Classic - Strange Coolant Issue
 

Gents,

I have a completely standard 99 Classic Turbo with a strange coolant issue. Say I have been driving along a motorway at motor way speeds, nothing too fast or anything then pull off at a junction and get stuck at traffic lights after about 20 seconds I get a coolant smell in the cabin. I have checked and checked for leaks but no sign of anything but I can get the smell under the bonnet when checking. Sometimes coolant is gone but it can go for weeks without losing a drop. I have seen it vent coolant from the reservoir where you top it up and I have seen the water in at reservoir bubbling.

I rarely get the same problem and certainly not to the same level driving through towns etc but I hardly every use the car for short journeys.

I have replaced the rad cap which made it slightly better but has since made it worse (stronger smell).

The temp gauge is just below the half way on the motorway but climbs slightly to half way when stuck in traffic etc. It does seem to take the fan a while to kick in but it does work.

The fluid level at the rad cap is always full when I check from cold.

So any ideas?

EDIT: Just to clarify - the smell does not continue. You just a get a wiff then it clears even if I get stuck in a complete standstill etc.

The plastic top ends of the radiator have a tendency to go brittle when older and crack, if yours are on the way out (a 12 year old rad has had a good life ;)) then it may be this.

Tony:)

the rads vent steam before leaking properly but the water bubbling in the reservoir isnt a good sign that can be a tell tale for the hg going

I only noticed the water bubbling once and there are no other symptoms of a blown HG. The car has only done 70k and I dont drive it hard and its been well serviced, never failed an MOT etc.

Im thinking it could be a sticking thermostat causing a sudden burst of hot water into the rad combined with a small leak or something like that. Maybe even a water pump issue so it is not pumping the water around enough at idle or something simple, but frustrating like that.

i had similar problems with my 94 waggon , rad blew in top left ( common fault) changed that which sorted problem for a while , then changed thermostat , seemed ok for a while , belts, tensioners and waterpump where next ! all seemed good . decided to sell as i wanted to try a legacy gtb, guy in germany bought it, Roman from jdmpower.de when he got home he emailed me to say the head had gone !

moral of the story is , how much have you got to spend ???
hope you get it sorted.

At the weekend I ran it from cold up to normal operating temperature (as seen on the gauge during normal driving) and the radiator was still cold. The top hose was properly warm but not the rad. Im going to get the thermostat changed.