cooling problems
 

Hi. My audi d2 4.2 40v had little engine clean up, heads removed, timing belt replaced, oil changed, new thermostat water pump, bought used radiator, because old one was leaking all it was dan cause it was eating a little bit of oil and alittle bit of cooling flued was dissapearing. but now there is new problem. it started with cooling not running big cycle in radiator, so I found out that new thermostat was foulty, after that I tried a test drive - it was running hot with heater on high and fan at max but still temperature was getting over 100 degrees. what could be the problem? I was thinking maybe cooling system on heating system hoses is mixed up and connected not in right places?

can anyone give me schematics to cooling hose connections?

Assuming the work was all done professionally and the cooling system has been bled properly at the bleeding screws, check the condition of the expansion tank.
Cracks or a bad cap seal can give those symptoms.

You could also take it back to where the work was done and say "please fix this"!

well if that guy had any teeth than I could go and he would fix it, cause he was an ass*ole and did bad job ... but I think problem is smth simple. what happens when 2. and 3. pipe are switched?

well, I have the opposite problem: my engine runs cold.

Warming up is all right. If I drive in town with lots of stop and go the engine can reach 90 C (supposedly working temp). However, a warm engine can get cold (75 C) after maybe 5 miles at reasonably high speeds (think 70 mph). And it's unlikely the coolant sensor or the thermostat, because after 100 miles this morning I popped the hood and touched briefly the coolant tank. The tank wasn't really hot (and coolant level was barely elevated if at all), and the engine bay wasn't either.

I think it would make sense to make a radiator that can shut off half of its capacity in cold weather. It was around 0 C this morning with perhaps 100% humidity (and France really feels colder than Sweden where I last lived).

add piece of cardboard (thick paper) inside the grill to block off air flow to half radiator... in Latvia when we have -30 we do it
but your problem could be in thermostat.

That would only reverse the direction of flow through the heater cores.

If they'd been reversed, they'd sort of cross each other.

If attached correctly, the upper hose, closest to the center of the car, goes toward the center to a pipe top rear of engine...the other hose drops down low before turning toward the center at the lower rear end of the engine.

I hope it's not the thermostat (at least before it got cold the engine was holding at 90 C) but don't really care.

If I alternate A/C recycle and non-recycle, the engine could hold at 85 C (recycle only causes frogging after a while).

I just hope I can drive this car for three years until I graduate. If it still works then, I'll probably garage it as a reminder of my poor years.

where could be that damn problem? I even tried to bleed that system one more time, installed new cap, new thermostat, inspected that coolant tank - everything is ok ... so where is that damn problem?