temperature rising...

temperature rising...

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natben

Original Poster:

2,743 posts

230 months

Saturday 5th October 2013
quotequote all
Cerbera 2003

My water temp is rising,
Both fans come on at 92,98deg,
The temp creeps up above 100deg,
If I rev the car above 2000rpm the temp settles back down again to 90deg (stationery)

I just changed the thermostat and the Blue expansion cap but it's still doing it^^.

I have bled the radiator to death, I don't think it's air in the system.

Up until recently both fans kicked in and reduced the temp, It never got near 100deg or above.

Any ideas???


Ant.

5,254 posts

280 months

Saturday 5th October 2013
quotequote all
What stat did you fit, they have to be a high flow.

s6boy

1,613 posts

224 months

Saturday 5th October 2013
quotequote all
Sounds like it could be the water pump starting to break down.

K4TRV

1,819 posts

251 months

Saturday 5th October 2013
quotequote all
Plug in the lap top and check the ECU temperature.......not necessarily the same as on the display - can be 5 to 10 C difference (cooler that is!)

Two alternatives - laser temp sensor to check what the temps really are, or, if you haven't a laptop, go to your friendly TVR Indie and get him to check?

Unless you have some other symptoms or issues, they do run hot??

HTHs ?

T

natben

Original Poster:

2,743 posts

230 months

Saturday 5th October 2013
quotequote all
Thanks for the replies,

I fitted a proper high flow 82deg thermostat from a TVR parts supplier, so that should be ok

I checked the water temperature on the lap top and it was accurate it wasn't exagerating the temp at all.

The water pump breaking down, well when I rev the engine the temp decreases so is it the water pump pushing water around the engine that reduces the temp which means it's OK, doesn't it? or is it an air lock being pushed around.

It's got me stummped!




m4tti

5,426 posts

154 months

Sunday 6th October 2013
quotequote all
Has this come out of the blue or were you doing something with the cooling system.

natben

Original Poster:

2,743 posts

230 months

Sunday 6th October 2013
quotequote all
I just happened out the blue. Reversing up the drive I noticed the temp was just creeping above 100deg where as before it never got above 95.

Laser Sag

2,860 posts

242 months

Sunday 6th October 2013
quotequote all
Are you sure both fans are actually coming on, the connectors close to the fans can fail so that one of the fans won't work.
Also worth checking the blue cap is sealing correctly, a friend with a Griff recently spent a lot of time and money on the same problem before finding that the cooling system wasn't maintains pressure.
Hope it is something as simple as one of the above.

crypto

229 posts

240 months

Sunday 6th October 2013
quotequote all
The waterpump is driven by a chain. So it pumps or maybe leaks, but never heard of a broken chain. Is the rad really hot when it reaches 100 degrees ? It looks something is preventing the flow of cooling ?

If I understand you correctly: when it reaches 100 degrees, the fans are running but the engine is unable to cool itself on idle ? So you have to rev. it up an then it comes down ?

When you bleed the system, did you open the heating, and do you have pressure on the system ? If nothing helps, I would try to take the thermostat out as a temporary measure to make sure the water runs always through the rad. It takes a little longer to warm up, but hopefully you can narrow down what the problem is.

Be careful ! This may also have an adverse effect because it will increase flow through the rad significantly and may have the effect that the water does not stay long enough in the rad to get cooled ! I don't think this will be the case with the S6 but just keep an eye on the temp (what you anyway do now).

Peter

Edited by crypto on Sunday 6th October 10:39

natben

Original Poster:

2,743 posts

230 months

Sunday 6th October 2013
quotequote all
Peter, thanks for your reply.

I am a mechanical numptie so I appreciate your help.

Your right it cools down when I rev up the engine on idol when it reaches 100deg. At normal driving speeds it's fine.

I have bled the radiator that much that the screw on the radiator (metal)is not tightning now against the plastic side panels on the rediator, although there is no water leeking from it. Do you think this would have an effect in that it might not be holding enough pressure in the system?.

I am worried that it might be the water pump but I'm hoping it's something else less expensive

natben

Original Poster:

2,743 posts

230 months

Sunday 6th October 2013
quotequote all
Laser Sag said:
Are you sure both fans are actually coming on, the connectors close to the fans can fail so that one of the fans won't work.
Also worth checking the blue cap is sealing correctly, a friend with a Griff recently spent a lot of time and money on the same problem before finding that the cooling system wasn't maintains pressure.
Hope it is something as simple as one of the above.
Thanks for the reply,

Both fans are definatley coming on at the correct temp and staying on until I rev the car then it temp drops below 90deg and they both turn off.
I just bought a new blue cap and Im confidentthat it is on tight enough.
The radiator screw is not tighting up anymore but there is no water leaking from it when up at 90/95/100deg, could this be the issue?. It might mean a new radiator as the screw threads into a plastic side panel on the radiator.

George

m4tti

5,426 posts

154 months

Sunday 6th October 2013
quotequote all
When did you do the thermostat.

