Engine temp/changing oil

[GarryM]

Ever since Oulton Park TVRCC track day, where my car got to 100degC, the temp now climbs to 90degC very quickly and stays there. Before Oulton it would usually stays at about 80degC unless sitting in traffic.

I'm guessing that the oil was cooked at Oulton and needs changing. Fresh oil will aid cooling. Does that sound right? Next question: if I just drop the oil out and refil without changing the filter, will that be OK? The oil was last changed just before Oulton so oil and filter are only a month old (Mobil 1 15/50). Advice appreciated.

[greenv8s]

GarryM said:

Ever since Oulton Park TVRCC track day, where my car got to 100degC, the temp now climbs to 90degC very quickly and stays there. Before Oulton it would usually stays at about 80degC unless sitting in traffic. I'm guessing that the oil was cooked at Oulton and needs changing. Fresh oil will aid cooling. Does that sound right? Next question: if I just drop the oil out and refil without changing the filter, will that be OK? The oil was last changed just before Oulton so oil and filter are only a month old (Mobil 1 15/50). Advice appreciated.

Don't think changing the oil will make any difference to cooling. Have you checked the coolant level, and bled the radiator?

[GarryM]

I've checked the expansion tank and the coolant level is fine. I haven't done anything more though. My car never seems to use coolant no matter how hard it's driven or how hot it gets, which surprises me. I may try flushing out the whole system and starting again - not done that before as it's an annual dealer job but I guess it can't be that hard? (hmm, I've said that before...)

Shame about the oil not helping as that seemed like an easy fix! Thanks for posting Peter.

[greenv8s]

I suggest you bleed the radiator anyway; if you have an air lock in the radiator, it will tend to run hotter than normal on the move.

[starmist]

Would have been a good idea if TVR had fitted a bleed valve to the top of the rad whilst modding the inlet connection!

[catretriever]

My car behaved similarly since I got it, always hovering around 90 deg and never seemingly needing coolant in the expansion tank. Then I topped up the coolant properly (i.e. via the swirl pot with the engine running etc...) and added some water wetter. The top up was fairly messy, with lots of coughing and spluttering of coolant from the swirl pot, but it must have got a good deal of air out of the system as the car now runs a good 10 deg cooler.

[greenv8s]

starmist said:

Would have been a good idea if TVR had fitted a bleed valve to the top of the rad whilst modding the inlet connection!

You should have a drain plug in the top corner, this serves as a bleed screw.

[IPAddis]

greenv8s said:

starmist said: Would have been a good idea if TVR had fitted a bleed valve to the top of the rad whilst modding the inlet connection! You should have a drain plug in the top corner, this serves as a bleed screw.

And apparently one of the best places to fill the system to remove air locks is via the throttle body heater hoses. Mines disconnected and you can manipulate the tube to be 6 inches above the engine, giving a nice high point.

Ian A.

[Noel V8]

Garry few issues here main one being that the standard TVR rad is just too small to cope with the motor Bigger rad needed 4 core is what we fit as standard to all our road cars as three is standard. Just get it recored. I can get five core rads fitted to the standard side tanks more than that and new tanks need made. MY race griff (the orange one) has a 7 core rad in it!! Just fit a suitable thermostate to ensuer you cant run too cold in winter 74 deg state should give you about 77 ish on the road which is fine. Suggest you change your oil at least every 3000 miles and stop putting mobil in it. Use a quality mineral 20/50 oil is best. I use a Valvline 20/50 race oil it's the buisness zero oil use.Been using it for years without any problems at all.

Noel V8

[GarryM]

Thanks Noel. We had a chat at Oulton towards the end of the day on the pit wall - I was there with my brother. I remember your comments about the radiator and the blanking plates you make up to keep the temperature just right. I love that car!

I see you don't like Mobil. Does that hold true for road cars? My Griff only sees a track a few times a year and although they are undoubtedly the most enjoyable miles I drive they are only a small percentage of annual mileage. I do change the Mobil regularly - probably works out at every 2-3,000 miles.

The radiator will be upgraded as per your advice. I'll wait until next year though.

[greenv8s]

Personally I'm not at all convinced by the rad too small theory, it seems common to come across problems caused by faulty stats, blocked or leaking radiators, air locks and so on but so far I haven't encountered any overheating problems with a healthy standard cooling system in normal road use. Uprating the radiator isn't a bad idea but unless you are working the car unusually hard I would be surprised if it was necessary.

One thing to watch out for if you are uprating the rad: assuming you retain the stat, then when you have been driving gently in cold conditions you can end up with no flow through the radiator and the only water circulation being via the bypass. The standard bypass is extremely small (and was omitted completely on some serpentine engines apparently) and doesn't flow enough to protect the heads under load. The bigger capacity the radiator, the more of an issue this is likely to be. If you take the stat out completely you avoid this issue, but that isn't a sensible solution for a road car. Some race cars do run like this, and blank the radiator to limit cooling to suit the condition - effectively leaving the engine temperature uncontrolled. Doesn't seem too clever to me but they seem to get away with it.

[heliox]

IPAddis said:

And apparently one of the best places to fill the system to remove air locks is via the throttle body heater hoses. Mines disconnected and you can manipulate the tube to be 6 inches above the engine, giving a nice high point. Ian A.

I use this method and its the best i've tried so far,later models seem to have the plem cooling disconected though so there arent any hoses there.

h