98 S70 upper radiator hose again

[scot850]

Check that short pipe to the coolant header bottle is not blocked. They can block where it enters the bottle.

Try loosening the upper hose at the thermostat end and see if the pipe is full of water. At this point I would remove and test the thermostat in case it has failed closed.

The top hose is the highest so most likely to see highest pressures due to the water pump trying to push against a closed thermostat if it is bad.

The last thing that I can think of is the water pump. I would check for the thermostat being stuck and then the head gasket leak first.

I have read of some poorly made water pumps where the impeller has come loose and does not circulate the coolant which will not help removing air locks and causes hot spots.

Neil.

[mar601]

Check that short pipe to the coolant header bottle is not blocked. They can block where it enters the bottle.
just did that -- it's clear

Try loosening the upper hose at the thermostat end and see if the pipe is full of water. At this point I would remove and test the thermostat in case it has failed closed.
loosened and pulled off the hose and not full but a small amount of coolant on the bottom dribbled out of the pipe (engine was cold)

The top hose is the highest so most likely to see highest pressures due to the water pump trying to push against a closed thermostat if it is bad.

The last thing that I can think of is the water pump. I would check for the thermostat being stuck and then the head gasket leak first.
OK. Bought the combustion test kit -- here monday. I just had the timing belt done several months ago and a new water pump. This the one I bought...
https://eeuroparts.com/product/aisin/WPV800

I have read of some poorly made water pumps where the impeller has come loose and does not circulate the coolant which will not help removing air locks and causes hot spots.

I bought a gates 33208 thermostat through amazon for the sake of convenience (will replace it with oem later) that and the tester are coming monday.

Neil. thanks Neil

[scot850]

I would think if it was and Aisin (OEM) water pump it is unlikely to be an issue.

AS you can't use the car, now is the time to remove the thermostat housing and check the thermostat in boiling water and see if it opens.

A better way is to find a way to support it in a pan of water and heat the water and check the temp with your new gauge and see when it opens if at all.

Now cautionary advice! Thermostat cover removal. The cover is held on with 2 x T40? headed bolts/screws. These can be a pig to remove if they have been on for a long time.

The access can also be challenging due to the positioning of the bolts. I have an extended Torx sockets which allows access without having to tilt at an angle which is the usual cause of rounding the head Torx.

I suggest taping the bolt heads firmly on the top. Don't go crazy as you can crack the housing!! Then soak with PB Blaster or like penetrating oil and leave over night. Repeat the tap again tomorrow on the bolt heads and then try to remove. Because the bolts are steel and the housing is aluminum they tend to fuse together on the threads and contact faces.

Just replaced the thermostat seal on a friends car last week as it was leaking. Fortunately the bolts came of easily.

Neil.

[mar601]

THANKS. Yeah, replaced one years ago and do have the T40 socket somewhere. Actually have a beck arnley thermostat coming because it has that "jiggle valve" I read about (143-0732). Just drove the car a few blocks and then let it idle -- that upper hose gets so hot and bloated and that's with the temperature reading about 185F. Pointing toward the thermostat housing. The hose gets so puffy I just shut off the car.
I did read that your expansion tank level can rise with combustion gases? And the cap can leak but I don't have either issue going on. Seriously, the car has never run better (which is why I'm going through all this). Even if it's very bad news, I'll probably get the work done because I can't afford anything new.

[scot850]

I hear you on the affording something new or newer. For me it is more about my like of annual mileage and the careless vehicle owners in Calgary (I was going to call them drivers. but that would be a stretch!).

Good Luck!

Neil.

[mar601]

Going to Calgary is big on my bucket list. Such a beautiful place.

[mar601]

How in the heck do you get past that line on the right T40 torx on the thermostat? I tried my socket with extension and bit and no way.
I'm looking at ordering one of these -- one is a Klein which is nice but wondering what you use to get access to that screw?
https://www.amazon.com/gp/product/B005G ... 0DER&psc=1

https://www.amazon.com/gp/product/B0CH1 ... RL4X&psc=1

Think one of these will do it? -- thanks

edit -- I have another question. My heater works fine. Can the core still be an issue if you have normal heating?

[mar601]

I'm an idiot. This is what I need...
https://www.amazon.com/TEKTON-Drive-Lo ... r=8-1&th=1

[scot850]

Sorry, from here we can't see US links. What I have is an extended 3/8" socket with a shaft that is about 4" or so long which is just long enough to clear the head.

Neil.

[abscate]

Links are broken here, too.