98 s70 overheating

[ashvolvo]

Use genuine parts only for the engine coolant temp sensor, do not use after market parts for it. It is called as Temperature sending unit. It is recommended that you change the ECT sensor and Thermostat together. They typically last between 60-80K miles before they start malfunctioning. Here are links from FCP

https://www.fcpeuro.com/products/volvo- ... -9125463oe

https://www.fcpeuro.com/products/volvo- ... s-271664oe

[RickHaleParker]

I think Wahler is commonly used without problems, about $12

Wahler is a BorgWarner aftermarket line. BorgWarner claims Wahler is built to the same quality, service life and operational reliability as OEM.

[dj_v70]

I don't believe any of these codes have anything to do with your overheating issue. Googling P0176 says it is for a fuel issue. Someone else will chime in if I am incorrect here.

Based on the information that you have provided so far, it doesn't sound like your issue is the thermostat.

You have noted that it takes something like 10 miles to get up to temperature. That is likely the thermostat stuck partially open. This is a common issue with these cars. A thermostat stuck open keeps your engine cooler, not hotter though, so it is unlikely to be your overheating issue. I bought my 2000 v70 with a thermostat that was stuck open, it took about 10 miles to get up to temperature also, it didn't overheat.

It isn't hard to replace thermostat, I recommend using youtube to get in-depth instructions.

[abscate]

Wahler, Vernet or OEM Volvo on those parts.

You will need a Torx bit set on the thermostat bolts. Lowe’s has a Kobalt brand which is decent. You want To get the bit firmly in the head socket then give it about 20 light raps with a small hammer. You are shocking the threads to loosen them up for removal. Don’t distort anything, just rattle their world a bit.

[ashvolvo]

Do not put after market for Temperate sender unit. Put Genuine Volvo

Here it is
https://www.fcpeuro.com/products/volvo- ... -9125463oe

here is the thermostat
https://www.fcpeuro.com/products/volvo- ... s-271664oe

You will need a T40 to open the 2 screws on top of the thermostat housing unit. sometimes they are a bit*h to take off.

[MoVolvos]

Thermostat sounds like a good probability as suggested above. Also check that the cooling fan is working.

Neil.

I agree. Every single description and detail of the problem described by Kprixie happened to my former 98 S70 T5. At first I thought it was a head gasket also but before doing the work I replace the expansion tank and cap but the problem persisted. What I found was the thermostat was missing. The problem could be an opened thermostat so the temperature fluctuated even goong low then overheat (needle in red). I am not sure that it is truly overheating but you have to take the precaution thinking it is.

[misha]

...Also does anyone know a good brand reliable for the sensor I can order myself online...

Vernet or Wahler.

[misha]

I think Wahler is commonly used without problems, about $12

Wahler is a BorgWarner aftermarket line. BorgWarner claims Wahler is built to the same quality, service life and operational reliability as OEM.

Wahler IS OEM(read OE).
On original thermostat it's stamped Volvo AND Wahler....at least on EU market cars.