Black Coolant - Is my 75 1.8 dead or alive?

[DeSade]

Basically I started to notice a loss in coolant without any visible leaks.

Then a slight shudder started to occasionally happen when pulling off.
Couple of days ago the shudder became worse and started to be continuous after driving about 10miles.

I had a quick look at engine and noticed that there seemed to be a small air leak from where the exhaust manifold entered what I presume to be the catalytic converter and put the shudder down to this and planned to get it fixed when I got the money.

However yesterday the shudder became worse it basically sounds like a hellicopter when driving after 10 miles or so, as if the exhaust has blown (which it hasnt) and when I stopped I noticed the cooling fans whirring away and they stayed on for about 5 mins after stopping. Then I checked the coolant level and I can only describe it as looking as if it has been mixed with ash, it is grey but not oily.

No warning lights have come on and the temperature gauge is as it always is ie normal.

I have a suspicion it may be HGF but am trying to rack my brain for other possibilities. Basically I am no expert on repairs or diagnosis just have a basic knowledge so I was wondering if anyone has any ideas at what could possibly be wrong. Is it dead or is there any light at the end of the tunnel?

[T-Cut]

Then I checked the coolant level and I can only describe it as looking as if it has been mixed with ash, it is grey but not oily.


It sounds like combustion gas/exhaust getting into the coolant. Most probably it is HGF.

TC

[DeSade]

Thnx .. not the answer I was hoping for but the one I expected lol. Oh well had it a month .. time to start saving so I can buy another one .. Hopefully one that lasts a bit longer ... :banghead:

[DeSade]

K after finding some more posts thought I might as well try wondarweld .. only slight snag I cant for the life of me find thermostat is it hidden under or behind something? Does it look like the yellowy coloured plastic one I found on forums or do they vary ?

[T-Cut]

What year is your car?

TC

[justmicky]

The thermostat housing is located at the rear of the cylinder block on the right hand side. Dunno about Yellow, but mine is black plastic.

If your cylinder head gasket has gone, Rad Weld will do no good at all. I speak from experience. In fact I learnt from this site that using a sealant may do more harm than good as the cooling system apparently has fine channels which can become blocked easily.

Is there any signs of Mayo at the oil filler cap?

[DeSade]

Sry year is 99, 16valve twin cam just turned 100k , manual ...

[James.uk]

Get the exhuast - cat leak fixed first.. A bandage will do as a temp fix.. :lol:

Now your other worry.. Are you actually losing any water? personaly I would change the coolant, water will do at this time of year just while we try to diagnos your problem. :lol:

Do those two fixes and report back please. :lol:
.

[DeSade]

Unfortunately leak/leaks are small holes in welding with no way of using bandage.. have bought some steel epoxy resin which i will try to force into gaps with knitting needle...

have found thermo thnx jm and already added wondarweld as it was loosing water ...

will get bck and say if worked ....

[James.uk]

>>>and already added wondarweld as it was loosing water<<<

I don't think that was a good idea :confused: I think you should replace the thermo housing if it leaks, and drain - refill the coolant asap. :shrug:
.

[DeSade]

K results as follows - Steel epoxy did trick on manifold after filling the car with fumes and smoking to hell for first couple of days ...

Wondarweld seems to have worked but havent done any long journeys yet .. still slight lack of power but presume that with the water etc in engine block/oil I will need to do oil change and flush ...

anyway it gets me from a to b atm so is better than b4 ...

[James.uk]

There is still a deff lack of evidance that would indicate a failed head gasket. :shrug:

Change the fluids, and do a compression test please. That will either confirm the hgfailed, or rule it out altogether. :lol:
.

[chris75]

Another quick diagnostic you can try , as you say the water in the tank is murky : When the engine is cold , if you release the cap on the tank , do you get a violent release of pressure and bubbling of water ? This would indicate exhaust gases in the coolant and therefore HGF . As said above , the readings from a compression test will reveal all. I have just done one where the readings were 180/150/150/180 psi .When the head was removed the two centre cylinders were leaking into each other and into the coolant outside the liners .Good luck !