Cooling question

[DWix]

I have recently been having some cooling issues and now have a lovely new alloy radiator and header tank.

Having been without the car for a month or so I cannot recall the speed at which I used to get enough air flow over the radiator to cool the engine. I think it used to be 30 to 40mph depending on ambient temp etc. Now it seems to be 50 mph plus (and I would expect it to be lower not higher now) - which indicates the cooling issue still isn't resolved!

Can you let me know at what speed you get enough airflow through the radiator to cool the engine for comparison?

[scotty_d]

Hard question to answer depends on the temperature out side on the day at a stand still on the hottest of days my Cerb will never see over 95 degrees max. today on a short drive 10 miles or so it was sitting 80-85 degrees at a speed of 50 mph with some town driving of 30mph max and did not see over 85.

Hope this is of help.

[spongy]

Bud what was the old rad etc like when you removed it?My rad is not looking to good and i was going to do mine this year but having said this my temp never seems to cause concern.when she had her mot she sat for about 35 minutes left running and did not get that hot(gear stick did)As the fans should cut in.have you bleed the system properly as it may be an air lock.I have just done one on a focus rs but they have no temp gauge so we cant compare temps,but it should run about 10 degrees cooler.

[DWix]

Old rad was shot, big pink stain where it had gone.

Now it has cooled and I have the coolant cap off it has taken 2.5 litres to refill so airlock or not I am still leaking somewhere. There was also a quiet high pitched noise when I turned the engine off - might this be some steam escaping? No sign of a leak or pink stain anywhere obvious but I guess I need to get home and properly poke around.

Thanks for your help and comments so far, got some great looks on the way home with the 'wow a TVR' mouthed as well which always cheers you up.

[scotty_d]

Just be very careful not to roast the Engine. A guy i know with a Cerb near me had a leak and kept topping it up and one day roasted the head gaskets. He has the engine out and sorting them but not a job you want to do if it can be avoided.

Scott

[C3BER]

If your system has not been filled correctly then after a hot run it will take water to top up. Cerbs can be a bugger to fill correctly sometimes.

I would run the car on your drive upto 98 when the second fan comes on if you have one and then see if you have a steam leak. The fill cap can be a bugger sometimes. I lost water once when a
rusty clip snapped and the water flooded out.

[DWix]

Thanks for the tips, will have a play tomorrow. Am pretty sure it would have been filled correctly (big name garage in the TVR world) but no harm in checking so will run as you say. My dash water temp dial is reading 15 degrees high so think I will set up a laptop to see the other engine readings too.


Just frustrating as it seems a non-obvious leak

[C3BER]

I don't want to ask the obvious about a blown gasket.

It took me three fills to sort my lack of water and now it's rock solid at two cm under the seal.

[DWix]

Blown gasket question thoroughly researched by the same team that did the re-build less than 10k ago with a definite negative (am a straight six cerb at the mo) and due a 12k service in 5 weeks where I will ask again. But no running issues at the moment at all other than getting a bit hot, in fact it seems to be better than ever other than this. Thanks for the query though, not many other places to look if I cannot find an external leak!

[pirateTVR]

My 4.2 at 70-90 sits at a steady 80 degrees although on A roads 50-60 I`m reading 85 degrees,in town stop-start alternating between 3rd and 4th 90-95.

I favour an aluminum radiator,primarily because I can fabricate them in house,although depending who supplied/manufactured the item they`re not always a solution to a cooling issue.If you don`t already own one I find a laser thermometer is an essential tool for chasing down cooling issues.

This guy is very informative and clears some misconceptions about aluminum versus copper http://www.caparadiator.com/aluminumvscopper.html

First time I`ve linked, I guess it`s a copy and paste job, sorry.

[DWix]

Thanks for all your comments above, latest update as follows: (fyi it is a speed six cerb)

Got the chance to do some tests with my brother in law (who is a mechanic) as I am a complete numpty (although my cerb is educating me slowly issue by issue). We did a hydro carbon test which showed hydrocarbons in the cooling system, and also with the tester on and the engine running you got bubbles coming up through the cooling system. He also thought the cooling system had far too much pressure in. So basically the head gasket is gone and this was obvious to him. Any dissenting views on this?

He also suggested getting the head laser tested to check the aluminium hadn't gone porous. I haven't heard of anyone getting this done - is it a good idea? The car had a full engine rebuild 10,000 miles ago so hopefully it shouldn't be too bad a job and I will be taking it to the same place that did the re-build as no doubt there may be something to learn here. Presumably when the head gasket starts to go it can be difficult to detect and diagnose - do people have a view on this?

Given my working arrangements at the moment I am not going to be able to drive the car much over the winter (and it isn't the best time anyway) so I am tempted to SORN it until Spring, then get it MOT'd, Taxed and 12k serviced and head gasket replaced then (they are all due this month or early Oct). Were I just to leave it as it is would I need to take any more care given it is being stored with a non working head gasket? Presumably not, but thought it sensible to ask.

I have to say I feel like I have been a little unlucky in my first year of ownership so far I have had the following issues and been stranded 4 times (including in southern Germany but thankfully after doing 170mph +):

Clutch slave and master replaced
New clutch slave seal failed
Speedo stopped working
Radiator replaced
Header tank replaced

So am I unlucky or just being punished for a previous life? Needless to say I do love it still but I may be responsible for some of the perceptions that TVR's aren't reliable as I am now v used to getting jibes from my friends!

DW

[ukkid35]

With a leaking head gasket you have a serious risk of the car sitting with coolant in the cylinders for some time causing corrosion to the sleeves (not to mention a hydro-lock when you try to start it). If you want to see what corroded sleeve look like check out my Rebuild thread for photos.

If you don't want to deal with it now, then you'll need to drain the cooling system at the very least, others will advise what other steps you can take to minimise any possible damage.

[DWix]

Thanks for the info, will re-read your rebuild thread and re-consider options