Higher Temp AFTER Engine Off

[Lee36328]

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.

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

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!!!

Hopefully the top overhaul did not cost much...

I guess sesat's advice was a good one.

Here's another one - I humbly and politely suggest that you look for another workshop...

 

[seech]

Anyone have any idea what the problem might be?

Top overhaul oso good. Engine so much smoother and revs much more cleanly so $$$ not all wasted. This mechanic I've known for quite a while and is usually fantastic. I think the problem is that no one knows what is causing the temp needle issue. I probably need to get another meter to see if mine is faulty.

Its really frustrating because I just want to fix the problem. I don't mind spending some $$$ but problem must be fixed.

Anyone have any theories as to why temp needle would be higher after switching engine off? The only thing I can think off is that coolant loss inside engine itself near the temp sensor so when engine off coolant stops circulating and there's air near the temp sensor therefore causing it to indicate higher temp.

 

[Lee36328]

Maybe try a little experiment, swap the temp gauge with another one, and eliminate this possibility once and for all?

 

[pussy]

please advise model is your engine ? it might help..

if it's a M20 B20/25, you need luck, if it's a m50 B20/25, it's quite easy to solve.

regards.

 

[e23_728i]

went to the electrician yesterday.. Seems that it was an electrical glitch which caused the false higher temp. reading, now reads mostly below the half mark. So relieved that this is finally sorted out...

 

[Lee36328]

Happy ending!

 

[fandango]

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...

was this because it was a turbocharged car with a timer? if not, then the battery must be really BIGGG....

seech, have u also changed the auxillary fan?

 

[e23_728i]

fan... it was the base 850 2.5 10v... quite enjoyed that car.. No car seems to have such a lovely engine note sixers excepted..

it was controlled by some sort of relay and max cut off time for the fan to run was about 8 minutes after shut off then it shuts off itself..

 

[seech]

please advise model is your engine ? it might help..

if it's a M20 B20/25, you need luck, if it's a m50 B20/25, it's quite easy to solve.

regards.

Pussy, its a M50 B20. You have any idea what's going on? Sorry didn't reply earlier, was away. Any help appreciated.

Was going to try swapping the meter to see if it is indeed the temp gauge.

 

[rifhamdi]

hi seech,

sorry to hear about your plight....

might want to check your water jacket (plugs) situated at the lower part of the engine or your plastic expansion tank. sometimes the plastic joining where the hose connects at the outlet leading back to the radiator might be cracked (very small crack which you would not notice but you will be losing coolant because you will required to top up quite frequently.... (coolant will seep out slowly)

hope this helps based on my personal experience and good luck!

 

[seech]

rifhamdi. Thanks. Will check it out. Waiting to hear what pussy's advice is also.

 

[jarance]

seech, after the top overhaul, it there anymore air bubbles in the radiator?

 

[pussy]

seech..i believe you have done every test, changed everything, check everything.

problem could be a fractured line at the head, did your mech did a leak pressure leak test ? the head did you skimed it prior fixing it back ?

or

you still runing the heater blower system ?

 

[seech]

pussy, didn't do pressure test but skimmed head before reinstall. heater blower disconnected.

jarance, still got little bit of bubbles and still losing a bit of water (sometimes... sometimes no water loss, sometimes need to add a little 1"-2" height in expansion tank). when I open radiator cap even when engine left overnight there is still a little bit of pressure in the expansion tank. Is this normal or should there be no pressure when engine has fully cooled down?

Dunno what else to do. Damn frustrated with this bloody problem. Checked the bentley service manual and am going to do the test to check if meter is working. Also found out my car doesn't have the fan switch so will install that to see if it helps.

 

[pussy]

pussy, didn't do pressure test but skimmed head before reinstall. heater blower disconnected.

jarance, still got little bit of bubbles and still losing a bit of water (sometimes... sometimes no water loss, sometimes need to add a little 1"-2" height in expansion tank). when I open radiator cap even when engine left overnight there is still a little bit of pressure in the expansion tank. Is this normal or should there be no pressure when engine has fully cooled down?

Dunno what else to do. Damn frustrated with this bloody problem. Checked the bentley service manual and am going to do the test to check if meter is working. Also found out my car doesn't have the fan switch so will install that to see if it helps.

hmmn..
okay let's do this one more time..i'll try to help you over the forum here. i list the down the checks and you fill up the blanks. even the when u open the cap next morning, there's pressure suggests that it good, but having bubbles ?ar eyou sure you are keeping the coolant tank level as by not over filling it?

1. radiator, did a leak test, check for leaks, check the plumbing? pressuretest leak?


2. hoses, the big return hose or known as the by pass hose from the block to the coolant tank reservior, the head hose, the trottle hoses, the #6 cylinder hose, the temperture solinoid hose, clamps.

3. since the clutch fan, waterpump, thermostat, all u have changed.

4. the tempreture sender sensor at the cylinder head, check them for faults, they can sometimes cause false readings to the ecu which can make your engine run hot.

5. is the O2 sensor working ? your plugs and coils fine ? is the sparkplugs correct gauge ?

6. is your block water jackets okay? no leak marks you have to see both left/right.


what i can say, if all the above you have check/changed and still no results, then there is only two solutions..

one: cheaper option, buy a radiator stop leak, contains copper seal compound, throw it into the water/ radiator, rev it for 20 minutes and drive for 1 week, it will plug whats causing the leak and will be good for years.

two; you have a cracked head.. period. change it.

best of luck.. this is how much i know by diagnosing your problems.

regards.

 

[pussy]

btw, your car is a e36 or e34 ? they all should have a fan switch or your second speed fan resistor is out..

if yours dun have the fan switch, then the problem could be that the engine runs hot causing some certain hose or clamps to burst a leak hence causing a high tempreture..due to inadequate cooling... being there myself.

 

[seech]

thanks for the help pussy. very sorry for taking so long to reply. ur username causes my office internet filter to block the site. so have to check at home.

Mine is E34. Little bubbles when I open bleed screw. Haven't done it lately so don't know if there's still bubbles after I bled it the other day.

Hoses shouldn't be the issue as I changed them all. Will do pressure test to confirm if block is leaking. Will also be checking out the temp gauge sensor and engine temp sensor. Just found out my car doesn't have the fan switch for activating aux fan so will be installing that. O2 sensor should need replacement. Would like to carry out a full diagnostics check. Want to check which workshop can do and how much they charge just for diagnostic check. U know how much MSpeed charges?

Appreciate all the help. Hopefully can solve this issue. Thanks to all.