Higher Temp AFTER Engine Off

[seech]

I notice that lately after I turned engine off and leave car for 5 - 10 mins and then turn car back on, temperature gauge jumps up to halfway between center and red. After restarting the car the temperature slowly moves back to center position. I also notice that on cool days temp gauge is just before center position and on hot days just after. Is this normal?The only explanation I can think of is that engine is still hot after switching engine off and continues to heat up water in radiator. After engine restarted fan cools radiator back down and temp returns to normal.Radiator and hoses are new and not leaking water. Haven't changed water pump or thermostat so not sure of their condition.Anyone experienced this before? Just worried something is wrong as I never noticed this happening before.

 

[sesat88]

Not normal la. Previously in my old rig this happened. Check your thermo and thermo housing. I think it is getting sticky and maybe also the wter pump.

If i were u, take to workshop and ask your mechanic to check the entire cooling system!!! Change as necessary!!! No joke, your cooling system fails then it be more headaches for u.

 

[seech]

Yeah man. Cooling system most critical. I got mech to change new radiator and all hoses but still like that..... Will get him to look at thermo and water pump.

After you changed those two items ok ka?

 

[tongsatriani]

It's the thermostat!!! Been there done that!!!

 

[bmw7833]

Yes, thermostat problem..i faced this problem b4, after changed the part, all settle..

Stop ur car immediately if the temperature gauge go to the red area..if u keep running, ur engine will gone..

Normally i will open bonnet once the break to cool down the engine if i cruising in long distance.

 

[seech]

Thanks guys. I couldn't understand why the car was not overheating during normal operation but only started heating up after the engine was switched off. Will get thermostat changed asap and see if problem persist.

BTW read in other bimmer forums about plastic bits of water pump failing. Since I bought car second hand I don't know if pump has been changed before. Does anyone know if local bimmers had plastic or metal water pumps? (if I'm not mistaken the plastic bits are the impellers)

 

[sesat88]

Thanks guys. I couldn't understand why the car was not overheating during normal operation but only started heating up after the engine was switched off. Will get thermostat changed asap and see if problem persist.

BTW read in other bimmer forums about plastic bits of water pump failing. Since I bought car second hand I don't know if pump has been changed before. Does anyone know if local bimmers had plastic or metal water pumps? (if I'm not mistaken the plastic bits are the impellers)

dude.. in malaysia here everything also boleh one So you get a mix
so it is a mix. the plastic impeller ones are cheaper that the metal by almost 50%

The older batches uses the plastic, but if the previous owner decided to save some $, he may have gone for the plastic instead of the metal.

Actually, the failure rate of the bearing of the pump is almost the same hence it really doesn't matter whether plastic or metal if the bearing does go off first. But if can afford might as well go for the metal impellers, no point looking for trouble right?

 

[sesat88]

p.s better put in some coolant.

some recommended ones....
1) water wetter - redline
2) kool-it - lubguard
3) toyota longlife coolant
4) bmw ori longlife coolant

 

[seech]

sesat88, yeah got bmy ori coolant in rad. Rad actually is not losing any water so no leaks only the weird temp issue. Will change thermostat and see. I think u r right with regards to the plastic impellers and the water pump bearings. I would imagine BMW taking that into account when they designed it. Thanks for the info.

 

[e23_728i]

This is such a timely post... Been noticing that my car has similar temperature issues too.. The radiator and all hoses was replaced some time ago along with a mod to electric fans instead of the mechanical fan. Everything has been fine until recently. The guys at the workshop where I go to have always been using BMW coolant and even bled the system again last week to try solve this hiccup.

Thought it was ok but when I drove it out at lunch time today, the temperature was smack into the 3/4 area in a traffic jam around the SS2 area, opened the bonnet to check, no leaks and coolant is ok and fans all running. Guess will have to ask the mechanics to check if it's the water pump or thermostat thats causing these problems..

 

[ichiwan2]

Had similar problem.

A few times, water/steam came out of via the cap, i.e., it got so hot that the water boiled out. It was especially worse when I had the air-conditioner on, i.e., temperature rose faster and reached boiling point like almost all the time. Otherwise, it just got to 3/4 way

Sent it to the mech for check up - changed thermostat - still not OK, changed this and that, had radiator "serviced" (not sure what they meant by serviced but looked like they opened up the top part of radiator and cleaned it up on the inside). Water pump still relatively new, cap was also relatively new....

