I was looking at the service manual for the 3800 series 3 engine and it appears I should have two coolant passages per side. I believe someone plugged them up with JB weld or maybe some type of mechanic in a can. Can someone confirm before I spend good money on a new one? Are the ported ones from Intense/ZZP worth the extra dollars if I have ported heads?





What is the sensor on the underside of the LIM?

[This message has been edited by frockfiero (edited 12-01-2022).]

I dont know of a reason to plug the coolant passages.

The ported one from ZZP is expensive and only beneficial when you run an intercooler, the top of the lim is enlarged to match the surface area of the intercooler plate. Portmatching is something you could do yourself. ZZP charges $499 for all that.

The sensor is the ECT coolant sensor, black and yellow wires go to the pcm, green wire to your coolant temp gauge.

Thanks for the reply. I think GM did something odd. Here is a new one from Dorman and I can see there is only one coolant passage.


Can I use the one I have with the pitting? It is certainly a different material than aluminum and feels a lot like Jb weld.


edit:
https://www.gmforum.com/gen...askets-271412/page2/
I found this post and it looks the same as mine, but the OP mentioned he could clean it off. Can I use a brass brush for aluminum? I tried a plastic razer and it did not take it off.

[This message has been edited by frockfiero (edited 12-02-2022).]