Incomprehensible collection thread - COOLING MISERY

[Lacquer Peel]

Fans work, I hope the dishwasher tablet treatment will sort it out.

It doesn't overheat with the thermostat removed and the heater works, that's what confuses me because the thermostat opens as it should in a hot pan.

Driving it to work today, it seems spot on.

[Dave_Q]

If it sat at 90deg on the motorway then the stat is fine. 

 

When it was going up the hills did you try putting the heating onto max to see if that dropped the temp? If the rad is marginal due to siltage or air blockage, you should still be able to reject some of the extra heat via the vents. 

[Lacquer Peel]

There was no heat at all.

[bub2006]

Doesn't sound promising. Hgf maybe

[Lacquer Peel]

I hope not. All I can tell at the moment is that coolant is circulating properly now I've ditched the thermostat.

Will take it for a run to Bridge of Brown later for a shakedown.

[HillmanImp]

For those that say I don't do enough recycling:

 

[dome]

Could it have been air in the system and you taking the thermostat out and bleeding it up has cured it?

 

Also check all the hoses are getting warm-that way you'll know water is circulating. 

[Lacquer Peel]

Water is definitely circulating now, hoses are hot and the heater works.

It just needs to pass the Brigabroon challenge.

[New POD]

I don't know much about cooling issues, but our MX5 recently was restored to normal running temperature, by fitting a new radiator. Previously, I'd replaced the thermostat, checked the waterpump when replacing cam belt, and replaced the fan switch twice. (It was a bit dodgy, in that the first one fell apart internally and ran the fan all the time, and the second (from mx5 parts) was so nasty that the connector had to be held in place fully to one side to make contact. The third (an ebay special) was listed as suitable for a Kia, and works perfectly.  The only thing that brought the temp down on hills or above 69 mph, was putting the heater on full. Hence the new rad.

[Lacquer Peel]

Yep it's buggered. I drove home via the moors, same deal as last night.

Going to get a sniff test kit to test it properly but I think it must be the head or head gasket.

I like it and have most of the parts to fix it including a recon head so it will live on.

[Dave_Q]

Do you have any mixing of oil and coolant? 

 

I think these have an oil cooler that can mix oil and coolant when it fails. 

 

Just a small straw to clutch at.

[Lacquer Peel]

No mixing of oil and coolant, it's probably gases sneaking into the coolant.

[Lacquer Peel]

 

I bought this snake oil because it's relatively cheap and I'm lazy.

The instructions say to deactivate the defective cylinder for it to work but how do I tell which cylinder is leaking without a compression test? Is the glow plug likely to be discoloured?

[Stanky]

The bore might be cleaner than the others due to steam? I'm much less familar with diesels though so could be talking shit. Remove glow plug and shine a torch down the hole?

[Asimo]

One last thought of clutching straws type hope: is the radiator fan wired up correctly so it moves the wind in the right direction? ISTR some poor sod going nuts with cooling issues as his fan was blowing against the flow of air due to the car moving.

[dollywobbler]

Had that many years ago on an Audi 100. Also, testing the fans work is not the same as testing that the switch works. I'd ensure all options are considered before deploying snake potions.

[Lacquer Peel]

One last thought of clutching straws type hope: is the radiator fan wired up correctly so it moves the wind in the right direction? ISTR some poor sod going nuts with cooling issues as his fan was blowing against the flow of air due to the car moving.

The fans help the temperature drop when they kick in.

 

I've booked into a garage to get it pressure tested. Snake oil is a last resort.

[Lacquer Peel]

I mentioned the problems to the previous owner and her husband phoned me. He was very nice and as baffled as me, he replaced the HG, cambelt and water pump last year.

Blockage? Silted radiator?

[Kiltox]

run a hose through the radiator and see what kind of flow you get at the outlet?

[Lacquer Peel]

What sort of flow should I be seeing? I ran a hose into the header tank and opened the tap on the bottom hose, it flows but not as quickly as I'd expect

[Split_Pin]

I would suggest getting a local place to hook up their pressure tester on the header tank and the other doofleshanker with the bubbles in it that tests for hydrocarbons in the cooling system. The AA man did that when my Corsa FTP even though it was just a stuck closed thermostat, just for peace of mind to help me rule out that problem. Best knowing 100% one way or the other.

 

Kind of seems like there's no way back from snake oil once you use it. I'd only use the tyre weld stuff in a cheapo steelie job.

[Lacquer Peel]

That's the plan. The good but expensive garage nearby can't see it til next week.

The proprietor remembered me and my veg burning Xantia even though I haven't been there for yonks.

[Dave_Q]

HG done doesn't necessarily mean the head was pressure tested or skimmed.

[Lacquer Peel]

Apparently it was, the previous owner's husband works in mechanical engineering so has all the kit at work to test it, that's taking his word for it but he seems very genuine.

[andrew e]

I may have missed it, but it does has actual coolant in it, not just water? Have you tested it?

[Lacquer Peel]

It's just water now.

[Captain Furious]

It doesn't exactly fit the symptoms that a friend of mines polo had, but that would only overheat when you were pottering around or sat still, on the open road it was fine

 

That was the water pump, we diagnosed it by waiting for the temp to increase, then (counter intuitively) revving it hard and it brought the temp straight down, concluded it just wasn't circulating water properly unless the engine was revving quite high.

[Lacquer Peel]

 

This is the result of the latest coolant flush, horrible dark water.

I hope it's just sludged up.

[Lacquer Peel]

Another thing I've noticed is when it overheats, such as driving at high speeds on my private A road the heater goes cold then comes back when the engine temperature drops back to 90C. Air lock?

[Laseraligningfoofooflanges]

That waters grot mate.. Was like that in the audi but with added debri! Hope its nothing sinister brother!