LS swap temp sending unit not working

[EightiesOnly]

Alright, so I recently finished my 5.3 swap in my '86. I'm using a custom temp sender adapter and the temp sender doesn't work properly. It just reads about 100* unless I put it in park and let it idle, then it rises to about 195-200. Once I start driving, it gradually goes all the way back down.

I removed the plug on the passenger side and put the adapter there.



I thought maybe the coolant flow is just below the sender while driving, but it's full of coolant and others on here have used adapters in this spot just fine.

Any suggestions?

[truckdude239]

Ive found that most coolant sesnors need the coolant flowing across the end of the sensor to work properly

[EightiesOnly]

Originally Posted by truckdude239

Ive found that most coolant sesnors need the coolant flowing across the end of the sensor to work properly

So perhaps the coolant is flowing across the end while idling in park better than while driving?

The better thing to do would have been to drill and tap the plug whole, but it's too late for that now.

[Andy4639]

You can get away with a shallow adapter but I think yours is to deep. Yes at idle the coolant isn't moving as fast through the system and it hits the sendor longer. But once you start driving the coolant is moving so fast and not getting to cover the whole area of the sender. My 2 cents worth anyway.

[Hart_Rod]

Try to find an adapter that will get the temp sensor closer to the head. Dakota digital sells some I think.

http://www.dakotadigital.com/index.c...rod/prd111.htm

[EightiesOnly]

Originally Posted by Hart_Rod

Try to find an adapter that will get the temp sensor closer to the head. Dakota digital sells some I think.

http://www.dakotadigital.com/index.c...rod/prd111.htm

I think I'll look into these Dakota Digitals. Does it not matter if the sender and gauge match?

[Andy4639]

Most gauges are matched to the sender. But you should be able to get one that works for a certain temp.