Overheating/gear Selection Problems

[Gas Gas Panic]

Hi,

Hope somebody can help me.

My wife's Colorado Auto Diesel (1998 75K miles) was playing up. She asked me to take it for a drive yesterday - I got about 2 miles before the temp guage was off the scale (from cold) and the gear box started acting up. It was struggling to select gears and juddering. Last time I had this it was low oil in the gear box on a Merc auto......but could be something else. However the problems did get worse the further I drove indicating a link to the temperature.

I flipped all the ventilation settings to hot and put it on full blast in an attemtp to cool it a bit - but to no effect. The air remaind ambient coming from the vents.

I popped the hood and there was coolant coming from the expansion tank........and it was a pale yellow colour, slightly greasy. I assume this is oil in with the coolant?

The coolant level (except from what had been expelled from the expansion tank) was ok.

I'm no mechanic, but it looks nasty to me. The car is old, but this is the first problem we have had with it since ownership 8 years ago. Would be a shame if it has died and is beyond economic repair.

So my questions are what do you think has happened? What's involved in fixing it?

Thanks

[sandgroper]

It has some of the symptoms of a thermostat not opening. The coolant inside the engine gets so hot it forces its way past the thermostat and radiator and causes the the coolant tank to overflow.

The pale yellow coolant ,if it is milky and frothy,could be signs of a blown head gasket or cracked head.

This could also cause the overflow of coolant past the radiator cap

The transmission problem is caused by overheating as it is cooled through the radiator(unless it has its own cooling system)

If the head is cracked it need to be tested ,welded and machined or replaced altogether.

I think my brothers 98 cost about $2500 in Australia.

If you dont repair it ,it will have a very low resale value

[Andy]

Also you might want to check that you don't have water in the auto box, the transmission oil cooler runs through the bottom of the rad and if that has gone you will have a bust gearbox.

[Gas Gas Panic]

Thanks for the reply Andy - spot on.

I found out what it was today. When looked at in full day light the coolant is a pale sticky pink. It's gearbox oil (which is redish) from a leak from the auto box oil cooler pipes that run into the radiator.

The low oil level in the auto box is causing the gear select problems as it overheats. Obviously the gunge in the coolant system is preventing the cabin cooling system matrix from working.

So new radiator, a good flush out and hopefully the gearbox isn't a write off.

Hopefully this may help somebody in the future.

Cheers

[Andy]

The best method would be to take it to a auto box place and get them to flush with a machine, because if you just drain the box some of the fluid remains in the torque convertor, the other alternative is to change the fluid a few times, driving it a few mile in between changes.

Good Luck !