Coolant pipe instead of a temperature sensor?

[Kenny_Z]

I've been slowly rebuilding Red's engine after I damaged it with a broken belt and an overheat. The passenger head was destroyed so I had to find a replacement. About a year of searching ebay and I got one pretty cheap. My mechanic checked it over and gave it a green light. I installed it and completely forgot that I needed to remove this odd pipe that is in place of the temperature sensor. Of course I remember the exact second I finish the last bolt's torque. It's in a horrible place to reach, I can't seem to get any tools to grip it, and I am pretty sure I am going to have to pull the head again to get this off. I thought I'd ask here if anyone had any tips or tricks or have ever seen this on a DeLorean head before?

http://uploads.m-cgi.com/kennyz/Delorean/pipe.jpg

[David T]

Getting that bit of rotten pipe out isn't going to easy especially "in situ". Even with the head off it will take a bit of effort. Looks like the pipe is pressed in. It will have to be removed and if there are no threads there you will have to tap them in so you can install the temperature sender. I don't see doing it any other way than removing the head.

[DMC-Ron]

Soak it with Kano Aerokroil (or your favorite penetrate oil). Reapply several times over a couple of days. Then get a small pipe wrench. Spray the pipe with coolant spray (hold the can upside down to freeze the pipe with the liquid). Give it a go with the pipe wrench (what have you got to lose?... if it doesn't work you have to take off the head anyway). If it does move, spin it out. If there are no threads, you may be able to we-wah it back and forth and work it out, but the effort may be pointless if you have no room to tap new threads.

Ron

[DMC-81]

There is a similar pipe nipple on the left/driver side head for the heater hose circuit. Heater hose (101754) attaches to it. I do recall that this was pressed in.

I agree with David. Even if you managed to remove it while the head is installed, resizing and/or tapping the hole for the sensor, or even effectively plugging the hole if you want to delete/move the sensor will be very difficult. It looks like the nipple is very rusty so grabbing it with enough force to extract it will be challenging, unless it collapses in on itself and you can remove it in pieces.

I'm assuming this is a non DeLorean head since the right head should already have a threaded hole for a sensor instead of a heater pipe nipple.

[Bitsyncmaster]

There is a similar pipe nipple on the left/driver side head for the heater hose circuit. Heater hose (101754) attaches to it. I do recall that this was pressed in.

I agree with David. Even if you managed to remove it while the head is installed, resizing and/or tapping the hole for the sensor, or even effectively plugging the hole if you want to delete/move the sensor will be very difficult. It looks like the nipple is very rusty so grabbing it with enough force to extract it will be challenging, unless it collapses in on itself and you can remove it in pieces.

I'm assuming this is a non DeLorean head since the right head should already have a threaded hole for a sensor instead of a heater pipe nipple.

My guess is also to collapse the pipe to remove it. I would use a hammer and punch or chisel to collapse one side of the pipe.

[FABombjoy]

Or, tee that fitting into the heater supply hose an build an in-line adapter for the temp gauge sender.

Something similar to this but with the matching sender thread or retapped to match:
https://www.pegasusautoracing.com/productdetails.asp?RecID=5991

Do it pre-factory bleeder tee so there is always some coolant flow to keep the gauge accurate... well, as accurate as that gauge can be.

[Kenny_Z]

Thanks for the information, everyone.


I'm assuming this is a non DeLorean head since the right head should already have a threaded hole for a sensor instead of a heater pipe nipple.

I thought that when I first got the head too. The seller was selling off a lot of DeLorean only parts at the same time (oil pan and the like). It is possible this was from a different vehicle though.

The picture makes it look worse than it is. That pipe isn't that rusty (it is covered in penetrating oil) and is extremely strong. I'd worry about breaking the head if I tried to break that pipe. It sounds like I should see if I can tap that pipe for threads or go with FABombjoy's suggestion. If I tap the pipe I know I am going to have to pull the head.

Going to ask a dumb question. That's a brand new head gasket that has never seen a heat cycle. If I pull the head should I replace that gasket anyway?

[FABombjoy]

Really you could tee the sender back into any return line to maintain some flow & gauge accuracy (heater return or head/heater bleeder to tank).

[DMC-81]

Or, tee that fitting into the heater supply hose an build an in-line adapter for the temp gauge sender.

Something similar to this but with the matching sender thread or retapped to match:
https://www.pegasusautoracing.com/productdetails.asp?RecID=5991

Do it pre-factory bleeder tee so there is always some coolant flow to keep the gauge accurate... well, as accurate as that gauge can be.

That's a good suggestion if the pipe nipple is that sturdy and you want to minimize any disruption by trying to remove it.

[Ron]

That's a brand new head gasket that has never seen a heat cycle. If I pull the head should I replace that gasket anyway?Absolutely.

[Kenny_Z]

Question. Any idea what tap matches the sender? I'm looking at either taping the pipe or the in-line adapter but I can't seem to match these threads to anything.