Coolant problems, the sequel. FFS..

[Victor Meldrew]

Well I can tell you what has been done so far...

No leaks visible from anywhere on the car, even with the heater matrix back together again.
Head off and pressure tested the head, all ok. (no faults found)
Liner heights check, all ok
Refit head and test run for 300miles at reasonable pace with no re-occurance.

Not found anything definitive yet as to what caused it then?

Check PRT function (longshot, no faults found)

Head scratching... take it away and see if its fixed it or not.

So Newcastle to Stewarton, no problems, steady pace, roads a bit damp in bits.

Stewarton to Falkirk, no problems..

Kinross to Glenrothes, the roads empty and dry.. opened her up a bit.. (wragged its neck half to death )
Coming over the hill at Glenrothes the temp started to show high, slowed a bitand watched it head up to 124 deg.
Stopped, out of the car and had a look in the header tank, still plenty coolant, some evidence of cap leakage, radiator stone cold..

So... where next..

[thinfourth]

Is your temp sensor duff?

The caterhams have a distinct history of crap sensors don't know if an elise uses the same sensor and at 124 i would of expected major system boiling over

Is your water pump working?

I had a BMW which exploded the pump and it was a known problem but i have never heard of a K having a dead pump

Is your thermostat stuck closed?

Not unheard of but i would expect that to be a constant problem not to suddenly rear its head with the car running fine before

[Rich H]

Stone cold rad is PRRT. Is it a landy part?

Can you give a sketch of the pipework layout? Could it be back to front? Sticking shut? I had an airlock under the PRRT which was a PITA to shift

Rich

[steve_weegie]

Sorry to hear this John. Can you get your hands on a Digital Thermometer? FD used an Infra Red one ( like this) on mine to measure temperatures across different parts of the engine - in your case i'd be very interested in seeing what temp the output pipe from the head was showing.

[Victor Meldrew]

I know Dan had the head pressure tested.. one possibility would be a liner, I am sure one of the experts has already suggested this. So now I need the sniffer to confirm if I am getting combustion gas in or not...

quote="thinfourth" Is your temp sensor duff?

Q;The caterhams have a distinct history of crap sensors don't know if an elise uses the same sensor and at 124 i would of expected major system boiling over
A;it was spuing water out of the header tank. The temps all look normal, reacting as it should do with the fan kicking in and out when it should.

Q;Is your water pump working?
A;It has run fine for almost 500 miles after the rebuild with the system behaving as normal...

Q;I had a BMW which exploded the pump and it was a known problem but i have never heard of a K having a dead pump
A; Dan didnt think it was likely, never heard of it himself.

Q;Is your thermostat stuck closed?
A; Dan had the PRT out of the car and checked it in a tub of boiled water with a thermometer and it worked fine.

Q;Not unheard of but i would expect that to be a constant problem not to suddenly rear its head with the car running fine before
A; its been happening for a good few months now but got significantly worse last month.
/quote

[Victor Meldrew]

quote="RICHARDHUMBLE"]

Q;Stone cold rad is PRRT. Is it a landy part?
A;Yep Dan fitted the rover kit.

Q;Can you give a sketch of the pipework layout? Could it be back to front? Sticking shut? I had an airlock under the PRRT which was a PITA to shift
A; I would struggle to be honest, I have looked through the books and tried to figure out which hose goes where, will have another look to so if I can figure it out. Dan fitted it so I am 100% certain that its in as it should be.

Rich[/quote

[Victor Meldrew]

quote="steve_weegie"]Sorry to hear this John.

Q;Can you get your hands on a Digital Thermometer? FD used an Infra Red one ( like this) on mine to measure temperatures across different parts of the engine - in your case i'd be very interested in seeing what temp the output pipe from the head was showing.
A; I have one, (gadget man obviously ) I will try to do a temp map on the system after its all bleed through and topped up...

I think you mentioned something about a restrictor somewhere on the PRT system on one of your previous posts. What was all that about?

