The other day I noticed coolant on my garage floor. I went for a drive and when I got back to the house there was coolant leaking on the ground. I found a crack in the resivoir. Yesterday I replaced it but the coolant would still boil out of it. I replaced the thermostat and the ECT sensor and still have the same problem. The temp on the gauge never reads over half way. The fan comes on when the thermostat housing reaches 210 with an IR temp gun but the resivoir is boiling over before that by a few mins. I did a block test and it came up negative. could it still be the head gasket or the pump? When the thermostat opens, the level in the resivoir goes down. 99 s80 t6

Thanks,
Bill

 

Maybe radiator is getting clogged?
How much of a temp difference from one side to the other at the radiator?
How full is the coolant bottle when you start?

 

The coolant level is at the full mark when I start. The radiator is reading pretty much the same on both sides, about 180, except when the fan comes on.

Thanks,
Bill

 

What Temp should the cooling fan come on at. It almost act's like it's not kicking on soon enough. If I run the AC I have no problem.

THanks,
Bill

 

Ok, so I replaced the cooling fan assy. no change. Please help. I'm out of money

 

You should have between 20 to 40 degrees different between sides on the radiator.
I forget the exact temp is should come on.
Seems like the coolant isn't being cooled enough.

 

hrm.. i had this very scenario happen to me after i did a timing belt on my volvo. i had to undo the reservoir overfill tube and i laid it on the side. when i put everything back together, the volvo kept losing coolant. i did head gasket tests and everything and it passed them all. then i remembered that coolant when underpressure has a higher boiling point, and so i figured my reservoir cap was bad or i had a leak somewhere putting the coolant in less pressure than expected when the car was up to op temps.. so started doing checking, and my cap was not on tight enough. i tightend it a couple more turns (in degrees i guess) and i have not had a leaking reservoir since. id try that or even get a new cap, that may resolve your issue....

 

I'll get a new cap on Monday and let you know if it helps.

Thanks,
Bill

 

If the replacing the resivior cap doesn't help, I'll try back flushing the radiator and let you know.

Thanks,
Bill

 

[sm=groupwave.gif]Figured it out. Volvo sent me the wrong resivoir. There it a chassis split on this year. they sent the one with the vent on it. I just thought it was a revised unit with a vent for excessive pressure, but while flusning through the heater core, the resivoir filled up, with the cap off, and started running out of the vent. They sent me the right one and problem solved.

Thanks,
Bill

 

makes sense.. good deal.. glad its resolved for you..

 

Sorry to hijack this thread but I figured it would be better to keep it in one.

I've had a number of problems with my car, but one I've getting at the moment is excessive heat. After a 20 minutes drive, not pushing it hard at all, some motorway (60mph) and some town I get home and the engine is very hot. I can hear what seems to be the coolant in the resivour boiling over, and the fan will come on for about 10 minutes. If I open the bonnet, then I cn feel its very hot in there. The temp guage read's normal, and its seems to be working. both the inlet and outlet hose's from teh radiator are very hot. I don't have a way to read the temp at the moment.

When I first got the car and I stop and heard the sound of the water boiling ( thats what it sounds like, I'm not saying that is what it is though) I was scared, I flushed the entire system, and replaced the coolant again, but its still got this same problem. We're coming in to summer here and I'm a little worried. tonight I could here a hiss from the resoviour cap but I couldn't tighten it any more.

thanks for any help guys,

Stu

 

Based on what I just went through, I would replace the resivoir cap first.

 

last post +1

 

Sweet, thanks guys