Two questions from a Argo noob

[holdmybeerwatchthis]

So I recently bought an 07 Avenger. I went through the machine and replaced a bunch of bearings an axle and did the usual maintenance thing. It runs really well and does it's job. However, it started doing something strange when the weather turned bitter cold -25C. First it would start fine, run for 30 secs or so then stop. When I hit the key again it would take a bit of convincing from the throttle to go, then it's fine. Yesterday I had it out and it took a considerable amount of cranking to get it started, but like before when warm it runs like a champ. I'm leaning towards an O2 sensor, I stopped to stretch my legs and the diagnostic light came on. I got a code 31, but the light never came back on after I read the code. I know from years of automotive work that computer controlled cars operate on a pre set program until the O2 sensor reaches temp, thus having heated sensors reduces warm up time, but I would assume that it would still run on pre set parameters for the first few mins.

Question 2 does anyone else have over cooling problems with these EFI engines? I changed the stat just out of instinct, but I actually had to tape a plastic bag the to air intake so it would run at normal temp. Do these engines have constant direct drive fan or are they clutched? This is also another reason I'm leaning towards an O2 sensor, if it's been running cold it'll be all gummed up.

Thanks

[wrench9]

Mine always ran cold I had over 1500 hours with no problems always started great warm or cold. I also changes the thermostat temp still stayed low. I purchased a 2013 XTI basically the same engine, temp is at proper range after it warms up

[holdmybeerwatchthis]

Good to know thanks. That answers the question about the fan then. I'm just a sissy, I want it to run at the normal range so it'll blow enough heat to keep me warm.

[philipatmaxfour]

Mr Beer..07 Avengers came with a 31hp efi or a 25 hp carbed engine. I assume you have the efi. Mine starts and runs in the cold but I did make a small temporary wall of 1/4 plate aluminum to restrict the warm air flow from the engine vent around the exhaust pipe on a really cold trip. It worked so well that I could ride in shirt sleeves but i melted the covering on the throttle cable near the engine. I think that ODG wrap tinfoil insulation at that point now. I put a switch on the brake fan till the engine warms. I wish you luck solving your starting problems.

[holdmybeerwatchthis]

Good idea. It is the 31 hp, should've posted that info.

[wrench9]

Even when it ran cold mine threw back enough heat to keep me warm I did have a windshield on it which would also help the heat get pulled back when you were driving along. I had made kind of a hollow curved tin cover and it went over the muffler top part I welded in two ends and used flexible duct pipe and a bilge blower from a boat I used this as a defroster and heater as the windshield would ice up if I didn't use it in the soft snow with tracks but it was too hot inside to leave it on all the time. It used the external heat from the muffler which was conducted through the hollow tin piece I fabricated to warm up the air.

[holdmybeerwatchthis]

Ya, I've noticed that too. My windshield ices up too. I actually took the panel completely out where the trans/brakes are. It blows so much heat it's almost unbearable, but it doesn't blow on the windshield. I don't know if the brake cooling fan is standard equipment, but it moves a lot of air. I recall that the late 70's/80's gm vehicles had skinny rotating dash vents. I'm going to see if I can mount one in the dash for defrost.

[wrench9]

The brake cooling fan is required without it the brakes will get hot enough to boil the brake fluid leaving you with no brakes. Cutting louvers in the dash may work you may need to hook up a small ductwork to them and a bilge blower drawing from under the hood to keep it defrosted.