Little worried about my thermostat change - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

smut · 11-23-2003, 19:22

Hi as some you guys would know after reading the thread about my car never warming up I replaced the thermostat with a genuine ford one. I am bit worried about my bouncing temp guage now though. Only on the freeway cruising at 2400rpm the temp goes right up to 3/4's then bounces down to just above the normal and it does this constantly!

Most of the time it goes to half and bounces down. I was told by dellboy999 that this is because I did not drill a 3mm in my thermostat is this correct or is my cooling system screwed now?

EFFalcon · 11-23-2003, 19:34

what dellboy suggested sounds right.
a 3mm hole is drilled in the thermostat to allow a constant flow of water through the system. though only a little amount of water can get through the hole it is enough to even out the temperatures.

the bouncing you're getting is most likely that the thermostat stays closed until the temp guage reads about 3/4, at which point the thermostat opens and the system is flooded with cold water, this brings the temp right down again and the thermostat closes until the temp is at 3/4 or so again.

smut · 11-23-2003, 19:46

So its not just making the temp guage play up? It is actually doing this to my engine.

FoMoCo4eva · 11-23-2003, 21:14

while on the subject...does anyone elses temp gauage go absolutely nuts when its really hot (outside temp). The needles go beserk and do not stop going up and down untill I turn he car off. It happens with the fuel guage as well.

Anyone got any ideas as to why this happens?

Thankgod its a Ghia because I rely on the thingy that tells me how mnay k's I have left on the average fuel consumption.

Dellboy999 · 11-23-2003, 21:19

Well my Ghia behaves its self in that department, but the cup weekend when it was really hot my car decided that it should beep the horn cause it felt like it, when the steering wheel was really hot, that was funny somewhat, but otherwise mine is ok.

Dellboy999

Axeman82 · 11-24-2003, 00:34

I had this problem and "kinda" fixed it by drilling the hole but I don't think it's a "fix" - more of a "mask".

And a month later I blew a head gasket. Coincidence? Maybe. But I am a bit skeptical.

But try the hole tip but the concern I have is why does something now happen when it never happened before? Obviously a part of the system is not how it used to be..

Dan..

Rmyers · 11-24-2003, 00:38

Quote:

Originally Posted by smut

So its not just making the temp guage play up? It is actually doing this to my engine.

Remember that the gauge reads the temperature of the water, not the block itself, so the actual engine isn't changing temperature as radically as the gauge is showing. My car has been doing the same thing since I got it, so I always assume it's normal.

YOOT · 11-24-2003, 01:19

It shouldn't bounce at all man, seriously its not hard to make a cooling system maintain a constant temperature at all hey.

I had my block/radiator all flushed and cleaned out and a new thermo stat installed and the temp guage started bouncing, never did it before. There is a jiggle pin in the side of the thermostat that is suposed to allow a small amount of water through to stop that problem (Ford know about it and this was the solution) but sometimes they don't work for whatever reason.

I drilled a 2mm hole in mine which was plenty, and my guage is steady as a rock now just below the N. On EL/EF it will sit just below the L cause their guages are reverse.

smut · 11-24-2003, 23:07

Where on the thermostat would I drill the hole?

YOOT · 11-24-2003, 23:40

see where the jiggle pin is? Well, put the hole in the same place but on the opposite side. It's like a ring or lip that runs around the circumference of the thermostat, you'll see the jiggle pin and where it s.