The V8 Owners Forum -

Damn this has me puzzled.

What sort of revs are you doing at 70 or 80 mph?
I presume reasonable and not over revving like 4500?


Have you checked for massive resistance in your drivetrain? Jack up rear, put in 5th get someone to push clutch down and turn the rear wheels, they should not have huge drag, but if they do it could multiply greatly as your speed increases. Do you get a lot of wear on your rear brake pads?
If IRS have you had the alignment checked, could also show as strange wear patterns on the tyres.

Have you felt your wheels after a run to see if they are hot, drag from brakes or bearings?


Sorry lots more questions

Ian

Really appreciate the thoughts, by the way. To answer ...

Damn this has me puzzled.
>Me too.

What sort of revs are you doing at 70 or 80 mph?
>80mph = 3058rpm
I have to say that fuel consumption is not great at about 22 but up from 19 via using TunorStudio VE Live.. Big engine, low revs & light car so was hoping for much more mpg. More VE Live to do.

Have you checked for massive resistance in your drivetrain?
>Don’t think I have although perhaps some. I have a fully reconditioned diff (by Classic Conversions) with new 2.15 ratio and Quaif LSD but I guess this should not cause drag.
However, I do have a slight occasional brake binding at junctions, etc., but soon frees up. My brake discs are cool and can be touched so I would assume not and no, I don’t have much brake dust. Tyres seem fine too.

(There has been a separate and quite long saga earlier this year when my brakes did bind hard on – smoke and very hot discs! The basic symptom was that by opening a rear bleed valve it relieved the pressure to free the wheels. It almost felt as though there was a bit of dirt stopping a pressure valve fully closing. I eventually replaced all the ABS (yes, I have full Sierra ABS installed) components and it went away so yes, I’m still nervous about binding, though.)

Cooling problem has been around from the start, though.

If IRS have you had the alignment checked, could also show as strange wear patterns on the tyres.
>Nope, De Dion.

Have you felt your wheels after a run to see if they are hot, drag from brakes or bearings?
>Yes.

Sorry lots more questions
>Yes, me too!

But surely the cooling system should cope with the engine running at maximum output? Like a thrash up the Alps?

I have an Engine Guardian digital readout fitted to all my cars - takes its temp reading from a sensor attached to the engine block or head, not the coolant, so it measures the actual temperature of the engine

http://www.ebay.com.au/itm/ENGINE-GUARD ... Sw9r1WEPVL

Hi, me again!

Did the Sierra ABS also have traction control?

And are you running the same size tyres fron and rear? Sierra ran same tyres all round.

If so is the differential between circumferences on the tyres causing traction control to kick in and pinch up brakes at speed causing extra drag, making engine work hard, generate more heat........

That is my thought for the day.




Ian

Hi Ian,

Sierra ABS does not have traction control but I do have Racelogic Traction Control System fitted although it is turned off (as it is currently sensing one wheel not turning when it is - on to do list but not obvious). Racelogic sensor cable connections piggy-back on Sierra ECU connections at ECU plug.

Same diameter wheels and same tyres, different widths through. 9" rear, 8" front.

Thanks for still thinking this through, by the way.

Did you fix the drive belt issue, if memory serves wasn't your tensioner on the wrong side (tension side) so would reduce belt tension at higher loads?

Can you post up a new pic of the current drive belt arrangement?

Tom.

Did you ever check the water pump? I once had a pump that for no reason did not flow properly. It had a cast impeller with a larger gap between the housing and impeller and for no obvious reason did not flow properly. I changed it and all was well ????

SuperV8 wrote:Did you fix the drive belt issue, if memory serves wasn't your tensioner on the wrong side (tension side) so would reduce belt tension at higher loads?

Can you post up a new pic of the current drive belt arrangement?

Tom.

Or where you using a narrow belt?
Or did you have minimal belt wrap arround the waterpump pulley?
I forget!

Tom.

SuperV8 wrote:Did you fix the drive belt issue, if memory serves wasn't your tensioner on the wrong side (tension side) so would reduce belt tension at higher loads?

Can you post up a new pic of the current drive belt arrangement?

Tom.

Yes, all replaced with a fixed pully mount and all now normal. No pics, I.m afraid

DEVONMAN wrote:Did you ever check the water pump?

No. My Son thinks this is the problem but I am not so sure. However I will remove the pump as part of the internal cowling task this winter as I have to strip a few things down anyway.

You could be just right!

Should of added that I now have a wide belt being the same size as originally fitted.

Before making the cowling (above posts) I thought I would take off the water pump and have a look to see if there was a problem here. From the photos it would seem to me that all is fine. There is a bit of rust on the surface of the impeller blades but that is all. The blades are all fine. There is also no play at all in the bearing.
Apart from a small amount of white crystal that can be seen in the inlet channel, all surfaces are very clean indeed so from that I deduce the waterways are all pretty much clean as well.

Since the pump is now off, I’ve ordered a new one (proper TVR one with roller bearings).

Looking at the second picture

To me it looks like the top half of the pump did not have water in it.

Bottom shows rust colour which is normal

Top is clean /no rust colour
And on left there is the salts deposit which normally happens when the fluid dries out. Should not be there inside a liquid filled area.

Not sure how to check if you have a blockage further along that route that the water should take. I would certainly be poking a coat hanger wire down there and seeing if anything is down and can be fished out.

Still got me puzzled.


Have a great Christmas break

Ian

In the centre of the photos, there is a black area on the gasket mating surface. It looks like it is corroded away. If so it would allow some coolant to feed back around with the blades instead of being guided out of the pump.