temperature rising...

[natben]

No I changed the Rad during the winter, The symptons I am experiencing were there with the old rad and are continuing with the new one.

I think the Rad is ok,

I think the thermostat is OK

I think the Temp sensor is ok as the fans come on at the correct temp.

So I think I will drain it down and refill from scratch, It doesn't cost anything only my time so worth another bash.

Thanks for everyones help with this. My car never went above 95 deg before then retreated very quickly back to 70/80deg when stationery so this is what I am looking to achieve as well as the coolant staying in the sytem and not spewing out.

Edited by natben on Tuesday 8th April 22:33

[natben]

HI Madjules tyhanks for your comments,

Could I ask what level your coolant is at in your expansion tank so I know I am not overfilling it.

[m4tti]

With everything you've swapped there must be a leak somewhere... it's an outside chance but possibly heater matrix, have you been venting the system with the heater switched on.

[scotty_d]

m4tti said:

With everything you've swapped there must be a leak somewhere... it's an outside chance but possibly heater matrix, have you been venting the system with the heater switched on.

The heater in a cerb has no on/off control via a valve so it is "on" all the time, just a blower to bring it in to the cabin.

When mine was leaking you would know about it when the passenger side window filled with steam and a puddle under the near side front outrigger.

As Matt has said worth a check at least.

Edited by scotty_d on Wednesday 9th April 08:16

[natben]

Hi Scotty, where about is the heater matrix on the Cerb.

I drained down the coolant and re-filled it and bled it a few times, on the drive way it reached low 90deg, both fans kicked in and it returned down to 70 quiet quickly.

I let it cool down then tried again and the same thing happenen reached mid 90s then cooled back down to 70 quiet quickly.

So I went for a 30min run and it was fine 70 deg on the motorway 80-90 in traffic returned home and sat in it on the driveway it reached 100 spewed the coolant out the expansion cap and I'm back to square one again.

[scotty_d]

The matrix is in the passenger foot well access is via a panel in behind the left hand side carpet.

The other access is in the wheel arch right above the out rigger,

George this is a truly awful job, if you don't suspect it leaking/blocked I would leave it well alone.

[m4tti]

I would get the cooling system pressure tested next.

[natben]

m4tti, sounds like a good idea I will make some enquiries at a few local garages and see what the score is.

Scotty I think I will leave it alone the last thing I need is something else to take apart and struggle with.
The Cerbera is really trying my patience and at the moment I am thinking that I need to get this sorted and then It may be heading on to the classifieds!!.

[Tuscanuwe]

Maybe headgasket or cylinderhead broken???????????????
Under load with higher pressures on combustion side this can pressurise the water system and
your temp are rising.
BMW Dealers can test if CO2 is in the expansion bottle, then this result can finalise your search.

Uwe

[spitfire4v8]

This has all the symptoms of a water pump not pumping at low revs.
Point the car uphill then:
Take the thermostat out again and put the housing back on the engine with no stat in.
Fill the system as you would normally but dont run the engine, leave it cold.
Remove the top radiator hose.
Start the engine with no throttle, do not let the revs go high.

Look at the top hose .. is water flowing from it? If no water flows, or only a trickle then you have no water circulating at tickover.

[madjules]

Hi Natben,

Sorry to hear you’ve had no joy yet.

To answer your question, I usually fill the tank about half full, to the split line you can see if you look into the tank. Mine does use a little water and needs to be topped up every now and again.

I agree with the guys and think you really need to get pressure test if it’s boiling off at 100. Mine can show 100/105 and still holds pressure.

Finally I did note mine had a genuine VW/Audi radiator cap fitted. Maybe worth checking if nothing else.

Good Luck.

[m4tti]

spitfire4v8 said:

This has all the symptoms of a water pump not pumping at low revs.
Point the car uphill then:
Take the thermostat out again and put the housing back on the engine with no stat in.
Fill the system as you would normally but dont run the engine, leave it cold.
Remove the top radiator hose.
Start the engine with no throttle, do not let the revs go high.

Look at the top hose .. is water flowing from it? If no water flows, or only a trickle then you have no water circulating at tickover.

