Still not 100% on the heat output but much much better. Even though the last few flushings were completely clear the coolant is now nasty looking (though not as bad) so am thinking some crud worked itself loose. A few days ago I dropped it off and the shop for oil change, tire rotation and alignment and they called recommending I pay them $115 to do a flush. I laughed and told them I'd take care of it, I'm pretty much an expert at this point. ;-)
Will drain and do another flush over the next few days before adding fresh coolant again and seeing how it does. Thanks again for all the feedback and suggestions guys.
After several months of it running fine last week it overheated with the A/C on. Now that local temps are in the mid 90s it runs hot at about 220 or so and the temp shoots up almost immediately when I turn on the A/C. Grrrr. I'm going to pick up and install a new thermostat today and thinking if that doesn't do it I'll replace the radiator. Coolant is still a bit rusty after doing all the flushes and back flushes I did back in Jan & Feb. Nowhere near as bad as before but still a little rust/sediment. Anyone have other suggestions? I'll also go back and read all the other threads about similar issues to hopefully get more guidance.
Get a Robertshaw thermostat and be done with that part. You may be looking for a new rad though, that rust and such may well have clogged you to the point that it can't keep up now that it's getting hot...
__________________ Violence may not be the answer but it sure cuts down on the stupid questions
Had a leaky top hose today so replaced that and installed a new t-stat. Drove around the neighborhood with the a/c on and sure enough the temp started climbing again. Coolant looked good with no rust/sediment like at the beginning of all this. Any idea what step to take next? Since this started in February I did:
multiple flushes & back flushes with and without cleaner
replaced coolant twice
replaced t-stat twice
replaced worn hoses.
Sometimes it's tricky to burp all the air out of a 4.0
Simple trick - right at the front of the head - driver's side, there's a stud sticking up. That's a headbolt - it runs through the water passage. Note that the engine is slightly higher in the front than the rear, if not, jack the front up till it is. That will become the highest point on the system.
Remove the headbolt - when it's cold, not hot. Fill the radiator till water runs out the headbolt hole. When it does, wait a moment. Repeat until it stays full. The air will come out first, then coolant.
Replace the headbolt, tighten it to the headbolt torque. It's solved the bleed/ airlock problem for me several times.
It's no wonder the country is falling apart - stupidity abounds!
If the burp above doesn't do anything I'm starting to strongly feel it might be electronic. Any idea what to start checking there? I've also flushed the heater core in the past and it came out nice in clean once I had flushed everything appropriately.
Okay, did what rrich suggested and bled the air out through the head bolt yesterday. Afterwards I ran on idle and a/c on high for about 15 minutes and engine stayed around 210/220. Drove around the neighborhood for another 10 minutes and just when I thought all was good the temp jumped up into the red. Dammit! Wondering if I should try it again today in case there's another bubble in there?
Next step - drain and flush system again, fill with cleaner/water and run for a few days. Any suggestions on the best chemicals to use for this? My buddy who works on/races Volkswagons and helped me with the headbolt thing (had the 12pt socket) seems to think there may be a small clog in the heater core. I need to get this resolved before the serious VA summer heat sets in.
Finally! I flushed and added cleaner again only to find the next day while doing local driving that it was boiling over to the overflow tank. Once home and cooled down I saw I was losing coolant because of this. Checked the radiator cap and noticed it was pretty beat. I'd checked it periodically and never noticed an issue with it before and made a mental to replace it anyway but forgot about it with everything else going on. I replaced cap and haven't had a problem since. Drove over 300 miles interstate and locally the last few days without a hitch.
I'm thinking that "maybe" there was a little clog still left and the cleaner cleared it the problem has been a bad cap the whole time. Could a faulty rad cap cause no inside heat? That was the original problem that which started me on the road to cleaning up my cooling system. Anyway, I now have heat and more importantly A/C without any overheating at all.
Thanks to everyone for their feedback over the last couple of months! It definitely saved me some big bucks taking it to a shop.