Raceline Water Rail, Thermostat Fitted Now Overheating!

[Guest b3nny]

Yesterday I noticed that my race line didn't have a stat fitted and it wouldn't get up to temperature, so I've got one today and dropped it in took her out for a spin and now it's overheating reached 120c and had to pull over to let it cool down, when cursing around 60 the temp just climbs and driving slowly the Temp starts to drop off quite quickly.

 

My fans have been wired by a previous owner to stay on all the time so I'm linking this to a underlaying problem hence the stat being removed.

 

Is there anything obvious that I haven't done? Basically took the housing off dropped the stat in put the housing back on a way I went? I read I didn't need to fit the o ring so haven't?

 

Help

[Guest b3nny]

I have the stat with the half ball facing towards the filler cap

[Guest b3nny]

Also the stat I have has a small hole drilled along side the half ball on the stat, this seems to have like a little toggle inserted, would this need removing giving you the said hole?

[Guest b3nny]

Should the bulb face up so I can see it with filler cap removed or the other way round?

 

Also how many holes are advised when drilling the stat?

[Guest b3nny]

Ok, just went out and swapped the stat round so the spring was was facing up towards the filler cap and it ran a lot better when driving hovered around the 90, increasing slightly when giving it some and dropped around 88 when driving normally around town, how ever when I came to a stop and let it tick over it crept back up to 100c fan was running all the time to. I'm guessing this isn't normal?

[Al Milton]

Drill a few more 3mm holes around the perimeter.

Should help with flow if the thermostat is causing a restriction on tickover.

 

As a thought, is the auxiliary drive belt tight enough, i.e. not slipping which may be causing the water pump to 'stall' or operate inefficiently on tickover?

Long shot but worth checking

[Guest b3nny]

It has one 3mm hole in there now with a tiny toggle which I have read could be removed for better flow, so I will try this tomorrow if this doesn't work how many extra holes is advised?

 

You mention the aux belt, it looks pretty worn and dry to be honest so changing it might not be a bad idea anyway.

[Al Milton]

I drilled another 4 or 5.

[Guest b3nny]

Ok cheers, I think I'll just try one at a time and see how it goes

 

[Andy Spencer]

I had two 3mm holes and worked fine for 7 years. You need some flow through the rail and stat to open it and this compromise worked fine for me...

Cheers

[Guest b3nny]

Removed the jiggle pin and added a extra 3mm hole and seems to hold temp well no between 90 to 92 on the road sat ticking over after a run for a few minutes and didn't rise above 95 although the fan was on so I will have to check it with the fan off as I've only just sorted why the fan has been constantly on.

 

As far as I know it's operating as it should now?

[Andy Spencer]

Sounds about right. Fan will be on when idling and stationary. Mine used to creep to 96 or 97 in heavy traffic when hot. Suspect you are about there with it.

Cheers

[kevin the chicken]

I agree, once the engine is up to temperature the fan will come on fairly promptly at idle or when crawling along. There is little or no airflow without forward motion in these types of cars and the engine is heavily enclosed. Top marks for persistence, I remember it didn't take me long to get thoroughly hacked off with water all over the garage floor!

[Guest b3nny]

Looks to be all sorted now just waiting on my fan switch as mines duff I think as it says it's on at 92 and off at 87 but was coming on at 87, so I've placed a order for a new one that turns on at 98 and off at 93 so to me sounds about right for the temperatures of the Zetec.

 

Thanks for all input.

Edited July 6, 2014 by b3nny