1998 Volvo S70 How to check water pump without pulling?

Post by **cn90** » 21 May 2015, 09:54

I think you are playing Russian Roulette.
At 250K and with overheating symptoms, I'd personally get a new Aisin WP and move on.

Post by **erikv11** » 21 May 2015, 10:35

Yes, if the water pump is in any way bad then replace it. I think that has been made infinitely clear here. But if it isn't, i.e. if the overheating symptoms go away with the ECT swap, then waiting a short while on the pump is not a big deal. OP can't just "replace the pump and move on" if the pump is not the problem.

greenman86 · Post by **greenman86** » 21 May 2015, 11:04

It sounds like you may have the head gasket going out on you. You mention the expansion tank boiling over in one of your previous posts. I would not be surprised if it was the case especially at the mileage you have given.

Post by **erikv11** » 21 May 2015, 11:12

That's a good call but check the whole thread: the coolant test is negative for exhaust gas contamination.

Post by **northernlights** » 21 May 2015, 12:03

greenman86 wrote:It sounds like you may have the head gasket going out on you. You mention the expansion tank boiling over in one of your previous posts. I would not be surprised if it was the case especially at the mileage you have given.

erikv11 wrote:That's a good call but check the whole thread: the coolant test is negative for exhaust gas contamination.

Head gasket, cracked head, cracked block or similar was my first thought also given the circumstances.

Is there a fitting on the block that you can attach a pressure gauge to? I think usually there is a coolant drain fitting under the exhaust manifold on the engine rear. If your water pump is really dead then you will not have pressure in the block when it is cold after startup. No flow = no pressure.

Post by **erikv11** » 21 May 2015, 13:34

This thread is actually a continuation, I too thought head gasket right away but OP tested it twice for combustion gases (https://www.matthewsvolvosite.com/forums ... =1&t=69181).

That's a neat trick about checking pressure, there is indeed a fitting on the block.

Post by **precopster** » 22 May 2015, 14:42

The suspense is killing me on this thread

roscoerich · Post by **roscoerich** » 27 May 2015, 12:54

Sorry for the delay. Had to be out of town for work over the holiday weekend. I finally replaced the ECT yesterday and no more over heating problems. Cannot believe it was that simple- even though I had replaced it about 2 years ago, I was expecting the worst. I will take heed to all the advice of replacing the water pump as soon as I can find the time. I can't thank everyone enough for all your help! Thank you! Thank you! Thank you all!
Now to try and pass inspection.....

Post by **misha** » 27 May 2015, 14:24

As long as water pump is not leaking and cooling system is working as it should...leave it alone.
Mine is still original and it will be replaced soon because it started to leak a little around shaft.Not a big deal....few drops of coolant from time to time.

However...if you are going to replace it,use Hepu,SKF or Volvo pump.

Replaced ect sensor from 2 years ago.....was it oem or aftermarket?Only ect sensors which can be safely used in these cars are Oem which is made by Valeo and Vernet.Nothing else will work or last.

Post by **erikv11** » 27 May 2015, 14:57

Good job sticking to the basic diagnostics routine and not just blindly replacing the water pump. Had you done that you would have been *really* frustrated!!

I agree with misha, the OEM pump is well known to last a very long time, you don't need to be in a hurry to replace one that shows no symptoms of failure but you will want to at least check it periodically for weeping.