Car Running Too Cold?

[Hanaldo]

Hey all,

Didn't want to whore the Hypergear thread again, so just a quick one.

Have been driving my car around again since Thursday when I finished off some work I was doing to it, the only performance modification being the HKS exhaust cam gear and dialling in the cams. Nothing else has changed. Since then, I have noticed the car runs abnormally cool. I have taken it for 2 or 3 long drives, ie. over an hour and a half each. And normally the water and oil temps would be up to around 80-85 degrees within 10 minutes of driving. Now they take about 10 minutes to get to 65, before eventually getting to around 75 where they then sit pretty steady.

I'm aware operating temp of the Neo engine is about 83 degrees, so I'm a bit puzzled as to why it is now running cooler than that. First I thought my gauges might be wrong, but I'm getting the same reading on all three of my temperature gauges, and even the stock gauge is sitting a little lower than it normally does. It is also running a tad richer, normally the AEM wideband reads between 14.5-15.5 on cruise, now it's between 13-14. So I'm pretty confident it is actually running cooler.

My first guess would be the thermostat sticking open? I'm just a little surprised that it still holds 75 rock solid once it gets there, it's no different sitting in traffic or cruising at 110. This has also coincided with some pretty cold weather over here, however today was 22 and it was still the same story. The car gets tuned on Tuesday, I just wanted to check before it goes on the dyno if this might be an issue?

Cheers,

Martin.

[GTSBoy]

Did you open the cooling system when you did the work?

[Hanaldo]

Yes, had to remove the radiator to do the cams.

[abr33]

Sounds like a sticky thermostat... However mine (33) sits on 75 when its freezing here, 5 and below. And takes 15 mins of highway driving to get there

[Hanaldo]

So if the thermostat was sticking, the temperature wouldn't vary? I thought it might drop a little bit at faster speeds with more air flow.

Can anyone see this causing problems with the tune? I doubt I'll be able to get a replacement thermostat before Tuesday, so will it be ok to get it tuned and replace it asap, or should I postpone the tune?

[abr33]

It is odd that its sits on 75 all the time..... On the dyno wont matter so long as you get the temps up even if by regulating the distance the dyno fan sits..

[Hanaldo]

Too easy, I'll get them to confirm that it is running cooler and not just my gauges.

Thanks for your help guys!

[GTSBoy]

I'd be worried it's not bled properly and your temp sensor is sitting in an air pocket.

[Hanaldo]

All three of them? 2 water temp sensors in different places, plus the stock temp sensor. Oil temp is also reading colder.

[GTSBoy]

Good point. Stuck thermo would seem more likely.

[blind_elk]

It's likely the thermostat isn't closing properly. As a result you are circulating cold water around the engine. So it takes longer for the water to come up to temperature. (had the same problem with my XF Falcon)

You should be able to get a replacement thermostat fitted before tomorrow.