Air in coolant system/over pressurising

[Foggy]

I am a bit stumped, after Oulton Park Gold Cup last year my rad burst, so I set about the arduous job of replacing it myself and to be fare, with my little mechanical knowledge and help from friends, did it quite successfully. Clam off, changed several other parts and fixings and put it all back together again. I thought that I had bled the system, but not entirely by the looks of it. I had a couple of long runs out and on 2 occasions the expansion tank over pressurised and spued coolant out of the back of the car, luckily on both occasions friends were following (both Porsches) and alerted me.

At home I managed to get to the radiator bleed screw and air came out for 15 to 20 seconds, I also bled the engine bleed screw, not so much came out. After each drive out, having now become paranoid, I check the radiator bleed screw and always plenty of air comes out, after so many times I am sure there wasn't that amount of air left in the system. The tank level drops to min and I top it up to about midway, after some runs out it is just short of the cap, then when bled again it drops down, oh and I have put a new cap on just incase. The temp generally runs between 86 - 92, but on the odd occasion it has risen to early 100's, I am finding that I am constantly watching the temp gauge. I have also checked the tightness of the clips on the top and bottom hoses on the rad and they are as tight as you could get.

The car has gone in for MoT at Carnetix in Melton and I asked them to take a look at it. They did and chemical test on the coolant and all seemed ok, they took the plugs out and checked the bores and tops of the pistons for wash and fluid and all seemed fine too. They then did a pressure test and it held well. There is no cream and the oil seems perfect and golden, which is confusing.

They are Subaru and Saab specialists and have experience of Scoobs HGF where fumes get into the coolant rather than coolant into the oil, but are not sure if this is the same with a K series engine.

I don't want to break it if this is the start of HGF, but we are just not sure.

Has anyone experience of these symptoms? I have read an old thread on here by DeanB, following a failure and MartinR's link to changing his HG when the oil was emulsified, however, this is not something I have. I don't want to have to shell out many 100's of pounds to change the HG if it isn't this, but I want the car to be perfect.

I presume a call to Gav, as he seems to be the expert, although he is a long long way from Melton. Any HELP that anyone can give would be really appreciated

 

Simon

[winthattt]

I always use Gav and trust him totally but Jon at Legacy Storm in Leicester is much closer to you and knows his stuff.  My car is on his web page from when he worked for Stratstone Lotus and did the oil cooler recall.  Like Gav, once the Lotus dealer went pop he set up on his own.

 

Keith

 

[nickashton]

I can also vouch for Gav. He did my HGF in march and since then the engine has been fine with no loss of coolant etc. He skimmed the head at the same time too  

Regards

Nick

 

[AlanS1]

Your symptoms do sound like a early head gasket issue, but the garage has carried out all the checks that any good garage would do. 

The K series engine is not anything special and is a very simple engine. 

Does it do it all the time or only after a good run and everything is really hot? Did the garage carry out the test in the same circumstances? 

My coolant level has always settled on the min mark. 

They can be a bitch to bleed the coolant system but once its done correctly that should be it. Is the cooling system standard and original?

 

[Martin R]

Take the car for a good run. Open the boot and feel the big hose coming out of the L/H sill into the engine bay. Is it warm? If it is you have circulation in the system. The coolant system will gradually self bleed through the small hose that goes into the top of the coolant bottle and the head.

Let the car cool down for about 1.5 - 2 hours and remove the coolant cap. If the is a large hiss and or coolant running back into the bottle you have probably got a blow across the fire ring on the head. If there is just a small or no hiss all is well  

[Foggy]

11 hours ago, AlanS1 said:

Your symptoms do sound like a early head gasket issue, but the garage has carried out all the checks that any good garage would do. 

The K series engine is not anything special and is a very simple engine. 

Does it do it all the time or only after a good run and everything is really hot? Did the garage carry out the test in the same circumstances? 

My coolant level has always settled on the min mark. 

They can be a bitch to bleed the coolant system but once its done correctly that should be it. Is the cooling system standard and original?

 

Hi Alan

 

It only seems to get high in the tank after a good run out and has sprayed out 2 or 3 times and not for a while. The garage took it for a good thrash to get it good and hot before doing the checks so that they could see what it was like.

Cooling system is totally standard. I think I need to speak with this Gav, who seems to have a very good reputation and perhaps see if he could pressure bleed it first, just to see if it is just that there is still excess air in the system. Then run it and then see if more comes in, if so we can start to eliminate other things.

 

I need it right for LitP

[Foggy]

8 hours ago, Martin R said:

Take the car for a good run. Open the boot and feel the big hose coming out of the L/H sill into the engine bay. Is it warm? If it is you have circulation in the system. The coolant system will gradually self bleed through the small hose that goes into the top of the coolant bottle and the head.

Let the car cool down for about 1.5 - 2 hours and remove the coolant cap. If the is a large hiss and or coolant running back into the bottle you have probably got a blow across the fire ring on the head. If there is just a small or no hiss all is well  

Thanks Martin

 

I will have a look at both of these things and see.

[Alex B]

Simon,

I'd say give it a another bleed and see if it replicates the symptoms. Can sometimes help to have the rear of the car on axle stands making the engine bay bleed that little bit higher .

[cjwjames]

I think between Martin R & a visit to GAV ( very top rated in knowledge and rectification of all things lotus) you can have it sorted x 

[jody391]

Foggy is it a std rad?

Mine sits at the low mark.

Did you have the rear end up high when bleeding?

Do you have a PRRT?

Did you have the front end up when changing/bleeding the rad?

When you took the old rad off did you disconect from the rad and drain from there or other?

[Foggy]

5 hours ago, jody391 said:

Foggy is it a std rad?

Mine sits at the low mark.

Did you have the rear end up high when bleeding?

Do you have a PRRT?

Did you have the front end up when changing/bleeding the rad?

When you took the old rad off did you disconect from the rad and drain from there or other?

Hi Jody

As far as I know it's standard, it's not a triple pass or anything like that.

My driveway slopes down to the garage quite a lot and I have faced the car forwards with the back up and bled.

Excuse my ignorance, but whats a PRRT?

When I took the rad off the car was flat, I disconnected the rad hoses and the coolant drained from there.

 

I think when time allow, I will call Gav and have a quick chat and maybe arrange to take in. Is he able to take calls during the day or is it better to try later in the day? 

 

[Alex B]

On 05/06/2017 at 19:19, Foggy said:

Hi Jody

As far as I know it's standard, it's not a triple pass or anything like that.

My driveway slopes down to the garage quite a lot and I have faced the car forwards with the back up and bled.

Excuse my ignorance, but whats a PRRT?

When I took the rad off the car was flat, I disconnected the rad hoses and the coolant drained from there.

 

I think when time allow, I will call Gav and have a quick chat and maybe arrange to take in. Is he able to take calls during the day or is it better to try later in the day? 

 

He will normally answer during working hours

[John FISH Curtis]

PRRT....   http://files.qedmotorsport.co.uk/k-series_qed_remote_thermostat_fitting.pdf