Loose Connection on Temp sensor?

[Griswald]

So after a cold start,
about 5-10 min into the drive,
the temp gauge starts to go up...

gets about 1/8" shy of the red line (NEVER in the red),
then quickly drops back down to about the 1/3 mark.

Then it usually floats between the 1/3-1/2 mark from there on out.
the longer the drive, the more stable it seems to be...less fluctuation.

It only does this once. And it does it every single time like clockwork, consistently. And it only does it on cold starts.

So, brand new OEM thermostat. could it be that the new spring on the t-stat is taking a few minutes to open up??

Or is this is a bad/loose connection on the wire clip that connects to the temp sensor in the middle of the manifold?

If anyone has had this issue, please let me know what you did to fix it.

thanks

 

[fourwd1]

You have a "brand new OEM thermostat" , did this start after you installed it? Or was it happening before and you replaced it and it still does it?

I've seen that before, the t-stat opens all at once and the temp drops quickly vs one that opens gradually.

 

[Griswald]

You have a "brand new OEM thermostat" , did this start after you installed it? Or was it happening before and you replaced it and it still does it?

I've seen that before, the t-stat opens all at once and the temp drops quickly vs one that opens gradually.

the previous t stat did not do this. I blew a gasket last year, finally replaced the engine, as well as several parts of the cooling system including the t stat.

it seems like it opens all at once. So, do you think this could be considered normal? A friend of mine said it could just be the T stat...normal, just new and stiff.

Once it opens, it seems to work just fine and hover between 1/3 - 1/2 ...rarely does it go above 1/2 at all...just in the very beginning of the drive.

 

[fourwd1]

If it's not overheating , I wouldn't worry

 

[fourwd1]

Just thought of something, when you installed it, did you put the jiggle valve at the 12:00 position?

 

[Griswald]

Just thought of something, when you installed it, did you put the jiggle valve at the 12:00 position?

pretty sure its at 6:00 now

 

[Griswald]

I (finally) hit the cyl head w a laser thermometer.
I shined it right on the head, kind of near the dip stick
Temp stayed pretty consistent right around 200F despite the fluctuation on the gauge...which went from 2/3 -1/3.

so...tomorrow I'm going to check the wire clip that connects to the temp sensor in the middle of the intake manifold...I am told it can do this ^^ if it doesn't have a good connection. I really hope I don't have to mess w the dash cluster (which of course is upgraded from an SR5 years ago).

anyone else experience this?

THANKS