 to get it all back as is, and what if the problem is still there despite bleeding and new hoses etc. This engine, as far as I can tell, has been a liability for 40 thousand miles and has had £3.5k spent on it by various owners. As they say in the song “time to say goodbye?”
In a plus point all the electrics work, unlike my previous MG which had so many warning lights on most of the time it was like driving Blackpool illuminations.
I digress, so if its to be an engine, where from? Seancar has already kindly come in with an offer. Looking at likely costs so far a replacement MG would be cheaper, but I’ve already come this far and don’t feel like quitting. It all really depends on the cost and potential reliability of a replacement engine.

Gate Keeper · 28th January 2013, 13:16

If you pm me I can refer you on to someone who is not a member of this forum. He has experience of having changed engines on his various Rover 75/ZT cars in the UK and did some work on my V6 last year. It is an option which you might think about at a later date. Do not be put off by my location.

Jezzer 1 · 28th January 2013, 14:43

Quote:

Originally Posted by Simon.h

Have you checked the oil cooler?
Maybe the last owner put radweld etc in it before the head gaskets were changed and its blocked. A member on here has problems with the coolant system and he found it blocked!

Which year is your ZT?

And I had the same problem with one of the Limos that was described as
'pressurising the cooling system' - oil cooler was completely blocked by KSeal or similar which a previous owner had poured in to stop a leak! there was a solid plug in there preventing coolant circulating correctly. Do check it.

Simon.h · 28th January 2013, 16:35

Quote:

Originally Posted by Jezzer 1

And I had the same problem with one of the Limos that was described as
'pressurising the cooling system' - oil cooler was completely blocked by KSeal or similar which a previous owner had poured in to stop a leak! there was a solid plug in there preventing coolant circulating correctly. Do check it.

So Tonybel, have you checked the oil cooler yet?

27th January 2013, 22:07	#12
tonybel Avid contributor MG ZT 190 SE Join Date: Apr 2010 Location: Stone Posts: 173 Thanks: 66 Thanked 29 Times in 24 Posts	Thanks for the reply. Hopefully we will have the heads back tomorrow and can then look further if they are OK. What did mike do? Strip and replace the block or switch engines? __________________ Running like a train & leaking like a sieve

28th January 2013, 04:30	#14
kaiser This is my second home 75 Tourer 2.5 Auto, 1.8T, 75V8ZT Join Date: Jun 2007 Location: Johannesburg ZA Posts: 6,200 Thanks: 1 Thanked 859 Times in 613 Posts	It should be bleeding obvious (pun intended!) that no amount of bleeding, is going to get rid of air in the system, if there is a constant leak. Since there has been no success in removing the air in the system, it has to be concluded that it is being continuously generated, by water continually being lost. There are only two ways water can be lost. As a drip on the floor, somewhere, or As an internal "consumption" that might not be seen easily. If there is water lost internally, you should be able to see it under the oil filler cap, as it should be full of mayonnaise, even when the engine is warm. A possible exception would be a total ejection through the exhaust, which is rare. If we look at all possibilities. Outside: water pump, metal pipes, thermostat, inlet manifold gasket, radiator, any pipe or connection. Inside: crack, leak past liners, inlet manifold gasket, oil cooler, leak behind water pump, leak at sump seal (certainly possible on 1.8) My original problem with my V6 was diagnosed as HGF, but was in retrospect leaks past liners. My subsequent loss of water in the 1.8T was leaks past liners and from unsealed water ways at the sump. That was totally cured by using Wondarweld. Following a much later cambelt incident, the engine has subsequently been rebuilt, and the liners glued with Loctite. http://www.the75andztclub.co.uk/foru...=1.8T+pictures. The engine is as new! (well, actually better, it uses no water, and I think/hope it will never!)

28th January 2013, 12:49	#17
tonybel Avid contributor MG ZT 190 SE Join Date: Apr 2010 Location: Stone Posts: 173 Thanks: 66 Thanked 29 Times in 24 Posts	ahh, some good advice there. Remember that this is not a new problem and I have been reading threads and getting advice for a year before taking current head removal action. When we changed the thermostat we also changed the inlet manifold gaskets and the hose with the bleed screw. They system was refilled by removing the headed tank (didn’t see it myself but they say they did and this lot are quite consensus and always go the last mile). Since then I have had the system more or less stable – before a longer run and the problem kicked in again. It is clear that the coolant system is being over pressured and this is affecting the integrity of the system. We have the heads off and can see all. Sadly there is not a lot to see… So a replacement engine is high on the list as, apart from anything else, I am fed up with it. How do I justify owning what I think is a great car if the blooming thing won’t go more than 10 miles without a problem? It’s a £1,000 to get it all back as is, and what if the problem is still there despite bleeding and new hoses etc. This engine, as far as I can tell, has been a liability for 40 thousand miles and has had £3.5k spent on it by various owners. As they say in the song “time to say goodbye?” In a plus point all the electrics work, unlike my previous MG which had so many warning lights on most of the time it was like driving Blackpool illuminations. I digress, so if its to be an engine, where from? Seancar has already kindly come in with an offer. Looking at likely costs so far a replacement MG would be cheaper, but I’ve already come this far and don’t feel like quitting. It all really depends on the cost and potential reliability of a replacement engine. __________________ Running like a train & leaking like a sieve Last edited by tonybel; 28th January 2013 at 12:52..

28th January 2013, 09:32	#16
Gate Keeper This is my second home 4X4 Join Date: Jul 2010 Location: Nairobi Posts: 20,084 Thanks: 8,286 Thanked 7,017 Times in 4,160 Posts	If all else fails before you spend more ££££ you could consider a recon engine. I have been down that road with another car and that solution can be fraught with issues. I do know someone who did it on his ZT and he changed the engine. It worked out ok. It is not an easy decision to take given you have had lots done by the garage.

28th January 2013, 13:16	#18
Gate Keeper This is my second home 4X4 Join Date: Jul 2010 Location: Nairobi Posts: 20,084 Thanks: 8,286 Thanked 7,017 Times in 4,160 Posts	If you pm me I can refer you on to someone who is not a member of this forum. He has experience of having changed engines on his various Rover 75/ZT cars in the UK and did some work on my V6 last year. It is an option which you might think about at a later date. Do not be put off by my location.