Thermostat and Coolant Bleeding Issues

[monty23psk]

Any updates?

[iamcreepingdeath]

Any updates?

yeah, sort of!!  (sorry about the late reply, the thread didn't show up bold like it is supposed to)

well, i have driven my car a ton, and as of yet, it has never overheated, which is a success, but the temp gauge likes to move around much more than it used to.  The car will run from a little over 1/4 temp up to 1/2 temp, depending on how i drive.  Also, the gauge will bounce a little every once in a while, its probably because i did not bleed the coolant sufficiently.

What gets me is how the temp gauge can consistently stay at one point, and then move and consistently stay at another point.  Its almost as if my t-stat randomly decides that it wants to be an 88 degree t-stat instead of a 75 degree one.

I am going to rig up a small tube on my bleeder valve so that when i bleed the radiator the coolant is directed back into the reservoir so i can bleed the rad forever and not lose coolant.  I think after i bleed it maybe the temp will be more consistent.

[monty23psk]

Mine is always moving, and according to what the car and aux fan are doing. This is good because it makes sense and tells me the gauge is working. Mine does not bounce though. Maybe it is not bleeding but a bad ground like the nut in the cluster.

[iamcreepingdeath]

Ok so up till now the temp has stayed between the 1/4 and 1/2 mark, fluctuating a bit, sometimes jumping but has never gone over 1/2

So on the way back home from work today, the temp gauge started hopping over the 1/2 mark, and stayed for long periods of time a little over the 1/2 mark.

What the fuck?  i have been messing with this stupid cooling system for way too long, and right now i am quite pissed off.  did the t-stat just decide it wanted to open at a higher temp???

So i pulled over and filled the expansion tank and bled the piss out of it till the coolant level dropped to the cold mark, then i re-filled it, and bled it again.

the result, nothing. temp still slightly over 1/2 and bouncing every once in a while.   WTF???  the temp needle used to stay pretty well under 1/2 totally consistently, now what??


EDIT:  so i said fuck it and i went ahead and ordered a brand new radiator from Pelican Parts.  Hopefully that fixes the problem.  If not, then I am going to pull apart the gauge cluster and tighten that grounding nut.  Heck, i'll just do that anyway.

[RED IS 91]

Most m42 cars stay around the 1/2 mark. At least mine does . Sometimes it's a little above and sometimes a little below.

[monty23psk]

How much over the 1/2 mark? If it didnt get close to the 3/4, I think you are ok. Also maybe the engine was used a little more and was warmer or maybe the outside temp was hotter than the last few days.

[iamcreepingdeath]

it didn't go far over 1/2, the point is that ever since i installed the 75 degree t-stat it never even went up to the 1/2 mark for weeks, and then suddenly last night something changed and it started going over.  And it was frigid last night, like 38 degrees and raining.

[monty23psk]

Weird but think you are ok.

[RED IS 91]

it didn't go far over 1/2, the point is that ever since i installed the 75 degree t-stat it never even went up to the 1/2 mark for weeks, and then suddenly last night something changed and it started going over.  And it was frigid last night, like 38 degrees and raining.

It may have burped an air bubble. ....................

[iamcreepingdeath]

ok so it was doing it again on the way home from work, and I smacked the gauge cluster with a few fingers (more like a violent "poke" at the temp gauge) and immediately the needle jumped back down to where it was supposed to be and pretty much stayed there for the rest of the trip, even though i drove like an asshole most of the way.

So that leads me to believe that i need to be ripping my gauge cluster out asap....

[monty23psk]

good troubleshooting...lol "poke technique". The ladies like that one too.

[iamcreepingdeath]

So it has been a long while, but anyway apparently my car is not overheating any more, so the problem was solved somehow, what i did notice is that if the temp needle started jumping, i have the gauge cluster a good smack and the needle drops back down where it is supposed to be immediately.

So i did get a new radiator and installed it anyway just in case, so my car does not overheat now, but i do have to smack the cluster every once in a while.

Oh and i did take it out and tighten the nut in the back, but it didn't help, so it must be a bad gauge, but im not too worried about it, i'll replace it some day.

Well thank you everyone for all of your help!  M42club is the best!!!!!!

[monty23psk]

Good to hear.

[AutoXSS]

brought this one back......................,

have the similar "lower passenger side" radiator hose cold issue. Never seems to get hot, just warm after long drives around town or interstate travel. The car never overheats and the needle stays pegged a hair over 1/2. It slowly creeps up to op temp and stays there. The needle never fluctuates. I have heat and it seems fine.

I searched for this thread, because i did my ICV cleaning and replaced my hoses. while doing it, i accidentally pulled a coolant hose leading to my TB. Could i have let some air in the system? Ever since then, my heater seems to work alittle less efficiently. It used to get too hot and i used to have to turn it down. Now, i run it at full all the time. Dont get me wrong, it works well, but not that "jeezzus, turn that thing down" heat. It is, of course, 20* cooler now, but it doesnt seem as hot.

I guess my question is, is the lower hose not being hot an issue? could it be tied into letting air into the system? Is it connected to my heat not being as hot?

[AutoXSS]

I had some fun today in the snow. I ran the hell outta the car today. When i got home i decided to check the lower hose. It was hot to the touch. I could feel pressure in both hoses as i squeezed them. The heater worked very well too, had to turn it down. Im gonna monitor the car this week and see it changes