1998 Volvo S70 GLT Overheating RESOLVED ECT

Post by **precopster** » 02 Aug 2013, 07:59

Coolant temp sensor would be on the shortlist as well as new fan relay. It reports the coolant temperature to the ECU.

Seepage of coolant into combustion chamber is defintely a possibility.

Teslacoilftw · Post by **Teslacoilftw** » 03 Aug 2013, 15:23

So here is an update. I think I have finally figured it out. I'm 95% Sure that it's the Water pump going out. In the last day or so I had the windows rolled down and started the car up it was a quiet day and I heard a what sounds like metal scraping against something It would go away after about 40mph the temp would come down. The temp would start going back up at idle... which is a typical sign that it's the water pump. Also I would start hearing it again when I slowed down... The car and its acceleration/idle have been working perfectly no sloppiness no sudden surges or jerks. The fan does in fact stay on after I turn off the car for about 5 mins or so.. that leads me to believe that the relay in itself is working for the most part.
So that leads me to the nasty question of....
Does anyone know a Mechanic in the Seattle area that doesn't charge 300$ to replace a water pump?

Post by **abscate** » 03 Aug 2013, 19:06

2.5 hours + $50 parts s a very reasonable price to replace a water pump on an S70. Too low, if anything.

Post by **abscate** » 17 Oct 2013, 04:58

There is a lot of pressure in the cooling system of these cars, Dmitri. That is normal.

Is your car overheating every time you run it or just sometimes?

Post by **rspi** » 17 Oct 2013, 10:50

When our S70 GLT had a bad head gasket, it was NOT overheating but after driving on the freeway for 5 to 10 minutes, the coolant level in our coolant reservoir was above the full mark and forcing coolant out of the cap. Make sure you have a good green cap. Do not open the cap when the car is warm/hot. And check the coolant level before you start the car in the morning.

Post by **precopster** » 18 Oct 2013, 15:05

When the coolant's temperature reports exactly 105 deg C the fan comes on. It stays on until the coolant temp drops to 98 deg C. You can view this on any good scanner with live readings.

However just because the ECT is reporting 105 deg C it doesn't mean this is accurate and this is why ECTs have a short span of life. They often go out of tolerance.

Replacing with a used one is only ok if you can independantly measure the coolant temp with a probe to verify it's accuracy.

1998 Volvo S70 GLT Overheating RESOLVED ECT

Re: 1998 Volvo S70 GLT Overheating