Change your coolant, maybe? Sounds like you possibly have the wrong mix in there.

 

i was using half water half prediluted coolant. is it possible to have a blown head and show no signs besides the pressure build up? it will rise whether i let it sit for and hour or drive it for 2 minutes.

 

also after the swap of couplings all vents blew warm air when i put the blower on hot and full. now i would say nowhere near warm as of tonight just trying it one more time. heater core clogged?
Could the ecc module be the cause of different vents blowing different?
or not blowing hot at all?
it does not blow on auto climate only blows on fan speeds
I dont think would still explain this situation. maybe a valve somewhere on the core? i just dont want to go through a whole day pulling the head off for a head gasket thats not blown.

 

if you're running 50% pre diluted coolant and 50% water, you're actually running 75% water and 25% coolant. this is pretty much the exact opposite of how it should be. Drain your coolant and run 75% undiluted coolant and 25% water and see if that fixes things.

 

tried the coolant still same effects. im leaning towards the water pump obviously not circulating coolant throughout the motor instead letting it sit and boil?

 

Sounds like a few problems

First, different temps from the HVAC system could mean the motors or the control arms aren't moving the vent covers properly, but it couuld be as easy as having to clean off the temp sensors in the vents above the ECC and up by the grab handles.

If the radiator hose is swelling, it'd be best to replace it - along with the other four radiator hoses.

I'll take a guess that your water pump is shot - I'm guessing your serp. belt is nice and tight?

"looks like its boiling/ letting air out then shoots up and out" - did you install the correct thermostat? You might want to pull it and double-check it's seated properly. I haven't replace one, but I recall reading how they're a bit finicky for the installation.

 

The water pump is off the timing belt.

You can go under your dash on the driver side. Check the heater core pipes. Are they getting hot at the same rate as the engine. If they don't get hot, could be the water pump going bad. I'd check there first. You can also check them where they go into the firewall on the engine side, but you really burn your hands on them under the dash. Volvo knows how to generate heat.

 

ok still havent figured out the a/c issue. But.. pulled the head off of curiousity.

head gasket had little pin holes in it where the coolant chambers where around the cylinders. Im guessing this was the answer. timing it right now starting it in about an hour will repost result hopefully i have found the answer to an issues numorous people are having or have had that i cant find the answer to. I also checked the water pump and was fairly new along with the timing belt. Thanks for all the advice. i figured i would go ahead and replace the gasket anyways. The serp wasnt tight in the case of water pump draggin the fins on the casing. two days ago i took the water pump off new gasket and belts. took her for spin she started right up sounded amazing drove even better than ever. "like the car was on its tippy toes" Gliding with barely any pressure on the gas pedal. she drove good for an hour straight . so i pushed her see if the problem was still a case. She was going going going. after 30 minutes of hard driving temp gauge rose straight to red. i used the "getting home" procedure you know the one with loads of patience. came home started taring aweay at her deeterming to fin the solution. hopefully she will ride nice tonight with no fits of any kind. Again thanks all for the advice. I am still tryting to figure out this a/c problem now though how do you suggest i clean the arms for the vents and also the grasp handle sensor???

 

I have overhauled this motor numerous times. just got stubbed on this one situation. no cracked block or head had to have been the gasket it had whole in it. As far has the heater core both pipes under dash run hot. i just replaced the top and lower heater hoses along with the firewall coupling for them. Heater core has no leaks very clean also. just no heat blows when i put heat on now except for driver side.
very simple task the coupling but harder to find how to perform repairs.
Thanks for the help

 

Why would that (75% coolant to 25% H2O) make the engine run cooler??

BTW: T3AM; have you thought the radiator might be clogged?

 

it won't make it run cooler in and of itself, but it WILL keep his coolant from boiling off.

 

the radiator flows free... can it still be clogged in that case?

 

Sounds like you need to have a leak down test done. Your going through a lot of labor and headache that could be solved with this test. It makes sense to me that you have a rupture between the cylinder and the cooling system. If the cylinder(s) are pushing air into your cooling system you will swell hoses, pressurize the system, have air get around the thermostat and overheat.

You should be spending all your time on your motor and forget about the heater until you protect your engine. I am only saying this because I did not and ended up having to replace my motor over a similar issue.

 

Just Bought a list of cooling parts im replacing everything i have a 1300 mile trip im about to go on. All the way up the east coast.

 

this is exactly what my 96 platinum wagon was doing. at 8.3 miles on the dot it would start to get hot, get hot then cool back down. Did a leak down test, held fine. replaced hoses, thermostat, overflow tank and cap, still a problem.
yanked apart the motor last week, found a hole in the head gasket. replaced it, and since then its staying where it should be.

i dont and never have liked gauges that are just lines with no real indication of what the temp actually is. i bought the scan2 from IPD and mine will run at about 197'F and peak at 215. i suspect the higher temps are for two reasons, its 107'f in dallas, and the air guide is missing off the underside of the car.

My S60 is really affected by the air guide, as well was my wifes 850 (rip). i think once a guide is on the temps should stay at a normal operating temp.

when i yanked the head off, i noticed that whomever applied the gasket material prior to my ownership did it in a very sloppy manner, took several hours to clean up all the oil passages, valleys and whatnot.

So far i've had no more signs of any major issues. i'll test it out this week with a few lengthy trips with and without traffic.