Hi,
We have a 90 'G 2L diesel masterace with what appears (from reading this site!) a fairly typical history of overheating. Re-cored rad (corrosion), new rad cap, 'stat, various hoses etc.
Engine is OK around town, a further small leak has just been fixed. Not sure if still losing water, too soon to ay. Water is quickly murky and orange. Usually loses water on a run, quite quickly. Temp gauge doesn't move once warm, except when it overheats when nothing stops it...
Questions:
1) Is the presence of fine bubbles in coolant, with cap off, a reliable indication of a head/gasket problem? Local dealer/garage has assured us that it isn't...
2) Last motorway run, heater went cold after about 30 miles then overheated (early morning). Return run, after engine running on and off all day, no problem. (topped up with tap water, no antifreeze) Anyone suggest where to look?
3) Heater takes a few miles to get going (I think always has), and isn't in the market for any prizes when it's fully warmed up. (The gauge sits at normal long before the heater does much.) Is this typical? The 'stat has, at least allegedy, been replaced fairly recently.
4) Can anyone suggest a mechanic or garage in the Poole/Bournemouth area who are really proficient with these vehicles?
Thanks for any responses,
Malcolm
- (#7015) Malcolm Bebb, 3 Feb 03
Ooh, sounds like a circulation issue...
Some fine bubbles can be OK, they're caused by cavitation in the water pump.
If you lost coolant one way, but were OK on the return, I'd suspect an airlock, aided and abetted by a duff rad cap. I note you have fitted a new one, but was it Denso/ Toyota, or a cheapie?
The heater does take a bit to get up to full temp, but you should be feeling warm air as soon as the gauge is moving. A duff stat would delay warmup, but if the gauge is in it's normal position, the heater should be hot!. You would be advised to start looking for kinks or blockages in the heater pipes. Try reverse flushing the front matrix, the control valve might be gunged up.
Perhaps someone else can help re. garages
- (#7016) david miller, 4 Feb 03
Malcolm,
David's advice, as usual, will be more than helpful and I would add the following. Have you checked the circulation to the rear heater also? With the engine starting from cold,(vehicle stationary) and the rear heater switch in the "auto" position, the rear fan should start blowing warm air after about 3/5 minutes, ie, at around 45c on my Durite gauge. If there is no warm air from the rear heater, after this time, feel around the rear heater pipes (under the car, behind the offside front wheel position). They should be getting hot but, if not, an air lock or blockage might be in this part of the cooling circuit and this appears to have some influence on the total coolant circulation. The remedy is to disconnect the hoses to the rear heater,(easily done, under the vehicle) flush the heater matrix and, also, back flush (with a garden hose at LOW flow/pressure)the water supply to this rear heater.
Also, have you checked the operation of the cooling fan?. If you have the viscous type, is it operating at higher engine temperatures and speeds. There is much in Ace Answers re this possible fault.
"The 'stat has, at least allegedy, been replaced fairly recently."
The stat is a critical item and, if you have not checked it, is there a stat fitted and, is it the right one? The system must have a stat for efficient operation but, a previous owner might have left it out in the erroneous assumption that this would help circulation.
I run my Masterace (in winter)with a standard Toyota stat,(part No T90916-03046) modified with one 3mm hole in the flange, It works perfectly.
- (#7017) John Davis, 4 Feb 03
I seem to recall someone singing the praises of a garage in Christchurch who know Townies well. The link should be on Townace Nutters site.
- (#7018) Ian Dunse, 4 Feb 03
Thanks for the info so far. I am beginning to think that we do have a suspect head/gasket, as the problem has got worse.
Running at standstill, with rad cap off (it's a Toyota cap), I get a lot of creamy froth and a lot of bigger bubbles. Revving the engine blows water out - seems to lose about a pint fairly quickly. It seems suspicious to me, but I don't know what it should look like with a 'good' one. Anyone able to describe?
The garage (Imperial Car Co, in Poole) said the coolant had been checked with some gadget which can identify the presence of combustion gases??? But I think we've had the rad done since then, so it's possible we have either multiple problems or just a new one.
Problems developed shortly after we had the vehicle, it has overheated several times. Did seem to improve for a while after new stat. No obvious wet patches under vehicle.
Get bubbling in the overflow tank after stopping, following a quite short run. The rear heater seems OK.
This afternoon I found that the front heater warms up (but only once we get going, despite the gauge indicating normal temp on the drive), Ok for a while, then blows cold for rest of trip. Stop for half an hour, drive off, and it does it again... Hmmm
The car otherwise starts and runs OK, and does not generally overheat on around-town use.
I have yet to check the fan.
TIA,
Malcolm
PS we have tried the recommended garage in Bournemouth (Waltham garage). It was they who replaced the stat, but they pointed out that they were not townie specialists. But still helpful and not over expensive. A little bemused at how they came to be recommended on the 'net as Townace specialist, though.
- (#7074) Malcolm Bebb, 7 Feb 03