Does anyone use a Low temp fan switch

[PJ57]

Hey all, after being stuck in traffic again yesterday, the temp on the Chim was bouncing between 110 and 100 on the temp gauge.
The cooling fans were coming on fine, and despite the weather and 1 hour crawling, the car didn't overheat, but seeing the gauge leaning over the HOT side of the gauge was un-nerving.

Has anyone used one of these low temp fan switches?
http://www.clever-trevor.net/TVR/Parts_details/K00...
or am I better to fit a new stock one?? as I understand the low temp one is pretty close to the thermostat opening temp, so will the fans be running almost constantly?

Thanks

Phil

[SILICONEKID345HP]

PJ57 said:

Hey all, after being stuck in traffic again yesterday, the temp on the Chim was bouncing between 110 and 100 on the temp gauge.
The cooling fans were coming on fine, and despite the weather and 1 hour crawling, the car didn't overheat, but seeing the gauge leaning over the HOT side of the gauge was un-nerving.

Has anyone used one of these low temp fan switches?
http://www.clever-trevor.net/TVR/Parts_details/K00...
or am I better to fit a new stock one?? as I understand the low temp one is pretty close to the thermostat opening temp, so will the fans be running almost constantly?

Thanks

Phil

Standard stat, lower temp otter switch is the way i went .

[brett84]

isn't yours controlled by your ECU Daz?

[nigelj77]

On my previous 2 chimaeras I had a fan override switch, means you can switch the fans on as soon as you get stuck in traffic rather then waiting for the heat to build up and eventually the fans kick in. Basically you fit a switch in parallel to the otter switch, wire it to somewhere under the dash, I plan to do this on my current 450 as it makes getting caught in traffic more bearable, might be worth doing the same with yours.

[SILICONEKID345HP]

brett84 said:

isn't yours controlled by your ECU Daz?

No did not bother .it works fine .Plus i have an over ride switch but never needed to use it ..I`m sure the early cars stay cooler ,might be the front grill .

[brett84]

I'd fit a switch if you don't have one already as I've heard loads of people report on failed otter switches

[PJ57]

Thanks guys, mine's a later 2000, and no issues with the fans coming on, just sitting a bit high on the temp gauge.
Will get a lower temp otter switch ordered tonight

[TVR Beaver]

92-87 is the standard unit isn't it?.. thats what mine has anyway... I like a 89-85 TBH... you can get other spec's.. think there's a list on here somewhere...

[brett84]

take your pick


Part No.A/F Size Thread Temp °C

50100 29 M22 x 1.5 82-68
50101 29 M22 x 1.5 84-79/88-83
50250 29 M22 x 1.5 86-76
50012 29 M22 x 1.5 86-77
50090 29 M22 x 1.5 86-81
50120 29 M22 x 1.5 88-79
50295 29 M22 x 1.5 88-79
50296 29 M22 x 1.5 88-79/110-102
50271 29 M22 x 1.5 88-83
50272 29 M22 x 1.5 88-83
50275 29 M22 x 1.5 88-83
50217 29 M22 x 1.5 88-83/92-87
50091 29 M22 x 1.5 88-83/92-87
50212 29 M22 x 1.5 88-83/92-87
50213 29 M22 x 1.5 88-83/92-87
50216 29 M22 x 1.5 88-83/92-87
50221 29 M22 x 1.5 88-83/92-87
50219 29 M22 x 1.5 88-83/92-97
50240 29 M22 x 1.5 90-80
50110 29 M22 x 1.5 92-82
50111 29 M22 x 1.5 92-82
50112 29 M22 x 1.5 92-82
50113 29 M22 x 1.5 92-82/95-80
50218 29 M22 x 1.5 92-82/97-92
50170 29 M22 x 1.5 92-87
50200 29 M22 x 1.5 92-87
50210 29 M22 x 1.5 92-87
50211 29 M22 x 1.5 92-87
50220 29 M22 x 1.5 92-87
50230 29 M22 x 1.5 92-87
50231 29 M22 x 1.5 92-87
50235 29 M22 x 1.5 92-87
50260 29 M22 x 1.5 92-87
50270 29 M22 x 1.5 92-87
50280 29 M22 x 1.5 92-87
50281 29 M22 x 1.5 92-87
50285 29 M22 x 1.5 92-87
50290 29 M22 x 1.5 92-87
50215 29 M22 x 1.5 92-87/97-92
50011 29 M22 x 1.5 93-88
50102 29 M22 x 1.5 93-88/97-92
50035 29 M22 x 1.5 95-85/102-92
50130 29 M22 x 1.5 95-86
50030 29 M22 x 1.5 95-90
50033 29 M22 x 1.5 95-90
50061 29 M22 x 1.5 95-90
50062 29 M22 x 1.5 95-90
50160 29 M22 x 1.5 95-90
50092 29 M22 x 1.5 95-90/100-95
50174 29 M22 x 1.5 95-90/100-95
50104 29 M22 x 1.5 97-92
50282 29 M22 x 1.5 97-92
50103 29 M22 x 1.5 97-92/101 -96
50214 29 M22 x 1.5 97-92/102-97
50190 29 M22 x 1.5 100-95
50195 29 M22 x 1.5 100-95
50196 29 M22 x 1.5 100-95
50197 29 M22 x 1.5 100-95
50198 29 M22 x 1.5 100-95/110-105
50000 29 M22 x 1.5 103-98
50013 29 M22 x 1.5 103-98
50014 29 M22 x 1.5 103-98
50191 29 M22 x 1.5 120-115