All gaskets were replaced with new ones

Did all the necessary, and still water in radiator boiled over....

Did some thinking and theorised that although the radiator was "serviced", suspected that the radiators tubes walls were encrusted with deposits, hence reducing the efficacy of the radiator.

Bit the bulllet and replaced the radiator. Seems to be stable now, with temperature rising only slightly in jams and I can switch on the air-conditioner on with no problems.

Still keeping my fingers crossed.

The last time I changed the radiator was in 1998. So it lasted about 8 years+

Something to consider...

 

[ramsing]

hi guys, just wondering if on a normal working cooling system, does the temp needle never pass the halfway mark? my needle never passes the halfway mark, even in very hot traffic jams.

and when you switch off the engine, radiator fan keeps spiinning for a couple of seconds more, maybe 4 or 5 seconds. are these any symptoms of anything?

thanks.

I also notice that on cool days temp gauge is just before center position and on hot days just after. Is this normal?

 

[fandango]

if it passes the half way mark then u got prob...yes the aux fan will spin even after u turn off the engine to make sure the water temp gets back to normal. no cause for worry there i think, unless the fan doesn't go off even after u pull out the key...

 

[seech]

More $$$. Got my mech to check the car and diagnosed problem as blown head gasket. Plenty of air bubble in rad. Since already spending $$$ will be changing thermostat and water pump at the same time. Hopefully this solves the problem.

 

[sesat88]

u may want to try to get second opinion prior to open chest surgery!

 

[pussy]

yes, it's the thermostat is at fault, but if you are using the ori 90deg, as for the 88, 82 and 73 &73deg, u will have that problem but nothing to worry..

e23 guy, the problem is not with your cooling, it's your tuning of your L-Jet engine, once you get it right, it works like a dream...

funny, different engines, different modes of fault finding..

 

[e23_728i]

thanks pussy... Don't think there's anything wrong with the tuning as it was checked by the mechanic a few days ago... Increased the concentration of the coolant, so keeping fingers crossed now.. Think the thermostat is running at 73 deg if not mistaken...

 

[e23_728i]

fandango, on my previous Volvo 850, if the engine temp is hot, even after you turn the engine of the fan will continue to run up to a max of 8 minutes then shut off.. If only I could do this mod onto the car...

 

[Iqlima]

fandango, on my previous Volvo 850, if the engine temp is hot, even after you turn the engine of the fan will continue to run up to a max of 8 minutes then shut off.. If only I could do this mod onto the car...

It's for E32 , use time relay and constant power to both high speed and low speed relay. Some discussion about it in bimmerboard http://www.bimmerboard.com/forums/posts/351433

 

[seech]

Need some HELP!!!!!

Ok. Update on progress about the mysterious higher temp AFTER engine off. Sent my car for a complete top overhaul as mech suspected leaking head gasket due to excessive bubbles in rad. Done..... Changed themostat, water pump. Done....

Problem is still there!!!! Losing a bit of coolant every day and temp needle still does the same thing!!! Dunno if temp gauge is faulty or what but when the engine running it seems to be working ok.

Symptoms: Water temp when running is slightly below center mark. If caught in a jam or hot day it moves to slightly above center. When I turn engine off and leave it for a while and turn ignition back on, temp needle is 3/4 mark!!! Need to constantly fill water daily (2-3" in the expansion tank). Engine oil is not milky so no coolant leaking in there. No smoke coming out of the exhaust.

Have changed: Radiator, all hoses, blocked off coolant to heater, fan clutch, head gasket, water pump, thermostat. Dunno what else needs to be changed.

Where is the water going and why is my temp gauge doing that after I switch off engine and turn back on? Notice two pipes from radiator going into the transmission. Are those necessary? Dunno if its leaking there.

Getting frustrated with my BMW (Banyak Makan Wang). I don't mind spending the $$$ but problem must be fixed. Right now I don't know what to do.

If cannot resolve I'll just rip out the whole engine and install a 1JZ. HAHAHAHA....

Seriously, anybody can help or offer any suggestions?