Coolant temp at 1/4 mark...but why, using 80* thermostat

[BaltimoreBimmer]

I did all the usual items for a tune up (tb, tensioner, cam seal + o ring, all water hoses + several throttle body hoses + breather hose, vcg, sparks, cap + rotor, ignition wires, belts, oil change, coolant flush, thermostat + o ring) and now my engine runs at the 1-4 mark. It seems to really stick there too. My car is a 1990 vert so it has an oil cooler, not sure if that makes a difference.

Either way, it ran at 12 o'clock before I messed with it. Now it runs at 1/4 mark. My question is: is it possible to have not bleed the system enough that it results in this, even though I am getting hot air and have cracked the bleeder screw on ramps and only coolant flows out.

Sometimes it will maybe start to creep up past 1/4 and make it to say 11 oclock, but usually as soon as I drive it will go back down...

Curious if this is something I should be concerned about. In the back of my mindi feel like it's not bled property, but it definitely is....b/c I followed jlevies tips per every thread ever.

Thoughts on why it's so cool? (And yes it's an 80c therm)


Edit: also, when I running it to bleed the system the very first time, there was an air bubble in the top hose and the needle crept past 12 to maybe 1 before I shut it off. So I know it can definitely can go up that high of it legit gets hot.

[jeffnhiscars]

If you had air in the system it would run hotter not cooler. My cars have completely refreshed cooling systems, including the radiators which does make a surprising difference, and the gauge runs at about 3/8 rising towards 1/2 at idle. Very normal and healthy.

It's also possible your new tstat is stuck open...it happens. A boil test will confirm.

Don't forget the gauges are not all that precise so you may want to get an infrared gun and check the hoses at the tstat housing when the car is up to temp.

[dnguyen1963]

The quality of t-stat has gone down big time. If you bought an 80C t-stat and it is running cool then it is most likely that the t-stat is stuck open.

[BaltimoreBimmer]

I fee like the thermo is probably not stuck open simply because of how difficult it was to initially get the coolant to blow hot. I had to bleed a few times and then physically unscrew and fill up the hoses going/coming from the thermostat housing.

Or does that not imply it was closed or that it's not stuck open?

I will have to boil test to confirm it seems

[digger]

if it takes forever to warmup it might be stuck open. id get a gun and see what the temp is for real rather than rely on gauge 100%

[TobyB]

My gauge runs below 3/8 and the real temp gauge says 180....
consistently, with an 80c t-stat. Sure you didn't take an 88c out?

fwiw,

t

[BaltimoreBimmer]

hmm, good point on not knowing which one I took out... Well, that piece is long gone. But alas, I am still having problems. A brief update:

So over the past week or so, I have not been daily driving my e30 but I have been enjoying it after work. I check my coolant level before starting up the car every time. It usually is fine. Then I noticed it was leaking out of the lower radiator hose (ok that's fine, I didn't tighten that one super duper b/c I was nervous of breaking the plastic radiator part it goes over) so I tightened it (and all the others a bit more as well). Leak vanished for the next several days.

Then I look under and I see a few more drops of coolant. Ok.... level seems fine hmm. Look all over splash shielf from the top with a flashlight and don't see the origination of the seeps...

Then today, I go to drive her (only noticed the dripping coolant this past weekend) and the coolant is below the fill line. But this time, I look and I see a bunch of coolant residue on the side of the air filter box as well as all over the hoses and wires in b/t that area and the block.....but not anywhere that i saw on the belts themselves... which is weird b/c they are probably what slung all of it around. I topped off the coolant and then wiped up all the dots. Go for a short drive, don't see any egregiously obvious new marks.

I have noticed over all, my engine smells a bit.... "oil burny" as in, it just smells off when you stand next to the front. I am not losing any oil, infact I actually over filled it initially which is what I thought was driving the cooler oil temps (just more of it!) but when I drained it to the proper level, it still didn't heat up...


edit: something else I thought of....when I was initially bleeding, I was running into issue at one point and had coolant/water boiling out of the escape tube on the reservoir. Idk if this should point me in a different direction or what. Idk
Any thoughts on whether the low temp is caused/causing the weird coolant loss issue? That would lead me to believe the system is not bled.... yet before this I bled it over and over and all I ended up doing was dripping coolant all over my block! (before going into the catch tub of course)

but for reals, when you bleed these you are supposed to just have it dribble down over all your clean parts??

I'm ranting....I will pull the thermostat as soon as I find a thermometer....(going to store)

[BaltimoreBimmer]

Ok I'm retarded. The reason for the slung about coolant? .........when I bleed it, it will sometimes work its way onto the belts. Then it slings it. Yay. Me.

[BaltimoreBimmer]

Ok. Picked up a thermo gun to measure the temperature of stuff. So.....what should I check other than the thermostat housing? Are there specific temps I am going for? My upper radiator hose seems quite hot.

First measurement was around 180 on the thermo housing. I'm going to poke around and see what's what, but if you guys have any suggestions so I can easily pinpoint the issue let me know!

I will be taking the thermo to test when I go to retension the TB tensioner (per bently)

[dnguyen1963]

Just shoot the gun everywhere to get a temp map of your engine. Start with t-stat housing (mine reads around 190F), the upper radiator hose, upper radiator, mid-radiator, lower radiator hose, and engine block. It is also good to check the heater block too (with and w/o the heater on).

[AndrewBird]

If there was an air bubble where the temp sensor is, it will cause the sensor to read low.

Jack the front driver side up and run the engine until fully warm with the coolant tank cap off. Leave the bleeder screw alone. Add coolant as necessary.

[jeffnhiscars]

Who told you to "retension" the timing belt ?

That's a no no. They are one time tension then replace..although you will get stories about people re and re the belts it is highly discouraged

[BaltimoreBimmer]

Ok, so here are my temperature results:

Thermostat to water pipe: 137.1 f
Thermostat housing: 180 f
Upper rad hose: 164.4 f
Valve Cover: 167 f

didn't get the block....will next time it's at operating temp...

But from this it appears that the greatest shift in temperature is on either half of the thermostat housing around the thermostat. I'm not positive what flows where, but the valve cover was reading 167f or 75c....which means my engine is indeed running a bit cool.

Leave the bleeder screw alone. Add coolant as necessary.

Andrew, quick question about bleeding on an e30. On my e46 you stare down the bleeder screw area so you can see air bubbles coming up through the coolant. On the e30 you seem to just unscrew the bleeder a little bit and wait for coolant to come out? Or do you do the same thing in that you are looking for bubbles legit in the coolant that is flowing out. B/c the way everyone explains it seems like they imply that once you see coolant at all, you are good.

Who told you to "retension" the timing belt ?

Jeff, I could have sworn I read that right out of the bently. I just rechecked and don't see anything so I feel like I am taking crazy pills. Perhaps I am mistaking it for the v belts? I'll look into that..

[digger]

ignore the VC temp that depends on alot more than instantaneous engine coolant temp

when the t-stat housing is 180F which is right next to the temp sensor what did the gauge read?

[BaltimoreBimmer]

ignore the VC temp that depends on alot more than instantaneous engine coolant temp

when the t-stat housing is 180F which is right next to the temp sensor what did the gauge read?

the gauge on the car read 1/4 mark dead on, maybe slightly to the right.