Smaug - Coldstart to Fan switch-on

[tigerdog]

Posting this to see if one of the resident interpreting gods will take a look. The file is what it says on the tin: coldstart to fan actuation. This is from Smaug, fitted with the Garrett 2560R turbo, RC Engineering 550cc injectors, 3-bar MAP sensor and stock ECU.

I believe Smaug's thermostat is stuck in the "open" position. If someone can confirm the initial warm-up time seems longer than usual it would confirm this.

Moreover, I'd appreciate someone who has experience in these things comparing and contrasting these readings with a standard setup.

[GeoffSmith]

I agree, thermostat stuck open.

[RayF]

Just loaded your file and I agree you have a thermostat problem - but take a look at how the temperature rises in comparision to a "normal" car:

My interpretation is that your (blue) thermostat is not opening properly. See how the normal (black) line has an up down wiggle where the thermostat opens. After the wiggle it then continues until the fans come on. So the thing that's missing in the blue trace is the thermostat opening.

Still the end result is the same - get a new one

BTW I'm relatively new to the Elan so I'd be pleased to hear if my interpretation is wrong, especially when I'm contradicting a God like Geoff
(Maybe due to this being an idle warm up rather than moving)

[GeoffSmith]

Ray,

I was suggesting the thermostat was open because of the sudden drop in temperature as the fans kicked in. If the thermostat was closed, there would not be any coolant flowing in the radiator loop, so the thermal switch would not activate the fans and the temperature would head North.

It could be the thermostat is stuck half open (or half closed ) of course.

Don't worry about contradicting me (I'm only a few months ahead of you anyway and we're both years behind others) as we all learn by considering the questions asked.

Geoff

[tigerdog]

Thanks for the interpretations. The thermostat is definitely open. Under normal driving in pleasant San Diego weather, the temp gauge barely leaves the peg (halfway to the 1st mark, max.) If I let the car idle (as in traffic) temp goes up but then drops way back down below the normal thermostat close temp. Yep, time for a new thermostat! At least it's not stuck closed!

[RayF]

Geoff,

Yes you're right, if it had been completely closed then it would have been boiling (doh ) . What I was looking at was the almost perfect match between the temp profiles. I would have expected the rise in temp to have been significantly slower with a thermostat open. Still I guess its the lack of the wiggle in the curve that's the give-away that the thermostat is deceased.

Thanks for the feedback guys

Ray

[tigerdog]

I would have expected the rise in temp to have been significantly slower with a thermostat open

I expected the same thing. Perhaps the rise is similar when the car is sitting at idle but would be much faster if your car had been moving. More load and working thermostat = faster warmup. More load and stuck open = slower warmup due to airflow through radiator.

[RayF]

Yes I see what you mean - if we compared two scans with cars moving there would be a big difference. Well it will be interesting to hear what you find when you take the old one out.

[tigerdog]

Nearly a year later - here's what it looks like with a working thermostat. The old one was stuck open, BTW.

[GeoffSmith]

I agree, thermostat stuck open.

Told ya!