Right here goes....

Recently fitted (couple of weeks ago) new headers, up-pipe, fmic, md321, fpr, simtek and a remap.
Car was running fine until the weekend, when lights were on dipped beam they kept on flickering onto high beam. Suspected some wires touching each other after the fmic install. When i got homw i noticed that the fans were running after i had driven the car. Left the car idling for a while but the fans never went off. Inspected under the bonnet to find that the radiator was freezing cold, as was the bottom hose. Top hose was hot as was the engine. Temperature gauge was in the middle as normal though.

Suspected that maybe the thermostat had failed i bought a new one and fitted it. Tested the old one and it was working fine. Filled up the coolant and tested. Same thing happened. Once upto temp the fans kicked in but the radiator was still cold??
At this point in noticed the interior fans stop working when the main fan is on. Also the AC doesnt work anymore. Went electrical fault finding today to find that the headers had melted away the wires under the radiator. Fixed all the wires, replaced the ac fuse and now i have got rid of all the faults apart from the radiator fans not stopping.

Does anyone have any ideas what i should be looking for? Where is the temp switch for the fans? Im pretty sure there is no airlock in the system.

Your help would be much appreciated.

 

I'm betting that you have melted the wiring loom that runs across the front beam, just in front of the manifold.

It carries the wiring for the lights, fans, and several other things. Happened to me when a full front splitter was fitted to my race car. Effected elec' windows, dash, and gauges too

Mates sorting it at Brands TA.

Check it, but don't drive the car until it's sorted, or the whole loom can short out.


Mark.

 

Yeah thats the one i melted and have repaired it. Well i repaired all the wires that i could see were shorting out and heatwrapped them too.

That fixed the headlights and the air con problem but im still stumped with why the fans come on so soon and dnt go off.

 

I had a similar problem with the fans constantly on with radiator & bottom hose cold with simtek. It turned out that the simtek base setting for the fans to kick in was 92c when it should be 96c. Once this was amended the problem went.

 

Im sure that it was running fine since the remap a few weeks ago and this problem has just started again.

 

Water pump is working, thermostat is opening, fans come on when they should but dont go off. Could i have fried something in the ecu when the wires burnt out?

Can you reset a simtek? If so how?

 

Your mapper will need to check this. If my memory serves me correctly the original base fan settings for the simtek is to switch on at 92c & turn off at 90c. Mine is now set to kick in @ 96c & off @ 94c- problem solved.

I went around the houses too, replacing the thermostat & fitting an electronic temp gauge because I was worrying that there was something wrong.

Speak to your mapper to rule this out first!

 

re check the wiring.

 

Ok i have found the problem now. Its definately the ecu. I removed the simtek and replaced with the ecutek and everything works as it should. Must have fried some settings in the ecu when the wires shorted out. Great!

 

My money is on the same problem I had. Your fans kick in when warm but don't turn off, right?

After my turbo 321t/ 740 injectors/ lateral headers & a mapped simtek I didn't notice the fans weren't turning off for about a week (some short runs & the fans didn't kick in at all). When you're marvelling with over 400hp for the first few times you tend to get distracted away from the little things

I have no experience mapping wise but I do know that my simtek's base fan setting were 4c too low for both ON & OFF. Maybe one of the experienced simtek mappers can confirm if the base setting is low on all simteks?

Let us know how you get on.

 

That the problem on the money smokingkills. Cant be 100% certain it has happened since the remap but it is doing it now. Fans kick in way too early and dont go off. Radiator is still cold when the fans kick in too.

 

Give your mapper a call to see if he has your map stored on his laptop & find out what temperatures he has the fans turning on & off. It is a very quick correction 5 mins tops with their laptop to fix

 

Yeah i have been trying to get hold of him for a few days now. Must be busy.

 

This has just happened to my car also, the melted wires are causing a high idle, it is intermittant, but revs also rise to 2.4k when i turn on the heated rear screen but wont drop when i turn the screen off!!, grrr, i need to repair the wires asap and also check i dont have the fan prob with my simtek also?