Have you seen that before? Has it been sprocket or impeller related?

[scotty_d]

Hi George
Have you made any progress as to why its doing this yet?

Scotty

[natben]

No Scotty,I have an mot due shortly and I have made enquiries about getting the car transported back to TVR Power.

I am going to drain the coolant down, remove the radiator and check I didn't damage it when I fitted it put it all back together and have one last try.

I have followed all the advice I have been given about bleeding the air out as well as having a chat with Dom as to how to do it but nothing has worked.

Maybe I am an idiot and should stick to cutting the grass as filling a Cerbera up with coolant seems to be beyond me.

[scotty_d]

I feel you're frustration George, they do test your patience some times ( well quite often) keep at it you will find the issue.

[spitfire4v8]

m4tti said:

spitfire4v8 said:

This has all the symptoms of a water pump not pumping at low revs.
Point the car uphill then:
Take the thermostat out again and put the housing back on the engine with no stat in.
Fill the system as you would normally but dont run the engine, leave it cold.
Remove the top radiator hose.
Start the engine with no throttle, do not let the revs go high.

Look at the top hose .. is water flowing from it? If no water flows, or only a trickle then you have no water circulating at tickover.

Have you seen that before? Has it been sprocket or impeller related?

Only ever seen it on really old engines where the impellor has rusted away, wouldn't have happened on a sp6 engine. Never seen the symptoms described by the OP on a sp6 at all, but I've seen an ajp8 with the same symptoms which was poor water flow at low engine speeds.

Edited by spitfire4v8 on Friday 18th April 10:33

[crypto]

natben said:

... Maybe I am an idiot and should stick to cutting the grass as filling a Cerbera up with coolant seems to be beyond me.

George,

I understand your frustration (and I can tell from experience, my car had the engine out 3 times with 2 full rebuilds). Cerbs will stress your patience and purse, f**k.

On mine, the temp sensor for the ECU and the Dashboard are about 15 degrees !! apart and when the one on the Dash is at 105 I start sweating (and I belief this because I have measured the engine with an infrared camera). In the area where I live, temps easily climb to over 40 in the sun. Personally I don't belief the S6 is able to cool itself on idle if outside temps are over 45 degrees celsius. And therefore I have a manual switch installed to activate the fans.

However, you have a beautiful car and I'm sure Dom will sort it out.

Good luck !!
Peter

[scotty_d]

crypto said:

In the area where I live, temps easily climb to over 40 in the sun. Personally I don't belief the S6 is able to cool itself on idle if outside temps are over 45 degrees celsius.

This is one issue we unfortunately never suffer from up here.

[m4tti]

Hi George,
did you get anywhere with this?

[natben]

It is with Dom at Power at the moment, It looks like the water pump is the culprit, but Dom is having a good look at it and will let me know shortly.
It is posible that the spindal that drives the water pump is slipping and not driving the blades around and so not forcing water through/around the engine as all other symptoms have been checked and are OK.

But water pump failure is very very very rare and requires the engine to be removed but knowing my luck I will have the "rare" faulty one!!!!.

This Cerbera Is really trying my patience and I am not a wealthy man and it is hurting me right now,selling it on buying my long suffering wife a new kitchen looks like a better option right now, but, I can't really go to all this pain and hassle to sell it on to someone else to enjoy!.

I don't think there is anything left mechanically on the car which has not been replaced in the last few years so it has to start rewarding me soon,I can't bear to add up how much I have spent on it. Most of the miles I have done in it have been returning back to Scotland from Power in Coventry and BHP performance in Blackpool!!! thats when I have been able to drive it,I have been keeping the local car transporters busy the last few years transporting it from Scotland down to England and let me tell you that aint cheap either. Then add on train tickets to England and Hotel costs and honestly I wonder why the hell I am so attached to the Dam thing. If it was a super model who was stinking rich and a nympho I would have dumpped her long ago for the pain and hassle she has cost me.
But I will hang on in there but It would be good to get some miles on it this summer. But of course I will get a working Cerbera and the summer will be one of the wettest on record .......wait and see!!.