[/quote

[steve_weegie]

Ok, process of elimination time...... What could possibly be causing this and how do we rule it out?

1. Failure of the cooling system - Unlikley, as the water pump is obviously working and the prt has been fitted correctly and the thermostat has been tested.

2. Hot combustion gas rapidly heating the coolant - If the head is fine, could it be a cracked liner? I'd think that gas blow-by past the fire ring would be unlikley as the top end has just been rebuit and you're seeing the same symptoms on 2 different head gaskets. Either way, a sniffer will rule this out.

3. Electrical problem? Could be, although if the stack is reading high temperatures and this corrosponds to the fan running, the likleyhood of both sensors failing is slim.... Doing a thermal map of the engine during one of its episodes will rule this out.

Do you need to bleed air out the system after a high temp episode?

I've got a sniffer and i'm in st anrews on monday. Happy to swing past if it'll help.

[Rich H]

Block sniffer required.

[Victor Meldrew]

quote="steve_weegie"]Ok, process of elimination time...... What could possibly be causing this and how do we rule it out?

1. Failure of the cooling system - Unlikley, as the water pump is obviously working and the prt has been fitted correctly and the thermostat has been tested.

2. Hot combustion gas rapidly heating the coolant - If the head is fine, could it be a cracked liner? I'd think that gas blow-by past the fire ring would be unlikley as the top end has just been rebuit and you're seeing the same symptoms on 2 different head gaskets. Either way, a sniffer will rule this out.

3. Electrical problem? Could be, although if the stack is reading high temperatures and this corrosponds to the fan running, the likleyhood of both sensors failing is slim.... Doing a thermal map of the engine during one of its episodes will rule this out.

Q;Do you need to bleed air out the system after a high temp episode?
A; I have deliberatly not done this yet as if its combustion gas that has migrated to the radiator, I thought leaving it in there will make the sniffer test more likely to pick something up.


Q;I've got a sniffer and i'm in st anrews on monday. Happy to swing past if it'll help.
A; Will see you then mate. Do you take tea or coffee?

Address on PM
[/quote]

[robin]

If you need to bleed air out of the system then you need to consider where that air came from; if there are no leaks, the only practical place is the cylinder.

If you don't need to bleed air out of the system then the chances are that the thermostat isn't operating properly.

Might be easiest to take a bunch of pictures of the stat housing and associated pipe work - I am sure that Dan will have fitted it properly, but it won't hurt to compare it to the info on the SELOC Techwiki and prt site to make double sure.

After that it's down to understanding the behaviour of the PRT to see where it could fail (it has a couple of different modes depending on rad temperature, engine temperature and engine speed).

But all a waste of time if you're getting gas into the rad - can only come from a leak (which you think there is none) or the engine. Block sniffer test straight after next episode might well make that clear. However, continued running at these temperatures won't be doing your cylinder head any good

Cheers,
Robin

[steve_weegie]

Cool, keep the gas in the system. We'll probably end up taking the car for a run (torture test....) before the sniffer test. Holding it on the brakes at a lowish speed and with the engine at max torque will ensure that we get a lot of combustion gas and heat into the liners, potentially opening up any suspect areas. If we get it do fail, we'll poke it with a thermometer then let it cool down and test the coolant.

I'm tracking down the sniffer right now Coffee, milk and one please

[Victor Meldrew]

Well Steve wont make it over Monday after almost turning his car into a mobile crematorium... Thankfully, he got away with it.. I will let him tell you the story...

Well then, anyone fancy nursing a sick car down to Dans for me? I go back to work on Tuesday night and I will only have a week left before we go to Donny when I get back... all in all it looks like my Donny trip could be arsed this year.

Might have to have another breakdown again when I am out and about.... buggeration.

[haggis catcher]

Sounds like your having a bleeding nightmare John. You still have a few weeks though to get the car sorted, so good luck.

[Victor Meldrew]

Spoke to Dan again this morning, Top bloke.

He's coming up on Wednesday with the trailer to pick up the car.

There is still hope we get it sorted for Donny.