[Chuffmeister]

Bear in mind that the standard stat is 82 degrees. The car will run around 85-86 degrees normally, with the temp rising in traffic/ idle. The fans need to turn off around 86 at the lowest. Any lower and you won't get the fans off at normal running temps. If you want the temp to be lower, then you'll need the 74 degree stat. However, you run the risk of the engine not warming sufficiently in the cold winter. Most cars run around the 90 degs mark, with fans kicking in around 95/96ish. The gauge is hopelessly inaccurate and is known to suffer from heat soak. Connect a laptop to the ECU to get a more accurate running temp.

TBH the car shouldn't overheat with a fully operational cooling system, so if it is, there's a problem somewhere that needs sorting.

[rigga]

Forget otter switches, hugely unreliable fit an adjustable one and set it to the temp YOU actually want.


Disclaimer mine has only been on a couple of weeks but has been 100% reliable

[sgrimshaw]

I can recommend the modwise two speed fan kit.

http://www.clarion-service.co.uk/cs/Two-Stage_Cool...

One of the best upgrades I've had done and less than £100 fitted.

[PJ57]

Thanks guys, will look at the override option down the line, as no reliability issues at the moment.
Sounds like a check on the gauge accuracy will be the way forward first.
Cheers
Phil

[rigga]

You really need to fit an overide as a matter of course, as whilst you currently have no reliability issues, should your otter switch fail it can cause you real engine issues, peace of mind and all that.

[spitfire4v8]

Make sure you're not disguising a fault rather than curing it.
Also the lucas needs to see something like 90deg for the long term lambda trim to be set properly .. so running a cool stat and otter might not allow the ecu to alter the long term trim at idle.

[spend]

I think the basic problem is that fitting the otter switch on the hot side of the rad is always a bit too predictive ~ so to refine it such that the fans aren't running excessively the margins are cut. Removing the rad and having the switch fitted in the return is the sensible way IMHO. If the rad is still returning 'cool' water there is no need for the fans to run at all whatever the heat coming out of the engine is IYSWIM?

The 82-68 worked fine on my rad return.

I certainly don't like the standard stat controlling the temp, as blocking the flow has to introduce uneven hot spots in the engine. Remote bypass stats, like fiat/cerbera or later LR schemas that ensure good flow around the engine are essential IMHO. They just bypass the rad to warm up but at least your pump is ensuring the temps around the engine are more even.

[TVR Beaver]

The problem I have with mine (not a real problem but something that bugs me).. is that the fans wont run if im moving at all.. they only come on when I'm standing.. even 10 MPH at 92 deg they will not kick in until I stop and the heat builds up?...
My mate has the switch in the swirl pot (1997 Griff) and his do come on without letting the temp max out first or having to stop to let it build up... I think having it in the rad is maybe not seeing what the engine is doing soon enough (180 to what your saying Dave but just my thoughts)

Or is it the water pump?.. it's not a great design, more something that thrashes about in there so at low RPM is it shifting the water quick enough?.. can you get an uprated pump at all.. I know when I had my Stag many years ago, you could buy a increaed flow unit... can you get them for the RV8? .. .If I thrash mine like mad all the time the temps come down and all is well.... May be thats the answer

[spend]

Not sure if we're talking apples & oranges John. When TVR put the switch in the rad it was on the inlet side, not the outlet side..

Water pump is surprisingly not a problem IME. Having dramatically re-geared a cars serp set-up (crank & pump pulley so only like 60% pump rpms compared to normal) I was concerned that it would not pump at idle & surprise surprise after hot runs the coolant flow was fine even idling down below 600rpm! That did have the cerb bypass style mod, which probably helps maybe in less restriction to pumping but I was really pleasantly shocked how well the standard pump worked? Looked quite funny with a tiny crank pulley and massive pump pulley

[TVR Beaver]

I guess mine already has the damping effect you are talking about by fitting the switch on the outlet from the rad.... and thats what I'm complaining about...

I see where you are coming from but I would have thought you'd want to know the temps in the hottest part of the engine as it happens.. so coolant around pot 7 say... if the waters up at 92 coming out the swirl pot and into the rad, how hot is it around 7?... thats why I was thinking a switch move closer to the engine would be best, like the ones fitted in the swirl pot.. .I'm guessing they moved it to the rad to give it a slightly damped effect?...
but if it's 100 deg at pot 7 don't you want the fans on and cooler water being pushed back in?..

Good to know the pumps are good BTW... that said can they fail or deteriorate with age in any way?.. it all looked nice and clean / new?...

[spend]

However hot the engine is.. if there is cool enough water in the rad why would you want the fans to run???? You are just making the temp swings even greater IMHO.

What you are outlining about uneven temps is why I remove the stat (which effectively cuts flow around the block) and fit a remote one so that the coolant is always circulating freely, with the remote stat just switching it into rad or bypassing it. Maybe a slightly longer warm up ~ but definitely a more even (around the block/heads) warm up...