ZT 190 pressurising..done loads..no luck to date!

[errol1]

Hi all,

I'm new to this forum so this is the first post.

I know that the KV6 pressurising problems have been done to death and I have read most of them and looked to solve the problem on my 190 with forum suggestions but..... it is still pressuring!! Below is a list of items done to date:-

1. New radiator & condensor
2. New lower hoses to oil cooler
3. New stat and parts to go with
4. Modified existing old 3 speed fan with new gold resistor and modified wiring to suit, now a 2 speed.
5. New water pump
6. Sniff test of coolant for any combustion gas...all ok
7. Replacement header tank cap
8. Replaced coolant at 50.50 OAT, refilled slowly with header tank raised.
9. New inlet mainfold gasket to front bank

Its still chucking coolant out past the cap when hot, all hoses, rad etc hot and at pressure. Heater is also running fine with hot air being pushed out.

Checked engine temp with OBD and 2 speed mod is cutting in at correct temps.

So I'm getting a bit fed up and not sure where to go next.

Any ideas gratefully received.

Thanks

[chipsceola]

Taken a long time as a member to ask for help, but have finally asked and am sure a K6 expert will respond shortly, meanwhile despite raising header tank, sounds like air in system.

[errol1]

Been lurking!

Joined a while back to deal with another problem on the 160 but found my answer in another post so not needed it until now!

Oh and no pink stuff in the V either!

[roverbarmy]

Are you filling to the correct level? It is waaaaay down as you look in the top of the tank. Lots of folks overfill and that doesn't allow for expansion when hot.

See HERE (http://www.the75andztclub.co.uk/forum/showthread.php?t=213343&highlight=coolant+level).
Mike

[Salad-Dodger]

I endorse what roverbarmy says, plus this.....
From cold, remove the cap and start the engine. Look down the header tank filler. Do you have any coolant coming from the small pipe in the neck? Also, if the coolant immediately rises to overflow, you may have a blocked water passage through the oil cooler. Also, order some new "O" rings for the filler cap. There are two and they are different sizes so get them in the correct place on the cap. You can eliminate the oil cooler by bi-passing the water pipes to see if the result is a positive one. Hope this helps some. Steve

[Stag>75]

8. Replaced coolant at 50.50 OAT, refilled slowly with header tank raised.



Here is a bleeding procedure:

http://www.the75andztclub.co.uk/forum/showpost.php?p=1547805&postcount=15

Might be worth trying again to see if there is any air left in there.

Then you might want to get the coolant tested for exhaust fumes in case there is a problem in the engine.

Failing that, perhaps check the header tank cap is the correct one. I believe there are different ones.

[T-Cut]

Is there any pressure released on opening the filler cap when the engine is completely cold?

TC

[errol1]

Yes I think so.

[SD1too]

Hello Nigel (errol1),

I can see where this thread is leading. Please let me reassure you that your engine, the KV6, is not susceptible to the head gasket failure commonly found with the 1.8 litre engine. This is because the gaskets are a completely different multi-layer construction.

You have received several very sensible replies suggesting possible causes of the ejection of coolant you have reported from your expansion tank cap. You need to address these straight away. I'll give you some further tips to help with this.

Checked engine temp with OBD and 2 speed mod is cutting in at correct temps.
OK. When the slow speed cuts in at 100° does it reduce the temperature to 96° in about 30 seconds to one minute?

... despite raising header tank, sounds like air in system.
When you raised the header tank, did you also open the bleed screw (with the engine not running) as described in MG Rover's refilling procedure?

Are you filling to the correct level? It is waaaaay down as you look in the top of the tank. Lots of folks overfill and that doesn't allow for expansion when hot.
This is particularly important Nigel. When you take off the expansion tank cap, can you see the 'MAX' marker towards the bottom of the tank? Please advise.


From cold, remove the cap and start the engine. Look down the header tank filler. Do you have any coolant coming from the small pipe in the neck?
Well, do you? If you don't, the system is venting air.
Also, if the coolant immediately rises to overflow, you may have a blocked water passage through the oil cooler.
This is important too. The oil cooler is easily blocked by the addition of 'magic' sealants such as K-seal. When the engine is up to normal temperature, grasp the bottom radiator hose at the site of the bleed screw. Is it very hot or cool?

Here is a bleeding procedure:

http://www.the75andztclub.co.uk/forum/showpost.php?p=1547805&postcount=15

Might be worth trying again to see if there is any air left in there.

Definitely. Follow this procedure exactly.

So, lots of positive things for you to do Nigel and the chances are that one of them will be responsible for your overflow of coolant. If you have any questions about any of this, fire away. :D

Simon

[DMGRS]

A coolant 'sniff test' would help in pinpointing the problem - if the boiling over of HGF, there would definitely be combustion gasses in the coolant.

[errol1]

Thanks for the updates all.

Will go over what I have already done to date and incorporate your advice and will report back. Feeling a little bit more optimistic!!!:shrug:

Cheers!

[Data]

I've had similar on my 190. Bypassed the oil cooler as that was blocked by k-seal.

Still had coolant coming out of the expansion cap when sitting traffic. I had replaced the cap already, but on a hunch I switched back to the old cap and have had no issues since.

So worth checking your new expansion cap......

Cheers,

Mark S.

[Danger_MouseUK]

It's worth noting that there are two different types of cap for the expansion tanks. the older black tanks came with a cap rated to 100psi? as they release excess coolant in a different way to the newer expansion tanks, which as a result came with a cap rated at 140psi?

The caps are comparable one way, backwards i think, but to the other. i.e. the older 100psi cap will not work with the newer tanks, but the 140psi caps will work with the older black tanks.

[SD1too]

... rated to 100psi? ... rated at 140psi?
The units are kilopascals (kPa) Mike. 1 kPa = 0.145 psi so the original cap has a rating of 100 kPa = 14.5psi = approximately 1 bar.

Why we have to have so many units of pressure which mean more or less the same thing I don't know. :shrug: :o

Simon :}

[Danger_MouseUK]

The units are kilopascals (kPa) Mike. 1 kPa = 0.145 psi so the original cap has a rating of 100 kPa = 14.5psi = approximately 1 bar.

Why we have to have so many units of pressure which mean more or less the same thing I don't know. :shrug: :o

Simon :}

haha, thanks, yeah I pretty much took a swag (scientific wild-a** guess).

[T-Cut]

haha, thanks, yeah I pretty much took a swag (scientific wild-a** guess).

You and Xpart too: http://www.rimmerbros.co.uk/Item--i-ESR1480

TC