1998 Volvo S70 How to check water pump without pulling?

roscoerich · Post by **roscoerich** » 19 May 2015, 11:38

Hello all, well the car is still overheating, I've replaced thermostat, radiator, heater core, and combustion gas test (negative) and was wondering if there is a way to check the water pump without pulling it?
Also, noticed the purple hose to the check air valve(which I think is the original) was pretty much deteriorated and not really even connected anymore. Would this be the culprit? I am going to check the air pump(original) as well, I heard some whining coming from it.
Is there a way to check the relays for the pump? Any advice would be greatly appreciated...

Post by **misha** » 19 May 2015, 12:51

Cooling fan working?

Post by **erikv11** » 19 May 2015, 13:13

The purple hose and the air pump will not in any way be related to overheating.

Post by **precopster** » 19 May 2015, 13:17

Also replace the coolant temp sensor with OEM.

If you monitor coolant temps with an OBDII device what temperature does the cooling fan activate? Should be at 105degC

I had a horrific time with overheating after a head gasket replacement on an 850 wagon 5 years ago because I failed to replace it.

s70vamp · Post by **s70vamp** » 19 May 2015, 14:26

have you checked the PVC ? eaither pull the dip stick up and see if any smoke or put a while surgeon glove over the oil filler cap and if it tries to blow it off then it may be blocked but if it tries to suck it in then its free. you could have a blockage

roscoerich · Post by **roscoerich** » 19 May 2015, 15:20

Thanks for your responses!
The cooling fan is working. I haven't checked the temperature at which it engages. Just bought an OBDII a few weeks ago, but haven't quite mastered it. PVC seems to be fine, but can't really run it long enough before overheating to be sure.
Funny enough, I just went to AutoZone before reading this post to pick up the engine coolant temp sensor and they said it wouldn't have anything to do with the car overheating so I talked myself out of it, better off ordering one online anyway.

Post by **cn90** » 19 May 2015, 16:10

How many miles in the car?

roscoerich · Post by **roscoerich** » 19 May 2015, 16:39

Odometer stopped long ago, but I'm sure there is at least 250,000 miles on her..

Post by **misha** » 19 May 2015, 17:58

roscoerich wrote:Hello all, well the car is still overheating, I've replaced thermostat, radiator, heater core, and combustion gas test (negative) and was wondering if there is a way to check the water pump without pulling it?

With all of that tested ok,plus cooling fans are working...could be that water pump failed internally.There were a few cases with internally broken water pump.

Dumb question,but do you have enough coolant in the system and what is the most important...is there a possibility that you have trapped air in the system since you were installing new thermostat,radiator and heater core?Did you bleed the system properly with expansion cap removed and engine idling untill cooling fan turns on?

roscoerich · Post by **roscoerich** » 19 May 2015, 18:26

Yes, left cap off until heat cycle, fan started, plenty of coolant. That was a worry of mine originally, but was told the cooling system the air bleeds out rather quickly, but with multiple attempts to ensure there was no air in the system and it's still overheating.