If it goes down with revs I'm guessing its more likely your thermostat failing. It's needing more revs to push past it. It maybe stuck partially closed.

K4TRV

1,819 posts

251 months

Sunday 6th October 2013
quotequote all
natben said:
Thanks for the reply,

Both fans are definatley coming on at the correct temp and staying on until I rev the car then it temp drops below 90deg and they both turn off.
I just bought a new blue cap and Im confidentthat it is on tight enough.
The radiator screw is not tighting up anymore but there is no water leaking from it when up at 90/95/100deg, could this be the issue?. It might mean a new radiator as the screw threads into a plastic side panel on the radiator.

George
You sound like you may need a new rad? You must have a sound seal everywhere on the cooling system. Despite seeing 100+ degrees, if the system is sound it will pressurise itself to 15 psi, if there are no poor seals?? This allows the cooling system to get to 125/130 C before boiling occurs.

If you have a screw on the rad which "may not" seal at 15 psi, you are going to find that the cooling system can't pressurise itself and at 100 C it will boil.

HTHs

Trev - Edited to add: Raising the revs and seeing the tempo drop is normal. If you have a sound system, it will eventually drop its temp after two fans running and cooling - raising the revs simply moves the cool water from the rad quicker?

Edited by K4TRV on Sunday 6th October 16:52

Walford

2,259 posts

165 months

Sunday 6th October 2013
quotequote all
Maplins sell a infrared thermometer,s for 50 quid, have a shoot around with one

Dont know much about TVR engines but would expect to see 12' cooler water coming out the rad, than what is going in (fans running)

remember colour and material, effect emissivity, but if you are pointing it at black rubber hose, it will all cancel out and the temp difference will be pretty close to reality


dvs_dave

8,581 posts

224 months

Sunday 6th October 2013
quotequote all
You sure your coolant level is ok? A pinhole in the rad will give these symptoms with no obvious leak as it evaporates almost immediately.

s6boy

1,613 posts

224 months

Monday 7th October 2013
quotequote all
natben said:
Thanks for the replies,

I fitted a proper high flow 82deg thermostat from a TVR parts supplier, so that should be ok

I checked the water temperature on the lap top and it was accurate it wasn't exagerating the temp at all.

The water pump breaking down, well when I rev the engine the temp decreases so is it the water pump pushing water around the engine that reduces the temp which means it's OK, doesn't it? or is it an air lock being pushed around.

It's got me stummped!
Apologies, I should have expanded more in my first reply.
My understanding is that sometimes the impellers(sp) in the water pump can break off causing reduced flow. This could explain the need to raise the revs. However I have no direct experience, only anecdotal so could have got the wrong end of the stick! Good luck though.

natben

Original Poster:

2,743 posts

230 months

Friday 4th April 2014
quotequote all
Still no luck,

I have just taken the car out for a short run after having it of the road for a few months and it spewed it's coolant out the expansion cap. I had to wait until it cooled down, release the expansion cap and it made a gargling sound then I topped it up and drove home just as it started to spew the coolent out again.

I went to the local shop bought a few cans of beer and am now concidering my position....!!!

Does anyone have have a simple step by step guide to filling a Cerbera speed six up with coolant?

I must still have an air lock in it or is the system not holding pressure or am I over filling it?

I have replaced the radiator the expansion cap and the thermostat so far.

robsco

7,822 posts

175 months

Friday 4th April 2014
quotequote all
Are you certain the expansion cap is on correctly? I have been having similar problems. The cap is a funny devil and although sometimes it feels tight, it might not be threading properly. If you keep trying to tighten the cap even as it feels tight, you may find that it "jumps" back onto its thread and seals properly.


s6boy

1,613 posts

224 months

Saturday 5th April 2014
quotequote all
That's a shame, I thought you'd got her fixed.

When bleeding the system do you have the front of the car raised on a slope or axle stand to allow an air lock to escape?

Just re-read previous answers and don't know why I said the water pump breaking down was anecdotal, as it happened on an old v6 Mondeo I had. Does temp remain normal when driving only going up at idle?


Eta: just saw you've replaced the rad so the system would have been drained down and refilled anyway so less likely to be an airlock.

Edited by s6boy on Saturday 5th April 08:49

Goaty Bill

1,779 posts

150 months

Saturday 5th April 2014
quotequote all
No expertise on filling the Cerbera speed 6 but, a quick look at engine photos confirms that you have all the same 'bits' as a Chimaera / Griffith.
There is a nicely detailed post on the filling procedure by ChimpOfDarkness (ChimpOnGas now) at Chimaera Forum
You might want to try it, take it for a short drive at temperature with the heater valve open/ on hot, then cool down and follow the procedure again.


And to help, here is a picture of my funnel for the filling procedure;
(flower pot securely taped to a homebase funnel)


Late last year, a local chap very kindly tested my system with a pressure test.
Found a couple of small but significant leaks, and showed finally that the radiator needed replacing.
Worth doing if a local garage can help you.