98 S70 Base No start below 10°F, poor heat in cold weather

[csturner]

Symptoms:

• Car will not start when temperature is below 10°F/-12°C. Cranks, but will not start.
  Radiator fan runs all the time. Temperature Gauge shows normal temps, but cools while on the highway.
  Heater can not keep the car warm in very cold temperatures on the highway. At 70mph at sub freezing temps, the temp gauge slowly decreases, and the heater puts out cold air.

Here in the Midwest(Northern Missouri), we have been experiencing very cold temperatures for a few weeks now. The only way to get my car started has been to push it into the dock area at work, and allow it to come up to temperature. Once the temperature is above 10°f, Emeli(my Volvo S70) starts right up.

In the morning, I plan on changing the Coolant Temperature Sensor and Thermostat. I will also be replacing the Airbox Sensor, Ambient Air Temperature Sensor and the Pre-Heater hose. I will post some photos of the process along with ohm readings ect., on the various parts I purchased and replaced.

[kcodyjr]

What's the symptom? Does it turn over? Any smell of gas?

What's the temperature gauge doing, generally?

[csturner]

Trying not to be long winded, I admit I could have added more details. I updated my post some.
For more detail, when the temperatures are very low, but not below 10°, I can generally get the car started by cranking the car for short burst, with a 6-10 sec pause between cranks. After a couple of cranks I will get a sputter out of the motor. Then a wait a few seconds, crank again, and generally she starts up, a bit sputtery at first. Below 10°, she never gets past the one sputter. But she cranks fine. Battery and Alternator are good.

When you turn on the key, the electric radiator fan immediately comes on. And when you shutdown, the same fan runs awhile.

I get off work at 6am, and have a 35 mile commute back home. 99% of that commute is 70mph highway. If I start my car 30+ minutes before I leave work, she will be nicely warmed up when I head out the door. The temp gauge will be around 60% to 75%, rad fan still running. On the drive home, with the heat on full blast, by the time I drive 10 miles out of town, the heat will be putting out cold air. And the temp gauge will be around 25% to 33%. By the time I am home, I am cold again. The heat will barely be putting out any warmth at all.

I guess I should note, the Airbox temp sensor and the Ambient Air temp sensor where both missing when I bought the car. The preheater hose was also missing. I am not missing any coolant. And never have to add any.

There was also an added wire going from the fan relay at the top of the radiator going back towards the fuse box. But it wasn't connected to anything when I bought the car. It has since been removed. The A/C relay near the windshield driver side, is also missing.

There is no smell of gas.

[kcodyjr]

Sounds to me like you're not getting fuel when it's that cold, but I suppose there's a remote chance it could be spark. Let's start with fuel. When it fails to start, press the schrader valve on the fuel rail to see if there's pressure. If not, 1st suspect is the fuel filter, 2nd is dirty injectors, and the catalyst is moisture in the tank. Change the filter if you haven't recently. Pour in some water remover. Heet brand will do. Also, a bottle of Techron to clean out the injectors. A full bottle into half a tank of premium.

As for your heating problem, you have a thermostat in the stuck-open position. Replace it and the ECT.

[jblackburn]

Yup, sounds like the thermostat went bad and took the coolant temp sensor with it (common).

That coolant temp sensor is what's making the fan scream and isn't allowing the proper fuel mixture to start in the cold.

[csturner]

Parts did not arrive today, but the code reader did. I pulled these codes:
faultCode7=P0131 P0131 -- ECM-248D -- Front heated oxygen sensor, bank 1 -- Signal too low
faultCode8=P0304 P0304 -- ECM-3240 -- Misfire cylinder 4, start-up ECM-324C -- Misfire cylinder 4, catalytic converter damage -- Catalytic converter damage ECM-324D -- Misfire cylinder 4, emissions impact -- Emissions impact
faultCode9=P0301 P0301 -- ECM-3210 -- Misfire cylinder 1, start-up ECM-321C -- Misfire cylinder 1, catalytic converter damage -- Catalytic converter damage ECM-321D -- Misfire cylinder 1, emissions impact -- Emissions impact
faultCode3=P0300 P0300 -- ECM-3100 -- Misfire, at least one cylinder -- Start-up ECM-310C -- Misfire, at least one cylinder -- Catalytic converter damage ECM-310D -- Misfire, at least one cylinder -- Emissions impact
faultCode4=P0303 P0303 -- ECM-3230 -- Misfire cylinder 3, start-up -- Start-up ECM-323C -- Misfire cylinder 3, catalytic converter damage -- Catalytic converter damage ECM-323D -- Misfire cylinder 3, emissions impact -- Emissions impact
faultCode5=P0452 P0452 Evaporative Emission Control System Pressure Sensor Low Input
faultCode6=P0116 P0116 Engine Coolant Temperature Circuit Range/Performance Problem
faultCode0=P0410 P0410 Secondary Air Injection System Malfunction
faultCode1=P1308 P1308 A/C Clutch Circuit Fault
faultCode2=P0302 P0302 Cylinder 2 Misfire Detected

As expected, the ECT shows a fault. All the Cylinder misfires, I am going to hope are from when she was running rough on those very cold mornings. The Air Pump isn't really unexpected on these cars, is it?

[kcodyjr]

The air pump is really a water pump at this time of year *cough*.

Clear them and see what comes back.

[rspi]

[abscate]

That p0116 code could point to your cold start problem. This sensor tells your car to inject the cold start fuel and if it doesn't get this you get a cranking no-start condition in cold weather.

[socompsp]

check your ECT and/or replace. is your coolant mixed properly? the fact you say you get poor heater performance leads me to suugest you have either partially frozen coolant causing a block, or your water pump could be weakening and not circulating as well as it should. rspi do you concur to this being a possible cause? your heater issue could also be related to the "doors" not switching from ac to heater core flow, if that makes since to you, i dont know how else to explain it.