Cooling system,

[TrixieS1]

I've got a 1988 S1 that is having a cooling problem that we can't seem to solve, done all the usual things, changed thermostat, changed sender , flushed and cleaned system , put in a new fan, got new cap with a good seal and tried different temp gage.
Car gets up to running temp after about 5 mins but then quickly goes right to top of red, when you open the bonnet it doesn't seem excessively hot but I'm not about to cook my engine on the off chance. The system is watertight and not losing any fluid so just really hoping someone has a solution that isn't one of the obvious ones, I'm getting so frustrated that this can't be solved, summer is getting on and I need my car, any suggestions greatfully recieved.

Edited by TrixieS1 on Monday 3rd June 21:28

[GreenV8S]

What are the top and bottom hose temperatures when the fan comes on? Is air blowing out the back of the rad hot?

[phillpot]

Guessing you're the guy asking same questions on FB?

Have you tried, as suggested, using a lazer infra red thermometer thingy too see just how hot it is ?

[magpies]

where are you located?

[v8s4me]

You haven't mentioned it but I assume the fan is coming on?

Sounds like it could be an airlock. Did you open the heater valve (slider set to hot) when you drained, flushed and refilled the rad?

[hoppo4.2]

is the pump actually working. the impeller could have dropped off the back stopping it from flowing any coolant round the system

[magpies]

I could post you my mechanical gauge and you could temporarily fit in the engine compartment and fit the sensor in place of your existing. Photo shows gauge at 95degC in a pan of boiling water.

[TrixieS1]

I'll try to answer the questions, yes we are the ones on the s page asking the questions, it's my car my husband is trying desperately to fix it for me but not making any progress so I thought I'd try here for any other ideas that we hadn't tried, not sure on the temps I'll get Ash on here later done everything else mentioned still no joy,. We're in Hereford so no one local to take it to that we could reach without overheating. I think it will have to be pump off next but we were hoping to avoid that, ah well desperate times call for desperate measures.

[Fefeu52]

Head gasket failure ? Common on the 2.8l engine with twin exhaust port, isn't it ?

[tvrash]

GreenV8S said:

What are the top and bottom hose temperatures when the fan comes on? Is air blowing out the back of the rad hot?

Dont know yet as the battery is buggered on my laser temp gun and on top of that the fan doesnt come on so I have it hardwired at the moment.
The fan is on the back of the radiator on this car.

[tvrash]

v8s4me said:

You haven't mentioned it but I assume the fan is coming on?

Sounds like it could be an airlock. Did you open the heater valve (slider set to hot) when you drained, flushed and refilled the rad?

The fan is currently hardwired as it doesnt come on via the switch.
Yes I made sure the heater valve was switched to open. I got loads of gunk out of the system but still no difference.

[TVRees]

A suggestion : Remove the thermostat and test again.
Does it make any difference ?

ALSO,
Flush the system again, pumping the flushing water from the lowest point to the highest point.

Edited by TVRees on Tuesday 4th June 22:18

[tvrash]

TVRees said:

A suggestion : Remove the thermostat and test again.
Does it make any difference ?

ALSO,
Flush the system again, pumping the flushing water from the lowest point to the highest point.

Edited by TVRees on Tuesday 4th June 22:18

I will give it a go, it's a new thermostat and a pain in the butt to remove.

[WotnoV8]

tvrash said:

I got loads of gunk out of the system but still no difference.

I would be tempted to remove the radiator and give it a good flush out. If it has had a leak in the system in the past it may be clogged up with radweld or similar.
How much coolant did you manage to get into the system? Worth measuring how much it takes to fill the system and compare to specified capacity which is 10.2 litres according to the handbook.

[tvrash]

WotnoV8 said:

I would be tempted to remove the radiator and give it a good flush out. If it has had a leak in the system in the past it may be clogged up with radweld or similar.
How much coolant did you manage to get into the system? Worth measuring how much it takes to fill the system and compare to specified capacity which is 10.2 litres according to the handbook.

I didn't measure to be honest, I just filled until it was full. Yeah removing radiator might be the next job I think.

[tvrash]

OK well I'm not sure this helping if it any indication of what the inside might look like.

[phillpot]

It's not very pretty buy doesn't necessarily bear any relationship to what's going on inside

[tvrash]

The radiator actually cleaned up well, no leaks or damage. I ran the jetwash through it until the water was completely clear so I will test again tomorrow. There was a lot of sludge inside.

[phillpot]

Fingers crossed that's done the job. Problem with radiators is half the tubes can be blocked solid and your pressure washer water will happily flow through the other half.

(I've always been a pessimist)


got a new battery for your temperature lazer whatsit yet?

[tvrash]

Ok, took it for a spin and temperature was around 60c then literally seconds later it was shooting up through the red. There is no way that the temp should have been able to go that high that quickly. I'm suspecting a dodgy temp sender, when we got home there was no steam and the engine didn't even seem that hot.
I tried by laser gun and was all over the place so I'm not relying on that.