Scooby cooling...any ideas?

Cleverchap · Posted: Fri Oct 05, 2007 9:13 pm Post subject: Scooby cooling...any ideas?

Got my system set up with rads at the front, matrix at the back and a flow-thru header/expansion tank like Elusive stranger et al. Trouble is the water temp at the block according to the temp guage is 105 degrees C, but the temp at the rads is only 60

The rads are warming up so this must mean that somethings going on but is this just an air lock and should I keep trying to bleed or what??
Any help would be great cheers guys.

ElusiveStranger · Posted: Sat Oct 06, 2007 2:03 am Post subject:

Do you know the gauge is accurate? For sure? You've tripple checked?

If so it sounds like:
1/ your stat isn't opening properly (water is constantly flowing through the matrix or you've done a bypass?) Water returning is hot, as in very hot, yes?

2/ an air lock

Rule out #1 easily - disconnect the matrix. Connect the H2O manifold steel pipe directly to the thermo line via the header tank.

If you don't have a decent thermometer, chuck water on the block. Water doesn't lie & boils around 100°C (if it's pure)

VDO gauges and Subaru senders don't work. I'm coming to the conclusion that VDO gauges & VDO senders are pretty pants too! Mine reads 10°C too low - a drop resistor is going in parallel with the sender. i'm now on the second gauge as the first would stick.
_________________
The advice you receive on here is worth the paper it's written on.
Your experiences are worth shed loads to others, including the f'ups - live and learn.
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'78 Bay, 2 litre 091 box, EJ20 NA & the ashtray's on the 'right' side.
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Bugger, missed out on "Live fast, die young"

Cleverchap · Posted: Sat Oct 06, 2007 7:20 pm Post subject:

Hey mate.
Have checked the gauge and its right. I swapped the stock sender unit for and Autometer sender and guage when I was building the car up.

Airlock is what I was thinking but not sure, got a constant flow of water coming back into the expansion bottle with no air bubbles. I have checked the stat and its stuck open (!) so no ideas whats going on there. In the end out of frustration I removed it altogether and rebleed the system and exactly the same thing is happening

I'll try again tomorrow with a new stat if I can get one on a Sunday.
I reckon the heat in the rads is just convection and the water pump isn't man enough to do the job. Will try and break it down tomorrow and see wether it is actually pumping or not. Any tips on water pump removal and servicing?
Also any ideas where I can get an in-line 12 volt aux pump that I can fit at the front of the bus to help increase flow??

ElusiveStranger · Posted: Sun Oct 07, 2007 2:50 am Post subject:

I have the Scooby 2002 Imp (turbo & NA) manual if you need a copy.
My rad's (XJ40) situated betwixt the chassis rails. Up until recently this hasn't given me grief - the first got a pin hole in the core.
I went down to Cornwall Jam & the rad fan cut in about 5 or 6 times on the way down. The fan (ECU controlled) cuts in around 98 and cools to approx 87
On the way back the fan cut in constantly - I think I have 'scale' build up.
There was no problems with the Scooby pump previously.

Can you sketch a drawing of the rad, header, motor set-up?
I know mine needed a bit of a 'blat' to cure the air lock problems after bleeding.
That's the prob having the rad lower than the motor.

I've not got a clue as to where to get an electric pump, sorry.
_________________
The advice you receive on here is worth the paper it's written on.
Your experiences are worth shed loads to others, including the f'ups - live and learn.
Wouldn't YOU rather learn by someone else's mistakes? So would they.

'78 Bay, 2 litre 091 box, EJ20 NA & the ashtray's on the 'right' side.
I don't lean forward for hills any more Grin

Bugger, missed out on "Live fast, die young"

Cleverchap · Posted: Tue Oct 16, 2007 7:54 pm Post subject:

Right then, my Davies Craig water pump arrived today and in typical British weather its peeing down so I can't fit it

I'll let you know how I get on as soon as it stops raining

As for sketching a diagram of my cooling system, I could but its so complicated I cant be arsed Grin

ES, you down this weekend for NDFF?? Maybe see you there (in the bus???)

ElusiveStranger · Posted: Tue Oct 16, 2007 10:39 pm Post subject:

What's stopping you? It's dry under the bus!

This is mine (roughly)
Red - hot feed
Blue - cold return
Pink - Expansion from rad.
Header's Vauxhal Fronteria

Re NDFF, indeedy!!! (VWKD t-shirt's packed! & will be flying the flag)
Going down on Thurs straight from work and staying @ a mates in Barny.
Hope to get some surfing on Fri - Saunton/Croyde/Wooly. Poss sleeping on the road near the Red Barn on Fri night Wink

Hooking up with the "Crewe & Nantwich" guys too
_________________
The advice you receive on here is worth the paper it's written on.
Your experiences are worth shed loads to others, including the f'ups - live and learn.
Wouldn't YOU rather learn by someone else's mistakes? So would they.

'78 Bay, 2 litre 091 box, EJ20 NA & the ashtray's on the 'right' side.
I don't lean forward for hills any more Grin

Bugger, missed out on "Live fast, die young"

Cleverchap · Posted: Wed Oct 17, 2007 5:49 pm Post subject:

Hey ES, cheers for the diagram.
My cooling system is essentially the same as yours except I dont have a pink expansion line from the rad, I've got a Rover 25 expansion tank that should be big enough to cope Happy

I'm waiting on a couple of straight reducer hoses so I can fit my water pump and then I can get rolling. Hope they arrive by tomorrow or I wont be able to make NDFF in the bus Sad