unfortunately they can't do a pressure test...
they don't have the cap for the reservoir that will fit the reservoir.
again... why so much bleeding?

 

Spark plug discussions here are like religious cult discussions. I'm in the Keep It Simple Stupid camp.

What we (should) know is that double-platinum spark plugs are best for wasted-spark systems like we have in the DIIs. See this link for the explanation. The linked article also explains why although copper plugs will work just fine initially they will degrade relatively quickly and cause misfires.

Part of being in the KISS camp is using the manufacturer-specified plug unless there is some good reason to not do so. I haven't yet heard or found one in the case of the DII.

The specified plug for the '99-'02 DIIs is the Champion RC11 PYP B4, also referred to as the Champion 7070. Double platinum, and today $9.59 each on Amazon. Mine are still going strong after six years and 46,000 miles, after the copper Champions an idiot "import specialist" shop installed crapped out after just 12,000 miles. And there's an Autolite double platinum "equivalent" out there for less than $5 (I haven't checked its detailed specs.)

 

Op. no color change that's a thumbs up

 

ran the scan on the truck and a ton of codes showed up...!

 

pic 1 of scanner reading

 

pic2 if scaneer

 

pic3 of scanner

 

pic4 of the scanner

 

What's up with all those P1000 that aren't even in the WM.

Could only find the P1591 searching WM and that's same system as P1590 in your OP.


Shop around...
And $4.29 at O'Reilly.

Noticed lately Amazon can be all over the place on prices and unless a Prime subscriber shipping is often slow as molasses.

......

 

Normal; it's a pressurized system, and for some reason, LR has the expansion tank as part of the circuit; the coolant flows through it. When it heats up, it builds pressure. The pressure allows the coolant to run hotter without boiling-off. Hotter running engines = more efficient combustion and better emissions.

You fill/bleed the system with a cold, running engine, with the bleeder open. When there is no air coming through the bleeder or expansion tank, you're done. It helps to lift the expansion tank higher than the engine during the process so any air in the system will work it's way up to it and out.

If the pressure gets too high from overheating, or if you over-fill the system, it will overflow at the expansion tank if your cap is working properly. Ya better top it off when it cools down..

Also, there are adapters available to pressure test at the exp.tank if you need to; do a search. You can also make your own.